Grease Pencil - Support for Grease Pencil in the Sequence Editor preview/image

space works again

This commit restores the support for using Grease Pencil in the Sequence Editor
image preview region, making it possible to scribble on footage for review
purposes again. Due to internal changes in how the Sequencer handles the image
drawing for this stuff (i.e. it is now fully based on View2D instead of trying
to implement its own little crazy offset+zoom stuff), a lot of the old code for
handling those offsets is no longer needed. Instead, one of the "standard" cases
is now used, and works quite well.

Bugfixes:
* View-space Grease Pencil drawing was done in wrong place (before view2d
restore)
* Grease Pencil entry in RNA had wrong/missing type

Credits:
* DingTo - initial patch/attempt at restoring support
* Aligorith - solved the "offset problems"

8 files changed, 98 insertions, 182 deletions

diff --git a/source/blender/editors/gpencil/drawgpencil.c b/source/blender/editors/gpencil/drawgpencil.c
index 1823bbce3a1..e4a24f13a0e 100644
--- a/source/blender/editors/gpencil/drawgpencil.c
+++ b/source/blender/editors/gpencil/drawgpencil.c
@@ -37,10 +37,8 @@
 
 #include "BLO_sys_types.h"
 
-#include "IMB_imbuf_types.h"
-
-#include "BLI_math.h"
 #include "BLI_blenlib.h"
+#include "BLI_math.h"
 #include "BLI_utildefines.h"
 
 #include "DNA_gpencil_types.h"
@@ -53,8 +51,6 @@
 #include "BKE_global.h"
 #include "BKE_gpencil.h"
 
-
-
 #include "WM_api.h"
 
 #include "BIF_gl.h"
@@ -64,7 +60,6 @@
 #include "ED_sequencer.h"
 #include "ED_view3d.h"
 
-
 #include "gpencil_intern.h"
 
 /* ************************************************** */
@@ -225,7 +220,7 @@ static void gp_draw_stroke_3d(bGPDspoint *points, int totpoints, short thickness
 			
 			/* need to roll-back one point to ensure that there are no gaps in the stroke */
 			if (i != 0) glVertex3fv(&(pt - 1)->x);
-
+			
 			/* now the point we want... */
 			glVertex3fv(&pt->x);
 			
@@ -340,7 +335,7 @@ static void gp_draw_stroke(bGPDspoint *points, int totpoints, short thickness_s,
 				mt[1] = m2[1] * pthick * 0.5f;
 				sc[0] = s0[0] - (m1[0] * pthick * 0.75f);
 				sc[1] = s0[1] - (m1[1] * pthick * 0.75f);
-
+				
 				t0[0] = sc[0] - mt[0];
 				t0[1] = sc[1] - mt[1];
 				t1[0] = sc[0] + mt[0];
@@ -382,7 +377,7 @@ static void gp_draw_stroke(bGPDspoint *points, int totpoints, short thickness_s,
 				mt[1] = mb[1] * pthick;
 				athick = len_v2(mt);
 				dfac = pthick - (athick * 2);
-
+				
 				if (((athick * 2.0f) < pthick) && (IS_EQF(athick, pthick) == 0)) {
 					mt[0] += (mb[0] * dfac);
 					mt[1] += (mb[1] * dfac);
@@ -429,7 +424,7 @@ static void gp_draw_stroke(bGPDspoint *points, int totpoints, short thickness_s,
 				mt[1] = m2[1] * pthick * 0.5f;
 				sc[0] = s1[0] + (m1[0] * pthick * 0.75f);
 				sc[1] = s1[1] + (m1[1] * pthick * 0.75f);
-
+				
 				t0[0] = sc[0] - mt[0];
 				t0[1] = sc[1] - mt[1];
 				t1[0] = sc[0] + mt[0];
@@ -669,7 +664,7 @@ static void gp_draw_data(bGPdata *gpd, int offsx, int offsy, int winx, int winy,
 // ............................
 
 /* draw grease-pencil sketches to specified 2d-view that uses ibuf corrections */
-void draw_gpencil_2dimage(bContext *C /* , ImBuf *ibuf */)
+void draw_gpencil_2dimage(bContext *C)
 {
 	ScrArea *sa = CTX_wm_area(C);
 	ARegion *ar = CTX_wm_region(C);
@@ -699,35 +694,20 @@ void draw_gpencil_2dimage(bContext *C /* , ImBuf *ibuf */)
 			dflag |= GP_DRAWDATA_ONLYV2D | GP_DRAWDATA_IEDITHACK;
 		}
 		break;
-#if 0   /* removed since 2.5x, needs to be added back */
 		case SPACE_SEQ: /* sequence */
 		{
-			SpaceSeq *sseq = (SpaceSeq *)sa->spacedata.first;
-			float zoom, zoomx, zoomy;
-
-			/* check that we have grease-pencil stuff to draw */
-			if (ELEM(NULL, sa, ibuf)) return;
-
-			/* calculate accessory values */
-			zoom = (float)(SEQ_ZOOM_FAC(sseq->zoom));
-			if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
-				/* XXX sequencer zoom should store it? */
-				zoomx = zoom; //  * (G.scene->r.xasp / G.scene->r.yasp);
-				zoomy = zoom;
-			} 
-			else
-				zoomx = zoomy = zoom;
-			
-			/* calculate transforms (Note: we use ibuf here, as we have it) */
-			sizex = (int)(zoomx * ibuf->x);
-			sizey = (int)(zoomy * ibuf->y);
-			offsx = (int)( (ar->winx - sizex) / 2 + sseq->xof);
-			offsy = (int)( (ar->winy - sizey) / 2 + sseq->yof);
+			/* just draw using standard scaling (settings here are currently ignored anyways) */
+			offsx = 0;
+			offsy = 0;
+			sizex = ar->winx;
+			sizey = ar->winy;
 			
-			dflag |= GP_DRAWDATA_ONLYI2D;
+			/* NOTE: I2D was used in 2.4x, but the old settings for that have been deprecated 
+			 * and everything moved to standard View2d 
+			 */
+			dflag |= GP_DRAWDATA_ONLYV2D;
 		}
 		break;
-#endif
 		default: /* for spacetype not yet handled */
 			offsx = 0;
 			offsy = 0;
diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index 71cbabe9114..7094aa086ba 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -80,6 +80,7 @@
 /* Get pointer to active Grease Pencil datablock, and an RNA-pointer to trace back to whatever owns it */
 bGPdata **gpencil_data_get_pointers(bContext *C, PointerRNA *ptr)
 {
+	ID *screen_id = (ID *)CTX_wm_screen(C);
 	Scene *scene = CTX_data_scene(C);
 	ScrArea *sa = CTX_wm_area(C);
 	
@@ -122,9 +123,12 @@ bGPdata **gpencil_data_get_pointers(bContext *C, PointerRNA *ptr)
 				
 			case SPACE_SEQ: /* Sequencer */
 			{
-				//SpaceSeq *sseq= (SpaceSeq *)CTX_wm_space_data(C);
+				SpaceSeq *sseq = (SpaceSeq *)CTX_wm_space_data(C);
 				
-				/* return the GP data for the active strips/image/etc. */
+				/* for now, Grease Pencil data is associated with the space (actually preview region only) */
+				// XXX our convention for everything else is to link to data though...
+				if (ptr) RNA_pointer_create(screen_id, &RNA_SpaceSequenceEditor, sseq, ptr);
+				return &sseq->gpd;
 			}
 			break;
 				
@@ -134,7 +138,7 @@ bGPdata **gpencil_data_get_pointers(bContext *C, PointerRNA *ptr)
 				
 				/* for now, Grease Pencil data is associated with the space... */
 				// XXX our convention for everything else is to link to data though...
-				if (ptr) RNA_pointer_create((ID *)CTX_wm_screen(C), &RNA_SpaceImageEditor, sima, ptr);
+				if (ptr) RNA_pointer_create(screen_id, &RNA_SpaceImageEditor, sima, ptr);
 				return &sima->gpd;
 			}
 			break;
@@ -143,7 +147,7 @@ bGPdata **gpencil_data_get_pointers(bContext *C, PointerRNA *ptr)
 			{
 				SpaceClip *sc = (SpaceClip *)CTX_wm_space_data(C);
 				MovieClip *clip = ED_space_clip(sc);
-
+				
 				if (clip) {
 					if (sc->gpencil_src == SC_GPENCIL_SRC_TRACK) {
 						MovieTrackingTrack *track = BKE_tracking_active_track(&clip->tracking);
@@ -214,7 +218,7 @@ static int gp_data_add_exec(bContext *C, wmOperator *op)
 	else {
 		/* decrement user count and add new datablock */
 		bGPdata *gpd = (*gpd_ptr);
-
+		
 		id_us_min(&gpd->id);
 		*gpd_ptr = gpencil_data_addnew("GPencil");
 	}
@@ -479,7 +483,7 @@ static int gp_camera_view_subrect(bContext *C, rctf *subrect)
 
 	if (v3d) {
 		RegionView3D *rv3d = ar->regiondata;
-
+		
 		/* for camera view set the subrect */
 		if (rv3d->persp == RV3D_CAMOB) {
 			Scene *scene = CTX_data_scene(C);
@@ -523,26 +527,26 @@ static void gp_stroke_to_bezier(bContext *C, bGPDlayer *gpl, bGPDstroke *gps, Cu
 	/* add points */
 	for (i = 0, bezt = nu->bezt; i < tot; i++, pt++, bezt++) {
 		float h1[3], h2[3];
-
+		
 		if (i) interp_v3_v3v3(h1, p3d_cur, p3d_prev, 0.3);
 		else interp_v3_v3v3(h1, p3d_cur, p3d_next, -0.3);
-
+		
 		if (i < tot - 1) interp_v3_v3v3(h2, p3d_cur, p3d_next, 0.3);
 		else interp_v3_v3v3(h2, p3d_cur, p3d_prev, -0.3);
-
+		
 		copy_v3_v3(bezt->vec[0], h1);
 		copy_v3_v3(bezt->vec[1], p3d_cur);
 		copy_v3_v3(bezt->vec[2], h2);
-
+		
 		/* set settings */
 		bezt->h1 = bezt->h2 = HD_FREE;
 		bezt->f1 = bezt->f2 = bezt->f3 = SELECT;
 		bezt->radius = bezt->weight = pt->pressure * gpl->thickness * 0.1f;
-
+		
 		/* shift coord vects */
 		copy_v3_v3(p3d_prev, p3d_cur);
 		copy_v3_v3(p3d_cur, p3d_next);
-
+		
 		if (i + 2 < tot) {
 			gp_strokepoint_convertcoords(C, gps, pt + 2, p3d_next, subrect);
 		}
diff --git a/source/blender/editors/gpencil/gpencil_paint.c b/source/blender/editors/gpencil/gpencil_paint.c
index 89d8ed9c465..5eef34f4afe 100644
--- a/source/blender/editors/gpencil/gpencil_paint.c
+++ b/source/blender/editors/gpencil/gpencil_paint.c
@@ -79,15 +79,6 @@ typedef struct tGPsdata {
 	rctf *subrect;      /* for using the camera rect within the 3d view */
 	rctf subrect_data;
 	
-	
-#if 0 // XXX review this 2d image stuff...
-	ImBuf *ibuf;        /* needed for GP_STROKE_2DIMAGE */
-	struct IBufViewSettings {
-		int offsx, offsy;           /* offsets */
-		int sizex, sizey;           /* dimensions to use as scale-factor */
-	} im2d_settings;    /* needed for GP_STROKE_2DIMAGE */
-#endif
-	
 	PointerRNA ownerPtr; /* pointer to owner of gp-datablock */
 	bGPdata *gpd;       /* gp-datablock layer comes from */
 	bGPDlayer *gpl;     /* layer we're working on */
@@ -269,7 +260,7 @@ static void gp_stroke_convertcoords(tGPsdata *p, const int mval[2], float out[3]
 			int mval_prj[2];
 			float rvec[3], dvec[3];
 			float mval_f[2];
-
+			
 			/* Current method just converts each point in screen-coordinates to
 			 * 3D-coordinates using the 3D-cursor as reference. In general, this
 			 * works OK, but it could of course be improved.
@@ -283,7 +274,7 @@ static void gp_stroke_convertcoords(tGPsdata *p, const int mval[2], float out[3]
 			
 			/* method taken from editview.c - mouse_cursor() */
 			project_int_noclip(p->ar, rvec, mval_prj);
-
+			
 			VECSUB2D(mval_f, mval_prj, mval);
 			ED_view3d_win_to_delta(p->ar, mval_f, dvec);
 			sub_v3_v3v3(out, rvec, dvec);
@@ -296,25 +287,6 @@ static void gp_stroke_convertcoords(tGPsdata *p, const int mval[2], float out[3]
 		mul_v3_m4v3(out, p->imat, out);
 	}
 	
-#if 0
-	/* 2d - on image 'canvas' (assume that p->v2d is set) */
-	else if (gpd->sbuffer_sflag & GP_STROKE_2DIMAGE) {
-		int sizex, sizey, offsx, offsy;
-		
-		/* get stored settings 
-		 *	- assume that these have been set already (there are checks that set sane 'defaults' just in case)
-		 */
-		sizex = p->im2d_settings.sizex;
-		sizey = p->im2d_settings.sizey;
-		offsx = p->im2d_settings.offsx;
-		offsy = p->im2d_settings.offsy;
-		
-		/* calculate new points */
-		out[0] = (float)(mval[0] - offsx) / (float)sizex;
-		out[1] = (float)(mval[1] - offsy) / (float)sizey;
-	}
-#endif
-	
 	/* 2d - relative to screen (viewport area) */
 	else {
 		if (p->subrect == NULL) { /* normal 3D view */
@@ -393,11 +365,11 @@ static short gp_stroke_addpoint(tGPsdata *p, const int mval[2], float pressure)
 	else if (p->paintmode == GP_PAINTMODE_DRAW_POLY) {
 		/* get pointer to destination point */
 		pt = (tGPspoint *)(gpd->sbuffer);
-
+		
 		/* store settings */
 		copy_v2_v2_int(&pt->x, mval);
 		pt->pressure = pressure;
-
+		
 		/* if there's stroke for this poly line session add (or replace last) point
 		 * to stroke. This allows to draw lines more interactively (see new segment
 		 * during mouse slide, i.e.) 
@@ -405,36 +377,36 @@ static short gp_stroke_addpoint(tGPsdata *p, const int mval[2], float pressure)
 		if (gp_stroke_added_check(p)) {
 			bGPDstroke *gps = p->gpf->strokes.last;
 			bGPDspoint *pts;
-
+			
 			/* first time point is adding to temporary buffer -- need to allocate new point in stroke */
 			if (gpd->sbuffer_size == 0) {
 				gps->points = MEM_reallocN(gps->points, sizeof(bGPDspoint) * (gps->totpoints + 1));
 				gps->totpoints++;
 			}
-
+			
 			pts = &gps->points[gps->totpoints - 1];
-
+			
 			/* special case for poly lines: normally, depth is needed only when creating new stroke from buffer,
 			 * but poly lines are converting to stroke instantly, so initialize depth buffer before converting coordinates 
 			 */
 			if (gpencil_project_check(p)) {
 				View3D *v3d = p->sa->spacedata.first;
-
+				
 				view3d_region_operator_needs_opengl(p->win, p->ar);
 				ED_view3d_autodist_init(p->scene, p->ar, v3d, (p->gpd->flag & GP_DATA_DEPTH_STROKE) ? 1 : 0);
 			}
-
+			
 			/* convert screen-coordinates to appropriate coordinates (and store them) */
 			gp_stroke_convertcoords(p, &pt->x, &pts->x, NULL);
-
+			
 			/* copy pressure */
 			pts->pressure = pt->pressure;
 		}
-
+		
 		/* increment counters */
 		if (gpd->sbuffer_size == 0)
 			gpd->sbuffer_size++;
-
+		
 		return GP_STROKEADD_NORMAL;
 	}
 	
@@ -482,7 +454,7 @@ static void gp_stroke_smooth(tGPsdata *p)
 	/* second pass: apply smoothed coordinates */
 	for (i = 0, spc = smoothArray; i < gpd->sbuffer_size; i++, spc++) {
 		tGPspoint *pc = (((tGPspoint *)gpd->sbuffer) + i);
-
+		
 		copy_v2_v2_int(&pc->x, &spc->x);
 	}
 	
@@ -639,10 +611,10 @@ static void gp_stroke_newfrombuffer(tGPsdata *p)
 	else if (p->paintmode == GP_PAINTMODE_DRAW_POLY) {
 		/* first point */
 		ptc = gpd->sbuffer;
-
+		
 		/* convert screen-coordinates to appropriate coordinates (and store them) */
 		gp_stroke_convertcoords(p, &ptc->x, &pt->x, NULL);
-
+		
 		/* copy pressure */
 		pt->pressure = ptc->pressure;
 	}
@@ -656,10 +628,10 @@ static void gp_stroke_newfrombuffer(tGPsdata *p)
 			int found_depth = 0;
 			
 			depth_arr = MEM_mallocN(sizeof(float) * gpd->sbuffer_size, "depth_points");
-
+			
 			for (i = 0, ptc = gpd->sbuffer; i < gpd->sbuffer_size; i++, ptc++, pt++) {
 				copy_v2_v2_int(mval, &ptc->x);
-
+				
 				if ((ED_view3d_autodist_depth(p->ar, mval, depth_margin, depth_arr + i) == 0) &&
 				    (i && (ED_view3d_autodist_depth_seg(p->ar, mval, mval_prev, depth_margin + 1, depth_arr + i) == 0)))
 				{
@@ -668,7 +640,7 @@ static void gp_stroke_newfrombuffer(tGPsdata *p)
 				else {
 					found_depth = TRUE;
 				}
-
+				
 				copy_v2_v2_int(mval_prev, mval);
 			}
 			
@@ -835,21 +807,6 @@ static void gp_stroke_eraser_dostroke(tGPsdata *p, int mval[], int mvalo[], shor
 		else if (gps->flag & GP_STROKE_2DSPACE) {			
 			UI_view2d_view_to_region(p->v2d, gps->points->x, gps->points->y, &x0, &y0);
 		}
-#if 0
-		else if (gps->flag & GP_STROKE_2DIMAGE) {			
-			int offsx, offsy, sizex, sizey;
-			
-			/* get stored settings */
-			sizex = p->im2d_settings.sizex;
-			sizey = p->im2d_settings.sizey;
-			offsx = p->im2d_settings.offsx;
-			offsy = p->im2d_settings.offsy;
-			
-			/* calculate new points */
-			x0 = (int)((gps->points->x * sizex) + offsx);
-			y0 = (int)((gps->points->y * sizey) + offsy);
-		}
-#endif
 		else {
 			if (p->subrect == NULL) { /* normal 3D view */
 				x0 = (int)(gps->points->x / 100 * p->ar->winx);
@@ -895,24 +852,6 @@ static void gp_stroke_eraser_dostroke(tGPsdata *p, int mval[], int mvalo[], shor
 				
 				UI_view2d_view_to_region(p->v2d, pt2->x, pt2->y, &x1, &y1);
 			}
-#if 0
-			else if (gps->flag & GP_STROKE_2DIMAGE) {
-				int offsx, offsy, sizex, sizey;
-				
-				/* get stored settings */
-				sizex = p->im2d_settings.sizex;
-				sizey = p->im2d_settings.sizey;
-				offsx = p->im2d_settings.offsx;
-				offsy = p->im2d_settings.offsy;
-				
-				/* calculate new points */
-				x0 = (int)((pt1->x * sizex) + offsx);
-				y0 = (int)((pt1->y * sizey) + offsy);
-				
-				x1 = (int)((pt2->x * sizex) + offsx);
-				y1 = (int)((pt2->y * sizey) + offsy);
-			}
-#endif
 			else {
 				if (p->subrect == NULL) { /* normal 3D view */
 					x0 = (int)(pt1->x / 100 * p->ar->winx);
@@ -1062,7 +1001,6 @@ static int gp_session_initdata(bContext *C, tGPsdata *p)
 #endif
 		}
 		break;
-#if 0 // XXX these other spaces will come over time...
 		case SPACE_SEQ:
 		{
 			SpaceSeq *sseq = curarea->spacedata.first;
@@ -1079,15 +1017,16 @@ static int gp_session_initdata(bContext *C, tGPsdata *p)
 					printf("Error: In active view (sequencer), active mode doesn't support Grease Pencil\n");
 				return 0;
 			}
+#if 0 // XXX will this sort of antiquated stuff be restored?
 			if ((sseq->flag & SEQ_DRAW_GPENCIL) == 0) {
 				p->status = GP_STATUS_ERROR;
 				if (G.debug & G_DEBUG)
 					printf("Error: In active view, Grease Pencil not shown\n");
 				return 0;
 			}
+#endif
 		}
 		break;
-#endif
 		case SPACE_IMAGE:
 		{
 			//SpaceImage *sima= curarea->spacedata.first;
@@ -1173,12 +1112,6 @@ static int gp_session_initdata(bContext *C, tGPsdata *p)
 	/* clear out buffer (stored in gp-data), in case something contaminated it */
 	gp_session_validatebuffer(p);
 	
-#if 0
-	/* set 'default' im2d_settings just in case something that uses this doesn't set it */
-	p->im2d_settings.sizex = 1;
-	p->im2d_settings.sizey = 1;
-#endif
-
 	return 1;
 }
 
@@ -1260,7 +1193,7 @@ static void gp_paint_initstroke(tGPsdata *p, short paintmode)
 		if (p->sa->spacetype == SPACE_VIEW3D) {
 			View3D *v3d = p->sa->spacedata.first;
 			RegionView3D *rv3d = p->ar->regiondata;
-
+			
 			/* for camera view set the subrect */
 			if (rv3d->persp == RV3D_CAMOB) {
 				ED_view3d_calc_camera_border(p->scene, p->ar, v3d, rv3d, &p->subrect_data, TRUE); /* no shift */
@@ -1290,41 +1223,13 @@ static void gp_paint_initstroke(tGPsdata *p, short paintmode)
 				p->gpd->sbuffer_sflag |= GP_STROKE_2DSPACE;
 			}
 			break;
-#if 0 // XXX other spacetypes to be restored in due course
+			
 			case SPACE_SEQ:
 			{
-				SpaceSeq *sseq = (SpaceSeq *)p->sa->spacedata.first;
-				int rectx, recty;
-				float zoom, zoomx, zoomy;
-				
-				/* set draw 2d-stroke flag */
-				p->gpd->sbuffer_sflag |= GP_STROKE_2DIMAGE;
-				
-				/* calculate zoom factor */
-				zoom = (float)(SEQ_ZOOM_FAC(sseq->zoom));
-				if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
-					zoomx = zoom * (p->scene->r.xasp / p->scene->r.yasp);
-					zoomy = zoom;
-				} 
-				else
-					zoomx = zoomy = zoom;
-				
-				/* calculate rect size to use to calculate the size of the drawing area
-				 *	- We use the size of the output image not the size of the ibuf being shown
-				 *	  as it is too messy getting the ibuf (and could be too slow). This should be
-				 *	  a reasonable for most cases anyway.
-				 */
-				rectx = (p->scene->r.size * p->scene->r.xsch) / 100;
-				recty = (p->scene->r.size * p->scene->r.ysch) / 100;
-				
-				/* set offset and scale values for opertations to use */
-				p->im2d_settings.sizex = (int)(zoomx * rectx);
-				p->im2d_settings.sizey = (int)(zoomy * recty);
-				p->im2d_settings.offsx = (int)((p->sa->winx - p->im2d_settings.sizex) / 2 + sseq->xof);
-				p->im2d_settings.offsy = (int)((p->sa->winy - p->im2d_settings.sizey) / 2 + sseq->yof);
+				p->gpd->sbuffer_sflag |= GP_STROKE_2DSPACE;
 			}
 			break;
-#endif
+			
 			case SPACE_IMAGE:
 			{
 				SpaceImage *sima = (SpaceImage *)p->sa->spacedata.first;
@@ -1743,13 +1648,13 @@ static int gpencil_draw_invoke(bContext *C, wmOperator *op, wmEvent *event)
 }
 
 /* gpencil modal operator stores area, which can be removed while using it (like fullscreen) */
-static int gpencil_area_exists(bContext *C, ScrArea *satest)
+static int gpencil_area_exists(bContext *C, ScrArea *sa_test)
 {
 	bScreen *sc = CTX_wm_screen(C);
 	ScrArea *sa;
 	
 	for (sa = sc->areabase.first; sa; sa = sa->next) {
-		if (sa == satest)
+		if (sa == sa_test)
 			return 1;
 	}
 	
@@ -1839,7 +1744,7 @@ static int gpencil_draw_modal(bContext *C, wmOperator *op, wmEvent *event)
 			sketch |= GPENCIL_SKETCH_SESSIONS_ON(p->scene);
 			/* polyline drawing is also 'sketching' -- all knots should be added during one session */
 			sketch |= p->paintmode == GP_PAINTMODE_DRAW_POLY;
-
+			
 			if (sketch) {
 				/* end stroke only, and then wait to resume painting soon */
 				//printf("\t\tGP - end stroke only\n");
@@ -1847,7 +1752,7 @@ static int gpencil_draw_modal(bContext *C, wmOperator *op, wmEvent *event)
 				
 				/* we've just entered idling state, so this event was processed (but no others yet) */
 				estate = OPERATOR_RUNNING_MODAL;
-
+				
 				/* stroke could be smoothed, send notifier to refresh screen */
 				WM_event_add_notifier(C, NC_SCREEN | ND_GPENCIL | NA_EDITED, NULL);
 			}
@@ -1860,7 +1765,7 @@ static int gpencil_draw_modal(bContext *C, wmOperator *op, wmEvent *event)
 		else if (event->val == KM_PRESS) {
 			/* not painting, so start stroke (this should be mouse-button down) */
 			p = gpencil_stroke_begin(C, op);
-
+			
 			if (p->status == GP_STATUS_ERROR) {
 				estate = OPERATOR_CANCELLED;
 			}
@@ -1916,7 +1821,7 @@ static int gpencil_draw_modal(bContext *C, wmOperator *op, wmEvent *event)
 		case OPERATOR_CANCELLED:
 			gpencil_draw_exit(C, op);
 			break;
-
+		
 		case OPERATOR_RUNNING_MODAL | OPERATOR_PASS_THROUGH:
 			/* event doesn't need to be handled */
 			//printf("unhandled event -> %d (mmb? = %d | mmv? = %d)\n", event->type, event->type == MIDDLEMOUSE, event->type==MOUSEMOVE);
diff --git a/source/blender/editors/include/ED_gpencil.h b/source/blender/editors/include/ED_gpencil.h
index 32eb63a26d5..8a480271635 100644
--- a/source/blender/editors/include/ED_gpencil.h
+++ b/source/blender/editors/include/ED_gpencil.h
@@ -76,7 +76,7 @@ void ED_operatortypes_gpencil(void);
 /* ------------ Grease-Pencil Drawing API ------------------ */
 /* drawgpencil.c */
 
-void draw_gpencil_2dimage(struct bContext *C /* , struct ImBuf *ibuf */);
+void draw_gpencil_2dimage(struct bContext *C);
 void draw_gpencil_view2d(struct bContext *C, short onlyv2d);
 void draw_gpencil_view3d(struct Scene *scene, struct View3D *v3d, struct ARegion *ar, short only3d);
 
diff --git a/source/blender/editors/space_sequencer/sequencer_buttons.c b/source/blender/editors/space_sequencer/sequencer_buttons.c
index aeedafa9992..1e452f2052d 100644
--- a/source/blender/editors/space_sequencer/sequencer_buttons.c
+++ b/source/blender/editors/space_sequencer/sequencer_buttons.c
@@ -25,8 +25,6 @@
  *  \ingroup spseq
  */
 
-
-
 #include <string.h>
 #include <stdio.h>
 
@@ -36,10 +34,13 @@
 #include "BLI_blenlib.h"
 #include "BLI_utildefines.h"
 
+#include "BLF_translation.h"
+
 #include "BKE_context.h"
 #include "BKE_screen.h"
 
 #include "ED_screen.h"
+#include "ED_gpencil.h"
 
 #include "WM_api.h"
 #include "WM_types.h"
@@ -48,6 +49,19 @@
 
 #include "sequencer_intern.h"
 
+/* **************************** buttons ********************************* */
+
+void sequencer_buttons_register(ARegionType *art)
+{
+	PanelType *pt;
+	
+	pt = MEM_callocN(sizeof(PanelType), "spacetype sequencer panel gpencil");
+	strcpy(pt->idname, "SEQUENCER_PT_gpencil");
+	strcpy(pt->label, N_("Grease Pencil"));
+	pt->draw= gpencil_panel_standard;
+	BLI_addtail(&art->paneltypes, pt);
+}
+
 /* **************** operator to open/close properties view ************* */
 
 static int sequencer_properties(bContext *C, wmOperator *UNUSED(op))
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index b674943b2dc..3119c2d44f8 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -58,6 +58,7 @@
 #include "BIF_glutil.h"
 
 #include "ED_anim_api.h"
+#include "ED_gpencil.h"
 #include "ED_markers.h"
 #include "ED_mask.h"
 #include "ED_types.h"
@@ -976,16 +977,16 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 	
 	/* draw grease-pencil (image aligned) */
 //	if (sseq->flag & SEQ_DRAW_GPENCIL)
-// XXX		draw_gpencil_2dimage(sa, ibuf);
+	draw_gpencil_2dimage(C);
 
 	IMB_freeImBuf(ibuf);
 	
-	/* draw grease-pencil (screen aligned) */
-//	if (sseq->flag & SEQ_DRAW_GPENCIL)
-// XXX		draw_gpencil_view2d(sa, 0);
-	
 	/* ortho at pixel level */
 	UI_view2d_view_restore(C);
+	
+	/* draw grease-pencil (screen aligned) */
+//	if (sseq->flag & SEQ_DRAW_GPENCIL)
+	draw_gpencil_view2d(C, 0);
 
 	//if (sc->mode == SC_MODE_MASKEDIT) {
 	if (sseq->mainb == SEQ_DRAW_IMG_IMBUF) {
diff --git a/source/blender/editors/space_sequencer/sequencer_intern.h b/source/blender/editors/space_sequencer/sequencer_intern.h
index 25a322c6905..14d2ccdbbbe 100644
--- a/source/blender/editors/space_sequencer/sequencer_intern.h
+++ b/source/blender/editors/space_sequencer/sequencer_intern.h
@@ -174,7 +174,7 @@ struct ImBuf *make_zebra_view_from_ibuf(struct ImBuf * ibuf, float perc);
 struct ImBuf *make_histogram_view_from_ibuf(struct ImBuf * ibuf);
 
 /* sequencer_buttons.c */
-
+void sequencer_buttons_register(struct ARegionType *art);
 void SEQUENCER_OT_properties(struct wmOperatorType *ot);
 
 #endif /* __SEQUENCER_INTERN_H__ */
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index 3643f92d334..dbfc554007a 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -485,6 +485,11 @@ static void sequencer_preview_area_listener(ARegion *ar, wmNotifier *wmn)
 {
 	/* context changes */
 	switch (wmn->category) {
+		case NC_SCREEN:
+			if (wmn->data == ND_GPENCIL) {
+				ED_region_tag_redraw(ar);
+			}
+			break;
 		case NC_SCENE:
 			switch (wmn->data) {
 				case ND_FRAME:
@@ -534,6 +539,11 @@ static void sequencer_buttons_area_listener(ARegion *ar, wmNotifier *wmn)
 {
 	/* context changes */
 	switch (wmn->category) {
+		case NC_SCREEN:
+			if (wmn->data == ND_GPENCIL) {
+				ED_region_tag_redraw(ar);
+			}
+			break;
 		case NC_SCENE:
 			switch (wmn->data) {
 				case ND_FRAME:
@@ -590,7 +600,7 @@ void ED_spacetype_sequencer(void)
 	art->init = sequencer_preview_area_init;
 	art->draw = sequencer_preview_area_draw;
 	art->listener = sequencer_preview_area_listener;
-	art->keymapflag = ED_KEYMAP_VIEW2D | ED_KEYMAP_FRAMES | ED_KEYMAP_ANIMATION;
+	art->keymapflag = ED_KEYMAP_VIEW2D | ED_KEYMAP_FRAMES | ED_KEYMAP_GPENCIL;
 	BLI_addhead(&st->regiontypes, art);
 	
 	/* regions: listview/buttons */
@@ -602,6 +612,8 @@ void ED_spacetype_sequencer(void)
 	art->init = sequencer_buttons_area_init;
 	art->draw = sequencer_buttons_area_draw;
 	BLI_addhead(&st->regiontypes, art);
+	
+	sequencer_buttons_register(art);
 
 	/* regions: header */
 	art = MEM_callocN(sizeof(ARegionType), "spacetype sequencer region");