Option to overlay mask over the footage

Currently supports only two modes:
- Show alpha channel of the mask
- Multiply footage by the mask, which will give
  you final-looking combined image.

TODO: Currently rasterization happens on every
      redraw, need to cache rasterized mask
      somewhere to make redraw more realtime.

9 files changed, 154 insertions, 8 deletions

diff --git a/source/blender/editors/include/ED_mask.h b/source/blender/editors/include/ED_mask.h
index 3e2dbe255df..8da36f015dc 100644
--- a/source/blender/editors/include/ED_mask.h
+++ b/source/blender/editors/include/ED_mask.h
@@ -57,7 +57,7 @@ void ED_operatormacros_mask(void);
 /* mask_draw.c */
 void ED_mask_draw(const struct bContext *C, const char draw_flag, const char draw_type);
 void ED_mask_draw_region(struct Mask *mask, struct ARegion *ar,
-                         const char draw_flag, const char draw_type,
+                         const char draw_flag, const char draw_type, const char overlay_mode,
                          const int width_i, const int height_i,
                          const float aspx, const float aspy,
                          const short do_scale_applied, const short do_draw_cb,
diff --git a/source/blender/editors/mask/mask_draw.c b/source/blender/editors/mask/mask_draw.c
index fec4ab87996..50d8e653737 100644
--- a/source/blender/editors/mask/mask_draw.c
+++ b/source/blender/editors/mask/mask_draw.c
@@ -35,6 +35,7 @@
 #include "BLI_utildefines.h"
 #include "BLI_math.h"
 #include "BLI_rect.h"
+#include "BLI_task.h"
 
 #include "BKE_context.h"
 #include "BKE_mask.h"
@@ -48,6 +49,7 @@
 #include "ED_mask.h"  /* own include */
 #include "ED_space_api.h"
 #include "BIF_gl.h"
+#include "BIF_glutil.h"
 
 #include "UI_resources.h"
 #include "UI_view2d.h"
@@ -535,10 +537,93 @@ void ED_mask_draw(const bContext *C,
 	draw_masklays(C, mask, draw_flag, draw_type, width, height);
 }
 
+typedef struct ThreadedMaskRasterizeState {
+	MaskRasterHandle *handle;
+	float *buffer;
+	int width, height;
+} ThreadedMaskRasterizeState;
+
+typedef struct ThreadedMaskRasterizeData {
+	int start_scanline;
+	int num_scanlines;
+} ThreadedMaskRasterizeData;
+
+static void mask_rasterize_func(TaskPool *pool, void *taskdata, int UNUSED(threadid))
+{
+	ThreadedMaskRasterizeState *state = (ThreadedMaskRasterizeState *) BLI_task_pool_userdata(pool);
+	ThreadedMaskRasterizeData *data = (ThreadedMaskRasterizeData *) taskdata;
+	int scanline;
+
+	for (scanline = 0; scanline < data->num_scanlines; scanline++) {
+		int x, y = data->start_scanline + scanline;
+		for (x = 0; x < state->width; x++) {
+			int index = y * state->width + x;
+			float xy[2];
+
+			xy[0] = (float) x / state->width;
+			xy[1] = (float) y / state->height;
+
+			state->buffer[index] = BKE_maskrasterize_handle_sample(state->handle, xy);
+		}
+	}
+}
+
+static float *threaded_mask_rasterize(Mask *mask, const int width, const int height)
+{
+	TaskScheduler *task_scheduler = BLI_task_scheduler_get();
+	TaskPool *task_pool;
+	MaskRasterHandle *handle;
+	ThreadedMaskRasterizeState state;
+	float *buffer;
+	int i, num_threads = BLI_task_scheduler_num_threads(task_scheduler), scanlines_per_thread;
+
+	buffer = MEM_mallocN(sizeof(float) * height * width, "rasterized mask buffer");
+
+	/* Initialize rasterization handle. */
+	handle = BKE_maskrasterize_handle_new();
+	BKE_maskrasterize_handle_init(handle, mask, width, height, TRUE, TRUE, TRUE);
+
+	state.handle = handle;
+	state.buffer = buffer;
+	state.width = width;
+	state.height = height;
+
+	task_pool = BLI_task_pool_create(task_scheduler, &state);
+
+	BLI_begin_threaded_malloc();
+
+	scanlines_per_thread = height / num_threads;
+	for (i = 0; i < num_threads; i++) {
+		ThreadedMaskRasterizeData *data = MEM_mallocN(sizeof(ThreadedMaskRasterizeData),
+		                                                "threaded mask rasterize data");
+
+		data->start_scanline = i * scanlines_per_thread;
+
+		if (i < num_threads - 1) {
+			data->num_scanlines = scanlines_per_thread;
+		}
+		else {
+			data->num_scanlines = height - data->start_scanline;
+		}
+
+		BLI_task_pool_push(task_pool, mask_rasterize_func, data, true, TASK_PRIORITY_LOW);
+	}
+
+	/* work and wait until tasks are done */
+	BLI_task_pool_work_and_wait(task_pool);
+
+	/* Free memory. */
+	BLI_task_pool_free(task_pool);
+	BLI_end_threaded_malloc();
+	BKE_maskrasterize_handle_free(handle);
+
+	return buffer;
+}
+
 /* sets up the opengl context.
  * width, height are to match the values from ED_mask_get_size() */
 void ED_mask_draw_region(Mask *mask, ARegion *ar,
-                         const char draw_flag, const char draw_type,
+                         const char draw_flag, const char draw_type, const char overlay_mode,
                          const int width_i, const int height_i,  /* convert directly into aspect corrected vars */
                          const float aspx, const float aspy,
                          const short do_scale_applied, const short do_draw_cb,
@@ -592,6 +677,37 @@ void ED_mask_draw_region(Mask *mask, ARegion *ar,
 		yofs = ((width - height) / -2.0f) * zoomy;
 	}
 
+	if (draw_flag & MASK_DRAWFLAG_OVERLAY) {
+		float *buffer = threaded_mask_rasterize(mask, width, height);
+		int format;
+
+		if (overlay_mode == MASK_OVERLAY_ALPHACHANNEL) {
+			glColor3f(1.0f, 1.0f, 1.0f);
+			format = GL_LUMINANCE;
+		}
+		else {
+			/* More blending types could be supported in the future. */
+			glEnable(GL_BLEND);
+			glBlendFunc(GL_DST_COLOR, GL_SRC_ALPHA);
+			format = GL_ALPHA;
+		}
+
+		glPushMatrix();
+		glTranslatef(x, y, 0);
+		glScalef(zoomx, zoomy, 0);
+		if (stabmat) {
+			glMultMatrixf(stabmat);
+		}
+		glaDrawPixelsTex(0.0f, 0.0f, width, height, format, GL_FLOAT, GL_NEAREST, buffer);
+		glPopMatrix();
+
+		if (overlay_mode != MASK_OVERLAY_ALPHACHANNEL) {
+			glDisable(GL_BLEND);
+		}
+
+		MEM_freeN(buffer);
+	}
+
 	/* apply transformation so mask editing tools will assume drawing from the origin in normalized space */
 	glPushMatrix();
 	glTranslatef(x + xofs, y + yofs, 0);
diff --git a/source/blender/editors/screen/glutil.c b/source/blender/editors/screen/glutil.c
index b70b06f2aa4..d356c3d8de3 100644
--- a/source/blender/editors/screen/glutil.c
+++ b/source/blender/editors/screen/glutil.c
@@ -531,7 +531,7 @@ void glaDrawPixelsTexScaled(float x, float y, int img_w, int img_h, int format,
 		components = 4;
 	else if (format == GL_RGB)
 		components = 3;
-	else if (format == GL_LUMINANCE)
+	else if (ELEM(format,  GL_LUMINANCE, GL_ALPHA))
 		components = 1;
 	else {
 		BLI_assert(!"Incompatible format passed to glaDrawPixelsTexScaled");
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index 3ede63adb72..adc902bf4ba 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -1191,7 +1191,9 @@ static void clip_main_area_draw(const bContext *C, ARegion *ar)
 			int mask_width, mask_height;
 			ED_mask_get_size(sa, &mask_width, &mask_height);
 			ED_mask_draw_region(mask, ar,
-			                    sc->mask_info.draw_flag, sc->mask_info.draw_type,
+			                    sc->mask_info.draw_flag,
+			                    sc->mask_info.draw_type,
+			                    sc->mask_info.overlay_mode,
 			                    mask_width, mask_height,
 			                    aspx, aspy,
 			                    TRUE, TRUE,
diff --git a/source/blender/editors/space_image/space_image.c b/source/blender/editors/space_image/space_image.c
index 5a8292abcab..7b20af340ae 100644
--- a/source/blender/editors/space_image/space_image.c
+++ b/source/blender/editors/space_image/space_image.c
@@ -674,7 +674,6 @@ static void image_main_area_draw(const bContext *C, ARegion *ar)
 	}
 	else if (sima->mode == SI_MODE_MASK) {
 		mask = ED_space_image_get_mask(sima);
-		draw_image_cursor(ar, sima->cursor);
 	}
 
 	ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST_VIEW);
@@ -715,7 +714,9 @@ static void image_main_area_draw(const bContext *C, ARegion *ar)
 			BLI_unlock_thread(LOCK_DRAW_IMAGE);
 
 		ED_mask_draw_region(mask, ar,
-		                    sima->mask_info.draw_flag, sima->mask_info.draw_type,
+		                    sima->mask_info.draw_flag,
+		                    sima->mask_info.draw_type,
+		                    sima->mask_info.overlay_mode,
 		                    width, height,
 		                    aspx, aspy,
 		                    TRUE, FALSE,
@@ -723,7 +724,9 @@ static void image_main_area_draw(const bContext *C, ARegion *ar)
 
 		ED_mask_draw_frames(mask, ar, CFRA, mask->sfra, mask->efra);
 
+		UI_view2d_view_ortho(v2d);
 		draw_image_cursor(ar, sima->cursor);
+		UI_view2d_view_restore(C);
 	}
 
 	/* scrollers? */
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index dca1b481334..cb69a7fe654 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1251,7 +1251,7 @@ void draw_image_seq(const bContext *C, Scene *scene, ARegion *ar, SpaceSeq *sseq
 			height = (scene->r.size * scene->r.ysch) / 100;
 
 			ED_mask_draw_region(mask, ar,
-			                    0, 0,  /* TODO */
+			                    0, 0, 0,  /* TODO */
 			                    width, height,
 			                    aspx, aspy,
 			                    FALSE, TRUE,
diff --git a/source/blender/makesdna/DNA_mask_types.h b/source/blender/makesdna/DNA_mask_types.h
index 4307ea57f15..a72e287c16f 100644
--- a/source/blender/makesdna/DNA_mask_types.h
+++ b/source/blender/makesdna/DNA_mask_types.h
@@ -178,6 +178,7 @@ enum {
 
 /* SpaceClip->mask_draw_flag */
 #define MASK_DRAWFLAG_SMOOTH    1
+#define MASK_DRAWFLAG_OVERLAY   2
 
 /* copy of eSpaceImage_UVDT */
 /* SpaceClip->mask_draw_type */
@@ -188,6 +189,12 @@ enum {
 	MASK_DT_WHITE   = 3
 };
 
+/* MaskSpaceInfo->overlay_mode */
+enum {
+	MASK_OVERLAY_ALPHACHANNEL = 0,
+	MASK_OVERLAY_COMBINED     = 1
+};
+
 /* masklay->blend */
 enum {
 	MASK_BLEND_ADD             = 0,
diff --git a/source/blender/makesdna/DNA_space_types.h b/source/blender/makesdna/DNA_space_types.h
index 0478ff567a0..5befaa87e7f 100644
--- a/source/blender/makesdna/DNA_space_types.h
+++ b/source/blender/makesdna/DNA_space_types.h
@@ -546,7 +546,8 @@ typedef struct MaskSpaceInfo
 	/* draw options */
 	char draw_flag;
 	char draw_type;
-	char pad3[6];
+	char overlay_mode;
+	char pad3[5];
 } MaskSpaceInfo;
 
 /* sseq->mainb */
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index aee6b060221..41ea74ebb8c 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -1336,6 +1336,12 @@ static void rna_def_space_mask_info(StructRNA *srna, int noteflag, const char *m
 {
 	PropertyRNA *prop;
 
+	static EnumPropertyItem overlay_mode_items[] = {
+		{MASK_OVERLAY_ALPHACHANNEL, "ALPHACHANNEL", ICON_NONE, "Alpha Channel", "Show alpha channel of the mask"},
+		{MASK_OVERLAY_COMBINED,     "COMBINED",     ICON_NONE, "Combined",      "Combine space background image with the mask"},
+		{0, NULL, 0, NULL, NULL}
+	};
+
 	prop = RNA_def_property(srna, "mask", PROP_POINTER, PROP_NONE);
 	RNA_def_property_pointer_sdna(prop, NULL, "mask_info.mask");
 	RNA_def_property_flag(prop, PROP_EDITABLE);
@@ -1354,6 +1360,17 @@ static void rna_def_space_mask_info(StructRNA *srna, int noteflag, const char *m
 	RNA_def_property_boolean_sdna(prop, NULL, "mask_info.draw_flag", MASK_DRAWFLAG_SMOOTH);
 	RNA_def_property_ui_text(prop, "Draw Smooth Splines", "");
 	RNA_def_property_update(prop, noteflag, NULL);
+
+	prop = RNA_def_property(srna, "show_mask_overlay", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "mask_info.draw_flag", MASK_DRAWFLAG_OVERLAY);
+	RNA_def_property_ui_text(prop, "Show Mask Overlay", "");
+	RNA_def_property_update(prop, noteflag, NULL);
+
+	prop = RNA_def_property(srna, "mask_overlay_mode", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "mask_info.overlay_mode");
+	RNA_def_property_enum_items(prop, overlay_mode_items);
+	RNA_def_property_ui_text(prop, "Overlay Mode", "Overlay mode of rasterized mask");
+	RNA_def_property_update(prop, noteflag, NULL);
 }
 
 static void rna_def_space_image_uv(BlenderRNA *brna)