mesa: per-buffer blend enabled flags

ctx->Color.BlendEnabled is now a GLbitfield instead of a GLboolean to
indicate blend on/off status for each color/draw buffer.

This is infrastructure for GL_EXT_draw_buffers2 and OpenGL 3.x

New functions include _mesa_EnableIndexed(), _mesa_DisableIndexed(), and
_mesa_IsEnabledIndexed().  The enable function corresponds to
glEnableIndexedEXT() for GL_EXT_draw_buffers2 or glEnablei() for GL3.

Note that there's quite a few tests for ctx->Color.BlendEnabled != 0 in
drivers, etc.  Those tests can remain as-is since the mask will be 0 or ~0
unless GL_EXT_draw_buffers2 is enabled.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mesa/swrast/s_span.c b/src/mesa/swrast/s_span.c
index d36c8132f6..00de13d495 100644
--- a/src/mesa/swrast/s_span.c
+++ b/src/mesa/swrast/s_span.c
@@ -1479,7 +1479,7 @@ _swrast_write_rgba_span( GLcontext *ctx, SWspan *span)
             if (ctx->Color._LogicOpEnabled) {
                _swrast_logicop_rgba_span(ctx, rb, span);
             }
-            else if (ctx->Color.BlendEnabled) {
+            else if ((ctx->Color.BlendEnabled >> buf) & 1) {
                _swrast_blend_span(ctx, rb, span);
             }