WebGL Aquarium in Chrome 24 actually hits this. v2: Move to core Mesa (wisely suggested by Ian); only consider components which actually exist.
Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> Cc: Ian Romanick <i...@freedesktop.org> Cc: Paul Berry <stereotype...@gmail.com> Cc: Anuj Phogat <anuj.pho...@gmail.com> --- src/mesa/main/clear.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) Good call, Ian! I was a bit sleepy last night when I wrote that code :) Here's an updated patch which moves it to core Mesa. It also only checks the writemask of enabled components. I didn't see any existing code to handle this. There's similar code which disables depth clears if Depth.Mask == 0, but I didn't see any for color. diff --git a/src/mesa/main/clear.c b/src/mesa/main/clear.c index 077c5fc..c9ca681 100644 --- a/src/mesa/main/clear.c +++ b/src/mesa/main/clear.c @@ -106,6 +106,23 @@ _mesa_ClearColorIuiEXT(GLuint r, GLuint g, GLuint b, GLuint a) } +static bool +color_buffer_writes_enabled(const struct gl_context *ctx, unsigned idx) +{ + struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[idx]; + GLuint c; + GLubyte colorMask = 0; + + if (rb) { + for (c = 0; c < _mesa_format_num_components(rb->Format); c++) { + colorMask |= ctx->Color.ColorMask[idx][c]; + } + } + + return colorMask != 0; +} + + /** * Clear buffers. * @@ -181,7 +198,7 @@ _mesa_Clear( GLbitfield mask ) for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) { GLint buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[i]; - if (buf >= 0) { + if (buf >= 0 && color_buffer_writes_enabled(ctx, i)) { bufferMask |= 1 << buf; } } -- 1.9.0 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev