Bugfix #25446 (and todo item)

The icons for materials were always lagging or not updating
at all. I also found it suspicious slow... 
It appeared that the icons now store a "mip level", where for
every change in Materials 2 render jobs for icons were started,
one for 32x32 pix, one for 96x96. The latter was cancelling out
the first job almost always.

Also made preview renders detect size, to set amount of tiles
to be rendered. Small icons use 1 part, larger previews 16 now.

All in all, behaves much smoother now! But, will also update
the thread Jobs manager to allow "delayed jobs" like for icons,
these are aggressively put as first in the jobs list.

1 files changed, 16 insertions, 5 deletions

diff --git a/source/blender/editors/render/render_preview.c b/source/blender/editors/render/render_preview.c
index 2eac7c20350..b60f948dc79 100644
--- a/source/blender/editors/render/render_preview.c
+++ b/source/blender/editors/render/render_preview.c
@@ -347,6 +347,7 @@ static Scene *preview_prepare_scene(Scene *scene, ID *id, int id_type, ShaderPre
 	
 	sce= pr_main->scene.first;
 	if(sce) {
+		
 		/* this flag tells render to not execute depsgraph or ipos etc */
 		sce->r.scemode |= R_PREVIEWBUTS;
 		/* set world always back, is used now */
@@ -358,9 +359,17 @@ static Scene *preview_prepare_scene(Scene *scene, ID *id, int id_type, ShaderPre
 		}
 		
 		sce->r.color_mgt_flag = scene->r.color_mgt_flag;
+		
+		/* prevent overhead for small renders and icons (32) */
+		if(id && sp->sizex < 40)
+			sce->r.xparts= sce->r.yparts= 1;
+		else
+			sce->r.xparts= sce->r.yparts= 4;
+		
 		/* exception: don't color manage texture previews or icons */
 		if((id && sp->pr_method==PR_ICON_RENDER) || id_type == ID_TE)
 			sce->r.color_mgt_flag &= ~R_COLOR_MANAGEMENT;
+		
 		if((id && sp->pr_method==PR_ICON_RENDER) && id_type != ID_WO)
 			sce->r.alphamode= R_ALPHAPREMUL;
 		else
@@ -380,7 +389,7 @@ static Scene *preview_prepare_scene(Scene *scene, ID *id, int id_type, ShaderPre
 				
 				init_render_material(mat, 0, NULL);		/* call that retrieves mode_l */
 				end_render_material(mat);
-				
+
 				/* turn on raytracing if needed */
 				if(mat->mode_l & MA_RAYMIRROR)
 					sce->r.mode |= R_RAYTRACE;
@@ -601,7 +610,7 @@ void ED_preview_draw(const bContext *C, void *idp, void *parentp, void *slotp, r
 			sbuts->preview= 0;
 			ok= 0;
 		}
-		
+	
 		if(ok==0) {
 			ED_preview_shader_job(C, sa, id, parent, slot, newx, newy, PR_BUTS_RENDER);
 		}
@@ -937,7 +946,7 @@ static void shader_preview_draw(void *spv, RenderResult *UNUSED(rr), volatile st
 static int shader_preview_break(void *spv)
 {
 	ShaderPreview *sp= spv;
-	
+
 	return *(sp->stop);
 }
 
@@ -962,7 +971,7 @@ static void shader_preview_render(ShaderPreview *sp, ID *id, int split, int firs
 	short idtype= GS(id->name);
 	char name[32];
 	int sizex;
-
+	
 	/* get the stuff from the builtin preview dbase */
 	sce= preview_prepare_scene(sp->scene, id, idtype, sp); // XXX sizex
 	if(sce==NULL) return;
@@ -1021,6 +1030,8 @@ static void shader_preview_render(ShaderPreview *sp, ID *id, int split, int firs
 
 	/* handle results */
 	if(sp->pr_method==PR_ICON_RENDER) {
+		char *rct= (char *)(sp->pr_rect + 32*16 + 16);
+		
 		if(sp->pr_rect)
 			RE_ResultGet32(re, sp->pr_rect);
 	}
@@ -1231,7 +1242,7 @@ void ED_preview_icon_job(const bContext *C, void *owner, ID *id, unsigned int *r
 	sp->pr_method= PR_ICON_RENDER;
 	sp->pr_rect= rect;
 	sp->id = id;
-	
+
 	/* setup job */
 	WM_jobs_customdata(steve, sp, shader_preview_free);
 	WM_jobs_timer(steve, 0.1, NC_MATERIAL, NC_MATERIAL);