[Mesa-dev] [PATCH 08/24] swrast: Use MapRenderbuffer for glReadPixels(GL_DEPTH_COMPONENT) fast-paths.
Eric Anholt
eric at anholt.net
Fri Oct 28 12:49:58 PDT 2011
This fixes issues with the code playing fast and loose with types of
buffers, and as a bonus avoids the wrappers that were previously used
to pull bits out of packed depth/stencil buffers.
---
src/mesa/swrast/s_readpix.c | 131 +++++++++++++++++++++----------------------
1 files changed, 63 insertions(+), 68 deletions(-)
diff --git a/src/mesa/swrast/s_readpix.c b/src/mesa/swrast/s_readpix.c
index 0d2e63f..187c27e 100644
--- a/src/mesa/swrast/s_readpix.c
+++ b/src/mesa/swrast/s_readpix.c
@@ -27,6 +27,7 @@
#include "main/colormac.h"
#include "main/feedback.h"
#include "main/formats.h"
+#include "main/format_unpack.h"
#include "main/image.h"
#include "main/imports.h"
#include "main/macros.h"
@@ -39,6 +40,57 @@
#include "s_span.h"
#include "s_stencil.h"
+/**
+ * Tries to implement glReadPixels() of GL_DEPTH_COMPONENT using memcpy of the
+ * mapping.
+ */
+static GLboolean
+fast_read_depth_pixels( struct gl_context *ctx,
+ GLint x, GLint y,
+ GLsizei width, GLsizei height,
+ GLenum type, GLvoid *pixels,
+ const struct gl_pixelstore_attrib *packing )
+{
+ struct gl_framebuffer *fb = ctx->ReadBuffer;
+ struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
+ GLubyte *map, *dst;
+ int stride, dstStride, j;
+
+ if (ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0)
+ return GL_FALSE;
+
+ if (packing->SwapBytes)
+ return GL_FALSE;
+
+ if (_mesa_get_format_datatype(rb->Format) != GL_UNSIGNED_INT)
+ return GL_FALSE;
+
+ if (!((type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16) ||
+ type == GL_UNSIGNED_INT))
+ return GL_FALSE;
+
+ ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
+ &map, &stride);
+
+ dstStride = _mesa_image_row_stride(packing, width, GL_DEPTH_COMPONENT, type);
+ dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
+ GL_DEPTH_COMPONENT, type, 0, 0);
+
+ for (j = 0; j < height; j++) {
+ if (type == GL_UNSIGNED_INT) {
+ _mesa_unpack_uint_z_row(rb->Format, width, map, (GLuint *)dst);
+ } else {
+ ASSERT(type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16);
+ memcpy(dst, map, width * 2);
+ }
+
+ map += stride;
+ dst += dstStride;
+ }
+ ctx->Driver.UnmapRenderbuffer(ctx, rb);
+
+ return GL_TRUE;
+}
/**
* Read pixels for format=GL_DEPTH_COMPONENT.
@@ -52,8 +104,7 @@ read_depth_pixels( struct gl_context *ctx,
{
struct gl_framebuffer *fb = ctx->ReadBuffer;
struct gl_renderbuffer *rb = fb->_DepthBuffer;
- const GLboolean biasOrScale
- = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
+ GLint j;
if (!rb)
return;
@@ -66,72 +117,16 @@ read_depth_pixels( struct gl_context *ctx,
/* width should never be > MAX_WIDTH since we did clipping earlier */
ASSERT(width <= MAX_WIDTH);
- if (type == GL_UNSIGNED_SHORT && fb->Visual.depthBits == 16
- && !biasOrScale && !packing->SwapBytes) {
- /* Special case: directly read 16-bit unsigned depth values. */
- GLint j;
- ASSERT(rb->Format == MESA_FORMAT_Z16);
- ASSERT(rb->DataType == GL_UNSIGNED_SHORT);
- for (j = 0; j < height; j++, y++) {
- void *dest =_mesa_image_address2d(packing, pixels, width, height,
- GL_DEPTH_COMPONENT, type, j, 0);
- rb->GetRow(ctx, rb, width, x, y, dest);
- }
- }
- else if (type == GL_UNSIGNED_INT && fb->Visual.depthBits == 24
- && !biasOrScale && !packing->SwapBytes) {
- /* Special case: directly read 24-bit unsigned depth values. */
- GLint j;
- ASSERT(rb->Format == MESA_FORMAT_X8_Z24 ||
- rb->Format == MESA_FORMAT_S8_Z24 ||
- rb->Format == MESA_FORMAT_Z24_X8 ||
- rb->Format == MESA_FORMAT_Z24_S8);
- ASSERT(rb->DataType == GL_UNSIGNED_INT ||
- rb->DataType == GL_UNSIGNED_INT_24_8);
- for (j = 0; j < height; j++, y++) {
- GLuint *dest = (GLuint *)
- _mesa_image_address2d(packing, pixels, width, height,
- GL_DEPTH_COMPONENT, type, j, 0);
- GLint k;
- rb->GetRow(ctx, rb, width, x, y, dest);
- /* convert range from 24-bit to 32-bit */
- if (rb->Format == MESA_FORMAT_X8_Z24 ||
- rb->Format == MESA_FORMAT_S8_Z24) {
- for (k = 0; k < width; k++) {
- /* Note: put MSByte of 24-bit value into LSByte */
- dest[k] = (dest[k] << 8) | ((dest[k] >> 16) & 0xff);
- }
- }
- else {
- for (k = 0; k < width; k++) {
- /* Note: fill in LSByte by replication */
- dest[k] = dest[k] | ((dest[k] >> 8) & 0xff);
- }
- }
- }
- }
- else if (type == GL_UNSIGNED_INT && fb->Visual.depthBits == 32
- && !biasOrScale && !packing->SwapBytes) {
- /* Special case: directly read 32-bit unsigned depth values. */
- GLint j;
- ASSERT(rb->Format == MESA_FORMAT_Z32);
- ASSERT(rb->DataType == GL_UNSIGNED_INT);
- for (j = 0; j < height; j++, y++) {
- void *dest = _mesa_image_address2d(packing, pixels, width, height,
- GL_DEPTH_COMPONENT, type, j, 0);
- rb->GetRow(ctx, rb, width, x, y, dest);
- }
- }
- else {
- /* General case (slower) */
- GLint j;
- for (j = 0; j < height; j++, y++) {
- GLfloat depthValues[MAX_WIDTH];
- GLvoid *dest = _mesa_image_address2d(packing, pixels, width, height,
- GL_DEPTH_COMPONENT, type, j, 0);
- _swrast_read_depth_span_float(ctx, rb, width, x, y, depthValues);
- _mesa_pack_depth_span(ctx, width, dest, type, depthValues, packing);
- }
+ if (fast_read_depth_pixels(ctx, x, y, width, height, type, pixels, packing))
+ return;
+
+ /* General case (slower) */
+ for (j = 0; j < height; j++, y++) {
+ GLfloat depthValues[MAX_WIDTH];
+ GLvoid *dest = _mesa_image_address2d(packing, pixels, width, height,
+ GL_DEPTH_COMPONENT, type, j, 0);
+ _swrast_read_depth_span_float(ctx, rb, width, x, y, depthValues);
+ _mesa_pack_depth_span(ctx, width, dest, type, depthValues, packing);
}
}
--
1.7.7
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