[Mesa-dev] [PATCH 3/3] swrast: Convert the simple glFramebufferBlit path to MapRenderbuffer.
Eric Anholt
eric at anholt.net
Tue Dec 13 12:53:29 PST 2011
There is one significant functional change here: the simple blit now
only handles exact matches of formats. From the
ARB_framebuffer_object spec:
"If the color formats of the read and draw framebuffers do not
match, and <mask> includes COLOR_BUFFER_BIT, pixel groups are
converted to match the destination format as in CopyPixels"
The previous code would generally do this, unless the RB DataTypes
didn't match, in which case it assertion failed. Rather than adding
special-case format conversion code to the simple path, fall back to
the slow paths which will need to handle format conversion as well.
---
src/mesa/swrast/s_blit.c | 188 +++++++++++++++++++++++----------------------
1 files changed, 96 insertions(+), 92 deletions(-)
diff --git a/src/mesa/swrast/s_blit.c b/src/mesa/swrast/s_blit.c
index 803ad2e..6f10c3a 100644
--- a/src/mesa/swrast/s_blit.c
+++ b/src/mesa/swrast/s_blit.c
@@ -454,7 +454,7 @@ blit_linear(struct gl_context *ctx,
* Simple case: Blit color, depth or stencil with no scaling or flipping.
* XXX we could easily support vertical flipping here.
*/
-static void
+static GLboolean
simple_blit(struct gl_context *ctx,
GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
@@ -463,9 +463,10 @@ simple_blit(struct gl_context *ctx,
struct gl_renderbuffer *readRb, *drawRb;
const GLint width = srcX1 - srcX0;
const GLint height = srcY1 - srcY0;
- GLint row, srcY, dstY, yStep;
- GLint comps, bytesPerRow;
- void *rowBuffer;
+ GLint row;
+ GLint bytesPerRow, srcStride, dstStride;
+ void *temp = NULL;
+ GLubyte *srcMap, *dstMap;
/* only one buffer */
ASSERT(_mesa_bitcount(buffer) == 1);
@@ -478,85 +479,93 @@ simple_blit(struct gl_context *ctx,
ASSERT(srcX1 - srcX0 == dstX1 - dstX0);
ASSERT(srcY1 - srcY0 == dstY1 - dstY0);
- /* From the GL_ARB_framebuffer_object spec:
- *
- * "If the source and destination buffers are identical, and the source
- * and destination rectangles overlap, the result of the blit operation
- * is undefined."
- *
- * However, we provide the expected result anyway by flipping the order of
- * the memcpy of rows.
- */
- if (srcY0 > dstY0) {
- /* src above dst: copy bottom-to-top */
- yStep = 1;
- srcY = srcY0;
- dstY = dstY0;
- }
- else {
- /* src below dst: copy top-to-bottom */
- yStep = -1;
- srcY = srcY1 - 1;
- dstY = dstY1 - 1;
- }
-
switch (buffer) {
case GL_COLOR_BUFFER_BIT:
readRb = ctx->ReadBuffer->_ColorReadBuffer;
drawRb = ctx->DrawBuffer->_ColorDrawBuffers[0];
- comps = 4;
break;
case GL_DEPTH_BUFFER_BIT:
- readRb = ctx->ReadBuffer->_DepthBuffer;
- drawRb = ctx->DrawBuffer->_DepthBuffer;
- comps = 1;
+ readRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
+ drawRb = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
break;
case GL_STENCIL_BUFFER_BIT:
- readRb = ctx->ReadBuffer->_StencilBuffer;
- drawRb = ctx->DrawBuffer->_StencilBuffer;
- comps = 1;
+ readRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
+ drawRb = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
break;
default:
_mesa_problem(ctx, "unexpected buffer in simple_blit()");
- return;
+ return GL_TRUE;
}
- ASSERT(readRb->DataType == drawRb->DataType);
+ if (readRb->Format != drawRb->Format)
+ return GL_FALSE;
- /* compute bytes per row */
- switch (readRb->DataType) {
- case GL_UNSIGNED_BYTE:
- bytesPerRow = comps * width * sizeof(GLubyte);
- break;
- case GL_UNSIGNED_SHORT:
- bytesPerRow = comps * width * sizeof(GLushort);
- break;
- case GL_UNSIGNED_INT:
- bytesPerRow = comps * width * sizeof(GLuint);
- break;
- case GL_FLOAT:
- bytesPerRow = comps * width * sizeof(GLfloat);
- break;
- default:
- _mesa_problem(ctx, "unexpected buffer type in simple_blit");
- return;
+ /* This path does direct memcpy of the data, and if the buffers are
+ * depth/stencil, it would end up stomping over the other one of depth or
+ * stencil even though it wasn't asked to.
+ */
+ if (_mesa_is_format_packed_depth_stencil(readRb->Format))
+ return GL_FALSE;
+
+ bytesPerRow = _mesa_get_format_bytes(readRb->Format) * width;
+
+ ctx->Driver.MapRenderbuffer(ctx, readRb, srcX0, srcY0, width, height,
+ GL_MAP_READ_BIT, &srcMap, &srcStride);
+ if (!srcMap) {
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
+ return GL_TRUE;
+ }
+
+ /* From the GL_ARB_framebuffer_object spec:
+ *
+ * "If the source and destination buffers are identical, and the source
+ * and destination rectangles overlap, the result of the blit operation
+ * is undefined."
+ *
+ * However, we provide the expected result anyway by copying to a temporary,
+ * since we can't do nested MapRenderbuffer()s on the same RB.
+ */
+ if (drawRb == readRb) {
+ temp = malloc(bytesPerRow * height);
+ if (!temp) {
+ ctx->Driver.UnmapRenderbuffer(ctx, readRb);
+ _mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
+ return GL_TRUE;
+ }
+
+ for (row = 0; row < height; row++) {
+ memcpy(temp + bytesPerRow * row, srcMap, bytesPerRow);
+
+ srcMap += srcStride;
+ }
+
+ ctx->Driver.UnmapRenderbuffer(ctx, readRb);
+ srcMap = temp;
+ srcStride = bytesPerRow;
}
- /* allocate the row buffer */
- rowBuffer = malloc(bytesPerRow);
- if (!rowBuffer) {
+ ctx->Driver.MapRenderbuffer(ctx, drawRb, dstX0, dstY0, width, height,
+ GL_MAP_WRITE_BIT, &dstMap, &dstStride);
+ if (!dstMap) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
- return;
+ return GL_TRUE;
}
for (row = 0; row < height; row++) {
- readRb->GetRow(ctx, readRb, width, srcX0, srcY, rowBuffer);
- drawRb->PutRow(ctx, drawRb, width, dstX0, dstY, rowBuffer, NULL);
- srcY += yStep;
- dstY += yStep;
+ memcpy(dstMap, srcMap, bytesPerRow);
+
+ srcMap += srcStride;
+ dstMap += dstStride;
+ }
+
+ if (temp) {
+ free(temp);
+ } else {
+ ctx->Driver.UnmapRenderbuffer(ctx, readRb);
}
+ ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
- free(rowBuffer);
+ return GL_TRUE;
}
@@ -575,6 +584,7 @@ _swrast_BlitFramebuffer(struct gl_context *ctx,
GL_STENCIL_BUFFER_BIT
};
GLint i;
+ GLboolean is_one_to_one;
if (!_mesa_clip_blit(ctx, &srcX0, &srcY0, &srcX1, &srcY1,
&dstX0, &dstY0, &dstX1, &dstY1)) {
@@ -584,41 +594,35 @@ _swrast_BlitFramebuffer(struct gl_context *ctx,
if (SWRAST_CONTEXT(ctx)->NewState)
_swrast_validate_derived(ctx);
- swrast_render_start(ctx);
-
- if (srcX1 - srcX0 == dstX1 - dstX0 &&
- srcY1 - srcY0 == dstY1 - dstY0 &&
- srcX0 < srcX1 &&
- srcY0 < srcY1 &&
- dstX0 < dstX1 &&
- dstY0 < dstY1) {
- /* no stretching or flipping.
- * filter doesn't matter.
- */
+ is_one_to_one = (srcX1 - srcX0 == dstX1 - dstX0 &&
+ srcY1 - srcY0 == dstY1 - dstY0 &&
+ srcX0 < srcX1 &&
+ srcY0 < srcY1 &&
+ dstX0 < dstX1 &&
+ dstY0 < dstY1);
+
+ if (filter == GL_NEAREST) {
for (i = 0; i < 3; i++) {
- if (mask & buffers[i]) {
- simple_blit(ctx, srcX0, srcY0, srcX1, srcY1,
- dstX0, dstY0, dstX1, dstY1, buffers[i]);
- }
+ if (mask & buffers[i]) {
+ if (is_one_to_one && !simple_blit(ctx,
+ srcX0, srcY0, srcX1, srcY1,
+ dstX0, dstY0, dstX1, dstY1,
+ buffers[i])) {
+ swrast_render_start(ctx);
+ blit_nearest(ctx, srcX0, srcY0, srcX1, srcY1,
+ dstX0, dstY0, dstX1, dstY1, buffers[i]);
+ swrast_render_finish(ctx);
+ }
+ }
}
}
else {
- if (filter == GL_NEAREST) {
- for (i = 0; i < 3; i++) {
- if (mask & buffers[i]) {
- blit_nearest(ctx, srcX0, srcY0, srcX1, srcY1,
- dstX0, dstY0, dstX1, dstY1, buffers[i]);
- }
- }
- }
- else {
- ASSERT(filter == GL_LINEAR);
- if (mask & GL_COLOR_BUFFER_BIT) { /* depth/stencil not allowed */
- blit_linear(ctx, srcX0, srcY0, srcX1, srcY1,
- dstX0, dstY0, dstX1, dstY1);
- }
+ ASSERT(filter == GL_LINEAR);
+ if (mask & GL_COLOR_BUFFER_BIT) { /* depth/stencil not allowed */
+ swrast_render_start(ctx);
+ blit_linear(ctx, srcX0, srcY0, srcX1, srcY1,
+ dstX0, dstY0, dstX1, dstY1);
+ swrast_render_finish(ctx);
}
}
-
- swrast_render_finish(ctx);
}
--
1.7.7.3
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