+
+/**
+ * Try to do a fast copy pixels.
+ */
+static GLboolean
+fast_copy_pixels(GLcontext *ctx,
+ GLint srcX, GLint srcY, GLsizei width, GLsizei height,
+ GLint dstX, GLint dstY, GLenum type)
+{
+ struct gl_framebuffer *srcFb = ctx->ReadBuffer;
+ struct gl_framebuffer *dstFb = ctx->DrawBuffer;
+ struct gl_renderbuffer *srcRb, *dstRb;
+ GLint row, yStep;
+
+ if (SWRAST_CONTEXT(ctx)->_RasterMask != 0x0 ||
+ ctx->Pixel.ZoomX != 1.0F ||
+ ctx->Pixel.ZoomY != 1.0F ||
+ ctx->_ImageTransferState) {
+ /* can't handle these */
+ return GL_FALSE;
+ }
+
+ if (type == GL_COLOR) {
+ if (dstFb->_NumColorDrawBuffers != 1)
+ return GL_FALSE;
+ srcRb = srcFb->_ColorReadBuffer;
+ dstRb = dstFb->_ColorDrawBuffers[0];
+ }
+ else if (type == GL_STENCIL) {
+ srcRb = srcFb->_StencilBuffer;
+ dstRb = dstFb->_StencilBuffer;
+ }
+ else if (type == GL_DEPTH) {
+ srcRb = srcFb->_DepthBuffer;
+ dstRb = dstFb->_DepthBuffer;
+ }
+ else {
+ ASSERT(type == GL_DEPTH_STENCIL_EXT);
+ /* XXX correct? */
+ srcRb = srcFb->Attachment[BUFFER_DEPTH].Renderbuffer;
+ dstRb = dstFb->Attachment[BUFFER_DEPTH].Renderbuffer;
+ }
+
+ /* src and dst renderbuffers must be same format and type */
+ if (!srcRb || !dstRb ||
+ srcRb->DataType != dstRb->DataType ||
+ srcRb->_BaseFormat != dstRb->_BaseFormat) {
+ return GL_FALSE;
+ }
+
+ /* clipping not supported */
+ if (srcX < 0 || srcX + width > (GLint) srcFb->Width ||
+ srcY < 0 || srcY + height > (GLint) srcFb->Height ||
+ dstX < dstFb->_Xmin || dstX + width > dstFb->_Xmax ||
+ dstY < dstFb->_Ymin || dstY + height > dstFb->_Ymax) {
+ return GL_FALSE;
+ }
+
+ /* overlapping src/dst doesn't matter, just determine Y direction */
+ if (srcY < dstY) {
+ /* top-down max-to-min */
+ srcY = srcY + height - 1;
+ dstY = dstY + height - 1;
+ yStep = -1;
+ }
+ else {
+ /* bottom-up min-to-max */
+ yStep = 1;
+ }
+
+ for (row = 0; row < height; row++) {
+ GLuint temp[MAX_WIDTH][4];
+ srcRb->GetRow(ctx, srcRb, width, srcX, srcY, temp);
+ dstRb->PutRow(ctx, dstRb, width, dstX, dstY, temp, NULL);
+ srcY += yStep;
+ dstY += yStep;
+ }
+
+ return GL_TRUE;
+}
+
+