[Bf-blender-cvs] [541e81ac96e] greasepencil-object: Fix color distorsion while drawing

[Antonio Vazquez]

Commit: 541e81ac96eb7fbd5265db53043908cc7b7425e3
Author: Antonio Vazquez
Date:   Wed Jul 12 14:12:14 2017 +0200
Branches: greasepencil-object
https://developer.blender.org/rB541e81ac96eb7fbd5265db53043908cc7b7425e3

Fix color distorsion while drawing

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

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

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 9a0eace5a30..95d2c259959 100644
--- a/source/blender/draw/engines/gpencil/gpencil_engine.c
+++ b/source/blender/draw/engines/gpencil/gpencil_engine.c
@@ -299,6 +299,11 @@ 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);
+	DRW_framebuffer_texture_attach(fbl->temp_color_fb, e_data.temp_fbcolor_color_tx, 0, 0);
 
 	/* Draw all pending objects */
 	if (stl->g_data->gp_cache_used > 0) {
@@ -307,12 +312,11 @@ 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);
 
-		/* attach temp textures */
-		DRW_framebuffer_texture_attach(fbl->temp_color_fb, e_data.temp_fbcolor_depth_tx, 0, 0);
-		DRW_framebuffer_texture_attach(fbl->temp_color_fb, e_data.temp_fbcolor_color_tx, 0, 0);
 
 		for (int i = 0; i < stl->g_data->gp_cache_used; ++i) {
 			Object *ob = stl->g_data->gp_object_cache[i].ob;
+			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) {
@@ -341,18 +345,31 @@ static void GPENCIL_draw_scene(void *vedata)
 		/* edit points */
 		DRW_draw_pass(psl->edit_pass);
 
-		/* detach temp textures */
-		DRW_framebuffer_texture_detach(e_data.temp_fbcolor_depth_tx);
-		DRW_framebuffer_texture_detach(e_data.temp_fbcolor_color_tx);
-		
-		/* attach again default framebuffer */
-		DRW_framebuffer_bind(dfbl->default_fb);
 	}
 	/* free memory */
 	MEM_SAFE_FREE(stl->g_data->gp_object_cache);
 
-	/* current drawing buffer */
-	DRW_draw_pass(psl->drawing_pass);
+	/* 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);
+
+	/* attach again default framebuffer */
+	DRW_framebuffer_bind(dfbl->default_fb);
 }
 
 static const DrawEngineDataSize GPENCIL_data_size = DRW_VIEWPORT_DATA_SIZE(GPENCIL_Data);