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().

2 files changed, 40 insertions, 14 deletions

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) {