Colour Management

- 1st stage: Linear Workflow

This implements automatic linear workflow in Blender's renderer. With the 
new Colour Management option on in the Render buttons, all inputs to the 
renderer and compositor are converted to linear colour space before 
rendering, and gamma corrected afterwards. In essence, this makes all 
manual gamma correction with nodes, etc unnecessary, since it's done 
automatically through the pipeline.

It's all explained much better in the notes/doc here, so please have a look:
http://wiki.blender.org/index.php/Dev:Source/Blender/Architecture/Colour_Management

And an example of the sort of difference it makes:
http://mke3.net/blender/devel/rendering/b25_colormanagement_test01.jpg

This also enables Colour Management in the default B.blend, and changes the 
default lamp falloff to inverse square, which is more correct, and much 
easier to use now it's all gamma corrected properly.

Next step is to look into profiles/soft proofing for the compositor.

Thanks to brecht for reviewing and fixing some oversights!

1 files changed, 14 insertions, 5 deletions

diff --git a/source/blender/editors/preview/previewrender.c b/source/blender/editors/preview/previewrender.c
index e79dbed0661..28b9c6b1833 100644
--- a/source/blender/editors/preview/previewrender.c
+++ b/source/blender/editors/preview/previewrender.c
@@ -293,6 +293,7 @@ static Scene *preview_prepare_scene(Scene *scene, int id_type, ShaderPreview *sp
 			sce->world->range= scene->world->range;
 		}
 		
+		sce->r.color_mgt_flag = scene->r.color_mgt_flag;
 		sce->r.cfra= scene->r.cfra;
 		
 		if(id_type==ID_MA) {
@@ -353,6 +354,9 @@ static Scene *preview_prepare_scene(Scene *scene, int id_type, ShaderPreview *sp
 			
 			sce->lay= 1<<MA_TEXTURE;
 			
+			/* exception: don't color manage texture previews */
+			sce->r.color_mgt_flag &= ~R_COLOR_MANAGEMENT;
+			
 			for(base= sce->base.first; base; base= base->next) {
 				if(base->object->id.name[2]=='t') {
 					Material *mat= give_current_material(base->object, base->object->actcol);
@@ -404,21 +408,27 @@ static Scene *preview_prepare_scene(Scene *scene, int id_type, ShaderPreview *sp
 	return NULL;
 }
 
-
 /* new UI convention: draw is in pixel space already. */
 /* uses ROUNDBOX button in block to get the rect */
 void ED_preview_draw(const bContext *C, void *idp, rcti *rect)
 {
 	if(idp) {
 		ScrArea *sa= CTX_wm_area(C);
+		Scene *sce = CTX_data_scene(C);
+		ID *id = (ID *)idp;
 		SpaceButs *sbuts= sa->spacedata.first;
 		RenderResult rres;
 		int newx= rect->xmax-rect->xmin, newy= rect->ymax-rect->ymin;
 		int ok= 0;
 		char name[32];
+		int gamma_correct=0;
+ 	
+		if (id && GS(id->name) != ID_TE) {
+			/* exception: don't color manage texture previews - show the raw values */
+			if (sce) gamma_correct = sce->r.color_mgt_flag & R_COLOR_MANAGEMENT;
+		}
 		
 		sprintf(name, "Preview %p", sa);
-		BLI_lock_malloc_thread();
 		RE_GetResultImage(RE_GetRender(name), &rres);
 
 		if(rres.rectf) {
@@ -428,11 +438,10 @@ void ED_preview_draw(const bContext *C, void *idp, rcti *rect)
 				rect->xmax= rect->xmin + rres.rectx;
 				rect->ymax= rect->ymin + rres.recty;
 			
-				glaDrawPixelsSafe(rect->xmin, rect->ymin, rres.rectx, rres.recty, rres.rectx, GL_RGBA, GL_FLOAT, rres.rectf);
+				glaDrawPixelsSafe_to32(rect->xmin, rect->ymin, rres.rectx, rres.recty, rres.rectx, rres.rectf, gamma_correct);
 				ok= 1;
 			}
 		}
-		BLI_unlock_malloc_thread();
 
 		/* check for spacetype... */
 		if(sbuts->spacetype==SPACE_BUTS && sbuts->preview) {
@@ -468,7 +477,7 @@ void view3d_previewrender_progress(RenderResult *rr, volatile rcti *renrect)
 	
 	glDrawBuffer(GL_FRONT);
 //	glaDefine2DArea(&sa->winrct);
-	glaDrawPixelsSafe_to32(ofsx, ofsy, rr->rectx, rr->recty, rr->rectx, rl->rectf);
+	glaDrawPixelsSafe_to32(ofsx, ofsy, rr->rectx, rr->recty, rr->rectx, rl->rectf, 0);
 	bglFlush();
 	glDrawBuffer(GL_BACK);