svn merge ^/branches/released . --username marha

1 files changed, 620 insertions, 0 deletions

diff --git a/mesalib/src/mesa/swrast/s_readpix.c b/mesalib/src/mesa/swrast/s_readpix.c
new file mode 100644
index 000000000..48b9408d2
--- /dev/null
+++ b/mesalib/src/mesa/swrast/s_readpix.c
@@ -0,0 +1,620 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.0.3
+ *
+ * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * 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.
+ */
+
+
+#include "main/glheader.h"
+#include "main/bufferobj.h"
+#include "main/colormac.h"
+#include "main/convolve.h"
+#include "main/context.h"
+#include "main/feedback.h"
+#include "main/image.h"
+#include "main/macros.h"
+#include "main/imports.h"
+#include "main/pixel.h"
+#include "main/state.h"
+
+#include "s_context.h"
+#include "s_depth.h"
+#include "s_span.h"
+#include "s_stencil.h"
+
+
+/*
+ * Read a block of color index pixels.
+ */
+static void
+read_index_pixels( GLcontext *ctx,
+                   GLint x, GLint y,
+                   GLsizei width, GLsizei height,
+                   GLenum type, GLvoid *pixels,
+                   const struct gl_pixelstore_attrib *packing )
+{
+   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
+   GLint i;
+
+   if (!rb)
+      return;
+
+   /* width should never be > MAX_WIDTH since we did clipping earlier */
+   ASSERT(width <= MAX_WIDTH);
+
+   /* process image row by row */
+   for (i = 0; i < height; i++) {
+      GLuint index[MAX_WIDTH];
+      GLvoid *dest;
+      ASSERT(rb->DataType == GL_UNSIGNED_INT);
+      rb->GetRow(ctx, rb, width, x, y + i, index);
+
+      dest = _mesa_image_address2d(packing, pixels, width, height,
+                                   GL_COLOR_INDEX, type, i, 0);
+
+      _mesa_pack_index_span(ctx, width, type, dest, index,
+                            &ctx->Pack, ctx->_ImageTransferState);
+   }
+}
+
+
+
+/**
+ * Read pixels for format=GL_DEPTH_COMPONENT.
+ */
+static void
+read_depth_pixels( GLcontext *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->_DepthBuffer;
+   const GLboolean biasOrScale
+      = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
+
+   if (!rb)
+      return;
+
+   /* clipping should have been done already */
+   ASSERT(x >= 0);
+   ASSERT(y >= 0);
+   ASSERT(x + width <= (GLint) rb->Width);
+   ASSERT(y + height <= (GLint) rb->Height);
+   /* 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->InternalFormat == GL_DEPTH_COMPONENT16);
+      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->InternalFormat == GL_DEPTH_COMPONENT24);
+      ASSERT(rb->DataType == GL_UNSIGNED_INT);
+      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 */
+         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 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->InternalFormat == GL_DEPTH_COMPONENT32);
+      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);
+      }
+   }
+}
+
+
+/**
+ * Read pixels for format=GL_STENCIL_INDEX.
+ */
+static void
+read_stencil_pixels( GLcontext *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->_StencilBuffer;
+   GLint j;
+
+   if (!rb)
+      return;
+
+   /* width should never be > MAX_WIDTH since we did clipping earlier */
+   ASSERT(width <= MAX_WIDTH);
+
+   /* process image row by row */
+   for (j=0;j<height;j++,y++) {
+      GLvoid *dest;
+      GLstencil stencil[MAX_WIDTH];
+
+      _swrast_read_stencil_span(ctx, rb, width, x, y, stencil);
+
+      dest = _mesa_image_address2d(packing, pixels, width, height,
+                                   GL_STENCIL_INDEX, type, j, 0);
+
+      _mesa_pack_stencil_span(ctx, width, type, dest, stencil, packing);
+   }
+}
+
+
+
+/**
+ * Optimized glReadPixels for particular pixel formats when pixel
+ * scaling, biasing, mapping, etc. are disabled.
+ * \return GL_TRUE if success, GL_FALSE if unable to do the readpixels
+ */
+static GLboolean
+fast_read_rgba_pixels( GLcontext *ctx,
+                       GLint x, GLint y,
+                       GLsizei width, GLsizei height,
+                       GLenum format, GLenum type,
+                       GLvoid *pixels,
+                       const struct gl_pixelstore_attrib *packing,
+                       GLbitfield transferOps)
+{
+   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
+
+   if (!rb)
+      return GL_FALSE;
+
+   ASSERT(rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB);
+
+   /* clipping should have already been done */
+   ASSERT(x + width <= (GLint) rb->Width);
+   ASSERT(y + height <= (GLint) rb->Height);
+
+   /* check for things we can't handle here */
+   if (transferOps ||
+       packing->SwapBytes ||
+       packing->LsbFirst) {
+      return GL_FALSE;
+   }
+
+   if (format == GL_RGBA && rb->DataType == type) {
+      const GLint dstStride = _mesa_image_row_stride(packing, width,
+                                                     format, type);
+      GLubyte *dest
+         = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
+                                             format, type, 0, 0);
+      GLint row;
+      ASSERT(rb->GetRow);
+      for (row = 0; row < height; row++) {
+         rb->GetRow(ctx, rb, width, x, y + row, dest);
+         dest += dstStride;
+      }
+      return GL_TRUE;
+   }
+
+   if (format == GL_RGB &&
+       rb->DataType == GL_UNSIGNED_BYTE &&
+       type == GL_UNSIGNED_BYTE) {
+      const GLint dstStride = _mesa_image_row_stride(packing, width,
+                                                     format, type);
+      GLubyte *dest
+         = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
+                                             format, type, 0, 0);
+      GLint row;
+      ASSERT(rb->GetRow);
+      for (row = 0; row < height; row++) {
+         GLubyte tempRow[MAX_WIDTH][4];
+         GLint col;
+         rb->GetRow(ctx, rb, width, x, y + row, tempRow);
+         /* convert RGBA to RGB */
+         for (col = 0; col < width; col++) {
+            dest[col * 3 + 0] = tempRow[col][0];
+            dest[col * 3 + 1] = tempRow[col][1];
+            dest[col * 3 + 2] = tempRow[col][2];
+         }
+         dest += dstStride;
+      }
+      return GL_TRUE;
+   }
+
+   /* not handled */
+   return GL_FALSE;
+}
+
+
+/**
+ * When we're using a low-precision color buffer (like 16-bit 5/6/5)
+ * we have to adjust our color values a bit to pass conformance.
+ * The problem is when a 5 or 6-bit color value is convert to an 8-bit
+ * value and then a floating point value, the floating point values don't
+ * increment uniformly as the 5 or 6-bit value is incremented.
+ *
+ * This function adjusts floating point values to compensate.
+ */
+static void
+adjust_colors(GLcontext *ctx, GLuint n, GLfloat rgba[][4])
+{
+   const GLuint rShift = 8 - ctx->Visual.redBits;
+   const GLuint gShift = 8 - ctx->Visual.greenBits;
+   const GLuint bShift = 8 - ctx->Visual.blueBits;
+   const GLfloat rScale = 1.0F / (GLfloat) ((1 << ctx->Visual.redBits  ) - 1);
+   const GLfloat gScale = 1.0F / (GLfloat) ((1 << ctx->Visual.greenBits) - 1);
+   const GLfloat bScale = 1.0F / (GLfloat) ((1 << ctx->Visual.blueBits ) - 1);
+   GLuint i;
+   for (i = 0; i < n; i++) {
+      GLint r, g, b;
+      /* convert float back to ubyte */
+      CLAMPED_FLOAT_TO_UBYTE(r, rgba[i][RCOMP]);
+      CLAMPED_FLOAT_TO_UBYTE(g, rgba[i][GCOMP]);
+      CLAMPED_FLOAT_TO_UBYTE(b, rgba[i][BCOMP]);
+      /* using only the N most significant bits of the ubyte value, convert to
+       * float in [0,1].
+       */
+      rgba[i][RCOMP] = (GLfloat) (r >> rShift) * rScale;
+      rgba[i][GCOMP] = (GLfloat) (g >> gShift) * gScale;
+      rgba[i][BCOMP] = (GLfloat) (b >> bShift) * bScale;
+   }
+}
+
+
+
+/*
+ * Read R, G, B, A, RGB, L, or LA pixels.
+ */
+static void
+read_rgba_pixels( GLcontext *ctx,
+                  GLint x, GLint y,
+                  GLsizei width, GLsizei height,
+                  GLenum format, GLenum type, GLvoid *pixels,
+                  const struct gl_pixelstore_attrib *packing )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLbitfield transferOps = ctx->_ImageTransferState;
+   struct gl_framebuffer *fb = ctx->ReadBuffer;
+   struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
+
+   if (!rb)
+      return;
+
+   if (type == GL_FLOAT && ((ctx->Color.ClampReadColor == GL_TRUE) ||
+                            (ctx->Color.ClampReadColor == GL_FIXED_ONLY_ARB &&
+                             rb->DataType != GL_FLOAT)))
+      transferOps |= IMAGE_CLAMP_BIT;
+
+   /* Try optimized path first */
+   if (fast_read_rgba_pixels(ctx, x, y, width, height,
+                             format, type, pixels, packing, transferOps)) {
+      return; /* done! */
+   }
+
+   /* width should never be > MAX_WIDTH since we did clipping earlier */
+   ASSERT(width <= MAX_WIDTH);
+
+   if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
+      GLfloat *dest, *src, *tmpImage, *convImage;
+      GLint row;
+
+      tmpImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
+      if (!tmpImage) {
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+         return;
+      }
+      convImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
+      if (!convImage) {
+         _mesa_free(tmpImage);
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+         return;
+      }
+
+      /* read full RGBA, FLOAT image */
+      dest = tmpImage;
+      for (row = 0; row < height; row++, y++) {
+         if (fb->Visual.rgbMode) {
+            _swrast_read_rgba_span(ctx, rb, width, x, y, GL_FLOAT, dest);
+         }
+         else {
+            GLuint index[MAX_WIDTH];
+            ASSERT(rb->DataType == GL_UNSIGNED_INT);
+            rb->GetRow(ctx, rb, width, x, y, index);
+            _mesa_apply_ci_transfer_ops(ctx,
+                                        transferOps & IMAGE_SHIFT_OFFSET_BIT,
+                                        width, index);
+            _mesa_map_ci_to_rgba(ctx, width, index, (GLfloat (*)[4]) dest);
+         }
+         _mesa_apply_rgba_transfer_ops(ctx, 
+                                      transferOps & IMAGE_PRE_CONVOLUTION_BITS,
+                                      width, (GLfloat (*)[4]) dest);
+         dest += width * 4;
+      }
+
+      /* do convolution */
+      if (ctx->Pixel.Convolution2DEnabled) {
+         _mesa_convolve_2d_image(ctx, &width, &height, tmpImage, convImage);
+      }
+      else {
+         ASSERT(ctx->Pixel.Separable2DEnabled);
+         _mesa_convolve_sep_image(ctx, &width, &height, tmpImage, convImage);
+      }
+      _mesa_free(tmpImage);
+
+      /* finish transfer ops and pack the resulting image */
+      src = convImage;
+      for (row = 0; row < height; row++) {
+         GLvoid *dest;
+         dest = _mesa_image_address2d(packing, pixels, width, height,
+                                      format, type, row, 0);
+         _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) src,
+                                    format, type, dest, packing,
+                                    transferOps & IMAGE_POST_CONVOLUTION_BITS);
+         src += width * 4;
+      }
+      _mesa_free(convImage);
+   }
+   else {
+      /* no convolution */
+      const GLint dstStride
+         = _mesa_image_row_stride(packing, width, format, type);
+      GLfloat (*rgba)[4] = swrast->SpanArrays->attribs[FRAG_ATTRIB_COL0];
+      GLint row;
+      GLubyte *dst
+         = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
+                                             format, type, 0, 0);
+
+      /* make sure we don't apply 1D convolution */
+      transferOps &= ~(IMAGE_CONVOLUTION_BIT |
+                       IMAGE_POST_CONVOLUTION_SCALE_BIAS);
+
+      for (row = 0; row < height; row++, y++) {
+
+         /* Get float rgba pixels */
+         if (fb->Visual.rgbMode) {
+            _swrast_read_rgba_span(ctx, rb, width, x, y, GL_FLOAT, rgba);
+         }
+         else {
+            /* read CI and convert to RGBA */
+            GLuint index[MAX_WIDTH];
+            ASSERT(rb->DataType == GL_UNSIGNED_INT);
+            rb->GetRow(ctx, rb, width, x, y, index);
+            _mesa_apply_ci_transfer_ops(ctx,
+                                        transferOps & IMAGE_SHIFT_OFFSET_BIT,
+                                        width, index);
+            _mesa_map_ci_to_rgba(ctx, width, index, rgba);
+         }
+
+         /* apply fudge factor for shallow color buffers */
+         if (fb->Visual.redBits < 8 ||
+             fb->Visual.greenBits < 8 ||
+             fb->Visual.blueBits < 8) {
+            adjust_colors(ctx, width, rgba);
+         }
+
+         /* pack the row of RGBA pixels into user's buffer */
+         _mesa_pack_rgba_span_float(ctx, width, rgba, format, type, dst,
+                                    packing, transferOps);
+
+         dst += dstStride;
+      }
+   }
+}
+
+
+/**
+ * Read combined depth/stencil values.
+ * We'll have already done error checking to be sure the expected
+ * depth and stencil buffers really exist.
+ */
+static void
+read_depth_stencil_pixels(GLcontext *ctx,
+                          GLint x, GLint y,
+                          GLsizei width, GLsizei height,
+                          GLenum type, GLvoid *pixels,
+                          const struct gl_pixelstore_attrib *packing )
+{
+   const GLboolean scaleOrBias
+      = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
+   const GLboolean stencilTransfer = ctx->Pixel.IndexShift
+      || ctx->Pixel.IndexOffset || ctx->Pixel.MapStencilFlag;
+   struct gl_renderbuffer *depthRb, *stencilRb;
+
+   depthRb = ctx->ReadBuffer->_DepthBuffer;
+   stencilRb = ctx->ReadBuffer->_StencilBuffer;
+
+   if (!depthRb || !stencilRb)
+      return;
+
+   depthRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
+   stencilRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
+
+   if (depthRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
+       stencilRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
+       depthRb == stencilRb &&
+       !scaleOrBias &&
+       !stencilTransfer) {
+      /* This is the ideal case.
+       * Reading GL_DEPTH_STENCIL pixels from combined depth/stencil buffer.
+       * Plus, no pixel transfer ops to worry about!
+       */
+      GLint i;
+      GLint dstStride = _mesa_image_row_stride(packing, width,
+                                               GL_DEPTH_STENCIL_EXT, type);
+      GLubyte *dst = (GLubyte *) _mesa_image_address2d(packing, pixels,
+                                                       width, height,
+                                                       GL_DEPTH_STENCIL_EXT,
+                                                       type, 0, 0);
+      for (i = 0; i < height; i++) {
+         depthRb->GetRow(ctx, depthRb, width, x, y + i, dst);
+         dst += dstStride;
+      }
+   }
+   else {
+      /* Reading GL_DEPTH_STENCIL pixels from separate depth/stencil buffers,
+       * or we need pixel transfer.
+       */
+      GLint i;
+      depthRb = ctx->ReadBuffer->_DepthBuffer;
+      stencilRb = ctx->ReadBuffer->_StencilBuffer;
+
+      for (i = 0; i < height; i++) {
+         GLstencil stencilVals[MAX_WIDTH];
+
+         GLuint *depthStencilDst = (GLuint *)
+            _mesa_image_address2d(packing, pixels, width, height,
+                                  GL_DEPTH_STENCIL_EXT, type, i, 0);
+
+         _swrast_read_stencil_span(ctx, stencilRb, width,
+                                   x, y + i, stencilVals);
+
+         if (!scaleOrBias && !stencilTransfer
+             && ctx->ReadBuffer->Visual.depthBits == 24) {
+            /* ideal case */
+            GLuint zVals[MAX_WIDTH]; /* 24-bit values! */
+            GLint j;
+            ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
+            /* note, we've already been clipped */
+            depthRb->GetRow(ctx, depthRb, width, x, y + i, zVals);
+            for (j = 0; j < width; j++) {
+               depthStencilDst[j] = (zVals[j] << 8) | (stencilVals[j] & 0xff);
+            }
+         }
+         else {
+            /* general case */
+            GLfloat depthVals[MAX_WIDTH];
+            _swrast_read_depth_span_float(ctx, depthRb, width, x, y + i,
+                                          depthVals);
+            _mesa_pack_depth_stencil_span(ctx, width, depthStencilDst,
+                                          depthVals, stencilVals, packing);
+         }
+      }
+   }
+}
+
+
+
+/**
+ * Software fallback routine for ctx->Driver.ReadPixels().
+ * By time we get here, all error checking will have been done.
+ */
+void
+_swrast_ReadPixels( GLcontext *ctx,
+		    GLint x, GLint y, GLsizei width, GLsizei height,
+		    GLenum format, GLenum type,
+		    const struct gl_pixelstore_attrib *packing,
+		    GLvoid *pixels )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   struct gl_pixelstore_attrib clippedPacking = *packing;
+
+   /* Need to do swrast_render_start() before clipping or anything else
+    * since this is where a driver may grab the hw lock and get an updated
+    * window size.
+    */
+   swrast_render_start(ctx);
+
+   if (ctx->NewState)
+      _mesa_update_state(ctx);
+
+   if (swrast->NewState)
+      _swrast_validate_derived( ctx );
+
+   /* Do all needed clipping here, so that we can forget about it later */
+   if (!_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
+      /* The ReadPixels region is totally outside the window bounds */
+      swrast_render_finish(ctx);
+      return;
+   }
+
+   pixels = _mesa_map_pbo_dest(ctx, &clippedPacking, pixels);
+   if (!pixels)
+      return;
+  
+   switch (format) {
+      case GL_COLOR_INDEX:
+         read_index_pixels(ctx, x, y, width, height, type, pixels,
+                           &clippedPacking);
+	 break;
+      case GL_STENCIL_INDEX:
+	 read_stencil_pixels(ctx, x, y, width, height, type, pixels,
+                             &clippedPacking);
+         break;
+      case GL_DEPTH_COMPONENT:
+	 read_depth_pixels(ctx, x, y, width, height, type, pixels,
+                           &clippedPacking);
+	 break;
+      case GL_RED:
+      case GL_GREEN:
+      case GL_BLUE:
+      case GL_ALPHA:
+      case GL_RGB:
+      case GL_LUMINANCE:
+      case GL_LUMINANCE_ALPHA:
+      case GL_RGBA:
+      case GL_BGR:
+      case GL_BGRA:
+      case GL_ABGR_EXT:
+         read_rgba_pixels(ctx, x, y, width, height,
+                          format, type, pixels, &clippedPacking);
+	 break;
+      case GL_DEPTH_STENCIL_EXT:
+         read_depth_stencil_pixels(ctx, x, y, width, height,
+                                   type, pixels, &clippedPacking);
+         break;
+      default:
+	 _mesa_problem(ctx, "unexpected format in _swrast_ReadPixels");
+         /* don't return yet, clean-up */
+   }
+
+   swrast_render_finish(ctx);
+
+   _mesa_unmap_pbo_dest(ctx, &clippedPacking);
+}