Matcap support in 3D Viewport.

Full log is here:
http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.66/Usability#Matcap_in_3D_viewport

Implementation notes:

- Matcaps are an extension of Solid draw mode, and don't show in other drawmodes.
  (It's mostly intended to aid modeling/sculpt)

- By design, Matcaps are a UI feature, and only stored locally for the UI itself, and
  won't affect rendering or materials.

- Currently a set of 16 (GPL licensed) Matcaps have been compiled into Blender. 
  It doesn't take memory or cpu time, until you use it.

- Brush Icons and Matcaps use same code now, and only get generated/allocated on
  actually using it (instead of on startup).

- The current set might get new or different images still, based on user feedback.

- Matcap images are 512x512 pixels, so each image takes 1 Mb memory. Unused matcaps get 
  freed immediately. The Matcap icon previews (128x128 pixels) stay in memory.

- Loading own matcap image files will be added later. That needs design and code work 
  to get it stable and memory-friendly.

- The GLSL code uses the ID PreviewImage for matcaps. I tested it using the existing
  Material previews, which has its limits... especially for textured previews the
  normal-mapped matcap won't look good.

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index f4672fe2b5e..d042e43f9ca 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -1850,8 +1850,8 @@ static PreviewImage *direct_link_preview_image(FileData *fd, PreviewImage *old_p
 			if (prv->rect[i]) {
 				prv->rect[i] = newdataadr(fd, prv->rect[i]);
 			}
+			prv->gputexture[i] = NULL;
 		}
-//		prv->gputexture[0] = prv->gputexture[1] = NULL;
 	}
 	
 	return prv;
@@ -5998,6 +5998,7 @@ static void direct_link_screen(FileData *fd, bScreen *sc)
 				v3d->afterdraw_xray.first = v3d->afterdraw_xray.last = NULL;
 				v3d->afterdraw_xraytransp.first = v3d->afterdraw_xraytransp.last = NULL;
 				v3d->properties_storage = NULL;
+				v3d->defmaterial = NULL;
 				
 				/* render can be quite heavy, set to wire on load */
 				if (v3d->drawtype == OB_RENDER)