=FSAA fix=

This commit fixes problems with FSAA (full-screen video card antialiasing) with selection.
It turns off FSAA for the backbuffered select drawing function.

Since opengl's extension system is incomphrehensible to me (at least not without committing glew), I've
basically done a little hack that detects if the value we need for glDisable (MULTISAMPLE_ARB) is defined,
and if not defines it.  Also, this commit only works on windows, because glx sadly seems to not support
arb_multisample at all, and in all likelihood neither does osx.

Joe

source/blender/src/drawview.c

@@ -1043,11 +1043,24 @@ static void drawviewborder(void)
 
 }
 
-
 void backdrawview3d(int test)
 {
 	struct Base *base;
 
+/*disable FSAA for backbuffer selection.  Do it only for windows
+  for now.
+  
+  hopefully calling glDisable won't cause horrible things to happen on
+  those cards that don't support the arb_multisample protocol.*/
+#ifdef WIN32
+	/*got this from ogl extension page.  rather bad though.*/
+	#ifndef MULTISAMPLE_ARB
+	#define MULTISAMPLE_ARB	0x809D
+	#endif
+
+	int m;
+#endif
+	
 	if(G.f & (G_VERTEXPAINT|G_FACESELECT|G_TEXTUREPAINT|G_WEIGHTPAINT));
 	else if(G.obedit && G.vd->drawtype>OB_WIRE && (G.vd->flag & V3D_ZBUF_SELECT));
 	else {
@@ -1065,6 +1078,11 @@ void backdrawview3d(int test)
 	}
 	persp(PERSP_VIEW);
 
+#ifdef WIN32
+	m = glIsEnabled(MULTISAMPLE_ARB);
+	if (m) glDisable(MULTISAMPLE_ARB);
+#endif
+
 #ifdef __APPLE__
 	glDrawBuffer(GL_AUX0);
 #endif	
@@ -1106,7 +1124,11 @@ void backdrawview3d(int test)
 
 	if(G.vd->flag & V3D_CLIPPING)
 		view3d_clr_clipping();
-	
+
+#ifdef WIN32
+	if (m) glEnable(MULTISAMPLE_ARB);
+#endif
+
 	/* it is important to end a view in a transform compatible with buttons */
 	persp(PERSP_WIN);  // set ortho
 	bwin_scalematrix(curarea->win, G.vd->blockscale, G.vd->blockscale, G.vd->blockscale);
@@ -2890,6 +2912,7 @@ void drawview3dspace(ScrArea *sa, void *spacedata)
 			!during_script()) {
 		BPY_do_pyscript((ID *)G.scene, SCRIPT_REDRAW);
 	}
+	
 }