source/blender/editors/gpencil/gpencil_paint.c

   1 /*
   2  * $Id$
   3  *
   4  * ***** BEGIN GPL LICENSE BLOCK *****
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  *
  20  * The Original Code is Copyright (C) 2008, Blender Foundation, Joshua Leung
  21  * This is a new part of Blender
  22  *
  23  * Contributor(s): Joshua Leung
  24  *
  25  * ***** END GPL LICENSE BLOCK *****
  26  */
  27
  28 /** \file blender/editors/gpencil/gpencil_paint.c
  29  *  \ingroup edgpencil
  30  */
  31
  32
  33 #include <stdio.h>
  34 #include <stddef.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <math.h>
  38
  39 #include "MEM_guardedalloc.h"
  40
  41 #include "BLI_blenlib.h"
  42 #include "BLI_math.h"
  43 #include "BLI_utildefines.h"
  44
  45 #include "BKE_gpencil.h"
  46 #include "BKE_context.h"
  47 #include "BKE_global.h"
  48 #include "BKE_report.h"
  49
  50 #include "DNA_object_types.h"
  51 #include "DNA_scene_types.h"
  52 #include "DNA_gpencil_types.h"
  53 #include "DNA_windowmanager_types.h"
  54
  55 #include "UI_view2d.h"
  56
  57 #include "ED_gpencil.h"
  58 #include "ED_screen.h"
  59 #include "ED_view3d.h"
  60
  61 #include "RNA_access.h"
  62
  63 #include "RNA_define.h"
  64 #include "WM_api.h"
  65 #include "WM_types.h"
  66
  67 #include "gpencil_intern.h"
  68
  69 /* ******************************************* */
  70 /* 'Globals' and Defines */
  71
  72 /* Temporary 'Stroke' Operation data */
  73 typedef struct tGPsdata {
  74         Scene *scene;       /* current scene from context */
  75
  76         wmWindow *win;          /* window where painting originated */
  77         ScrArea *sa;            /* area where painting originated */
  78         ARegion *ar;        /* region where painting originated */
  79         View2D *v2d;            /* needed for GP_STROKE_2DSPACE */
  80         rctf *subrect;          /* for using the camera rect within the 3d view */
  81         rctf subrect_data;
  82
  83
  84 #if 0 // XXX review this 2d image stuff...
  85         ImBuf *ibuf;            /* needed for GP_STROKE_2DIMAGE */
  86         struct IBufViewSettings {
  87                 int offsx, offsy;                       /* offsets */
  88                 int sizex, sizey;                       /* dimensions to use as scale-factor */
  89         } im2d_settings;        /* needed for GP_STROKE_2DIMAGE */
  90 #endif
  91
  92         PointerRNA ownerPtr;/* pointer to owner of gp-datablock */
  93         bGPdata *gpd;           /* gp-datablock layer comes from */
  94         bGPDlayer *gpl;         /* layer we're working on */
  95         bGPDframe *gpf;         /* frame we're working on */
  96
  97         short status;           /* current status of painting */
  98         short paintmode;        /* mode for painting */
  99
 100         int mval[2];            /* current mouse-position */
 101         int mvalo[2];           /* previous recorded mouse-position */
 102
 103         float pressure;         /* current stylus pressure */
 104         float opressure;        /* previous stylus pressure */
 105
 106         short radius;           /* radius of influence for eraser */
 107         short flags;            /* flags that can get set during runtime */
 108 } tGPsdata;
 109
 110 /* values for tGPsdata->status */
 111 enum {
 112         GP_STATUS_IDLING = 0,   /* stroke isn't in progress yet */
 113         GP_STATUS_PAINTING,             /* a stroke is in progress */
 114         GP_STATUS_ERROR,                /* something wasn't correctly set up */
 115         GP_STATUS_DONE                  /* painting done */
 116 };
 117
 118 /* Return flags for adding points to stroke buffer */
 119 enum {
 120         GP_STROKEADD_INVALID    = -2,           /* error occurred - insufficient info to do so */
 121         GP_STROKEADD_OVERFLOW   = -1,           /* error occurred - cannot fit any more points */
 122         GP_STROKEADD_NORMAL,                            /* point was successfully added */
 123         GP_STROKEADD_FULL                                       /* cannot add any more points to buffer */
 124 };
 125
 126 /* Runtime flags */
 127 enum {
 128         GP_PAINTFLAG_FIRSTRUN           = (1<<0),       /* operator just started */
 129 };
 130
 131 /* ------ */
 132
 133 /* maximum sizes of gp-session buffer */
 134 #define GP_STROKE_BUFFER_MAX    5000
 135
 136 /* Macros for accessing sensitivity thresholds... */
 137         /* minimum number of pixels mouse should move before new point created */
 138 #define MIN_MANHATTEN_PX        (U.gp_manhattendist)
 139         /* minimum length of new segment before new point can be added */
 140 #define MIN_EUCLIDEAN_PX        (U.gp_euclideandist)
 141
 142 /* ------ */
 143 /* Forward defines for some functions... */
 144
 145 static void gp_session_validatebuffer(tGPsdata *p);
 146
 147 /* ******************************************* */
 148 /* Context Wrangling... */
 149
 150 /* check if context is suitable for drawing */
 151 static int gpencil_draw_poll (bContext *C)
 152 {
 153         if (ED_operator_regionactive(C)) {
 154                 /* check if current context can support GPencil data */
 155                 if (gpencil_data_get_pointers(C, NULL) != NULL) {
 156                         /* check if Grease Pencil isn't already running */
 157                         if ((G.f & G_GREASEPENCIL) == 0)
 158                                 return 1;
 159                         else
 160                                 CTX_wm_operator_poll_msg_set(C, "Grease Pencil operator is already active");
 161                 }
 162                 else {
 163                         CTX_wm_operator_poll_msg_set(C, "Failed to find Grease Pencil data to draw into");
 164                 }
 165         }
 166         else {
 167                 CTX_wm_operator_poll_msg_set(C, "Active region not set");
 168         }
 169
 170         return 0;
 171 }
 172
 173 /* check if projecting strokes into 3d-geometry in the 3D-View */
 174 static int gpencil_project_check (tGPsdata *p)
 175 {
 176         bGPdata *gpd= p->gpd;
 177         return ((gpd->sbuffer_sflag & GP_STROKE_3DSPACE) && (p->gpd->flag & (GP_DATA_DEPTH_VIEW | GP_DATA_DEPTH_STROKE)));
 178 }
 179
 180 /* ******************************************* */
 181 /* Calculations/Conversions */
 182
 183 /* Utilities --------------------------------- */
 184
 185 /* get the reference point for stroke-point conversions */
 186 static void gp_get_3d_reference (tGPsdata *p, float *vec)
 187 {
 188         View3D *v3d= p->sa->spacedata.first;
 189         float *fp= give_cursor(p->scene, v3d);
 190
 191         /* the reference point used depends on the owner... */
 192 #if 0 // XXX: disabled for now, since we can't draw relative to the owner yet
 193         if (p->ownerPtr.type == &RNA_Object)
 194         {
 195                 Object *ob= (Object *)p->ownerPtr.data;
 196
 197                 /* active Object
 198                  *      - use relative distance of 3D-cursor from object center
 199                  */
 200                 sub_v3_v3v3(vec, fp, ob->loc);
 201         }
 202         else
 203 #endif
 204         {
 205                 /* use 3D-cursor */
 206                 copy_v3_v3(vec, fp);
 207         }
 208 }
 209
 210 /* Stroke Editing ---------------------------- */
 211
 212 /* check if the current mouse position is suitable for adding a new point */
 213 static short gp_stroke_filtermval (tGPsdata *p, int mval[2], int pmval[2])
 214 {
 215         int dx= abs(mval[0] - pmval[0]);
 216         int dy= abs(mval[1] - pmval[1]);
 217
 218         /* if buffer is empty, just let this go through (i.e. so that dots will work) */
 219         if (p->gpd->sbuffer_size == 0)
 220                 return 1;
 221
 222         /* check if mouse moved at least certain distance on both axes (best case)
 223          *      - aims to eliminate some jitter-noise from input when trying to draw straight lines freehand
 224          */
 225         else if ((dx > MIN_MANHATTEN_PX) && (dy > MIN_MANHATTEN_PX))
 226                 return 1;
 227
 228         /* check if the distance since the last point is significant enough
 229          *      - prevents points being added too densely
 230          *      - distance here doesn't use sqrt to prevent slowness... we should still be safe from overflows though
 231          */
 232         else if ((dx*dx + dy*dy) > MIN_EUCLIDEAN_PX*MIN_EUCLIDEAN_PX)
 233                 return 1;
 234
 235         /* mouse 'didn't move' */
 236         else
 237                 return 0;
 238 }
 239
 240 /* convert screen-coordinates to buffer-coordinates */
 241 // XXX this method needs a total overhaul!
 242 static void gp_stroke_convertcoords (tGPsdata *p, short mval[2], float out[3], float *depth)
 243 {
 244         bGPdata *gpd= p->gpd;
 245
 246         /* in 3d-space - pt->x/y/z are 3 side-by-side floats */
 247         if (gpd->sbuffer_sflag & GP_STROKE_3DSPACE) {
 248                 if (gpencil_project_check(p) && (view_autodist_simple(p->ar, mval, out, 0, depth))) {
 249                         /* projecting onto 3D-Geometry
 250                          *      - nothing more needs to be done here, since view_autodist_simple() has already done it
 251                          */
 252                 }
 253                 else {
 254                         const short mx=mval[0], my=mval[1];
 255                         float rvec[3], dvec[3];
 256
 257                         /* Current method just converts each point in screen-coordinates to
 258                          * 3D-coordinates using the 3D-cursor as reference. In general, this
 259                          * works OK, but it could of course be improved.
 260                          *
 261                          * TODO:
 262                          *      - investigate using nearest point(s) on a previous stroke as
 263                          *        reference point instead or as offset, for easier stroke matching
 264                          */
 265
 266                         gp_get_3d_reference(p, rvec);
 267
 268                         /* method taken from editview.c - mouse_cursor() */
 269                         project_short_noclip(p->ar, rvec, mval);
 270                         window_to_3d_delta(p->ar, dvec, mval[0]-mx, mval[1]-my);
 271                         sub_v3_v3v3(out, rvec, dvec);
 272                 }
 273         }
 274
 275         /* 2d - on 'canvas' (assume that p->v2d is set) */
 276         else if ((gpd->sbuffer_sflag & GP_STROKE_2DSPACE) && (p->v2d)) {
 277                 float x, y;
 278
 279                 UI_view2d_region_to_view(p->v2d, mval[0], mval[1], &x, &y);
 280
 281                 out[0]= x;
 282                 out[1]= y;
 283         }
 284
 285 #if 0
 286         /* 2d - on image 'canvas' (assume that p->v2d is set) */
 287         else if (gpd->sbuffer_sflag & GP_STROKE_2DIMAGE) {
 288                 int sizex, sizey, offsx, offsy;
 289
 290                 /* get stored settings
 291                  *      - assume that these have been set already (there are checks that set sane 'defaults' just in case)
 292                  */
 293                 sizex= p->im2d_settings.sizex;
 294                 sizey= p->im2d_settings.sizey;
 295                 offsx= p->im2d_settings.offsx;
 296                 offsy= p->im2d_settings.offsy;
 297
 298                 /* calculate new points */
 299                 out[0]= (float)(mval[0] - offsx) / (float)sizex;
 300                 out[1]= (float)(mval[1] - offsy) / (float)sizey;
 301         }
 302 #endif
 303
 304         /* 2d - relative to screen (viewport area) */
 305         else {
 306                 if (p->subrect == NULL) { /* normal 3D view */
 307                         out[0] = (float)(mval[0]) / (float)(p->ar->winx) * 100;
 308                         out[1] = (float)(mval[1]) / (float)(p->ar->winy) * 100;
 309                 }
 310                 else { /* camera view, use subrect */
 311                         out[0]= ((mval[0] - p->subrect->xmin) / ((p->subrect->xmax - p->subrect->xmin))) * 100;
 312                         out[1]= ((mval[1] - p->subrect->ymin) / ((p->subrect->ymax - p->subrect->ymin))) * 100;
 313                 }
 314         }
 315 }
 316
 317 /* add current stroke-point to buffer (returns whether point was successfully added) */
 318 static short gp_stroke_addpoint (tGPsdata *p, int mval[2], float pressure)
 319 {
 320         bGPdata *gpd= p->gpd;
 321         tGPspoint *pt;
 322
 323         /* check painting mode */
 324         if (p->paintmode == GP_PAINTMODE_DRAW_STRAIGHT) {
 325                 /* straight lines only - i.e. only store start and end point in buffer */
 326                 if (gpd->sbuffer_size == 0) {
 327                         /* first point in buffer (start point) */
 328                         pt= (tGPspoint *)(gpd->sbuffer);
 329
 330                         /* store settings */
 331                         pt->x= mval[0];
 332                         pt->y= mval[1];
 333                         pt->pressure= pressure;
 334
 335                         /* increment buffer size */
 336                         gpd->sbuffer_size++;
 337                 }
 338                 else {
 339                         /* normally, we just reset the endpoint to the latest value
 340                          *      - assume that pointers for this are always valid...
 341                          */
 342                         pt= ((tGPspoint *)(gpd->sbuffer) + 1);
 343
 344                         /* store settings */
 345                         pt->x= mval[0];
 346                         pt->y= mval[1];
 347                         pt->pressure= pressure;
 348
 349                         /* if this is just the second point we've added, increment the buffer size
 350                          * so that it will be drawn properly...
 351                          * otherwise, just leave it alone, otherwise we get problems
 352                          */
 353                         if (gpd->sbuffer_size != 2)
 354                                 gpd->sbuffer_size= 2;
 355                 }
 356
 357                 /* can keep carrying on this way :) */
 358                 return GP_STROKEADD_NORMAL;
 359         }
 360         else if (p->paintmode == GP_PAINTMODE_DRAW) { /* normal drawing */
 361                 /* check if still room in buffer */
 362                 if (gpd->sbuffer_size >= GP_STROKE_BUFFER_MAX)
 363                         return GP_STROKEADD_OVERFLOW;
 364
 365                 /* get pointer to destination point */
 366                 pt= ((tGPspoint *)(gpd->sbuffer) + gpd->sbuffer_size);
 367
 368                 /* store settings */
 369                 pt->x= mval[0];
 370                 pt->y= mval[1];
 371                 pt->pressure= pressure;
 372
 373                 /* increment counters */
 374                 gpd->sbuffer_size++;
 375
 376                 /* check if another operation can still occur */
 377                 if (gpd->sbuffer_size == GP_STROKE_BUFFER_MAX)
 378                         return GP_STROKEADD_FULL;
 379                 else
 380                         return GP_STROKEADD_NORMAL;
 381         }
 382
 383         /* return invalid state for now... */
 384         return GP_STROKEADD_INVALID;
 385 }
 386
 387
 388 /* temp struct for gp_stroke_smooth() */
 389 typedef struct tGpSmoothCo {
 390         short x;
 391         short y;
 392 } tGpSmoothCo;
 393
 394 /* smooth a stroke (in buffer) before storing it */
 395 static void gp_stroke_smooth (tGPsdata *p)
 396 {
 397         bGPdata *gpd= p->gpd;
 398         tGpSmoothCo *smoothArray, *spc;
 399         int i=0, cmx=gpd->sbuffer_size;
 400
 401         /* only smooth if smoothing is enabled, and we're not doing a straight line */
 402         if (!(U.gp_settings & GP_PAINT_DOSMOOTH) || (p->paintmode == GP_PAINTMODE_DRAW_STRAIGHT))
 403                 return;
 404
 405         /* don't try if less than 2 points in buffer */
 406         if ((cmx <= 2) || (gpd->sbuffer == NULL))
 407                 return;
 408
 409         /* create a temporary smoothing coordinates buffer, use to store calculated values to prevent sequential error */
 410         smoothArray = MEM_callocN(sizeof(tGpSmoothCo)*cmx, "gp_stroke_smooth smoothArray");
 411
 412         /* first pass: calculate smoothing coordinates using weighted-averages */
 413         for (i=0, spc=smoothArray; i < gpd->sbuffer_size; i++, spc++) {
 414                 const tGPspoint *pc= (((tGPspoint *)gpd->sbuffer) + i);
 415                 const tGPspoint *pb= (i-1 > 0)?(pc-1):(pc);
 416                 const tGPspoint *pa= (i-2 > 0)?(pc-2):(pb);
 417                 const tGPspoint *pd= (i+1 < cmx)?(pc+1):(pc);
 418                 const tGPspoint *pe= (i+2 < cmx)?(pc+2):(pd);
 419
 420                 spc->x= (short)(0.1*pa->x + 0.2*pb->x + 0.4*pc->x + 0.2*pd->x + 0.1*pe->x);
 421                 spc->y= (short)(0.1*pa->y + 0.2*pb->y + 0.4*pc->y + 0.2*pd->y + 0.1*pe->y);
 422         }
 423
 424         /* second pass: apply smoothed coordinates */
 425         for (i=0, spc=smoothArray; i < gpd->sbuffer_size; i++, spc++) {
 426                 tGPspoint *pc= (((tGPspoint *)gpd->sbuffer) + i);
 427
 428                 pc->x = spc->x;
 429                 pc->y = spc->y;
 430         }
 431
 432         /* free temp array */
 433         MEM_freeN(smoothArray);
 434 }
 435
 436 /* simplify a stroke (in buffer) before storing it
 437  *      - applies a reverse Chaikin filter
 438  *      - code adapted from etch-a-ton branch (editarmature_sketch.c)
 439  */
 440 static void gp_stroke_simplify (tGPsdata *p)
 441 {
 442         bGPdata *gpd= p->gpd;
 443         tGPspoint *old_points= (tGPspoint *)gpd->sbuffer;
 444         short num_points= gpd->sbuffer_size;
 445         short flag= gpd->sbuffer_sflag;
 446         short i, j;
 447
 448         /* only simplify if simplification is enabled, and we're not doing a straight line */
 449         if (!(U.gp_settings & GP_PAINT_DOSIMPLIFY) || (p->paintmode == GP_PAINTMODE_DRAW_STRAIGHT))
 450                 return;
 451
 452         /* don't simplify if less than 4 points in buffer */
 453         if ((num_points <= 4) || (old_points == NULL))
 454                 return;
 455
 456         /* clear buffer (but don't free mem yet) so that we can write to it
 457          *      - firstly set sbuffer to NULL, so a new one is allocated
 458          *      - secondly, reset flag after, as it gets cleared auto
 459          */
 460         gpd->sbuffer= NULL;
 461         gp_session_validatebuffer(p);
 462         gpd->sbuffer_sflag = flag;
 463
 464 /* macro used in loop to get position of new point
 465  *      - used due to the mixture of datatypes in use here
 466  */
 467 #define GP_SIMPLIFY_AVPOINT(offs, sfac) \
 468         { \
 469                 co[0] += (float)(old_points[offs].x * sfac); \
 470                 co[1] += (float)(old_points[offs].y * sfac); \
 471                 pressure += old_points[offs].pressure * sfac; \
 472         }
 473
 474         for (i = 0, j = 0; i < num_points; i++)
 475         {
 476                 if (i - j == 3)
 477                 {
 478                         float co[2], pressure;
 479                         int mco[2];
 480
 481                         /* initialise values */
 482                         co[0]= 0;
 483                         co[1]= 0;
 484                         pressure = 0;
 485
 486                         /* using macro, calculate new point */
 487                         GP_SIMPLIFY_AVPOINT(j, -0.25f);
 488                         GP_SIMPLIFY_AVPOINT(j+1, 0.75f);
 489                         GP_SIMPLIFY_AVPOINT(j+2, 0.75f);
 490                         GP_SIMPLIFY_AVPOINT(j+3, -0.25f);
 491
 492                         /* set values for adding */
 493                         mco[0]= (int)co[0];
 494                         mco[1]= (int)co[1];
 495
 496                         /* ignore return values on this... assume to be ok for now */
 497                         gp_stroke_addpoint(p, mco, pressure);
 498
 499                         j += 2;
 500                 }
 501         }
 502
 503         /* free old buffer */
 504         MEM_freeN(old_points);
 505 }
 506
 507
 508 /* make a new stroke from the buffer data */
 509 static void gp_stroke_newfrombuffer (tGPsdata *p)
 510 {
 511         bGPdata *gpd= p->gpd;
 512         bGPDstroke *gps;
 513         bGPDspoint *pt;
 514         tGPspoint *ptc;
 515         int i, totelem;
 516         /* since strokes are so fine, when using their depth we need a margin otherwise they might get missed */
 517         int depth_margin = (p->gpd->flag & GP_DATA_DEPTH_STROKE) ? 4 : 0;
 518
 519         /* get total number of points to allocate space for
 520          *      - drawing straight-lines only requires the endpoints
 521          */
 522         if (p->paintmode == GP_PAINTMODE_DRAW_STRAIGHT)
 523                 totelem = (gpd->sbuffer_size >= 2) ? 2: gpd->sbuffer_size;
 524         else
 525                 totelem = gpd->sbuffer_size;
 526
 527         /* exit with error if no valid points from this stroke */
 528         if (totelem == 0) {
 529                 if (G.f & G_DEBUG)
 530                         printf("Error: No valid points in stroke buffer to convert (tot=%d) \n", gpd->sbuffer_size);
 531                 return;
 532         }
 533
 534         /* allocate memory for a new stroke */
 535         gps= MEM_callocN(sizeof(bGPDstroke), "gp_stroke");
 536
 537         /* allocate enough memory for a continuous array for storage points */
 538         pt= gps->points= MEM_callocN(sizeof(bGPDspoint)*totelem, "gp_stroke_points");
 539
 540         /* copy appropriate settings for stroke */
 541         gps->totpoints= totelem;
 542         gps->thickness= p->gpl->thickness;
 543         gps->flag= gpd->sbuffer_sflag;
 544
 545         /* copy points from the buffer to the stroke */
 546         if (p->paintmode == GP_PAINTMODE_DRAW_STRAIGHT) {
 547                 /* straight lines only -> only endpoints */
 548                 {
 549                         /* first point */
 550                         ptc= gpd->sbuffer;
 551
 552                         /* convert screen-coordinates to appropriate coordinates (and store them) */
 553                         gp_stroke_convertcoords(p, &ptc->x, &pt->x, NULL);
 554
 555                         /* copy pressure */
 556                         pt->pressure= ptc->pressure;
 557
 558                         pt++;
 559                 }
 560
 561                 if (totelem == 2) {
 562                         /* last point if applicable */
 563                         ptc= ((tGPspoint *)gpd->sbuffer) + (gpd->sbuffer_size - 1);
 564
 565                         /* convert screen-coordinates to appropriate coordinates (and store them) */
 566                         gp_stroke_convertcoords(p, &ptc->x, &pt->x, NULL);
 567
 568                         /* copy pressure */
 569                         pt->pressure= ptc->pressure;
 570                 }
 571         }
 572         else {
 573                 float *depth_arr= NULL;
 574
 575                 /* get an array of depths, far depths are blended */
 576                 if (gpencil_project_check(p)) {
 577                         short mval[2], mval_prev[2]= {0};
 578                         int interp_depth = 0;
 579                         int found_depth = 0;
 580
 581                         depth_arr= MEM_mallocN(sizeof(float) * gpd->sbuffer_size, "depth_points");
 582
 583                         for (i=0, ptc=gpd->sbuffer; i < gpd->sbuffer_size; i++, ptc++, pt++) {
 584                                 mval[0]= ptc->x; mval[1]= ptc->y;
 585
 586                                 if ((view_autodist_depth(p->ar, mval, depth_margin, depth_arr+i) == 0) &&
 587                                         (i && (view_autodist_depth_segment(p->ar, mval, mval_prev, depth_margin + 1, depth_arr+i) == 0))
 588                                 ) {
 589                                         interp_depth= TRUE;
 590                                 }
 591                                 else {
 592                                         found_depth= TRUE;
 593                                 }
 594
 595                                 VECCOPY2D(mval_prev, mval);
 596                         }
 597
 598                         if (found_depth == FALSE) {
 599                                 /* eeh... not much we can do.. :/, ignore depth in this case, use the 3D cursor */
 600                                 for (i=gpd->sbuffer_size-1; i >= 0; i--)
 601                                         depth_arr[i] = 0.9999f;
 602                         }
 603                         else {
 604                                 if (p->gpd->flag & GP_DATA_DEPTH_STROKE_ENDPOINTS) {
 605                                         /* remove all info between the valid endpoints */
 606                                         int first_valid = 0;
 607                                         int last_valid = 0;
 608
 609                                         for (i=0; i < gpd->sbuffer_size; i++) {
 610                                                 if (depth_arr[i] != FLT_MAX)
 611                                                         break;
 612                                         }
 613                                         first_valid= i;
 614
 615                                         for (i=gpd->sbuffer_size-1; i >= 0; i--) {
 616                                                 if (depth_arr[i] != FLT_MAX)
 617                                                         break;
 618                                         }
 619                                         last_valid= i;
 620
 621                                         /* invalidate non-endpoints, so only blend between first and last */
 622                                         for (i=first_valid+1; i < last_valid; i++)
 623                                                 depth_arr[i]= FLT_MAX;
 624
 625                                         interp_depth= TRUE;
 626                                 }
 627
 628                                 if (interp_depth) {
 629                                         interp_sparse_array(depth_arr, gpd->sbuffer_size, FLT_MAX);
 630                                 }
 631                         }
 632                 }
 633
 634
 635                 pt= gps->points;
 636
 637                 /* convert all points (normal behaviour) */
 638                 for (i=0, ptc=gpd->sbuffer; i < gpd->sbuffer_size && ptc; i++, ptc++, pt++) {
 639                         /* convert screen-coordinates to appropriate coordinates (and store them) */
 640                         gp_stroke_convertcoords(p, &ptc->x, &pt->x, depth_arr ? depth_arr+i:NULL);
 641
 642                         /* copy pressure */
 643                         pt->pressure= ptc->pressure;
 644                 }
 645
 646                 if (depth_arr)
 647                         MEM_freeN(depth_arr);
 648         }
 649
 650         /* add stroke to frame */
 651         BLI_addtail(&p->gpf->strokes, gps);
 652 }
 653
 654 /* --- 'Eraser' for 'Paint' Tool ------ */
 655
 656 /* eraser tool - remove segment from stroke/split stroke (after lasso inside) */
 657 static short gp_stroke_eraser_splitdel (bGPDframe *gpf, bGPDstroke *gps, int i)
 658 {
 659         bGPDspoint *pt_tmp= gps->points;
 660         bGPDstroke *gsn = NULL;
 661
 662         /* if stroke only had two points, get rid of stroke */
 663         if (gps->totpoints == 2) {
 664                 /* free stroke points, then stroke */
 665                 MEM_freeN(pt_tmp);
 666                 BLI_freelinkN(&gpf->strokes, gps);
 667
 668                 /* nothing left in stroke, so stop */
 669                 return 1;
 670         }
 671
 672         /* if last segment, just remove segment from the stroke */
 673         else if (i == gps->totpoints - 2) {
 674                 /* allocate new points array, and assign most of the old stroke there */
 675                 gps->totpoints--;
 676                 gps->points= MEM_callocN(sizeof(bGPDspoint)*gps->totpoints, "gp_stroke_points");
 677                 memcpy(gps->points, pt_tmp, sizeof(bGPDspoint)*gps->totpoints);
 678
 679                 /* free temp buffer */
 680                 MEM_freeN(pt_tmp);
 681
 682                 /* nothing left in stroke, so stop */
 683                 return 1;
 684         }
 685
 686         /* if first segment, just remove segment from the stroke */
 687         else if (i == 0) {
 688                 /* allocate new points array, and assign most of the old stroke there */
 689                 gps->totpoints--;
 690                 gps->points= MEM_callocN(sizeof(bGPDspoint)*gps->totpoints, "gp_stroke_points");
 691                 memcpy(gps->points, pt_tmp + 1, sizeof(bGPDspoint)*gps->totpoints);
 692
 693                 /* free temp buffer */
 694                 MEM_freeN(pt_tmp);
 695
 696                 /* no break here, as there might still be stuff to remove in this stroke */
 697                 return 0;
 698         }
 699
 700         /* segment occurs in 'middle' of stroke, so split */
 701         else {
 702                 /* duplicate stroke, and assign 'later' data to that stroke */
 703                 gsn= MEM_dupallocN(gps);
 704                 gsn->prev= gsn->next= NULL;
 705                 BLI_insertlinkafter(&gpf->strokes, gps, gsn);
 706
 707                 gsn->totpoints= gps->totpoints - i;
 708                 gsn->points= MEM_callocN(sizeof(bGPDspoint)*gsn->totpoints, "gp_stroke_points");
 709                 memcpy(gsn->points, pt_tmp + i, sizeof(bGPDspoint)*gsn->totpoints);
 710
 711                 /* adjust existing stroke  */
 712                 gps->totpoints= i;
 713                 gps->points= MEM_callocN(sizeof(bGPDspoint)*gps->totpoints, "gp_stroke_points");
 714                 memcpy(gps->points, pt_tmp, sizeof(bGPDspoint)*i);
 715
 716                 /* free temp buffer */
 717                 MEM_freeN(pt_tmp);
 718
 719                 /* nothing left in stroke, so stop */
 720                 return 1;
 721         }
 722 }
 723
 724 /* eraser tool - check if part of stroke occurs within last segment drawn by eraser */
 725 static short gp_stroke_eraser_strokeinside (int mval[], int UNUSED(mvalo[]), short rad, short x0, short y0, short x1, short y1)
 726 {
 727         /* simple within-radius check for now */
 728         if (edge_inside_circle(mval[0], mval[1], rad, x0, y0, x1, y1))
 729                 return 1;
 730
 731         /* not inside */
 732         return 0;
 733 }
 734
 735 /* eraser tool - evaluation per stroke */
 736 // TODO: this could really do with some optimisation (KD-Tree/BVH?)
 737 static void gp_stroke_eraser_dostroke (tGPsdata *p, int mval[], int mvalo[], short rad, rcti *rect, bGPDframe *gpf, bGPDstroke *gps)
 738 {
 739         bGPDspoint *pt1, *pt2;
 740         int x0=0, y0=0, x1=0, y1=0;
 741         short xyval[2];
 742         int i;
 743
 744         if (gps->totpoints == 0) {
 745                 /* just free stroke */
 746                 if (gps->points)
 747                         MEM_freeN(gps->points);
 748                 BLI_freelinkN(&gpf->strokes, gps);
 749         }
 750         else if (gps->totpoints == 1) {
 751                 /* get coordinates */
 752                 if (gps->flag & GP_STROKE_3DSPACE) {
 753                         project_short(p->ar, &gps->points->x, xyval);
 754                         x0= xyval[0];
 755                         y0= xyval[1];
 756                 }
 757                 else if (gps->flag & GP_STROKE_2DSPACE) {
 758                         UI_view2d_view_to_region(p->v2d, gps->points->x, gps->points->y, &x0, &y0);
 759                 }
 760 #if 0
 761                 else if (gps->flag & GP_STROKE_2DIMAGE) {
 762                         int offsx, offsy, sizex, sizey;
 763
 764                         /* get stored settings */
 765                         sizex= p->im2d_settings.sizex;
 766                         sizey= p->im2d_settings.sizey;
 767                         offsx= p->im2d_settings.offsx;
 768                         offsy= p->im2d_settings.offsy;
 769
 770                         /* calculate new points */
 771                         x0= (int)((gps->points->x * sizex) + offsx);
 772                         y0= (int)((gps->points->y * sizey) + offsy);
 773                 }
 774 #endif
 775                 else {
 776                         if (p->subrect == NULL) { /* normal 3D view */
 777                                 x0= (int)(gps->points->x / 100 * p->ar->winx);
 778                                 y0= (int)(gps->points->y / 100 * p->ar->winy);
 779                         }
 780                         else { /* camera view, use subrect */
 781                                 x0= (int)((gps->points->x / 100) * (p->subrect->xmax - p->subrect->xmin)) + p->subrect->xmin;
 782                                 y0= (int)((gps->points->y / 100) * (p->subrect->ymax - p->subrect->ymin)) + p->subrect->ymin;
 783                         }
 784                 }
 785
 786                 /* do boundbox check first */
 787                 if (BLI_in_rcti(rect, x0, y0)) {
 788                         /* only check if point is inside */
 789                         if ( ((x0-mval[0])*(x0-mval[0]) + (y0-mval[1])*(y0-mval[1])) <= rad*rad ) {
 790                                 /* free stroke */
 791                                 MEM_freeN(gps->points);
 792                                 BLI_freelinkN(&gpf->strokes, gps);
 793                         }
 794                 }
 795         }
 796         else {
 797                 /* loop over the points in the stroke, checking for intersections
 798                  *      - an intersection will require the stroke to be split
 799                  */
 800                 for (i=0; (i+1) < gps->totpoints; i++) {
 801                         /* get points to work with */
 802                         pt1= gps->points + i;
 803                         pt2= gps->points + i + 1;
 804
 805                         /* get coordinates */
 806                         if (gps->flag & GP_STROKE_3DSPACE) {
 807                                 project_short(p->ar, &pt1->x, xyval);
 808                                 x0= xyval[0];
 809                                 y0= xyval[1];
 810
 811                                 project_short(p->ar, &pt2->x, xyval);
 812                                 x1= xyval[0];
 813                                 y1= xyval[1];
 814                         }
 815                         else if (gps->flag & GP_STROKE_2DSPACE) {
 816                                 UI_view2d_view_to_region(p->v2d, pt1->x, pt1->y, &x0, &y0);
 817
 818                                 UI_view2d_view_to_region(p->v2d, pt2->x, pt2->y, &x1, &y1);
 819                         }
 820 #if 0
 821                         else if (gps->flag & GP_STROKE_2DIMAGE) {
 822                                 int offsx, offsy, sizex, sizey;
 823
 824                                 /* get stored settings */
 825                                 sizex= p->im2d_settings.sizex;
 826                                 sizey= p->im2d_settings.sizey;
 827                                 offsx= p->im2d_settings.offsx;
 828                                 offsy= p->im2d_settings.offsy;
 829
 830                                 /* calculate new points */
 831                                 x0= (int)((pt1->x * sizex) + offsx);
 832                                 y0= (int)((pt1->y * sizey) + offsy);
 833
 834                                 x1= (int)((pt2->x * sizex) + offsx);
 835                                 y1= (int)((pt2->y * sizey) + offsy);
 836                         }
 837 #endif
 838                         else {
 839                                 if(p->subrect == NULL) { /* normal 3D view */
 840                                         x0= (int)(pt1->x / 100 * p->ar->winx);
 841                                         y0= (int)(pt1->y / 100 * p->ar->winy);
 842                                         x1= (int)(pt2->x / 100 * p->ar->winx);
 843                                         y1= (int)(pt2->y / 100 * p->ar->winy);
 844                                 }
 845                                 else { /* camera view, use subrect */
 846                                         x0= (int)((pt1->x / 100) * (p->subrect->xmax - p->subrect->xmin)) + p->subrect->xmin;
 847                                         y0= (int)((pt1->y / 100) * (p->subrect->ymax - p->subrect->ymin)) + p->subrect->ymin;
 848                                         x1= (int)((pt2->x / 100) * (p->subrect->xmax - p->subrect->xmin)) + p->subrect->xmin;
 849                                         y1= (int)((pt2->y / 100) * (p->subrect->ymax - p->subrect->ymin)) + p->subrect->ymin;
 850                                 }
 851                         }
 852
 853                         /* check that point segment of the boundbox of the eraser stroke */
 854                         if (BLI_in_rcti(rect, x0, y0) || BLI_in_rcti(rect, x1, y1)) {
 855                                 /* check if point segment of stroke had anything to do with
 856                                  * eraser region  (either within stroke painted, or on its lines)
 857                                  *      - this assumes that linewidth is irrelevant
 858                                  */
 859                                 if (gp_stroke_eraser_strokeinside(mval, mvalo, rad, x0, y0, x1, y1)) {
 860                                         /* if function returns true, break this loop (as no more point to check) */
 861                                         if (gp_stroke_eraser_splitdel(gpf, gps, i))
 862                                                 break;
 863                                 }
 864                         }
 865                 }
 866         }
 867 }
 868
 869 /* erase strokes which fall under the eraser strokes */
 870 static void gp_stroke_doeraser (tGPsdata *p)
 871 {
 872         bGPDframe *gpf= p->gpf;
 873         bGPDstroke *gps, *gpn;
 874         rcti rect;
 875
 876         /* rect is rectangle of eraser */
 877         rect.xmin= p->mval[0] - p->radius;
 878         rect.ymin= p->mval[1] - p->radius;
 879         rect.xmax= p->mval[0] + p->radius;
 880         rect.ymax= p->mval[1] + p->radius;
 881
 882         /* loop over strokes, checking segments for intersections */
 883         for (gps= gpf->strokes.first; gps; gps= gpn) {
 884                 gpn= gps->next;
 885                 gp_stroke_eraser_dostroke(p, p->mval, p->mvalo, p->radius, &rect, gpf, gps);
 886         }
 887 }
 888
 889 /* ******************************************* */
 890 /* Sketching Operator */
 891
 892 /* clear the session buffers (call this before AND after a paint operation) */
 893 static void gp_session_validatebuffer (tGPsdata *p)
 894 {
 895         bGPdata *gpd= p->gpd;
 896
 897         /* clear memory of buffer (or allocate it if starting a new session) */
 898         if (gpd->sbuffer)
 899                 memset(gpd->sbuffer, 0, sizeof(tGPspoint)*GP_STROKE_BUFFER_MAX);
 900         else
 901                 gpd->sbuffer= MEM_callocN(sizeof(tGPspoint)*GP_STROKE_BUFFER_MAX, "gp_session_strokebuffer");
 902
 903         /* reset indices */
 904         gpd->sbuffer_size = 0;
 905
 906         /* reset flags */
 907         gpd->sbuffer_sflag= 0;
 908 }
 909
 910 /* init new painting session */
 911 static tGPsdata *gp_session_initpaint (bContext *C)
 912 {
 913         tGPsdata *p = NULL;
 914         bGPdata **gpd_ptr = NULL;
 915         ScrArea *curarea= CTX_wm_area(C);
 916         ARegion *ar= CTX_wm_region(C);
 917
 918         /* make sure the active view (at the starting time) is a 3d-view */
 919         if (curarea == NULL) {
 920                 if (G.f & G_DEBUG)
 921                         printf("Error: No active view for painting \n");
 922                 return NULL;
 923         }
 924
 925         /* create new context data */
 926         p= MEM_callocN(sizeof(tGPsdata), "GPencil Drawing Data");
 927
 928         /* pass on current scene and window */
 929         p->scene= CTX_data_scene(C);
 930         p->win= CTX_wm_window(C);
 931
 932         switch (curarea->spacetype) {
 933                 /* supported views first */
 934                 case SPACE_VIEW3D:
 935                 {
 936                         // View3D *v3d= curarea->spacedata.first;
 937                         // RegionView3D *rv3d= ar->regiondata;
 938
 939                         /* set current area
 940                          *      - must verify that region data is 3D-view (and not something else)
 941                          */
 942                         p->sa= curarea;
 943                         p->ar= ar;
 944
 945                         if (ar->regiondata == NULL) {
 946                                 p->status= GP_STATUS_ERROR;
 947                                 if (G.f & G_DEBUG)
 948                                         printf("Error: 3D-View active region doesn't have any region data, so cannot be drawable \n");
 949                                 return p;
 950                         }
 951
 952 #if 0 // XXX will this sort of antiquated stuff be restored?
 953                         /* check that gpencil data is allowed to be drawn */
 954                         if ((v3d->flag2 & V3D_DISPGP)==0) {
 955                                 p->status= GP_STATUS_ERROR;
 956                                 if (G.f & G_DEBUG)
 957                                         printf("Error: In active view, Grease Pencil not shown \n");
 958                                 return p;
 959                         }
 960 #endif
 961                 }
 962                         break;
 963
 964                 case SPACE_NODE:
 965                 {
 966                         //SpaceNode *snode= curarea->spacedata.first;
 967
 968                         /* set current area */
 969                         p->sa= curarea;
 970                         p->ar= ar;
 971                         p->v2d= &ar->v2d;
 972
 973 #if 0 // XXX will this sort of antiquated stuff be restored?
 974                         /* check that gpencil data is allowed to be drawn */
 975                         if ((snode->flag & SNODE_DISPGP)==0) {
 976                                 p->status= GP_STATUS_ERROR;
 977                                 if (G.f & G_DEBUG)
 978                                         printf("Error: In active view, Grease Pencil not shown \n");
 979                                 return;
 980                         }
 981 #endif
 982                 }
 983                         break;
 984 #if 0 // XXX these other spaces will come over time...
 985                 case SPACE_SEQ:
 986                 {
 987                         SpaceSeq *sseq= curarea->spacedata.first;
 988
 989                         /* set current area */
 990                         p->sa= curarea;
 991                         p->ar= ar;
 992                         p->v2d= &ar->v2d;
 993
 994                         /* check that gpencil data is allowed to be drawn */
 995                         if (sseq->mainb == SEQ_DRAW_SEQUENCE) {
 996                                 p->status= GP_STATUS_ERROR;
 997                                 if (G.f & G_DEBUG)
 998                                         printf("Error: In active view (sequencer), active mode doesn't support Grease Pencil \n");
 999                                 return;
1000                         }
1001                         if ((sseq->flag & SEQ_DRAW_GPENCIL)==0) {
1002                                 p->status= GP_STATUS_ERROR;
1003                                 if (G.f & G_DEBUG)
1004                                         printf("Error: In active view, Grease Pencil not shown \n");
1005                                 return;
1006                         }
1007                 }
1008                         break;
1009 #endif
1010                 case SPACE_IMAGE:
1011                 {
1012                         //SpaceImage *sima= curarea->spacedata.first;
1013
1014                         /* set the current area */
1015                         p->sa= curarea;
1016                         p->ar= ar;
1017                         p->v2d= &ar->v2d;
1018                         //p->ibuf= BKE_image_get_ibuf(sima->image, &sima->iuser);
1019
1020 #if 0 // XXX disabled for now
1021                         /* check that gpencil data is allowed to be drawn */
1022                         if ((sima->flag & SI_DISPGP)==0) {
1023                                 p->status= GP_STATUS_ERROR;
1024                                 if (G.f & G_DEBUG)
1025                                         printf("Error: In active view, Grease Pencil not shown \n");
1026                                 return p;
1027                         }
1028 #endif
1029                 }
1030                         break;
1031
1032                 /* unsupported views */
1033                 default:
1034                 {
1035                         p->status= GP_STATUS_ERROR;
1036                         if (G.f & G_DEBUG)
1037                                 printf("Error: Active view not appropriate for Grease Pencil drawing \n");
1038                         return p;
1039                 }
1040                         break;
1041         }
1042
1043         /* get gp-data */
1044         gpd_ptr= gpencil_data_get_pointers(C, &p->ownerPtr);
1045         if (gpd_ptr == NULL) {
1046                 p->status= GP_STATUS_ERROR;
1047                 if (G.f & G_DEBUG)
1048                         printf("Error: Current context doesn't allow for any Grease Pencil data \n");
1049                 return p;
1050         }
1051         else {
1052                 /* if no existing GPencil block exists, add one */
1053                 if (*gpd_ptr == NULL)
1054                         *gpd_ptr= gpencil_data_addnew("GPencil");
1055                 p->gpd= *gpd_ptr;
1056         }
1057
1058         /* set edit flags - so that buffer will get drawn */
1059         G.f |= G_GREASEPENCIL;
1060
1061         /* clear out buffer (stored in gp-data), in case something contaminated it */
1062         gp_session_validatebuffer(p);
1063
1064 #if 0
1065         /* set 'default' im2d_settings just in case something that uses this doesn't set it */
1066         p->im2d_settings.sizex= 1;
1067         p->im2d_settings.sizey= 1;
1068 #endif
1069
1070         /* return context data for running paint operator */
1071         return p;
1072 }
1073
1074 /* cleanup after a painting session */
1075 static void gp_session_cleanup (tGPsdata *p)
1076 {
1077         bGPdata *gpd= (p) ? p->gpd : NULL;
1078
1079         /* error checking */
1080         if (gpd == NULL)
1081                 return;
1082
1083         /* free stroke buffer */
1084         if (gpd->sbuffer) {
1085                 MEM_freeN(gpd->sbuffer);
1086                 gpd->sbuffer= NULL;
1087         }
1088
1089         /* clear flags */
1090         gpd->sbuffer_size= 0;
1091         gpd->sbuffer_sflag= 0;
1092 }
1093
1094 /* init new stroke */
1095 static void gp_paint_initstroke (tGPsdata *p, short paintmode)
1096 {
1097         /* get active layer (or add a new one if non-existent) */
1098         p->gpl= gpencil_layer_getactive(p->gpd);
1099         if (p->gpl == NULL)
1100                 p->gpl= gpencil_layer_addnew(p->gpd);
1101         if (p->gpl->flag & GP_LAYER_LOCKED) {
1102                 p->status= GP_STATUS_ERROR;
1103                 if (G.f & G_DEBUG)
1104                         printf("Error: Cannot paint on locked layer \n");
1105                 return;
1106         }
1107
1108         /* get active frame (add a new one if not matching frame) */
1109         p->gpf= gpencil_layer_getframe(p->gpl, p->scene->r.cfra, 1);
1110         if (p->gpf == NULL) {
1111                 p->status= GP_STATUS_ERROR;
1112                 if (G.f & G_DEBUG)
1113                         printf("Error: No frame created (gpencil_paint_init) \n");
1114                 return;
1115         }
1116         else
1117                 p->gpf->flag |= GP_FRAME_PAINT;
1118
1119         /* set 'eraser' for this stroke if using eraser */
1120         p->paintmode= paintmode;
1121         if (p->paintmode == GP_PAINTMODE_ERASER)
1122                 p->gpd->sbuffer_sflag |= GP_STROKE_ERASER;
1123
1124         /* set 'initial run' flag, which is only used to denote when a new stroke is starting */
1125         p->flags |= GP_PAINTFLAG_FIRSTRUN;
1126
1127
1128         /* when drawing in the camera view, in 2D space, set the subrect */
1129         if (!(p->gpd->flag & GP_DATA_VIEWALIGN)) {
1130                 if (p->sa->spacetype == SPACE_VIEW3D) {
1131                         View3D *v3d= p->sa->spacedata.first;
1132                         RegionView3D *rv3d= p->ar->regiondata;
1133
1134                         /* for camera view set the subrect */
1135                         if (rv3d->persp == RV3D_CAMOB) {
1136                                 view3d_calc_camera_border(p->scene, p->ar, NULL, v3d, &p->subrect_data, -1); /* negative shift */
1137                                 p->subrect= &p->subrect_data;
1138                         }
1139                 }
1140         }
1141
1142         /* check if points will need to be made in view-aligned space */
1143         if (p->gpd->flag & GP_DATA_VIEWALIGN) {
1144                 switch (p->sa->spacetype) {
1145                         case SPACE_VIEW3D:
1146                         {
1147                                 View3D *v3d= p->sa->spacedata.first;
1148                                 RegionView3D *rv3d= p->ar->regiondata;
1149                                 float rvec[3];
1150
1151                                 /* for camera view set the subrect */
1152                                 if (rv3d->persp == RV3D_CAMOB) {
1153                                         view3d_calc_camera_border(p->scene, p->ar, NULL, v3d, &p->subrect_data, -1); /* negative shift */
1154                                         p->subrect= &p->subrect_data;
1155                                 }
1156
1157                                 /* get reference point for 3d space placement */
1158                                 gp_get_3d_reference(p, rvec);
1159                                 initgrabz(rv3d, rvec[0], rvec[1], rvec[2]);
1160
1161                                 p->gpd->sbuffer_sflag |= GP_STROKE_3DSPACE;
1162                         }
1163                                 break;
1164
1165                         case SPACE_NODE:
1166                         {
1167                                 p->gpd->sbuffer_sflag |= GP_STROKE_2DSPACE;
1168                         }
1169                                 break;
1170 #if 0 // XXX other spacetypes to be restored in due course
1171                         case SPACE_SEQ:
1172                         {
1173                                 SpaceSeq *sseq= (SpaceSeq *)p->sa->spacedata.first;
1174                                 int rectx, recty;
1175                                 float zoom, zoomx, zoomy;
1176
1177                                 /* set draw 2d-stroke flag */
1178                                 p->gpd->sbuffer_sflag |= GP_STROKE_2DIMAGE;
1179
1180                                 /* calculate zoom factor */
1181                                 zoom= (float)(SEQ_ZOOM_FAC(sseq->zoom));
1182                                 if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
1183                                         zoomx = zoom * (p->scene->r.xasp / p->scene->r.yasp);
1184                                         zoomy = zoom;
1185                                 }
1186                                 else
1187                                         zoomx = zoomy = zoom;
1188
1189                                 /* calculate rect size to use to calculate the size of the drawing area
1190                                  *      - We use the size of the output image not the size of the ibuf being shown
1191                                  *        as it is too messy getting the ibuf (and could be too slow). This should be
1192                                  *        a reasonable for most cases anyway.
1193                                  */
1194                                 rectx= (p->scene->r.size * p->scene->r.xsch) / 100;
1195                                 recty= (p->scene->r.size * p->scene->r.ysch) / 100;
1196
1197                                 /* set offset and scale values for opertations to use */
1198                                 p->im2d_settings.sizex= (int)(zoomx * rectx);
1199                                 p->im2d_settings.sizey= (int)(zoomy * recty);
1200                                 p->im2d_settings.offsx= (int)((p->sa->winx-p->im2d_settings.sizex)/2 + sseq->xof);
1201                                 p->im2d_settings.offsy= (int)((p->sa->winy-p->im2d_settings.sizey)/2 + sseq->yof);
1202                         }
1203                                 break;
1204 #endif
1205                         case SPACE_IMAGE:
1206                         {
1207                                 SpaceImage *sima= (SpaceImage *)p->sa->spacedata.first;
1208
1209                                 /* only set these flags if the image editor doesn't have an image active,
1210                                  * otherwise user will be confused by strokes not appearing after they're drawn
1211                                  *
1212                                  * Admittedly, this is a bit hacky, but it works much nicer from an ergonomic standpoint!
1213                                  */
1214                                 if ELEM(NULL, sima, sima->image) {
1215                                         /* make strokes be drawn in screen space */
1216                                         p->gpd->sbuffer_sflag &= ~GP_STROKE_2DSPACE;
1217                                         p->gpd->flag &= ~GP_DATA_VIEWALIGN;
1218                                 }
1219                                 else
1220                                         p->gpd->sbuffer_sflag |= GP_STROKE_2DSPACE;
1221                         }
1222                                 break;
1223                 }
1224         }
1225 }
1226
1227 /* finish off a stroke (clears buffer, but doesn't finish the paint operation) */
1228 static void gp_paint_strokeend (tGPsdata *p)
1229 {
1230         /* for surface sketching, need to set the right OpenGL context stuff so that
1231          * the conversions will project the values correctly...
1232          */
1233         if (gpencil_project_check(p)) {
1234                 View3D *v3d= p->sa->spacedata.first;
1235
1236                 /* need to restore the original projection settings before packing up */
1237                 view3d_region_operator_needs_opengl(p->win, p->ar);
1238                 view_autodist_init(p->scene, p->ar, v3d, (p->gpd->flag & GP_DATA_DEPTH_STROKE) ? 1:0);
1239         }
1240
1241         /* check if doing eraser or not */
1242         if ((p->gpd->sbuffer_sflag & GP_STROKE_ERASER) == 0) {
1243                 /* smooth stroke before transferring? */
1244                 gp_stroke_smooth(p);
1245
1246                 /* simplify stroke before transferring? */
1247                 gp_stroke_simplify(p);
1248
1249                 /* transfer stroke to frame */
1250                 gp_stroke_newfrombuffer(p);
1251         }
1252
1253         /* clean up buffer now */
1254         gp_session_validatebuffer(p);
1255 }
1256
1257 /* finish off stroke painting operation */
1258 static void gp_paint_cleanup (tGPsdata *p)
1259 {
1260         /* finish off a stroke */
1261         gp_paint_strokeend(p);
1262
1263         /* "unlock" frame */
1264         if (p->gpf)
1265                 p->gpf->flag &= ~GP_FRAME_PAINT;
1266 }
1267
1268 /* ------------------------------- */
1269
1270 static void gpencil_draw_exit (bContext *C, wmOperator *op)
1271 {
1272         tGPsdata *p= op->customdata;
1273
1274         /* clear edit flags */
1275         G.f &= ~G_GREASEPENCIL;
1276
1277         /* restore cursor to indicate end of drawing */
1278         WM_cursor_restore(CTX_wm_window(C));
1279
1280         /* don't assume that operator data exists at all */
1281         if (p) {
1282                 /* check size of buffer before cleanup, to determine if anything happened here */
1283                 if (p->paintmode == GP_PAINTMODE_ERASER) {
1284                         // TODO clear radial cursor thing
1285                         // XXX draw_sel_circle(NULL, p.mvalo, 0, p.radius, 0);
1286                 }
1287
1288                 /* cleanup */
1289                 gp_paint_cleanup(p);
1290                 gp_session_cleanup(p);
1291
1292                 /* finally, free the temp data */
1293                 MEM_freeN(p);
1294         }
1295
1296         op->customdata= NULL;
1297 }
1298
1299 static int gpencil_draw_cancel (bContext *C, wmOperator *op)
1300 {
1301         /* this is just a wrapper around exit() */
1302         gpencil_draw_exit(C, op);
1303         return OPERATOR_CANCELLED;
1304 }
1305
1306 /* ------------------------------- */
1307
1308
1309 static int gpencil_draw_init (bContext *C, wmOperator *op)
1310 {
1311         tGPsdata *p;
1312         int paintmode= RNA_enum_get(op->ptr, "mode");
1313
1314         /* check context */
1315         p= op->customdata= gp_session_initpaint(C);
1316         if ((p == NULL) || (p->status == GP_STATUS_ERROR)) {
1317                 /* something wasn't set correctly in context */
1318                 gpencil_draw_exit(C, op);
1319                 return 0;
1320         }
1321
1322         /* init painting data */
1323         gp_paint_initstroke(p, paintmode);
1324         if (p->status == GP_STATUS_ERROR) {
1325                 gpencil_draw_exit(C, op);
1326                 return 0;
1327         }
1328
1329         /* radius for eraser circle is defined in userprefs now */
1330         p->radius= U.gp_eraser;
1331
1332         /* everything is now setup ok */
1333         return 1;
1334 }
1335
1336 /* ------------------------------- */
1337
1338 /* update UI indicators of status, including cursor and header prints */
1339 static void gpencil_draw_status_indicators (tGPsdata *p)
1340 {
1341         /* header prints */
1342         switch (p->status) {
1343                 case GP_STATUS_PAINTING:
1344                         /* only print this for paint-sessions, otherwise it gets annoying */
1345                         if (GPENCIL_SKETCH_SESSIONS_ON(p->scene))
1346                                 ED_area_headerprint(p->sa, "Grease Pencil: Drawing/erasing stroke... Release to end stroke");
1347                         break;
1348
1349                 case GP_STATUS_IDLING:
1350                         /* print status info */
1351                         switch (p->paintmode) {
1352                                 case GP_PAINTMODE_ERASER:
1353                                         ED_area_headerprint(p->sa, "Grease Pencil Erase Session: Hold and drag LMB or RMB to erase | ESC/Enter to end");
1354                                         break;
1355                                 case GP_PAINTMODE_DRAW_STRAIGHT:
1356                                         ED_area_headerprint(p->sa, "Grease Pencil Line Session: Hold and drag LMB to draw | ESC/Enter to end");
1357                                         break;
1358                                 case GP_PAINTMODE_DRAW:
1359                                         ED_area_headerprint(p->sa, "Grease Pencil Freehand Session: Hold and drag LMB to draw | ESC/Enter to end");
1360                                         break;
1361
1362                                 default: /* unhandled future cases */
1363                                         ED_area_headerprint(p->sa, "Grease Pencil Session: ESC/Enter to end");
1364                                         break;
1365                         }
1366                         break;
1367
1368                 case GP_STATUS_ERROR:
1369                 case GP_STATUS_DONE:
1370                         /* clear status string */
1371                         ED_area_headerprint(p->sa, NULL);
1372                         break;
1373         }
1374 }
1375
1376 /* ------------------------------- */
1377
1378 /* create a new stroke point at the point indicated by the painting context */
1379 static void gpencil_draw_apply (wmOperator *op, tGPsdata *p)
1380 {
1381         /* handle drawing/erasing -> test for erasing first */
1382         if (p->paintmode == GP_PAINTMODE_ERASER) {
1383                 /* do 'live' erasing now */
1384                 gp_stroke_doeraser(p);
1385
1386                 /* store used values */
1387                 p->mvalo[0]= p->mval[0];
1388                 p->mvalo[1]= p->mval[1];
1389                 p->opressure= p->pressure;
1390         }
1391         /* only add current point to buffer if mouse moved (even though we got an event, it might be just noise) */
1392         else if (gp_stroke_filtermval(p, p->mval, p->mvalo)) {
1393                 /* try to add point */
1394                 short ok= gp_stroke_addpoint(p, p->mval, p->pressure);
1395
1396                 /* handle errors while adding point */
1397                 if ((ok == GP_STROKEADD_FULL) || (ok == GP_STROKEADD_OVERFLOW)) {
1398                         /* finish off old stroke */
1399                         gp_paint_strokeend(p);
1400
1401                         /* start a new stroke, starting from previous point */
1402                         gp_stroke_addpoint(p, p->mvalo, p->opressure);
1403                         ok= gp_stroke_addpoint(p, p->mval, p->pressure);
1404                 }
1405                 else if (ok == GP_STROKEADD_INVALID) {
1406                         /* the painting operation cannot continue... */
1407                         BKE_report(op->reports, RPT_ERROR, "Cannot paint stroke");
1408                         p->status = GP_STATUS_ERROR;
1409
1410                         if (G.f & G_DEBUG)
1411                                 printf("Error: Grease-Pencil Paint - Add Point Invalid \n");
1412                         return;
1413                 }
1414
1415                 /* store used values */
1416                 p->mvalo[0]= p->mval[0];
1417                 p->mvalo[1]= p->mval[1];
1418                 p->opressure= p->pressure;
1419         }
1420 }
1421
1422 /* handle draw event */
1423 static void gpencil_draw_apply_event (wmOperator *op, wmEvent *event)
1424 {
1425         tGPsdata *p= op->customdata;
1426         ARegion *ar= p->ar;
1427         PointerRNA itemptr;
1428         float mousef[2];
1429         int tablet=0;
1430
1431         /* convert from window-space to area-space mouse coordintes */
1432         // NOTE: float to ints conversions, +1 factor is probably used to ensure a bit more accurate rounding...
1433         p->mval[0]= event->x - ar->winrct.xmin + 1;
1434         p->mval[1]= event->y - ar->winrct.ymin + 1;
1435
1436         /* handle pressure sensitivity (which is supplied by tablets) */
1437         if (event->custom == EVT_DATA_TABLET) {
1438                 wmTabletData *wmtab= event->customdata;
1439
1440                 tablet= (wmtab->Active != EVT_TABLET_NONE);
1441                 p->pressure= wmtab->Pressure;
1442
1443                 //if (wmtab->Active == EVT_TABLET_ERASER)
1444                         // TODO... this should get caught by the keymaps which call drawing in the first place
1445         }
1446         else
1447                 p->pressure= 1.0f;
1448
1449         /* fill in stroke data (not actually used directly by gpencil_draw_apply) */
1450         RNA_collection_add(op->ptr, "stroke", &itemptr);
1451
1452         mousef[0]= p->mval[0];
1453         mousef[1]= p->mval[1];
1454         RNA_float_set_array(&itemptr, "mouse", mousef);
1455         RNA_float_set(&itemptr, "pressure", p->pressure);
1456         RNA_boolean_set(&itemptr, "is_start", (p->flags & GP_PAINTFLAG_FIRSTRUN));
1457
1458         /* special exception for start of strokes (i.e. maybe for just a dot) */
1459         if (p->flags & GP_PAINTFLAG_FIRSTRUN) {
1460                 p->flags &= ~GP_PAINTFLAG_FIRSTRUN;
1461
1462                 p->mvalo[0]= p->mval[0];
1463                 p->mvalo[1]= p->mval[1];
1464                 p->opressure= p->pressure;
1465
1466                 /* special exception here for too high pressure values on first touch in
1467                  *  windows for some tablets, then we just skip first touch ..
1468                  */
1469                 if (tablet && (p->pressure >= 0.99f))
1470                         return;
1471         }
1472
1473         /* apply the current latest drawing point */
1474         gpencil_draw_apply(op, p);
1475
1476         /* force refresh */
1477         ED_region_tag_redraw(p->ar); /* just active area for now, since doing whole screen is too slow */
1478 }
1479
1480 /* ------------------------------- */
1481
1482 /* operator 'redo' (i.e. after changing some properties, but also for repeat last) */
1483 static int gpencil_draw_exec (bContext *C, wmOperator *op)
1484 {
1485         tGPsdata *p = NULL;
1486
1487         //printf("GPencil - Starting Re-Drawing \n");
1488
1489         /* try to initialise context data needed while drawing */
1490         if (!gpencil_draw_init(C, op)) {
1491                 if (op->customdata) MEM_freeN(op->customdata);
1492                 //printf("\tGP - no valid data \n");
1493                 return OPERATOR_CANCELLED;
1494         }
1495         else
1496                 p= op->customdata;
1497
1498         //printf("\tGP - Start redrawing stroke \n");
1499
1500         /* loop over the stroke RNA elements recorded (i.e. progress of mouse movement),
1501          * setting the relevant values in context at each step, then applying
1502          */
1503         RNA_BEGIN(op->ptr, itemptr, "stroke")
1504         {
1505                 float mousef[2];
1506
1507                 //printf("\t\tGP - stroke elem \n");
1508
1509                 /* get relevant data for this point from stroke */
1510                 RNA_float_get_array(&itemptr, "mouse", mousef);
1511                 p->mval[0] = (short)mousef[0];
1512                 p->mval[1] = (short)mousef[1];
1513                 p->pressure= RNA_float_get(&itemptr, "pressure");
1514
1515                 if (RNA_boolean_get(&itemptr, "is_start")) {
1516                         /* if first-run flag isn't set already (i.e. not true first stroke),
1517                          * then we must terminate the previous one first before continuing
1518                          */
1519                         if ((p->flags & GP_PAINTFLAG_FIRSTRUN) == 0) {
1520                                 // TODO: both of these ops can set error-status, but we probably don't need to worry
1521                                 gp_paint_strokeend(p);
1522                                 gp_paint_initstroke(p, p->paintmode);
1523                         }
1524                 }
1525
1526                 /* if first run, set previous data too */
1527                 if (p->flags & GP_PAINTFLAG_FIRSTRUN) {
1528                         p->flags &= ~GP_PAINTFLAG_FIRSTRUN;
1529
1530                         p->mvalo[0]= p->mval[0];
1531                         p->mvalo[1]= p->mval[1];
1532                         p->opressure= p->pressure;
1533                 }
1534
1535                 /* apply this data as necessary now (as per usual) */
1536                 gpencil_draw_apply(op, p);
1537         }
1538         RNA_END;
1539
1540         //printf("\tGP - done \n");
1541
1542         /* cleanup */
1543         gpencil_draw_exit(C, op);
1544
1545         /* refreshes */
1546         WM_event_add_notifier(C, NC_SCREEN|ND_GPENCIL|NA_EDITED, NULL); // XXX need a nicer one that will work
1547
1548         /* done */
1549         return OPERATOR_FINISHED;
1550 }
1551
1552 /* ------------------------------- */
1553
1554 /* start of interactive drawing part of operator */
1555 static int gpencil_draw_invoke (bContext *C, wmOperator *op, wmEvent *event)
1556 {
1557         tGPsdata *p = NULL;
1558         wmWindow *win= CTX_wm_window(C);
1559
1560         if (G.f & G_DEBUG)
1561                 printf("GPencil - Starting Drawing \n");
1562
1563         /* try to initialise context data needed while drawing */
1564         if (!gpencil_draw_init(C, op)) {
1565                 if (op->customdata)
1566                         MEM_freeN(op->customdata);
1567                 if (G.f & G_DEBUG)
1568                         printf("\tGP - no valid data \n");
1569                 return OPERATOR_CANCELLED;
1570         }
1571         else
1572                 p= op->customdata;
1573
1574         // TODO: set any additional settings that we can take from the events?
1575         // TODO? if tablet is erasing, force eraser to be on?
1576
1577         // TODO: move cursor setting stuff to stroke-start so that paintmode can be changed midway...
1578
1579         /* if eraser is on, draw radial aid */
1580         if (p->paintmode == GP_PAINTMODE_ERASER) {
1581                 // TODO: this involves mucking around with radial control, so we leave this for now..
1582         }
1583
1584         /* set cursor */
1585         if (p->paintmode == GP_PAINTMODE_ERASER)
1586                 WM_cursor_modal(win, BC_CROSSCURSOR); // XXX need a better cursor
1587         else
1588                 WM_cursor_modal(win, BC_PAINTBRUSHCURSOR);
1589
1590         /* special hack: if there was an initial event, then we were invoked via a hotkey, and
1591          * painting should start immediately. Otherwise, this was called from a toolbar, in which
1592          * case we should wait for the mouse to be clicked.
1593          */
1594         if (event->type) {
1595                 /* hotkey invoked - start drawing */
1596                 //printf("\tGP - set first spot\n");
1597                 p->status= GP_STATUS_PAINTING;
1598
1599                 /* handle the initial drawing - i.e. for just doing a simple dot */
1600                 gpencil_draw_apply_event(op, event);
1601         }
1602         else {
1603                 /* toolbar invoked - don't start drawing yet... */
1604                 //printf("\tGP - hotkey invoked... waiting for click-drag\n");
1605         }
1606
1607         /* add a modal handler for this operator, so that we can then draw continuous strokes */
1608         WM_event_add_modal_handler(C, op);
1609         return OPERATOR_RUNNING_MODAL;
1610 }
1611
1612 /* gpencil modal operator stores area, which can be removed while using it (like fullscreen) */
1613 static int gpencil_area_exists(bContext *C, ScrArea *satest)
1614 {
1615         bScreen *sc= CTX_wm_screen(C);
1616         ScrArea *sa;
1617
1618         for(sa= sc->areabase.first; sa; sa= sa->next)
1619                 if(sa==satest)
1620                         return 1;
1621         return 0;
1622 }
1623
1624 /* events handling during interactive drawing part of operator */
1625 static int gpencil_draw_modal (bContext *C, wmOperator *op, wmEvent *event)
1626 {
1627         tGPsdata *p= op->customdata;
1628         int estate = OPERATOR_PASS_THROUGH; /* default exit state - not handled, so let others have a share of the pie */
1629
1630         //printf("\tGP - handle modal event...\n");
1631
1632         /* exit painting mode (and/or end current stroke) */
1633         if (ELEM4(event->type, RETKEY, PADENTER, ESCKEY, SPACEKEY)) {
1634                 /* exit() ends the current stroke before cleaning up */
1635                 //printf("\t\tGP - end of paint op + end of stroke\n");
1636                 p->status= GP_STATUS_DONE;
1637                 estate = OPERATOR_FINISHED;
1638         }
1639
1640         /* toggle painting mode upon mouse-button movement */
1641         if (ELEM(event->type, LEFTMOUSE, RIGHTMOUSE)) {
1642                 /* if painting, end stroke */
1643                 if (p->status == GP_STATUS_PAINTING) {
1644                         /* basically, this should be mouse-button up = end stroke
1645                          * BUT what happens next depends on whether we 'painting sessions' is enabled
1646                          */
1647                         if (GPENCIL_SKETCH_SESSIONS_ON(p->scene)) {
1648                                 /* end stroke only, and then wait to resume painting soon */
1649                                 //printf("\t\tGP - end stroke only\n");
1650                                 gp_paint_cleanup(p);
1651                                 p->status= GP_STATUS_IDLING;
1652
1653                                 /* we've just entered idling state, so this event was processed (but no others yet) */
1654                                 estate = OPERATOR_RUNNING_MODAL;
1655                         }
1656                         else {
1657                                 //printf("\t\tGP - end of stroke + op\n");
1658                                 p->status= GP_STATUS_DONE;
1659                                 estate = OPERATOR_FINISHED;
1660                         }
1661                 }
1662                 else {
1663                         /* not painting, so start stroke (this should be mouse-button down) */
1664
1665                         /* we must check that we're still within the area that we're set up to work from
1666                          * otherwise we could crash (see bug #20586)
1667                          */
1668                         if (CTX_wm_area(C) != p->sa) {
1669                                 //printf("\t\t\tGP - wrong area execution abort! \n");
1670                                 p->status= GP_STATUS_ERROR;
1671                                 estate = OPERATOR_CANCELLED;
1672                         }
1673                         else {
1674                                 //printf("\t\tGP - start stroke \n");
1675                                 p->status= GP_STATUS_PAINTING;
1676
1677                                 /* we may need to set up paint env again if we're resuming */
1678                                 // XXX: watch it with the paintmode! in future, it'd be nice to allow changing paint-mode when in sketching-sessions
1679                                 // XXX: with tablet events, we may event want to check for eraser here, for nicer tablet support
1680                                 gp_paint_initstroke(p, p->paintmode);
1681
1682                                 if (p->status == GP_STATUS_ERROR) {
1683                                         estate = OPERATOR_CANCELLED;
1684                                 }
1685                         }
1686                 }
1687         }
1688
1689
1690
1691         /* handle mode-specific events */
1692         if (p->status == GP_STATUS_PAINTING) {
1693                 /* handle painting mouse-movements? */
1694                 if (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE) || (p->flags & GP_PAINTFLAG_FIRSTRUN))
1695                 {
1696                         /* handle drawing event */
1697                         //printf("\t\tGP - add point\n");
1698                         gpencil_draw_apply_event(op, event);
1699
1700                         /* finish painting operation if anything went wrong just now */
1701                         if (p->status == GP_STATUS_ERROR) {
1702                                 //printf("\t\t\t\tGP - add error done! \n");
1703                                 estate = OPERATOR_CANCELLED;
1704                         }
1705                         else {
1706                                 /* event handled, so just tag as running modal */
1707                                 //printf("\t\t\t\tGP - add point handled!\n");
1708                                 estate = OPERATOR_RUNNING_MODAL;
1709                         }
1710                 }
1711                 /* there shouldn't be any other events, but just in case there are, let's swallow them
1712                  * (i.e. to prevent problems with with undo)
1713                  */
1714                 else {
1715                         /* swallow event to save ourselves trouble */
1716                         estate = OPERATOR_RUNNING_MODAL;
1717                 }
1718         }
1719         else if (p->status == GP_STATUS_IDLING) {
1720                 /* standard undo/redo shouldn't be allowed to execute or else it causes crashes, so catch it here */
1721                 // FIXME: this is a hardcoded hotkey that can't be changed
1722                 // TODO: catch redo as well, but how?
1723                 if (event->type == ZKEY) {
1724                         /* oskey = cmd key on macs as they seem to use cmd-z for undo as well? */
1725                         if ((event->ctrl) || (event->oskey)) {
1726                                 /* just delete last stroke, which will look like undo to the end user */
1727                                 //printf("caught attempted undo event... deleting last stroke \n");
1728                                 gpencil_frame_delete_laststroke(p->gpl, p->gpf);
1729
1730                                 /* event handled, so force refresh */
1731                                 ED_region_tag_redraw(p->ar); /* just active area for now, since doing whole screen is too slow */
1732                                 estate = OPERATOR_RUNNING_MODAL;
1733                         }
1734                 }
1735         }
1736
1737         /* gpencil modal operator stores area, which can be removed while using it (like fullscreen) */
1738         if(0==gpencil_area_exists(C, p->sa))
1739                 estate= OPERATOR_CANCELLED;
1740         else
1741                 /* update status indicators - cursor, header, etc. */
1742                 gpencil_draw_status_indicators(p);
1743
1744         /* process last operations before exiting */
1745         switch (estate) {
1746                 case OPERATOR_FINISHED:
1747                         /* one last flush before we're done */
1748                         gpencil_draw_exit(C, op);
1749                         WM_event_add_notifier(C, NC_SCREEN|ND_GPENCIL|NA_EDITED, NULL); // XXX need a nicer one that will work
1750                         break;
1751
1752                 case OPERATOR_CANCELLED:
1753                         gpencil_draw_exit(C, op);
1754                         break;
1755
1756                 case OPERATOR_RUNNING_MODAL|OPERATOR_PASS_THROUGH:
1757                         /* event doesn't need to be handled */
1758                         //printf("unhandled event -> %d (mmb? = %d | mmv? = %d)\n", event->type, event->type == MIDDLEMOUSE, event->type==MOUSEMOVE);
1759                         break;
1760         }
1761
1762         /* return status code */
1763         return estate;
1764 }
1765
1766 /* ------------------------------- */
1767
1768 static EnumPropertyItem prop_gpencil_drawmodes[] = {
1769         {GP_PAINTMODE_DRAW, "DRAW", 0, "Draw Freehand", ""},
1770         {GP_PAINTMODE_DRAW_STRAIGHT, "DRAW_STRAIGHT", 0, "Draw Straight Lines", ""},
1771         {GP_PAINTMODE_ERASER, "ERASER", 0, "Eraser", ""},
1772         {0, NULL, 0, NULL, NULL}
1773 };
1774
1775 void GPENCIL_OT_draw (wmOperatorType *ot)
1776 {
1777         /* identifiers */
1778         ot->name= "Grease Pencil Draw";
1779         ot->idname= "GPENCIL_OT_draw";
1780         ot->description= "Make annotations on the active data";
1781
1782         /* api callbacks */
1783         ot->exec= gpencil_draw_exec;
1784         ot->invoke= gpencil_draw_invoke;
1785         ot->modal= gpencil_draw_modal;
1786         ot->cancel= gpencil_draw_cancel;
1787         ot->poll= gpencil_draw_poll;
1788
1789         /* flags */
1790         ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO|OPTYPE_BLOCKING;
1791
1792         /* settings for drawing */
1793         RNA_def_enum(ot->srna, "mode", prop_gpencil_drawmodes, 0, "Mode", "Way to intepret mouse movements.");
1794
1795         RNA_def_collection_runtime(ot->srna, "stroke", &RNA_OperatorStrokeElement, "Stroke", "");
1796 }