Orange branch feature; Material Layering

(WIP, don't bugs for this in tracker yet please!)

- New Panel "Layers" in Material buttons, allows to add unlimited amount
  of materials on top of each other.
- Every Layer is actually just another Material, which gets rendered/shaded
  (including texture), and then added on top of previous layer with an
  operation like Mix, Add, Mult, etc.
- Layers render fully independent, so bumpmaps are not passed on to next
  layers.
- Per Layer you can set if it influences Diffuse, Specular or Alpha
- If a Material returns alpha (like from texture), the alpha value is
  used for adding the layers too.
- New texture "Map To" channel allows to have a texture work on a Layer
- Each layer, including basis Material, can be turned on/off individually

Notes:

- at this moment, the full shading pass happens for each layer, including
  shadow, AO and raytraced mirror or transparency...
- I had to remove old hacks from preview render, which corrected reflected
  normals for preview texturing.
- still needs loadsa testing!

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/src/interface_panel.c b/source/blender/src/interface_panel.c
index 54bab5703a3..c9892ed7f1e 100644
--- a/source/blender/src/interface_panel.c
+++ b/source/blender/src/interface_panel.c
@@ -652,7 +652,7 @@ void uiSetPanel_view2d(ScrArea *sa)
 	
 	pa= sa->panels.first;
 	while(pa) {
-		if(pa->active) {
+		if(pa->active && pa->paneltab==NULL) {
 			done= 1;
 			if(pa->ofsx < minx) minx= pa->ofsx;
 			if(pa->ofsx+pa->sizex > maxx) maxx= pa->ofsx+pa->sizex;
@@ -696,7 +696,7 @@ void uiMatchPanel_view2d(ScrArea *sa)
 	
 	pa= sa->panels.first;
 	while(pa) {
-		if(pa->active) {
+		if(pa->active && pa->paneltab==NULL) {
 			done= 1;
 			if(pa->ofsx < G.v2d->tot.xmin) G.v2d->tot.xmin= pa->ofsx;
 			if(pa->ofsx+pa->sizex > G.v2d->tot.xmax)