From: Brian Paul <brianp@vmware.com>
Date: Tue, 29 Dec 2009 23:17:14 +0000 (-0700)
Subject: mesa: implement per-buffer color masking
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fd5511d27fc44096117c47ab503fb5b47f993061;p=mesa.git

mesa: implement per-buffer color masking

This is part of the GL_EXT_draw_buffers2 extension and part of GL 3.0.

The ctx->Color.ColorMask field is now a 2-D array.  Until drivers are
modified to support per-buffer color masking, they can just look at
the 0th color mask.

The new _mesa_ColorMaskIndexed() function will be called by
glColorMaskIndexedEXT() or glColorMaski().
---

diff --git a/src/mesa/drivers/common/driverfuncs.c b/src/mesa/drivers/common/driverfuncs.c
index 9b271f85e92..5c5e17820d6 100644
--- a/src/mesa/drivers/common/driverfuncs.c
+++ b/src/mesa/drivers/common/driverfuncs.c
@@ -264,11 +264,23 @@ _mesa_init_driver_state(GLcontext *ctx)
                                  ctx->Color.BlendDstRGB,
                                  ctx->Color.BlendSrcA, ctx->Color.BlendDstA);
 
-   ctx->Driver.ColorMask(ctx,
-                         ctx->Color.ColorMask[RCOMP],
-                         ctx->Color.ColorMask[GCOMP],
-                         ctx->Color.ColorMask[BCOMP],
-                         ctx->Color.ColorMask[ACOMP]);
+   if (ctx->Driver.ColorMaskIndexed) {
+      GLuint i;
+      for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+         ctx->Driver.ColorMaskIndexed(ctx, i,
+                                      ctx->Color.ColorMask[0][RCOMP],
+                                      ctx->Color.ColorMask[0][GCOMP],
+                                      ctx->Color.ColorMask[0][BCOMP],
+                                      ctx->Color.ColorMask[0][ACOMP]);
+      }
+   }
+   else {
+      ctx->Driver.ColorMask(ctx,
+                            ctx->Color.ColorMask[0][RCOMP],
+                            ctx->Color.ColorMask[0][GCOMP],
+                            ctx->Color.ColorMask[0][BCOMP],
+                            ctx->Color.ColorMask[0][ACOMP]);
+   }
 
    ctx->Driver.CullFace(ctx, ctx->Polygon.CullFaceMode);
    ctx->Driver.DepthFunc(ctx, ctx->Depth.Func);
diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index da2c06677a6..0676173745c 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -111,7 +111,7 @@ struct save_state
    GLboolean ColorLogicOpEnabled;
 
    /** META_COLOR_MASK */
-   GLubyte ColorMask[4];
+   GLubyte ColorMask[MAX_DRAW_BUFFERS][4];
 
    /** META_DEPTH_TEST */
    struct gl_depthbuffer_attrib Depth;
@@ -347,11 +347,12 @@ _mesa_meta_begin(GLcontext *ctx, GLbitfield state)
    }
 
    if (state & META_COLOR_MASK) {
-      COPY_4V(save->ColorMask, ctx->Color.ColorMask);
-      if (!ctx->Color.ColorMask[0] ||
-          !ctx->Color.ColorMask[1] ||
-          !ctx->Color.ColorMask[2] ||
-          !ctx->Color.ColorMask[3])
+      memcpy(save->ColorMask, ctx->Color.ColorMask,
+             sizeof(ctx->Color.ColorMask));
+      if (!ctx->Color.ColorMask[0][0] ||
+          !ctx->Color.ColorMask[0][1] ||
+          !ctx->Color.ColorMask[0][2] ||
+          !ctx->Color.ColorMask[0][3])
          _mesa_ColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    }
 
@@ -581,9 +582,22 @@ _mesa_meta_end(GLcontext *ctx)
    }
 
    if (state & META_COLOR_MASK) {
-      if (!TEST_EQ_4V(ctx->Color.ColorMask, save->ColorMask))
-         _mesa_ColorMask(save->ColorMask[0], save->ColorMask[1],
-                         save->ColorMask[2], save->ColorMask[3]);
+      GLuint i;
+      for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+         if (!TEST_EQ_4V(ctx->Color.ColorMask[i], save->ColorMask[i])) {
+            if (i == 0) {
+               _mesa_ColorMask(save->ColorMask[i][0], save->ColorMask[i][1],
+                               save->ColorMask[i][2], save->ColorMask[i][3]);
+            }
+            else {
+               _mesa_ColorMaskIndexed(i,
+                                      save->ColorMask[i][0],
+                                      save->ColorMask[i][1],
+                                      save->ColorMask[i][2],
+                                      save->ColorMask[i][3]);
+            }
+         }
+      }
    }
 
    if (state & META_DEPTH_TEST) {
diff --git a/src/mesa/drivers/directfb/idirectfbgl_mesa.c b/src/mesa/drivers/directfb/idirectfbgl_mesa.c
index 93593403c13..62a3269d171 100644
--- a/src/mesa/drivers/directfb/idirectfbgl_mesa.c
+++ b/src/mesa/drivers/directfb/idirectfbgl_mesa.c
@@ -407,10 +407,10 @@ dfbClear( GLcontext *ctx, GLbitfield mask )
 #define BUFFER_BIT_MASK (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT | \
                          BUFFER_BIT_BACK_LEFT  | BUFFER_BIT_BACK_RIGHT  )
      if (mask & BUFFER_BIT_MASK  &&
-         ctx->Color.ColorMask[0] &&
-         ctx->Color.ColorMask[1] &&
-         ctx->Color.ColorMask[2] &&
-         ctx->Color.ColorMask[3])
+         ctx->Color.ColorMask[0][0] &&
+         ctx->Color.ColorMask[0][1] &&
+         ctx->Color.ColorMask[0][2] &&
+         ctx->Color.ColorMask[0][3])
      {
           DFBRegion clip;
           GLubyte   a, r, g, b;
diff --git a/src/mesa/drivers/dri/gamma/gamma_state.c b/src/mesa/drivers/dri/gamma/gamma_state.c
index 59272f9bc91..bdd1c86ab71 100644
--- a/src/mesa/drivers/dri/gamma/gamma_state.c
+++ b/src/mesa/drivers/dri/gamma/gamma_state.c
@@ -813,10 +813,10 @@ static void gammaUpdateMasks( GLcontext *ctx )
 
 
    GLuint mask = gammaPackColor( gmesa->gammaScreen->cpp,
-				ctx->Color.ColorMask[RCOMP],
-				ctx->Color.ColorMask[GCOMP],
-				ctx->Color.ColorMask[BCOMP],
-				ctx->Color.ColorMask[ACOMP] );
+				ctx->Color.ColorMask[0][RCOMP],
+				ctx->Color.ColorMask[0][GCOMP],
+				ctx->Color.ColorMask[0][BCOMP],
+				ctx->Color.ColorMask[0][ACOMP] );
 
    if (gmesa->gammaScreen->cpp == 2) mask |= mask << 16;
 
diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index 8810f2a3808..7aca3aac8e4 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -575,7 +575,7 @@ brw_update_renderbuffer_surface(struct brw_context *brw,
       key.draw_offset = 0;
    }
    /* _NEW_COLOR */
-   memcpy(key.color_mask, ctx->Color.ColorMask,
+   memcpy(key.color_mask, ctx->Color.ColorMask[0],
 	  sizeof(key.color_mask));
 
    /* As mentioned above, disable writes to the alpha component when the
diff --git a/src/mesa/drivers/dri/intel/intel_clear.c b/src/mesa/drivers/dri/intel/intel_clear.c
index f682ee3de5b..956f2339ff0 100644
--- a/src/mesa/drivers/dri/intel/intel_clear.c
+++ b/src/mesa/drivers/dri/intel/intel_clear.c
@@ -68,7 +68,7 @@ static void
 intelClear(GLcontext *ctx, GLbitfield mask)
 {
    struct intel_context *intel = intel_context(ctx);
-   const GLuint colorMask = *((GLuint *) & ctx->Color.ColorMask);
+   const GLuint colorMask = *((GLuint *) & ctx->Color.ColorMask[0]);
    GLbitfield tri_mask = 0;
    GLbitfield blit_mask = 0;
    GLbitfield swrast_mask = 0;
diff --git a/src/mesa/drivers/dri/intel/intel_pixel.c b/src/mesa/drivers/dri/intel/intel_pixel.c
index 993e427a992..5142f3dcd99 100644
--- a/src/mesa/drivers/dri/intel/intel_pixel.c
+++ b/src/mesa/drivers/dri/intel/intel_pixel.c
@@ -88,10 +88,10 @@ intel_check_blit_fragment_ops(GLcontext * ctx, GLboolean src_alpha_is_one)
       return GL_FALSE;
    }
 
-   if (!(ctx->Color.ColorMask[0] &&
-	 ctx->Color.ColorMask[1] &&
-	 ctx->Color.ColorMask[2] &&
-	 ctx->Color.ColorMask[3])) {
+   if (!(ctx->Color.ColorMask[0][0] &&
+	 ctx->Color.ColorMask[0][1] &&
+	 ctx->Color.ColorMask[0][2] &&
+	 ctx->Color.ColorMask[0][3])) {
       DBG("fallback due to color masking\n");
       return GL_FALSE;
    }
diff --git a/src/mesa/drivers/dri/intel/intel_pixel_copy.c b/src/mesa/drivers/dri/intel/intel_pixel_copy.c
index 622aaa22d67..689a00cb00b 100644
--- a/src/mesa/drivers/dri/intel/intel_pixel_copy.c
+++ b/src/mesa/drivers/dri/intel/intel_pixel_copy.c
@@ -83,10 +83,10 @@ intel_check_copypixel_blit_fragment_ops(GLcontext * ctx)
             ctx->Depth.Test ||
             ctx->Fog.Enabled ||
             ctx->Stencil._Enabled ||
-            !ctx->Color.ColorMask[0] ||
-            !ctx->Color.ColorMask[1] ||
-            !ctx->Color.ColorMask[2] ||
-            !ctx->Color.ColorMask[3] ||
+            !ctx->Color.ColorMask[0][0] ||
+            !ctx->Color.ColorMask[0][1] ||
+            !ctx->Color.ColorMask[0][2] ||
+            !ctx->Color.ColorMask[0][3] ||
             ctx->Texture._EnabledUnits ||
 	    ctx->FragmentProgram._Enabled ||
 	    ctx->Color.BlendEnabled);
diff --git a/src/mesa/drivers/dri/mach64/mach64_state.c b/src/mesa/drivers/dri/mach64/mach64_state.c
index 3a023187ce7..902905de71e 100644
--- a/src/mesa/drivers/dri/mach64/mach64_state.c
+++ b/src/mesa/drivers/dri/mach64/mach64_state.c
@@ -527,10 +527,10 @@ static void mach64UpdateMasks( GLcontext *ctx )
    /* mach64 can't color mask with alpha blending enabled */
    if ( !ctx->Color.BlendEnabled ) {
       mask = mach64PackColor( mmesa->mach64Screen->cpp,
-			      ctx->Color.ColorMask[RCOMP],
-			      ctx->Color.ColorMask[GCOMP],
-			      ctx->Color.ColorMask[BCOMP],
-			      ctx->Color.ColorMask[ACOMP] );
+			      ctx->Color.ColorMask[0][RCOMP],
+			      ctx->Color.ColorMask[0][GCOMP],
+			      ctx->Color.ColorMask[0][BCOMP],
+			      ctx->Color.ColorMask[0][ACOMP] );
    }
 
    if ( mmesa->setup.dp_write_mask != mask ) {
diff --git a/src/mesa/drivers/dri/mga/mgapixel.c b/src/mesa/drivers/dri/mga/mgapixel.c
index 977dfa0b760..05b30ba61e2 100644
--- a/src/mesa/drivers/dri/mga/mgapixel.c
+++ b/src/mesa/drivers/dri/mga/mgapixel.c
@@ -134,10 +134,10 @@ check_color_per_fragment_ops( const GLcontext *ctx )
 		    ctx->Fog.Enabled ||
 		    ctx->Scissor.Enabled ||
 		    ctx->Stencil._Enabled ||
-		    !ctx->Color.ColorMask[0] ||
-		    !ctx->Color.ColorMask[1] ||
-		    !ctx->Color.ColorMask[2] ||
-		    !ctx->Color.ColorMask[3] ||
+		    !ctx->Color.ColorMask[0][0] ||
+		    !ctx->Color.ColorMask[0][1] ||
+		    !ctx->Color.ColorMask[0][2] ||
+		    !ctx->Color.ColorMask[0][3] ||
 		    ctx->Color.ColorLogicOpEnabled ||
 		    ctx->Texture._EnabledUnits
            ) &&
@@ -150,10 +150,10 @@ static GLboolean
 check_depth_per_fragment_ops( const GLcontext *ctx )
 {
    return ( ctx->Current.RasterPosValid &&
-	    ctx->Color.ColorMask[RCOMP] == 0 &&
-	    ctx->Color.ColorMask[BCOMP] == 0 &&
-	    ctx->Color.ColorMask[GCOMP] == 0 &&
-	    ctx->Color.ColorMask[ACOMP] == 0 &&
+	    ctx->Color.ColorMask[0][RCOMP] == 0 &&
+	    ctx->Color.ColorMask[0][BCOMP] == 0 &&
+	    ctx->Color.ColorMask[0][GCOMP] == 0 &&
+	    ctx->Color.ColorMask[0][ACOMP] == 0 &&
 	    ctx->Pixel.ZoomX == 1.0F &&
 	    ( ctx->Pixel.ZoomY == 1.0F || ctx->Pixel.ZoomY == -1.0F ) );
 }
@@ -525,10 +525,10 @@ mgaTryDrawPixels( GLcontext *ctx,
 	      mmesa->mgaScreen->backOffset);
 
       planemask = mgaPackColor(cpp,
-			       ctx->Color.ColorMask[RCOMP],
-			       ctx->Color.ColorMask[GCOMP],
-			       ctx->Color.ColorMask[BCOMP],
-			       ctx->Color.ColorMask[ACOMP]);
+			       ctx->Color.ColorMask[0][RCOMP],
+			       ctx->Color.ColorMask[0][GCOMP],
+			       ctx->Color.ColorMask[0][BCOMP],
+			       ctx->Color.ColorMask[0][ACOMP]);
 
       if (cpp == 2)
 	 planemask |= planemask << 16;
diff --git a/src/mesa/drivers/dri/mga/mgastate.c b/src/mesa/drivers/dri/mga/mgastate.c
index 7c830ec0974..1e51057534b 100644
--- a/src/mesa/drivers/dri/mga/mgastate.c
+++ b/src/mesa/drivers/dri/mga/mgastate.c
@@ -374,13 +374,11 @@ static void mgaDDColorMask(GLcontext *ctx,
 {
    mgaContextPtr mmesa = MGA_CONTEXT( ctx );
    mgaScreenPrivate *mgaScreen = mmesa->mgaScreen;
-
-
    GLuint mask = mgaPackColor(mgaScreen->cpp,
-			      ctx->Color.ColorMask[RCOMP],
-			      ctx->Color.ColorMask[GCOMP],
-			      ctx->Color.ColorMask[BCOMP],
-			      ctx->Color.ColorMask[ACOMP]);
+			      ctx->Color.ColorMask[0][RCOMP],
+			      ctx->Color.ColorMask[0][GCOMP],
+			      ctx->Color.ColorMask[0][BCOMP],
+			      ctx->Color.ColorMask[0][ACOMP]);
 
    if (mgaScreen->cpp == 2)
       mask = mask | (mask << 16);
diff --git a/src/mesa/drivers/dri/r128/r128_state.c b/src/mesa/drivers/dri/r128/r128_state.c
index 4ae7bf5b97d..ac175d59ec3 100644
--- a/src/mesa/drivers/dri/r128/r128_state.c
+++ b/src/mesa/drivers/dri/r128/r128_state.c
@@ -702,10 +702,10 @@ static void r128UpdateMasks( GLcontext *ctx )
    r128ContextPtr rmesa = R128_CONTEXT(ctx);
 
    GLuint mask = r128PackColor( rmesa->r128Screen->cpp,
-				ctx->Color.ColorMask[RCOMP],
-				ctx->Color.ColorMask[GCOMP],
-				ctx->Color.ColorMask[BCOMP],
-				ctx->Color.ColorMask[ACOMP] );
+				ctx->Color.ColorMask[0][RCOMP],
+				ctx->Color.ColorMask[0][GCOMP],
+				ctx->Color.ColorMask[0][BCOMP],
+				ctx->Color.ColorMask[0][ACOMP] );
 
    if ( rmesa->setup.plane_3d_mask_c != mask ) {
       rmesa->setup.plane_3d_mask_c = mask;
diff --git a/src/mesa/drivers/dri/r200/r200_pixel.c b/src/mesa/drivers/dri/r200/r200_pixel.c
index 95773871e02..94e43c7d66f 100644
--- a/src/mesa/drivers/dri/r200/r200_pixel.c
+++ b/src/mesa/drivers/dri/r200/r200_pixel.c
@@ -88,10 +88,10 @@ check_color_per_fragment_ops( const GLcontext *ctx )
 		    ctx->Fog.Enabled ||
 		    ctx->Scissor.Enabled ||
 		    ctx->Stencil._Enabled ||
-		    !ctx->Color.ColorMask[0] ||
-		    !ctx->Color.ColorMask[1] ||
-		    !ctx->Color.ColorMask[2] ||
-		    !ctx->Color.ColorMask[3] ||
+		    !ctx->Color.ColorMask[0][0] ||
+		    !ctx->Color.ColorMask[0][1] ||
+		    !ctx->Color.ColorMask[0][2] ||
+		    !ctx->Color.ColorMask[0][3] ||
 		    ctx->Color.ColorLogicOpEnabled ||
 		    ctx->Texture._EnabledUnits
            ) &&
@@ -400,10 +400,10 @@ r200TryDrawPixels( GLcontext *ctx,
    case GL_RGBA:
    case GL_BGRA:
       planemask = radeonPackColor(cpp,
-				ctx->Color.ColorMask[RCOMP],
-				ctx->Color.ColorMask[GCOMP],
-				ctx->Color.ColorMask[BCOMP],
-				ctx->Color.ColorMask[ACOMP]);
+				ctx->Color.ColorMask[0][RCOMP],
+				ctx->Color.ColorMask[0][GCOMP],
+				ctx->Color.ColorMask[0][BCOMP],
+				ctx->Color.ColorMask[0][ACOMP]);
 
       if (cpp == 2)
 	 planemask |= planemask << 16;
diff --git a/src/mesa/drivers/dri/r200/r200_state.c b/src/mesa/drivers/dri/r200/r200_state.c
index 6d99c039ded..529cb622640 100644
--- a/src/mesa/drivers/dri/r200/r200_state.c
+++ b/src/mesa/drivers/dri/r200/r200_state.c
@@ -721,10 +721,10 @@ static void r200ColorMask( GLcontext *ctx,
    if (!rrb)
      return;
    mask = radeonPackColor( rrb->cpp,
-			   ctx->Color.ColorMask[RCOMP],
-			   ctx->Color.ColorMask[GCOMP],
-			   ctx->Color.ColorMask[BCOMP],
-			   ctx->Color.ColorMask[ACOMP] );
+			   ctx->Color.ColorMask[0][RCOMP],
+			   ctx->Color.ColorMask[0][GCOMP],
+			   ctx->Color.ColorMask[0][BCOMP],
+			   ctx->Color.ColorMask[0][ACOMP] );
 
 
    if (!(r && g && b && a))
diff --git a/src/mesa/drivers/dri/r300/r300_state.c b/src/mesa/drivers/dri/r300/r300_state.c
index 23f81fe7901..f90bfd4f4f2 100644
--- a/src/mesa/drivers/dri/r300/r300_state.c
+++ b/src/mesa/drivers/dri/r300/r300_state.c
@@ -1768,9 +1768,10 @@ static void r300ResetHwState(r300ContextPtr r300)
 	radeon_firevertices(&r300->radeon);
 
 	r300ColorMask(ctx,
-		      ctx->Color.ColorMask[RCOMP],
-		      ctx->Color.ColorMask[GCOMP],
-		      ctx->Color.ColorMask[BCOMP], ctx->Color.ColorMask[ACOMP]);
+		      ctx->Color.ColorMask[0][RCOMP],
+		      ctx->Color.ColorMask[0][GCOMP],
+		      ctx->Color.ColorMask[0][BCOMP],
+                      ctx->Color.ColorMask[0][ACOMP]);
 
 	r300Enable(ctx, GL_DEPTH_TEST, ctx->Depth.Test);
 	r300DepthMask(ctx, ctx->Depth.Mask);
diff --git a/src/mesa/drivers/dri/r600/r700_clear.c b/src/mesa/drivers/dri/r600/r700_clear.c
index 526d3843d16..c0ac54a8445 100644
--- a/src/mesa/drivers/dri/r600/r700_clear.c
+++ b/src/mesa/drivers/dri/r600/r700_clear.c
@@ -50,7 +50,7 @@ void r700Clear(GLcontext * ctx, GLbitfield mask)
 {
     context_t *context = R700_CONTEXT(ctx);
     __DRIdrawablePrivate *dPriv = radeon_get_drawable(&context->radeon);
-    const GLuint colorMask = *((GLuint *) & ctx->Color.ColorMask);
+    const GLuint colorMask = *((GLuint *) & ctx->Color.ColorMask[0]);
     GLbitfield swrast_mask = 0, tri_mask = 0;
     int i;
     struct gl_framebuffer *fb = ctx->DrawBuffer;
diff --git a/src/mesa/drivers/dri/r600/r700_state.c b/src/mesa/drivers/dri/r600/r700_state.c
index 16b05d5cd9a..fc6fb29fd6f 100644
--- a/src/mesa/drivers/dri/r600/r700_state.c
+++ b/src/mesa/drivers/dri/r600/r700_state.c
@@ -1724,10 +1724,10 @@ void r700InitState(GLcontext * ctx) //-------------------
     r700InitSQConfig(ctx);
 
     r700ColorMask(ctx,
-		  ctx->Color.ColorMask[RCOMP],
-		  ctx->Color.ColorMask[GCOMP],
-		  ctx->Color.ColorMask[BCOMP],
-		  ctx->Color.ColorMask[ACOMP]);
+		  ctx->Color.ColorMask[0][RCOMP],
+		  ctx->Color.ColorMask[0][GCOMP],
+		  ctx->Color.ColorMask[0][BCOMP],
+		  ctx->Color.ColorMask[0][ACOMP]);
 
     r700Enable(ctx, GL_DEPTH_TEST, ctx->Depth.Test);
     r700DepthMask(ctx, ctx->Depth.Mask);
diff --git a/src/mesa/drivers/dri/radeon/radeon_state.c b/src/mesa/drivers/dri/radeon/radeon_state.c
index f6c733ab209..1fcb5452047 100644
--- a/src/mesa/drivers/dri/radeon/radeon_state.c
+++ b/src/mesa/drivers/dri/radeon/radeon_state.c
@@ -521,10 +521,10 @@ static void radeonColorMask( GLcontext *ctx,
      return;
 
    mask = radeonPackColor( rrb->cpp,
-			   ctx->Color.ColorMask[RCOMP],
-			   ctx->Color.ColorMask[GCOMP],
-			   ctx->Color.ColorMask[BCOMP],
-			   ctx->Color.ColorMask[ACOMP] );
+			   ctx->Color.ColorMask[0][RCOMP],
+			   ctx->Color.ColorMask[0][GCOMP],
+			   ctx->Color.ColorMask[0][BCOMP],
+			   ctx->Color.ColorMask[0][ACOMP] );
 
    if ( rmesa->hw.msk.cmd[MSK_RB3D_PLANEMASK] != mask ) {
       RADEON_STATECHANGE( rmesa, msk );
diff --git a/src/mesa/drivers/dri/savage/savageioctl.c b/src/mesa/drivers/dri/savage/savageioctl.c
index 77ab8d16e0a..706fc97935a 100644
--- a/src/mesa/drivers/dri/savage/savageioctl.c
+++ b/src/mesa/drivers/dri/savage/savageioctl.c
@@ -360,15 +360,15 @@ static void savageDDClear( GLcontext *ctx, GLbitfield mask )
    depthMask = 0;
    switch (imesa->savageScreen->cpp) {
    case 2:
-       colorMask = PACK_COLOR_565(ctx->Color.ColorMask[0],
-				  ctx->Color.ColorMask[1],
-				  ctx->Color.ColorMask[2]);
+       colorMask = PACK_COLOR_565(ctx->Color.ColorMask[0][0],
+				  ctx->Color.ColorMask[0][1],
+				  ctx->Color.ColorMask[0][2]);
        break;
    case 4:
-       colorMask = PACK_COLOR_8888(ctx->Color.ColorMask[3],
-				   ctx->Color.ColorMask[2],
-				   ctx->Color.ColorMask[1],
-				   ctx->Color.ColorMask[0]);
+       colorMask = PACK_COLOR_8888(ctx->Color.ColorMask[0][3],
+				   ctx->Color.ColorMask[0][2],
+				   ctx->Color.ColorMask[0][1],
+				   ctx->Color.ColorMask[0][0]);
        break;
    }
 
diff --git a/src/mesa/drivers/dri/tdfx/tdfx_pixels.c b/src/mesa/drivers/dri/tdfx/tdfx_pixels.c
index 18729d5ae08..a3b1775e900 100644
--- a/src/mesa/drivers/dri/tdfx/tdfx_pixels.c
+++ b/src/mesa/drivers/dri/tdfx/tdfx_pixels.c
@@ -611,10 +611,10 @@ tdfx_drawpixels_R8G8B8A8(GLcontext * ctx, GLint x, GLint y,
        ctx->Fog.Enabled ||
        ctx->Scissor.Enabled ||
        ctx->Stencil._Enabled ||
-       !ctx->Color.ColorMask[0] ||
-       !ctx->Color.ColorMask[1] ||
-       !ctx->Color.ColorMask[2] ||
-       !ctx->Color.ColorMask[3] ||
+       !ctx->Color.ColorMask[0][0] ||
+       !ctx->Color.ColorMask[0][1] ||
+       !ctx->Color.ColorMask[0][2] ||
+       !ctx->Color.ColorMask[0][3] ||
        ctx->Color.ColorLogicOpEnabled ||
        ctx->Texture._EnabledUnits ||
        fxMesa->Fallback)       
diff --git a/src/mesa/drivers/dri/tdfx/tdfx_render.c b/src/mesa/drivers/dri/tdfx/tdfx_render.c
index 2cd8e12d955..79d63f72acc 100644
--- a/src/mesa/drivers/dri/tdfx/tdfx_render.c
+++ b/src/mesa/drivers/dri/tdfx/tdfx_render.c
@@ -76,8 +76,8 @@ static void tdfxClear( GLcontext *ctx, GLbitfield mask )
 
    if (fxMesa->glCtx->Visual.redBits != 8) {
       /* can only do color masking if running in 24/32bpp on Napalm */
-      if (ctx->Color.ColorMask[RCOMP] != ctx->Color.ColorMask[GCOMP] ||
-          ctx->Color.ColorMask[GCOMP] != ctx->Color.ColorMask[BCOMP]) {
+      if (ctx->Color.ColorMask[0][RCOMP] != ctx->Color.ColorMask[0][GCOMP] ||
+          ctx->Color.ColorMask[0][GCOMP] != ctx->Color.ColorMask[0][BCOMP]) {
          softwareMask |= (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT));
          mask &= ~(BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT);
       }
@@ -721,7 +721,7 @@ void tdfxEmitHwStateLocked( tdfxContextPtr fxMesa )
 	 fxMesa->Glide.grColorMask( fxMesa->Color.ColorMask[RCOMP] ||
                                     fxMesa->Color.ColorMask[GCOMP] ||
                                     fxMesa->Color.ColorMask[BCOMP],
-                                    /*fxMesa->Color.ColorMask[ACOMP]*/GL_FALSE/*[dBorca] no-no*/ );
+                                    /*fxMesa->Color.ColorMask[0][ACOMP]*/GL_FALSE/*[dBorca] no-no*/ );
       }
       fxMesa->dirty &= ~TDFX_UPLOAD_COLOR_MASK;
    }
diff --git a/src/mesa/drivers/dri/unichrome/via_state.c b/src/mesa/drivers/dri/unichrome/via_state.c
index 840e4e42da9..a9db6c45f7d 100644
--- a/src/mesa/drivers/dri/unichrome/via_state.c
+++ b/src/mesa/drivers/dri/unichrome/via_state.c
@@ -1238,12 +1238,12 @@ static void viaChooseColorState(GLcontext *ctx)
     else
         vmesa->regHROP = HC_HROP_P;
 
-    vmesa->regHFBBMSKL = PACK_COLOR_888(ctx->Color.ColorMask[0],
-					ctx->Color.ColorMask[1],
-					ctx->Color.ColorMask[2]);
-    vmesa->regHROP |= ctx->Color.ColorMask[3];
+    vmesa->regHFBBMSKL = PACK_COLOR_888(ctx->Color.ColorMask[0][0],
+					ctx->Color.ColorMask[0][1],
+					ctx->Color.ColorMask[0][2]);
+    vmesa->regHROP |= ctx->Color.ColorMask[0][3];
 
-    if (ctx->Color.ColorMask[3])
+    if (ctx->Color.ColorMask[0][3])
         vmesa->regEnable |= HC_HenAW_MASK;
     else
         vmesa->regEnable &= ~HC_HenAW_MASK;
diff --git a/src/mesa/drivers/windows/gdi/wmesa.c b/src/mesa/drivers/windows/gdi/wmesa.c
index 8929b22af16..76c825a0904 100644
--- a/src/mesa/drivers/windows/gdi/wmesa.c
+++ b/src/mesa/drivers/windows/gdi/wmesa.c
@@ -301,10 +301,10 @@ static void clear(GLcontext *ctx, GLbitfield mask)
 
     /* Let swrast do all the work if the masks are not set to
      * clear all channels. */
-    if (ctx->Color.ColorMask[0] != 0xff ||
-	ctx->Color.ColorMask[1] != 0xff ||
-	ctx->Color.ColorMask[2] != 0xff ||
-	ctx->Color.ColorMask[3] != 0xff) {
+    if (!ctx->Color.ColorMask[0][0] ||
+	!ctx->Color.ColorMask[0][1] ||
+	!ctx->Color.ColorMask[0][2] ||
+	!ctx->Color.ColorMask[0][3]) {
 	_swrast_Clear(ctx, mask);
 	return;
     }
diff --git a/src/mesa/drivers/windows/gldirect/dx7/gld_driver_dx7.c b/src/mesa/drivers/windows/gldirect/dx7/gld_driver_dx7.c
index d5fa6428006..7b202dfda70 100644
--- a/src/mesa/drivers/windows/gldirect/dx7/gld_driver_dx7.c
+++ b/src/mesa/drivers/windows/gldirect/dx7/gld_driver_dx7.c
@@ -269,7 +269,7 @@ void gld_Clear_DX7(
 	D3DRECT		d3dClearRect;
 
 	// TODO: Colourmask
-	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
+	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask[0];
 
 	if (!gld->pDev)
 		return;
@@ -427,10 +427,10 @@ void gld_NEW_COLOR(
 
 /*
 	// Color mask - unsupported by DX7
-	if (ctx->Color.ColorMask[0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
-	if (ctx->Color.ColorMask[1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
-	if (ctx->Color.ColorMask[2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
-	if (ctx->Color.ColorMask[3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
+	if (ctx->Color.ColorMask[0][0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
+	if (ctx->Color.ColorMask[0][1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
+	if (ctx->Color.ColorMask[0][2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
+	if (ctx->Color.ColorMask[0][3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
 	_GLD_DX7_DEV(SetRenderState(gld->pDev, D3DRENDERSTATE_COLORWRITEENABLE, dwFlags));
 */
 }
diff --git a/src/mesa/drivers/windows/gldirect/dx8/gld_driver_dx8.c b/src/mesa/drivers/windows/gldirect/dx8/gld_driver_dx8.c
index 7afa9190cdf..7eeb9db2d15 100644
--- a/src/mesa/drivers/windows/gldirect/dx8/gld_driver_dx8.c
+++ b/src/mesa/drivers/windows/gldirect/dx8/gld_driver_dx8.c
@@ -269,7 +269,7 @@ void gld_Clear_DX8(
 	D3DRECT		d3dClearRect;
 
 	// TODO: Colourmask
-	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
+	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask[0];
 
 	if (!gld->pDev)
 		return;
@@ -426,10 +426,10 @@ void gld_NEW_COLOR(
 	_GLD_DX8_DEV(SetRenderState(gld->pDev, D3DRS_DESTBLEND, dest));
 
 	// Color mask
-	if (ctx->Color.ColorMask[0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
-	if (ctx->Color.ColorMask[1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
-	if (ctx->Color.ColorMask[2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
-	if (ctx->Color.ColorMask[3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
+	if (ctx->Color.ColorMask[0][0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
+	if (ctx->Color.ColorMask[0][1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
+	if (ctx->Color.ColorMask[0][2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
+	if (ctx->Color.ColorMask[0][3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
 	_GLD_DX8_DEV(SetRenderState(gld->pDev, D3DRS_COLORWRITEENABLE, dwFlags));
 }
 
diff --git a/src/mesa/drivers/windows/gldirect/dx9/gld_driver_dx9.c b/src/mesa/drivers/windows/gldirect/dx9/gld_driver_dx9.c
index c191564d6eb..0558462dea0 100644
--- a/src/mesa/drivers/windows/gldirect/dx9/gld_driver_dx9.c
+++ b/src/mesa/drivers/windows/gldirect/dx9/gld_driver_dx9.c
@@ -269,7 +269,7 @@ void gld_Clear_DX9(
 	D3DRECT		d3dClearRect;
 
 	// TODO: Colourmask
-	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
+	const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask[0];
 
 	if (!gld->pDev)
 		return;
@@ -424,10 +424,10 @@ void gld_NEW_COLOR(
 	_GLD_DX9_DEV(SetRenderState(gld->pDev, D3DRS_DESTBLEND, dest));
 
 	// Color mask
-	if (ctx->Color.ColorMask[0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
-	if (ctx->Color.ColorMask[1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
-	if (ctx->Color.ColorMask[2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
-	if (ctx->Color.ColorMask[3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
+	if (ctx->Color.ColorMask[0][0]) dwFlags |= D3DCOLORWRITEENABLE_RED;
+	if (ctx->Color.ColorMask[0][1]) dwFlags |= D3DCOLORWRITEENABLE_GREEN;
+	if (ctx->Color.ColorMask[0][2]) dwFlags |= D3DCOLORWRITEENABLE_BLUE;
+	if (ctx->Color.ColorMask[0][3]) dwFlags |= D3DCOLORWRITEENABLE_ALPHA;
 	_GLD_DX9_DEV(SetRenderState(gld->pDev, D3DRS_COLORWRITEENABLE, dwFlags));
 }
 
diff --git a/src/mesa/drivers/x11/xm_dd.c b/src/mesa/drivers/x11/xm_dd.c
index a27d7045abe..df04e3a1011 100644
--- a/src/mesa/drivers/x11/xm_dd.c
+++ b/src/mesa/drivers/x11/xm_dd.c
@@ -381,7 +381,7 @@ clear_buffers(GLcontext *ctx, GLbitfield buffers)
 {
    if (ctx->DrawBuffer->Name == 0) {
       /* this is a window system framebuffer */
-      const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask;
+      const GLuint *colorMask = (GLuint *) &ctx->Color.ColorMask[0];
       XMesaBuffer b = XMESA_BUFFER(ctx->DrawBuffer);
       const GLint x = ctx->DrawBuffer->_Xmin;
       const GLint y = ctx->DrawBuffer->_Ymin;
diff --git a/src/mesa/main/attrib.c b/src/mesa/main/attrib.c
index 88ce0a4281b..30e97a6e386 100644
--- a/src/mesa/main/attrib.c
+++ b/src/mesa/main/attrib.c
@@ -919,10 +919,22 @@ _mesa_PopAttrib(void)
                                 color->ClearColor[2],
                                 color->ClearColor[3]);
                _mesa_IndexMask(color->IndexMask);
-               _mesa_ColorMask((GLboolean) (color->ColorMask[0] != 0),
-                               (GLboolean) (color->ColorMask[1] != 0),
-                               (GLboolean) (color->ColorMask[2] != 0),
-                               (GLboolean) (color->ColorMask[3] != 0));
+               if (1/*ctx->Extensions.EXT_draw_buffers2*/) {
+                  _mesa_ColorMask((GLboolean) (color->ColorMask[0][0] != 0),
+                                  (GLboolean) (color->ColorMask[0][1] != 0),
+                                  (GLboolean) (color->ColorMask[0][2] != 0),
+                                  (GLboolean) (color->ColorMask[0][3] != 0));
+               }
+               else {
+                  GLuint i;
+                  for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+                     _mesa_ColorMaskIndexed(i, 
+                                  (GLboolean) (color->ColorMask[i][0] != 0),
+                                  (GLboolean) (color->ColorMask[i][1] != 0),
+                                  (GLboolean) (color->ColorMask[i][2] != 0),
+                                  (GLboolean) (color->ColorMask[i][3] != 0));
+                  }
+               }
                {
                   /* Need to determine if more than one color output is
                    * specified.  If so, call glDrawBuffersARB, else call
diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
index 5a9d94e12d0..b8170dd4686 100644
--- a/src/mesa/main/blend.c
+++ b/src/mesa/main/blend.c
@@ -484,6 +484,8 @@ _mesa_ColorMask( GLboolean red, GLboolean green,
 {
    GET_CURRENT_CONTEXT(ctx);
    GLubyte tmp[4];
+   GLuint i;
+   GLboolean flushed;
    ASSERT_OUTSIDE_BEGIN_END(ctx);
 
    if (MESA_VERBOSE & VERBOSE_API)
@@ -497,14 +499,58 @@ _mesa_ColorMask( GLboolean red, GLboolean green,
    tmp[BCOMP] = blue   ? 0xff : 0x0;
    tmp[ACOMP] = alpha  ? 0xff : 0x0;
 
-   if (TEST_EQ_4UBV(tmp, ctx->Color.ColorMask))
+   flushed = GL_FALSE;
+   for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+      if (!TEST_EQ_4V(tmp, ctx->Color.ColorMask[i])) {
+         if (!flushed) {
+            FLUSH_VERTICES(ctx, _NEW_COLOR);
+         }
+         flushed = GL_TRUE;
+         COPY_4UBV(ctx->Color.ColorMask[i], tmp);
+      }
+   }
+
+   if (ctx->Driver.ColorMask)
+      ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
+}
+
+
+/**
+ * For GL_EXT_draw_buffers2 and GL3
+ */
+void GLAPIENTRY
+_mesa_ColorMaskIndexed( GLuint buf, GLboolean red, GLboolean green,
+                        GLboolean blue, GLboolean alpha )
+{
+   GLubyte tmp[4];
+   GET_CURRENT_CONTEXT(ctx);
+   ASSERT_OUTSIDE_BEGIN_END(ctx);
+
+   if (MESA_VERBOSE & VERBOSE_API)
+      _mesa_debug(ctx, "glColorMaskIndexed %u %d %d %d %d\n",
+                  buf, red, green, blue, alpha);
+
+   if (buf >= ctx->Const.MaxDrawBuffers) {
+      _mesa_error(ctx, GL_INVALID_VALUE, "glColorMaskIndexed(buf=%u)", buf);
+      return;
+   }
+
+   /* Shouldn't have any information about channel depth in core mesa
+    * -- should probably store these as the native booleans:
+    */
+   tmp[RCOMP] = red    ? 0xff : 0x0;
+   tmp[GCOMP] = green  ? 0xff : 0x0;
+   tmp[BCOMP] = blue   ? 0xff : 0x0;
+   tmp[ACOMP] = alpha  ? 0xff : 0x0;
+
+   if (TEST_EQ_4V(tmp, ctx->Color.ColorMask[buf]))
       return;
 
    FLUSH_VERTICES(ctx, _NEW_COLOR);
-   COPY_4UBV(ctx->Color.ColorMask, tmp);
+   COPY_4UBV(ctx->Color.ColorMask[buf], tmp);
 
-   if (ctx->Driver.ColorMask)
-      ctx->Driver.ColorMask( ctx, red, green, blue, alpha );
+   if (ctx->Driver.ColorMaskIndexed)
+      ctx->Driver.ColorMaskIndexed(ctx, buf, red, green, blue, alpha);
 }
 
 
@@ -555,10 +601,7 @@ void _mesa_init_color( GLcontext * ctx )
 {
    /* Color buffer group */
    ctx->Color.IndexMask = ~0u;
-   ctx->Color.ColorMask[0] = 0xff;
-   ctx->Color.ColorMask[1] = 0xff;
-   ctx->Color.ColorMask[2] = 0xff;
-   ctx->Color.ColorMask[3] = 0xff;
+   memset(ctx->Color.ColorMask, 0xff, sizeof(ctx->Color.ColorMask));
    ctx->Color.ClearIndex = 0;
    ASSIGN_4V( ctx->Color.ClearColor, 0, 0, 0, 0 );
    ctx->Color.AlphaEnabled = GL_FALSE;
diff --git a/src/mesa/main/blend.h b/src/mesa/main/blend.h
index 5c0f2783a73..b4fd7470ebe 100644
--- a/src/mesa/main/blend.h
+++ b/src/mesa/main/blend.h
@@ -72,6 +72,10 @@ extern void GLAPIENTRY
 _mesa_ColorMask( GLboolean red, GLboolean green,
                  GLboolean blue, GLboolean alpha );
 
+extern void GLAPIENTRY
+_mesa_ColorMaskIndexed( GLuint buf, GLboolean red, GLboolean green,
+                        GLboolean blue, GLboolean alpha );
+
 
 extern void GLAPIENTRY
 _mesa_ClampColorARB(GLenum target, GLenum clamp);
diff --git a/src/mesa/main/dd.h b/src/mesa/main/dd.h
index 6dadf5c079b..496b0d2ba8b 100644
--- a/src/mesa/main/dd.h
+++ b/src/mesa/main/dd.h
@@ -625,6 +625,8 @@ struct dd_function_table {
    /** Enable and disable writing of frame buffer color components */
    void (*ColorMask)(GLcontext *ctx, GLboolean rmask, GLboolean gmask,
                      GLboolean bmask, GLboolean amask );
+   void (*ColorMaskIndexed)(GLcontext *ctx, GLuint buf, GLboolean rmask,
+                            GLboolean gmask, GLboolean bmask, GLboolean amask);
    /** Cause a material color to track the current color */
    void (*ColorMaterial)(GLcontext *ctx, GLenum face, GLenum mode);
    /** Specify whether front- or back-facing facets can be culled */
diff --git a/src/mesa/main/get.c b/src/mesa/main/get.c
index aff67466bcb..44396a0491c 100644
--- a/src/mesa/main/get.c
+++ b/src/mesa/main/get.c
@@ -210,10 +210,10 @@ _mesa_GetBooleanv( GLenum pname, GLboolean *params )
          params[0] = ENUM_TO_BOOLEAN(ctx->Light.ColorMaterialMode);
          break;
       case GL_COLOR_WRITEMASK:
-         params[0] = INT_TO_BOOLEAN(ctx->Color.ColorMask[RCOMP] ? 1 : 0);
-         params[1] = INT_TO_BOOLEAN(ctx->Color.ColorMask[GCOMP] ? 1 : 0);
-         params[2] = INT_TO_BOOLEAN(ctx->Color.ColorMask[BCOMP] ? 1 : 0);
-         params[3] = INT_TO_BOOLEAN(ctx->Color.ColorMask[ACOMP] ? 1 : 0);
+         params[0] = INT_TO_BOOLEAN(ctx->Color.ColorMask[0][RCOMP] ? 1 : 0);
+         params[1] = INT_TO_BOOLEAN(ctx->Color.ColorMask[0][GCOMP] ? 1 : 0);
+         params[2] = INT_TO_BOOLEAN(ctx->Color.ColorMask[0][BCOMP] ? 1 : 0);
+         params[3] = INT_TO_BOOLEAN(ctx->Color.ColorMask[0][ACOMP] ? 1 : 0);
          break;
       case GL_CULL_FACE:
          params[0] = ctx->Polygon.CullFlag;
@@ -2045,10 +2045,10 @@ _mesa_GetFloatv( GLenum pname, GLfloat *params )
          params[0] = ENUM_TO_FLOAT(ctx->Light.ColorMaterialMode);
          break;
       case GL_COLOR_WRITEMASK:
-         params[0] = (GLfloat)(ctx->Color.ColorMask[RCOMP] ? 1 : 0);
-         params[1] = (GLfloat)(ctx->Color.ColorMask[GCOMP] ? 1 : 0);
-         params[2] = (GLfloat)(ctx->Color.ColorMask[BCOMP] ? 1 : 0);
-         params[3] = (GLfloat)(ctx->Color.ColorMask[ACOMP] ? 1 : 0);
+         params[0] = (GLfloat)(ctx->Color.ColorMask[0][RCOMP] ? 1 : 0);
+         params[1] = (GLfloat)(ctx->Color.ColorMask[0][GCOMP] ? 1 : 0);
+         params[2] = (GLfloat)(ctx->Color.ColorMask[0][BCOMP] ? 1 : 0);
+         params[3] = (GLfloat)(ctx->Color.ColorMask[0][ACOMP] ? 1 : 0);
          break;
       case GL_CULL_FACE:
          params[0] = BOOLEAN_TO_FLOAT(ctx->Polygon.CullFlag);
@@ -3880,10 +3880,10 @@ _mesa_GetIntegerv( GLenum pname, GLint *params )
          params[0] = ENUM_TO_INT(ctx->Light.ColorMaterialMode);
          break;
       case GL_COLOR_WRITEMASK:
-         params[0] = ctx->Color.ColorMask[RCOMP] ? 1 : 0;
-         params[1] = ctx->Color.ColorMask[GCOMP] ? 1 : 0;
-         params[2] = ctx->Color.ColorMask[BCOMP] ? 1 : 0;
-         params[3] = ctx->Color.ColorMask[ACOMP] ? 1 : 0;
+         params[0] = ctx->Color.ColorMask[0][RCOMP] ? 1 : 0;
+         params[1] = ctx->Color.ColorMask[0][GCOMP] ? 1 : 0;
+         params[2] = ctx->Color.ColorMask[0][BCOMP] ? 1 : 0;
+         params[3] = ctx->Color.ColorMask[0][ACOMP] ? 1 : 0;
          break;
       case GL_CULL_FACE:
          params[0] = BOOLEAN_TO_INT(ctx->Polygon.CullFlag);
@@ -5716,10 +5716,10 @@ _mesa_GetInteger64v( GLenum pname, GLint64 *params )
          params[0] = ENUM_TO_INT64(ctx->Light.ColorMaterialMode);
          break;
       case GL_COLOR_WRITEMASK:
-         params[0] = (GLint64)(ctx->Color.ColorMask[RCOMP] ? 1 : 0);
-         params[1] = (GLint64)(ctx->Color.ColorMask[GCOMP] ? 1 : 0);
-         params[2] = (GLint64)(ctx->Color.ColorMask[BCOMP] ? 1 : 0);
-         params[3] = (GLint64)(ctx->Color.ColorMask[ACOMP] ? 1 : 0);
+         params[0] = (GLint64)(ctx->Color.ColorMask[0][RCOMP] ? 1 : 0);
+         params[1] = (GLint64)(ctx->Color.ColorMask[0][GCOMP] ? 1 : 0);
+         params[2] = (GLint64)(ctx->Color.ColorMask[0][BCOMP] ? 1 : 0);
+         params[3] = (GLint64)(ctx->Color.ColorMask[0][ACOMP] ? 1 : 0);
          break;
       case GL_CULL_FACE:
          params[0] = BOOLEAN_TO_INT64(ctx->Polygon.CullFlag);
@@ -7448,11 +7448,20 @@ _mesa_GetBooleanIndexedv( GLenum pname, GLuint index, GLboolean *params )
 
    switch (pname) {
       case GL_BLEND:
-         if (index >= MAX_DRAW_BUFFERS) {
+         if (index >= ctx->Const.MaxDrawBuffers) {
             _mesa_error(ctx, GL_INVALID_VALUE, "glGetBooleanIndexedv(index=%u), index", pname);
          }
          params[0] = INT_TO_BOOLEAN(((ctx->Color.BlendEnabled >> index) & 1));
          break;
+      case GL_COLOR_WRITEMASK:
+         if (index >= ctx->Const.MaxDrawBuffers) {
+            _mesa_error(ctx, GL_INVALID_VALUE, "glGetBooleanIndexedv(index=%u), index", pname);
+         }
+         params[0] = INT_TO_BOOLEAN(ctx->Color.ColorMask[index][RCOMP] ? 1 : 0);
+         params[1] = INT_TO_BOOLEAN(ctx->Color.ColorMask[index][GCOMP] ? 1 : 0);
+         params[2] = INT_TO_BOOLEAN(ctx->Color.ColorMask[index][BCOMP] ? 1 : 0);
+         params[3] = INT_TO_BOOLEAN(ctx->Color.ColorMask[index][ACOMP] ? 1 : 0);
+         break;
       default:
          _mesa_error(ctx, GL_INVALID_ENUM, "glGetBooleanIndexedv(pname=0x%x)", pname);
    }
@@ -7472,11 +7481,20 @@ _mesa_GetIntegerIndexedv( GLenum pname, GLuint index, GLint *params )
 
    switch (pname) {
       case GL_BLEND:
-         if (index >= MAX_DRAW_BUFFERS) {
+         if (index >= ctx->Const.MaxDrawBuffers) {
             _mesa_error(ctx, GL_INVALID_VALUE, "glGetIntegerIndexedv(index=%u), index", pname);
          }
          params[0] = ((ctx->Color.BlendEnabled >> index) & 1);
          break;
+      case GL_COLOR_WRITEMASK:
+         if (index >= ctx->Const.MaxDrawBuffers) {
+            _mesa_error(ctx, GL_INVALID_VALUE, "glGetIntegerIndexedv(index=%u), index", pname);
+         }
+         params[0] = ctx->Color.ColorMask[index][RCOMP] ? 1 : 0;
+         params[1] = ctx->Color.ColorMask[index][GCOMP] ? 1 : 0;
+         params[2] = ctx->Color.ColorMask[index][BCOMP] ? 1 : 0;
+         params[3] = ctx->Color.ColorMask[index][ACOMP] ? 1 : 0;
+         break;
       default:
          _mesa_error(ctx, GL_INVALID_ENUM, "glGetIntegerIndexedv(pname=0x%x)", pname);
    }
@@ -7497,11 +7515,20 @@ _mesa_GetInteger64Indexedv( GLenum pname, GLuint index, GLint64 *params )
 
    switch (pname) {
       case GL_BLEND:
-         if (index >= MAX_DRAW_BUFFERS) {
+         if (index >= ctx->Const.MaxDrawBuffers) {
             _mesa_error(ctx, GL_INVALID_VALUE, "glGetInteger64Indexedv(index=%u), index", pname);
          }
          params[0] = (GLint64)(((ctx->Color.BlendEnabled >> index) & 1));
          break;
+      case GL_COLOR_WRITEMASK:
+         if (index >= ctx->Const.MaxDrawBuffers) {
+            _mesa_error(ctx, GL_INVALID_VALUE, "glGetInteger64Indexedv(index=%u), index", pname);
+         }
+         params[0] = (GLint64)(ctx->Color.ColorMask[index][RCOMP] ? 1 : 0);
+         params[1] = (GLint64)(ctx->Color.ColorMask[index][GCOMP] ? 1 : 0);
+         params[2] = (GLint64)(ctx->Color.ColorMask[index][BCOMP] ? 1 : 0);
+         params[3] = (GLint64)(ctx->Color.ColorMask[index][ACOMP] ? 1 : 0);
+         break;
       default:
          _mesa_error(ctx, GL_INVALID_ENUM, "glGetInteger64Indexedv(pname=0x%x)", pname);
    }
diff --git a/src/mesa/main/get_gen.py b/src/mesa/main/get_gen.py
index 8b6500fae17..18708be2603 100644
--- a/src/mesa/main/get_gen.py
+++ b/src/mesa/main/get_gen.py
@@ -126,10 +126,10 @@ StateVars = [
 	( "GL_COLOR_MATERIAL_PARAMETER", GLenum,
 	  ["ctx->Light.ColorMaterialMode"], "", None ),
 	( "GL_COLOR_WRITEMASK", GLint,
-	  [ "ctx->Color.ColorMask[RCOMP] ? 1 : 0",
-		"ctx->Color.ColorMask[GCOMP] ? 1 : 0",
-		"ctx->Color.ColorMask[BCOMP] ? 1 : 0",
-		"ctx->Color.ColorMask[ACOMP] ? 1 : 0" ], "", None ),
+	  [ "ctx->Color.ColorMask[0][RCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[0][GCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[0][BCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[0][ACOMP] ? 1 : 0" ], "", None ),
 	( "GL_CULL_FACE", GLboolean, ["ctx->Polygon.CullFlag"], "", None ),
 	( "GL_CULL_FACE_MODE", GLenum, ["ctx->Polygon.CullFaceMode"], "", None ),
 	( "GL_CURRENT_COLOR", GLfloatN,
@@ -1035,7 +1035,14 @@ StateVars = [
 
 # These are queried via glGetIntegetIndexdvEXT() or glGetIntegeri_v()
 IndexedStateVars = [
-	( "GL_BLEND", GLint, ["((ctx->Color.BlendEnabled >> index) & 1)"], "MAX_DRAW_BUFFERS", None ),
+	( "GL_BLEND", GLint, ["((ctx->Color.BlendEnabled >> index) & 1)"],
+	  "ctx->Const.MaxDrawBuffers", None ),
+	( "GL_COLOR_WRITEMASK", GLint,
+	  [ "ctx->Color.ColorMask[index][RCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[index][GCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[index][BCOMP] ? 1 : 0",
+		"ctx->Color.ColorMask[index][ACOMP] ? 1 : 0" ],
+	  "ctx->Const.MaxDrawBuffers", None ),
 	# XXX more to come...
 ]
 
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 170c35b11c6..7ef2852242f 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -564,7 +564,7 @@ struct gl_colorbuffer_attrib
    GLclampf ClearColor[4];		/**< Color to use for glClear */
 
    GLuint IndexMask;			/**< Color index write mask */
-   GLubyte ColorMask[4];		/**< Each flag is 0xff or 0x0 */
+   GLubyte ColorMask[MAX_DRAW_BUFFERS][4];/**< Each flag is 0xff or 0x0 */
 
    GLenum DrawBuffer[MAX_DRAW_BUFFERS];	/**< Which buffer to draw into */
 
diff --git a/src/mesa/state_tracker/st_atom_blend.c b/src/mesa/state_tracker/st_atom_blend.c
index 35c09c3e08f..43e62c29f3e 100644
--- a/src/mesa/state_tracker/st_atom_blend.c
+++ b/src/mesa/state_tracker/st_atom_blend.c
@@ -200,13 +200,13 @@ update_blend( struct st_context *st )
    }
 
    /* Colormask - maybe reverse these bits? */
-   if (st->ctx->Color.ColorMask[0])
+   if (st->ctx->Color.ColorMask[0][0])
       blend->colormask |= PIPE_MASK_R;
-   if (st->ctx->Color.ColorMask[1])
+   if (st->ctx->Color.ColorMask[0][1])
       blend->colormask |= PIPE_MASK_G;
-   if (st->ctx->Color.ColorMask[2])
+   if (st->ctx->Color.ColorMask[0][2])
       blend->colormask |= PIPE_MASK_B;
-   if (st->ctx->Color.ColorMask[3])
+   if (st->ctx->Color.ColorMask[0][3])
       blend->colormask |= PIPE_MASK_A;
 
    if (st->ctx->Color.DitherFlag)
diff --git a/src/mesa/state_tracker/st_cb_accum.c b/src/mesa/state_tracker/st_cb_accum.c
index a6b9765452a..da7b97d3253 100644
--- a/src/mesa/state_tracker/st_cb_accum.c
+++ b/src/mesa/state_tracker/st_cb_accum.c
@@ -229,7 +229,7 @@ accum_return(GLcontext *ctx, GLfloat value,
 {
    struct pipe_context *pipe = ctx->st->pipe;
    struct pipe_screen *screen = pipe->screen;
-   const GLubyte *colormask = ctx->Color.ColorMask;
+   const GLubyte *colormask = ctx->Color.ColorMask[0];
    enum pipe_transfer_usage usage;
    struct pipe_transfer *color_trans;
    size_t stride = acc_strb->stride;
diff --git a/src/mesa/state_tracker/st_cb_clear.c b/src/mesa/state_tracker/st_cb_clear.c
index 72b30e7c043..192d765f453 100644
--- a/src/mesa/state_tracker/st_cb_clear.c
+++ b/src/mesa/state_tracker/st_cb_clear.c
@@ -232,13 +232,13 @@ clear_with_quad(GLcontext *ctx,
       blend.rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;
       blend.alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
       if (color) {
-         if (ctx->Color.ColorMask[0])
+         if (ctx->Color.ColorMask[0][0])
             blend.colormask |= PIPE_MASK_R;
-         if (ctx->Color.ColorMask[1])
+         if (ctx->Color.ColorMask[0][1])
             blend.colormask |= PIPE_MASK_G;
-         if (ctx->Color.ColorMask[2])
+         if (ctx->Color.ColorMask[0][2])
             blend.colormask |= PIPE_MASK_B;
-         if (ctx->Color.ColorMask[3])
+         if (ctx->Color.ColorMask[0][3])
             blend.colormask |= PIPE_MASK_A;
          if (st->ctx->Color.DitherFlag)
             blend.dither = 1;
@@ -300,10 +300,10 @@ check_clear_color_with_quad(GLcontext *ctx, struct gl_renderbuffer *rb)
         ctx->Scissor.Height < rb->Height))
       return TRUE;
 
-   if (!ctx->Color.ColorMask[0] ||
-       !ctx->Color.ColorMask[1] ||
-       !ctx->Color.ColorMask[2] ||
-       !ctx->Color.ColorMask[3])
+   if (!ctx->Color.ColorMask[0][0] ||
+       !ctx->Color.ColorMask[0][1] ||
+       !ctx->Color.ColorMask[0][2] ||
+       !ctx->Color.ColorMask[0][3])
       return TRUE;
 
    return FALSE;
diff --git a/src/mesa/swrast/s_accum.c b/src/mesa/swrast/s_accum.c
index c6c7dbf5cf0..2d8c361e5d7 100644
--- a/src/mesa/swrast/s_accum.c
+++ b/src/mesa/swrast/s_accum.c
@@ -528,7 +528,7 @@ accum_return(GLcontext *ctx, GLfloat value,
          for (buffer = 0; buffer < fb->_NumColorDrawBuffers; buffer++) {
             struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buffer];
             if (masking) {
-               _swrast_mask_rgba_span(ctx, rb, &span);
+               _swrast_mask_rgba_span(ctx, rb, &span, buffer);
             }
             rb->PutRow(ctx, rb, width, xpos, ypos + i, span.array->rgba, NULL);
          }
diff --git a/src/mesa/swrast/s_clear.c b/src/mesa/swrast/s_clear.c
index 002718ded85..2d27797d435 100644
--- a/src/mesa/swrast/s_clear.c
+++ b/src/mesa/swrast/s_clear.c
@@ -40,7 +40,8 @@
  * Clear the color buffer when glColorMask is in effect.
  */
 static void
-clear_rgba_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb)
+clear_rgba_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb,
+                               GLuint buf)
 {
    const GLint x = ctx->DrawBuffer->_Xmin;
    const GLint y = ctx->DrawBuffer->_Ymin;
@@ -95,7 +96,7 @@ clear_rgba_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb)
    for (i = 0; i < height; i++) {
       span.x = x;
       span.y = y + i;
-      _swrast_mask_rgba_span(ctx, rb, &span);
+      _swrast_mask_rgba_span(ctx, rb, &span, buf);
       /* write masked row */
       rb->PutRow(ctx, rb, width, x, y + i, span.array->rgba, NULL);
    }
@@ -145,7 +146,7 @@ clear_ci_buffer_with_masking(GLcontext *ctx, struct gl_renderbuffer *rb)
  * Clear an rgba color buffer without channel masking.
  */
 static void
-clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb)
+clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb, GLuint buf)
 {
    const GLint x = ctx->DrawBuffer->_Xmin;
    const GLint y = ctx->DrawBuffer->_Ymin;
@@ -158,10 +159,10 @@ clear_rgba_buffer(GLcontext *ctx, struct gl_renderbuffer *rb)
 
    ASSERT(ctx->Visual.rgbMode);
 
-   ASSERT(ctx->Color.ColorMask[0] &&
-          ctx->Color.ColorMask[1] &&
-          ctx->Color.ColorMask[2] &&
-          ctx->Color.ColorMask[3]);             
+   ASSERT(ctx->Color.ColorMask[buf][0] &&
+          ctx->Color.ColorMask[buf][1] &&
+          ctx->Color.ColorMask[buf][2] &&
+          ctx->Color.ColorMask[buf][3]);             
 
    ASSERT(rb->PutMonoRow);
 
@@ -246,43 +247,24 @@ clear_ci_buffer(GLcontext *ctx, struct gl_renderbuffer *rb)
 static void
 clear_color_buffers(GLcontext *ctx)
 {
-   GLboolean masking;
    GLuint buf;
 
-   if (ctx->Visual.rgbMode) {
-      if (ctx->Color.ColorMask[0] && 
-          ctx->Color.ColorMask[1] && 
-          ctx->Color.ColorMask[2] && 
-          ctx->Color.ColorMask[3]) {
-         masking = GL_FALSE;
-      }
-      else {
-         masking = GL_TRUE;
-      }
-   }
-   else {
-      struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
-      const GLuint indexMask = (1 << _mesa_get_format_bits(rb->Format, GL_INDEX_BITS)) - 1;
-      if ((ctx->Color.IndexMask & indexMask) == indexMask) {
-         masking = GL_FALSE;
-      }
-      else {
-         masking = GL_TRUE;
-      }
-   }
-
    for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
       struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[buf];
       if (ctx->Visual.rgbMode) {
-         if (masking) {
-            clear_rgba_buffer_with_masking(ctx, rb);
+         if (ctx->Color.ColorMask[buf][0] == 0 || 
+             ctx->Color.ColorMask[buf][1] == 0 || 
+             ctx->Color.ColorMask[buf][2] == 0 || 
+             ctx->Color.ColorMask[buf][3] == 0) {
+            clear_rgba_buffer_with_masking(ctx, rb, buf);
          }
          else {
-            clear_rgba_buffer(ctx, rb);
+            clear_rgba_buffer(ctx, rb, buf);
          }
       }
       else {
-         if (masking) {
+         const GLuint indexMask = (1 << _mesa_get_format_bits(rb->Format, GL_INDEX_BITS)) - 1;
+         if ((ctx->Color.IndexMask & indexMask) != indexMask) {
             clear_ci_buffer_with_masking(ctx, rb);
          }
          else {
diff --git a/src/mesa/swrast/s_context.c b/src/mesa/swrast/s_context.c
index abf00085651..f9092c215a7 100644
--- a/src/mesa/swrast/s_context.c
+++ b/src/mesa/swrast/s_context.c
@@ -55,6 +55,7 @@ _swrast_update_rasterflags( GLcontext *ctx )
 {
    SWcontext *swrast = SWRAST_CONTEXT(ctx);
    GLbitfield rasterMask = 0;
+   GLuint i;
 
    if (ctx->Color.AlphaEnabled)           rasterMask |= ALPHATEST_BIT;
    if (ctx->Color.BlendEnabled)           rasterMask |= BLEND_BIT;
@@ -63,8 +64,15 @@ _swrast_update_rasterflags( GLcontext *ctx )
    if (ctx->Scissor.Enabled)              rasterMask |= CLIP_BIT;
    if (ctx->Stencil._Enabled)             rasterMask |= STENCIL_BIT;
    if (ctx->Visual.rgbMode) {
-      const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
-      if (colorMask != 0xffffffff)        rasterMask |= MASKING_BIT;
+      for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+         if (!ctx->Color.ColorMask[i][0] ||
+             !ctx->Color.ColorMask[i][1] ||
+             !ctx->Color.ColorMask[i][2] ||
+             !ctx->Color.ColorMask[i][3]) {
+            rasterMask |= MASKING_BIT;
+            break;
+         }
+      }
       if (ctx->Color._LogicOpEnabled)     rasterMask |= LOGIC_OP_BIT;
       if (ctx->Texture._EnabledUnits)     rasterMask |= TEXTURE_BIT;
    }
@@ -92,13 +100,23 @@ _swrast_update_rasterflags( GLcontext *ctx )
       /* more than one color buffer designated for writing (or zero buffers) */
       rasterMask |= MULTI_DRAW_BIT;
    }
-   else if (ctx->Visual.rgbMode && *((GLuint *) ctx->Color.ColorMask) == 0) {
-      rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
-   }
    else if (!ctx->Visual.rgbMode && ctx->Color.IndexMask==0) {
       rasterMask |= MULTI_DRAW_BIT; /* all color index bits disabled */
    }
 
+   if (ctx->Visual.rgbMode) {
+      for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
+         if (ctx->Color.ColorMask[i][0] +
+             ctx->Color.ColorMask[i][1] +
+             ctx->Color.ColorMask[i][2] +
+             ctx->Color.ColorMask[i][3] == 0) {
+            rasterMask |= MULTI_DRAW_BIT; /* all RGBA channels disabled */
+            break;
+         }
+      }
+   }
+
+
    if (ctx->FragmentProgram._Current) {
       rasterMask |= FRAGPROG_BIT;
    }
diff --git a/src/mesa/swrast/s_masking.c b/src/mesa/swrast/s_masking.c
index df779b07392..69c2feb6da8 100644
--- a/src/mesa/swrast/s_masking.c
+++ b/src/mesa/swrast/s_masking.c
@@ -41,7 +41,7 @@
  */
 void
 _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
-                       SWspan *span)
+                       SWspan *span, GLuint buf)
 {
    const GLuint n = span->end;
    void *rbPixels;
@@ -58,7 +58,7 @@ _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
     */
    if (span->array->ChanType == GL_UNSIGNED_BYTE) {
       /* treat 4xGLubyte as 1xGLuint */
-      const GLuint srcMask = *((GLuint *) ctx->Color.ColorMask);
+      const GLuint srcMask = *((GLuint *) ctx->Color.ColorMask[buf]);
       const GLuint dstMask = ~srcMask;
       const GLuint *dst = (const GLuint *) rbPixels;
       GLuint *src = (GLuint *) span->array->rgba8;
@@ -70,10 +70,10 @@ _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
    else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
       /* 2-byte components */
       /* XXX try to use 64-bit arithmetic someday */
-      const GLushort rMask = ctx->Color.ColorMask[RCOMP] ? 0xffff : 0x0;
-      const GLushort gMask = ctx->Color.ColorMask[GCOMP] ? 0xffff : 0x0;
-      const GLushort bMask = ctx->Color.ColorMask[BCOMP] ? 0xffff : 0x0;
-      const GLushort aMask = ctx->Color.ColorMask[ACOMP] ? 0xffff : 0x0;
+      const GLushort rMask = ctx->Color.ColorMask[buf][RCOMP] ? 0xffff : 0x0;
+      const GLushort gMask = ctx->Color.ColorMask[buf][GCOMP] ? 0xffff : 0x0;
+      const GLushort bMask = ctx->Color.ColorMask[buf][BCOMP] ? 0xffff : 0x0;
+      const GLushort aMask = ctx->Color.ColorMask[buf][ACOMP] ? 0xffff : 0x0;
       const GLushort (*dst)[4] = (const GLushort (*)[4]) rbPixels;
       GLushort (*src)[4] = span->array->rgba16;
       GLuint i;
@@ -86,10 +86,10 @@ _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
    }
    else {
       /* 4-byte components */
-      const GLuint rMask = ctx->Color.ColorMask[RCOMP] ? ~0x0 : 0x0;
-      const GLuint gMask = ctx->Color.ColorMask[GCOMP] ? ~0x0 : 0x0;
-      const GLuint bMask = ctx->Color.ColorMask[BCOMP] ? ~0x0 : 0x0;
-      const GLuint aMask = ctx->Color.ColorMask[ACOMP] ? ~0x0 : 0x0;
+      const GLuint rMask = ctx->Color.ColorMask[buf][RCOMP] ? ~0x0 : 0x0;
+      const GLuint gMask = ctx->Color.ColorMask[buf][GCOMP] ? ~0x0 : 0x0;
+      const GLuint bMask = ctx->Color.ColorMask[buf][BCOMP] ? ~0x0 : 0x0;
+      const GLuint aMask = ctx->Color.ColorMask[buf][ACOMP] ? ~0x0 : 0x0;
       const GLuint (*dst)[4] = (const GLuint (*)[4]) rbPixels;
       GLuint (*src)[4] = (GLuint (*)[4]) span->array->attribs[FRAG_ATTRIB_COL0];
       GLuint i;
diff --git a/src/mesa/swrast/s_masking.h b/src/mesa/swrast/s_masking.h
index 3260ca34e32..fed47f8cfbe 100644
--- a/src/mesa/swrast/s_masking.h
+++ b/src/mesa/swrast/s_masking.h
@@ -32,7 +32,7 @@
 
 extern void
 _swrast_mask_rgba_span(GLcontext *ctx, struct gl_renderbuffer *rb,
-                       SWspan *span);
+                       SWspan *span, GLuint buf);
 
 
 extern void
diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index 00de13d4954..a311d4b4bd0 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1278,7 +1278,7 @@ void
 _swrast_write_rgba_span( GLcontext *ctx, SWspan *span)
 {
    const SWcontext *swrast = SWRAST_CONTEXT(ctx);
-   const GLuint colorMask = *((GLuint *) ctx->Color.ColorMask);
+   const GLuint *colorMask = (GLuint *) ctx->Color.ColorMask;
    const GLbitfield origInterpMask = span->interpMask;
    const GLbitfield origArrayMask = span->arrayMask;
    const GLbitfield origArrayAttribs = span->arrayAttribs;
@@ -1389,7 +1389,7 @@ _swrast_write_rgba_span( GLcontext *ctx, SWspan *span)
    /* We had to wait until now to check for glColorMask(0,0,0,0) because of
     * the occlusion test.
     */
-   if (colorMask == 0x0) {
+   if (fb->_NumColorDrawBuffers == 1 && colorMask[0] == 0x0) {
       /* no colors to write */
       goto end;
    }
@@ -1483,8 +1483,8 @@ _swrast_write_rgba_span( GLcontext *ctx, SWspan *span)
                _swrast_blend_span(ctx, rb, span);
             }
 
-            if (colorMask != 0xffffffff) {
-               _swrast_mask_rgba_span(ctx, rb, span);
+            if (colorMask[buf] != 0xffffffff) {
+               _swrast_mask_rgba_span(ctx, rb, span, buf);
             }
 
             if (span->arrayMask & SPAN_XY) {
diff --git a/src/mesa/swrast/s_triangle.c b/src/mesa/swrast/s_triangle.c
index 5bec6066967..11184b72ce3 100644
--- a/src/mesa/swrast/s_triangle.c
+++ b/src/mesa/swrast/s_triangle.c
@@ -1030,10 +1030,10 @@ _swrast_choose_triangle( GLcontext *ctx )
           ctx->Depth.Func == GL_LESS &&
           !ctx->Stencil._Enabled) {
          if ((rgbmode &&
-              ctx->Color.ColorMask[0] == 0 &&
-              ctx->Color.ColorMask[1] == 0 &&
-              ctx->Color.ColorMask[2] == 0 &&
-              ctx->Color.ColorMask[3] == 0)
+              ctx->Color.ColorMask[0][0] == 0 &&
+              ctx->Color.ColorMask[0][1] == 0 &&
+              ctx->Color.ColorMask[0][2] == 0 &&
+              ctx->Color.ColorMask[0][3] == 0)
              ||
              (!rgbmode && ctx->Color.IndexMask == 0)) {
             USE(occlusion_zless_triangle);