[Bf-blender-cvs] [05058ab4430] greasepencil-object: Fix T52100: Buffer stroke is not visible if paint over fill

[Antonio Vazquez]

Commit: 05058ab4430f08c04f7f8256a3ed0893ef47cf4a
Author: Antonio Vazquez
Date:   Tue Jul 18 10:20:14 2017 +0200
Branches: greasepencil-object
https://developer.blender.org/rB05058ab4430f08c04f7f8256a3ed0893ef47cf4a

Fix T52100: Buffer stroke is not visible if paint over fill

If paint  a stroke over a fill area, the drawing stroke was not visible while drawing and only when finish the stroke.

The drawing pass was mixing the with mix pass and now reuse the stroke mix. This solve the problem and increase the drawing speed because only one mix pass is necessary

===================================================================

M	source/blender/draw/engines/gpencil/gpencil_engine.c

===================================================================

diff --git a/source/blender/draw/engines/gpencil/gpencil_engine.c b/source/blender/draw/engines/gpencil/gpencil_engine.c
index 1031dc2eb6b..73aed3eefcb 100644
--- a/source/blender/draw/engines/gpencil/gpencil_engine.c
+++ b/source/blender/draw/engines/gpencil/gpencil_engine.c
@@ -299,7 +299,6 @@ static void GPENCIL_draw_scene(void *vedata)
 	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
 	float clearcol[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
 	int init_grp, end_grp;
-	bool is_drawing_session = false;
 
 	/* attach temp textures */
 	DRW_framebuffer_texture_attach(fbl->temp_color_fb, e_data.temp_fbcolor_depth_tx, 0, 0);
@@ -312,59 +311,43 @@ static void GPENCIL_draw_scene(void *vedata)
 		qsort(stl->g_data->gp_object_cache, stl->g_data->gp_cache_used, 
 			sizeof(tGPencilObjectCache), gpencil_object_cache_compare_zdepth);
 
-
 		for (int i = 0; i < stl->g_data->gp_cache_used; ++i) {
 			Object *ob = stl->g_data->gp_object_cache[i].ob;
-			if (!is_drawing_session) {
-				is_drawing_session = (bool)(ob->gpd->sbuffer_size > 0);
-			}
 			init_grp = stl->g_data->gp_object_cache[i].init_grp;
 			end_grp = stl->g_data->gp_object_cache[i].end_grp;
-			if (end_grp >= init_grp) {
-				/* Render stroke in separated framebuffer */
-				DRW_framebuffer_bind(fbl->temp_color_fb);
-				DRW_framebuffer_clear(true, true, false, clearcol, 1.0f);
-
-				/* Stroke Pass: DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND | DRW_STATE_WRITE_DEPTH
-				 * draw only a subset that usually start with a fill and end with stroke because the
-				 * shading groups are created by pairs */
-				if (G.debug_value == 668) {
-					printf("GPENCIL_draw_scene: %s %d->%d\n", ob->id.name, init_grp, end_grp);
-				}
+			/* Render stroke in separated framebuffer */
+			DRW_framebuffer_bind(fbl->temp_color_fb);
+			DRW_framebuffer_clear(true, true, false, clearcol, 1.0f);
 
+			/* Stroke Pass: DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND | DRW_STATE_WRITE_DEPTH
+			 * draw only a subset that usually start with a fill and end with stroke because the
+			 * shading groups are created by pairs */
+			if (G.debug_value == 668) {
+				printf("GPENCIL_draw_scene: %s %d->%d\n", ob->id.name, init_grp, end_grp);
+			}
+
+			if (end_grp >= init_grp) {
 				DRW_draw_pass_subset(psl->stroke_pass,
 					stl->shgroups[init_grp].shgrps_fill != NULL ? stl->shgroups[init_grp].shgrps_fill : stl->shgroups[init_grp].shgrps_stroke,
 					stl->shgroups[end_grp].shgrps_stroke);
+			}
+			/* Current buffer drawing */
+			if (ob->gpd->sbuffer_size > 0) {
+				DRW_draw_pass(psl->drawing_pass);
+			}
 
-				/* Combine with scene buffer */
-				DRW_framebuffer_bind(dfbl->default_fb);
+			/* Combine with scene buffer */
+			DRW_framebuffer_bind(dfbl->default_fb);
 
-				/* Mix Pass: DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS */
-				DRW_draw_pass(psl->mix_pass);
-			}
+			/* Mix Pass: DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS */
+			DRW_draw_pass(psl->mix_pass);
 		}
 		/* edit points */
 		DRW_draw_pass(psl->edit_pass);
-
 	}
 	/* free memory */
 	MEM_SAFE_FREE(stl->g_data->gp_object_cache);
 
-	/* current drawing buffer 
-	 * Need to use the mix_pass in order to get the same color while drawing. If the pass is not mixed with the
-	 * same pass than strokes, there is a change in the color between drawing stroke and final stroke due the process
-	 * to mix. This is slower, but needed and while drawing the time delay is negligible
-	*/
-	if (is_drawing_session) {
-		DRW_framebuffer_bind(fbl->temp_color_fb);
-		DRW_framebuffer_clear(true, true, false, clearcol, 1.0f);
-
-		DRW_draw_pass(psl->drawing_pass);
-
-		DRW_framebuffer_bind(dfbl->default_fb);
-		DRW_draw_pass(psl->mix_pass);
-	}
-
 	/* detach temp textures */
 	DRW_framebuffer_texture_detach(e_data.temp_fbcolor_depth_tx);
 	DRW_framebuffer_texture_detach(e_data.temp_fbcolor_color_tx);