Grease Pencil: Basic Support for Image Editor Again

* Grease Pencil works again from Image Editor now. For now, the GPencil datablock is linked to the Image Editor space, but this can be changed if need be.

* Made Grease Pencil hotkeys into a separate Grease Pencil keymap, which can get included automagically like for frames/ui/v2d/etc. by supplying ED_KEYMAP_GPENCIL as part of st->keymapflag

* Temporarily restored the nasty hack to make View2D-aligned sketches in Image Editor to use OpenGL lines only. I still dunno why this doesn't work normally. 
(Probably related is that strokes are not visible when there's no image visible atm).

4 files changed, 40 insertions, 23 deletions

diff --git a/source/blender/editors/space_image/image_buttons.c b/source/blender/editors/space_image/image_buttons.c
index ac0a5c7f53a..2eb070e0e6d 100644
--- a/source/blender/editors/space_image/image_buttons.c
+++ b/source/blender/editors/space_image/image_buttons.c
@@ -67,6 +67,7 @@
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
 
+#include "ED_gpencil.h"
 #include "ED_image.h"
 #include "ED_mesh.h"
 #include "ED_space_api.h"
@@ -1438,6 +1439,12 @@ void image_buttons_register(ARegionType *art)
 	strcpy(pt->label, "Curves");
 	pt->draw= image_panel_curves;
 	BLI_addtail(&art->paneltypes, pt);
+	
+	pt= MEM_callocN(sizeof(PanelType), "spacetype image panel gpencil");
+	strcpy(pt->idname, "IMAGE_PT_gpencil");
+	strcpy(pt->label, "Grease Pencil");
+	pt->draw= gpencil_panel_standard;
+	BLI_addtail(&art->paneltypes, pt);
 }
 
 static int image_properties(bContext *C, wmOperator *op)
diff --git a/source/blender/editors/space_image/image_draw.c b/source/blender/editors/space_image/image_draw.c
index 2f5fc805367..cf9bac1ebee 100644
--- a/source/blender/editors/space_image/image_draw.c
+++ b/source/blender/editors/space_image/image_draw.c
@@ -44,6 +44,7 @@
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
 
+#include "BKE_context.h"
 #include "BKE_colortools.h"
 #include "BKE_global.h"
 #include "BKE_image.h"
@@ -53,6 +54,7 @@
 #include "BIF_gl.h"
 #include "BIF_glutil.h"
 
+#include "ED_gpencil.h"
 #include "ED_image.h"
 #include "ED_screen.h"
 
@@ -525,22 +527,26 @@ static void draw_image_buffer_repeated(SpaceImage *sima, ARegion *ar, Scene *sce
 /* draw uv edit */
 
 /* draw grease pencil */
-
-static void draw_image_grease_pencil(SpaceImage *sima, ImBuf *ibuf)
+void draw_image_grease_pencil(bContext *C, short onlyv2d)
 {
-	/* XXX bring back */
-	/* draw grease-pencil ('image' strokes) */
-	if (sima->flag & SI_DISPGP)
-		; // XXX draw_gpencil_2dimage(sa, ibuf);
-
-#if 0
-	mywinset(sa->win);	/* restore scissor after gla call... */
-	wmOrtho2(-0.375, sa->winx-0.375, -0.375, sa->winy-0.375);
-#endif
-	
-	/* draw grease-pencil (screen strokes) */
-	if (sima->flag & SI_DISPGP)
-		; // XXX draw_gpencil_2dview(sa, NULL);
+	/* draw in View2D space? */
+	if (onlyv2d) {
+		/* assume that UI_view2d_ortho(C) has been called... */
+		SpaceImage *sima= (SpaceImage *)CTX_wm_space_data(C);
+		ImBuf *ibuf= ED_space_image_buffer(sima);
+		
+		/* draw grease-pencil ('image' strokes) */
+		//if (sima->flag & SI_DISPGP)
+			draw_gpencil_2dimage(C, ibuf);
+	}
+	else {
+		/* assume that UI_view2d_restore(C) has been called... */
+		SpaceImage *sima= (SpaceImage *)CTX_wm_space_data(C);
+		
+		/* draw grease-pencil ('screen' strokes) */
+		//if (sima->flag & SI_DISPGP)
+			draw_gpencil_2dview(C, 0);
+	}
 }
 
 /* XXX becomes WM paint cursor */
@@ -689,9 +695,6 @@ void draw_image_main(SpaceImage *sima, ARegion *ar, Scene *scene)
 	else
 		draw_image_buffer(sima, ar, scene, ima, ibuf, 0.0f, 0.0f, zoomx, zoomy);
 
-	/* grease pencil */
-	draw_image_grease_pencil(sima, ibuf);
-
 	/* paint helpers */
 	draw_image_paint_helpers(sima, ar, scene, zoomx, zoomy);
 
diff --git a/source/blender/editors/space_image/image_intern.h b/source/blender/editors/space_image/image_intern.h
index aa97e339c68..a33475c1213 100644
--- a/source/blender/editors/space_image/image_intern.h
+++ b/source/blender/editors/space_image/image_intern.h
@@ -53,6 +53,7 @@ void IMAGE_OT_toolbox(struct wmOperatorType *ot);
 /* image_draw.c */
 void draw_image_main(struct SpaceImage *sima, struct ARegion *ar, struct Scene *scene);
 void draw_image_info(struct ARegion *ar, int channels, int x, int y, char *cp, float *fp, int *zp, float *zpf);
+void draw_image_grease_pencil(struct bContext *C, short onlyv2d);
 
 /* image_ops.c */
 int space_image_main_area_poll(struct bContext *C);
diff --git a/source/blender/editors/space_image/space_image.c b/source/blender/editors/space_image/space_image.c
index 1506df89c45..bb647e68917 100644
--- a/source/blender/editors/space_image/space_image.c
+++ b/source/blender/editors/space_image/space_image.c
@@ -54,6 +54,7 @@
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
 
+#include "ED_gpencil.h"
 #include "ED_image.h"
 #include "ED_mesh.h"
 #include "ED_space_api.h"
@@ -430,16 +431,22 @@ static void image_main_area_draw(const bContext *C, ARegion *ar)
 	
 	/* we set view2d from own zoom and offset each time */
 	image_main_area_set_view2d(sima, ar, scene);
-		
+	
 	/* we draw image in pixelspace */
 	draw_image_main(sima, ar, scene);
 
 	/* and uvs in 0.0-1.0 space */
 	UI_view2d_view_ortho(C, v2d);
-	draw_uvedit_main(sima, ar, scene, obedit);
-	ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST);
+		draw_uvedit_main(sima, ar, scene, obedit);
+		ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST);
+		
+		/* Grease Pencil too (in addition to UV's) */
+		draw_image_grease_pencil((bContext *)C, 1); 
 	UI_view2d_view_restore(C);
 	
+	/* draw Grease Pencil - screen space only */
+	draw_image_grease_pencil((bContext *)C, 0);
+	
 	/* scrollers? */
 	/*scrollers= UI_view2d_scrollers_calc(C, v2d, V2D_UNIT_VALUES, V2D_GRID_CLAMP, V2D_ARG_DUMMY, V2D_ARG_DUMMY);
 	UI_view2d_scrollers_draw(C, v2d, scrollers);
@@ -558,11 +565,10 @@ void ED_spacetype_image(void)
 	/* regions: main window */
 	art= MEM_callocN(sizeof(ARegionType), "spacetype image region");
 	art->regionid = RGN_TYPE_WINDOW;
-	art->keymapflag= ED_KEYMAP_FRAMES;
+	art->keymapflag= ED_KEYMAP_FRAMES|ED_KEYMAP_GPENCIL;
 	art->init= image_main_area_init;
 	art->draw= image_main_area_draw;
 	art->listener= image_main_area_listener;
-	art->keymapflag= 0;
 
 	BLI_addhead(&st->regiontypes, art);