/*
* Mesa 3-D graphics library
- * Version: 7.1
*
* Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
- * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
*/
}
+/**
+ * Returns true if color writes are enabled for the given color attachment.
+ *
+ * Beyond checking ColorMask, this uses _mesa_format_has_color_component to
+ * ignore components that don't actually exist in the format (such as X in
+ * XRGB).
+ */
+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 < 4; c++) {
+ if (_mesa_format_has_color_component(rb->Format, c))
+ colorMask |= ctx->Color.ColorMask[idx][c];
+ }
+ }
+
+ return colorMask != 0;
+}
+
+
/**
* Clear buffers.
*
if (mask & GL_COLOR_BUFFER_BIT) {
GLuint i;
for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
- bufferMask |= (1 << ctx->DrawBuffer->_ColorDrawBufferIndexes[i]);
+ GLint buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
+
+ if (buf >= 0 && color_buffer_writes_enabled(ctx, i)) {
+ bufferMask |= 1 << buf;
+ }
}
}
const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
GLbitfield mask = 0x0;
- switch (drawbuffer) {
+ /* From the GL 4.0 specification:
+ * If buffer is COLOR, a particular draw buffer DRAW_BUFFERi is
+ * specified by passing i as the parameter drawbuffer, and value
+ * points to a four-element vector specifying the R, G, B, and A
+ * color to clear that draw buffer to. If the draw buffer is one
+ * of FRONT, BACK, LEFT, RIGHT, or FRONT_AND_BACK, identifying
+ * multiple buffers, each selected buffer is cleared to the same
+ * value.
+ *
+ * Note that "drawbuffer" and "draw buffer" have different meaning.
+ * "drawbuffer" specifies DRAW_BUFFERi, while "draw buffer" is what's
+ * assigned to DRAW_BUFFERi. It could be COLOR_ATTACHMENT0, FRONT, BACK,
+ * etc.
+ */
+ if (drawbuffer < 0 || drawbuffer >= (GLint)ctx->Const.MaxDrawBuffers) {
+ return INVALID_MASK;
+ }
+
+ switch (ctx->DrawBuffer->ColorDrawBuffer[drawbuffer]) {
case GL_FRONT:
if (att[BUFFER_FRONT_LEFT].Renderbuffer)
mask |= BUFFER_BIT_FRONT_LEFT;
mask |= BUFFER_BIT_BACK_RIGHT;
break;
default:
- if (drawbuffer < 0 || drawbuffer >= (GLint)ctx->Const.MaxDrawBuffers) {
- mask = INVALID_MASK;
- }
- else if (att[BUFFER_COLOR0 + drawbuffer].Renderbuffer) {
- mask |= (BUFFER_BIT_COLOR0 << drawbuffer);
+ {
+ GLint buf = ctx->DrawBuffer->_ColorDrawBufferIndexes[drawbuffer];
+
+ if (buf >= 0 && att[buf].Renderbuffer) {
+ mask |= 1 << buf;
+ }
}
}