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

1 files changed, 898 insertions, 0 deletions

diff --git a/mesalib/src/mesa/swrast/s_drawpix.c b/mesalib/src/mesa/swrast/s_drawpix.c
new file mode 100644
index 000000000..6970b2e9c
--- /dev/null
+++ b/mesalib/src/mesa/swrast/s_drawpix.c
@@ -0,0 +1,898 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  7.1
+ *
+ * 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/context.h"
+#include "main/convolve.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_span.h"
+#include "s_stencil.h"
+#include "s_zoom.h"
+
+
+
+/**
+ * Try to do a fast and simple RGB(a) glDrawPixels.
+ * Return:  GL_TRUE if success, GL_FALSE if slow path must be used instead
+ */
+static GLboolean
+fast_draw_rgba_pixels(GLcontext *ctx, GLint x, GLint y,
+                      GLsizei width, GLsizei height,
+                      GLenum format, GLenum type,
+                      const struct gl_pixelstore_attrib *userUnpack,
+                      const GLvoid *pixels)
+{
+   const GLint imgX = x, imgY = y;
+   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
+   GLenum rbType;
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   SWspan span;
+   GLboolean simpleZoom;
+   GLint yStep;  /* +1 or -1 */
+   struct gl_pixelstore_attrib unpack;
+   GLint destX, destY, drawWidth, drawHeight; /* post clipping */
+
+   if (!rb)
+      return GL_TRUE; /* no-op */
+
+   rbType = rb->DataType;
+
+   if ((swrast->_RasterMask & ~CLIP_BIT) ||
+       ctx->Texture._EnabledCoordUnits ||
+       userUnpack->SwapBytes ||
+       ctx->_ImageTransferState) {
+      /* can't handle any of those conditions */
+      return GL_FALSE;
+   }
+
+   INIT_SPAN(span, GL_BITMAP);
+   span.arrayMask = SPAN_RGBA;
+   span.arrayAttribs = FRAG_BIT_COL0;
+   _swrast_span_default_attribs(ctx, &span);
+
+   /* copy input params since clipping may change them */
+   unpack = *userUnpack;
+   destX = x;
+   destY = y;
+   drawWidth = width;
+   drawHeight = height;
+
+   /* check for simple zooming and clipping */
+   if (ctx->Pixel.ZoomX == 1.0F &&
+       (ctx->Pixel.ZoomY == 1.0F || ctx->Pixel.ZoomY == -1.0F)) {
+      if (!_mesa_clip_drawpixels(ctx, &destX, &destY,
+                                 &drawWidth, &drawHeight, &unpack)) {
+         /* image was completely clipped: no-op, all done */
+         return GL_TRUE;
+      }
+      simpleZoom = GL_TRUE;
+      yStep = (GLint) ctx->Pixel.ZoomY;
+      ASSERT(yStep == 1 || yStep == -1);
+   }
+   else {
+      /* non-simple zooming */
+      simpleZoom = GL_FALSE;
+      yStep = 1;
+      if (unpack.RowLength == 0)
+         unpack.RowLength = width;
+   }
+
+   /*
+    * Ready to draw!
+    */
+
+   if (format == GL_RGBA && type == rbType) {
+      const GLubyte *src
+         = (const GLubyte *) _mesa_image_address2d(&unpack, pixels, width,
+                                                   height, format, type, 0, 0);
+      const GLint srcStride = _mesa_image_row_stride(&unpack, width,
+                                                     format, type);
+      if (simpleZoom) {
+         GLint row;
+         for (row = 0; row < drawHeight; row++) {
+            rb->PutRow(ctx, rb, drawWidth, destX, destY, src, NULL);
+            src += srcStride;
+            destY += yStep;
+         }
+      }
+      else {
+         /* with zooming */
+         GLint row;
+         for (row = 0; row < drawHeight; row++) {
+            span.x = destX;
+            span.y = destY + row;
+            span.end = drawWidth;
+            span.array->ChanType = rbType;
+            _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span, src);
+            src += srcStride;
+         }
+         span.array->ChanType = CHAN_TYPE;
+      }
+      return GL_TRUE;
+   }
+
+   if (format == GL_RGB && type == rbType) {
+      const GLubyte *src
+         = (const GLubyte *) _mesa_image_address2d(&unpack, pixels, width,
+                                                   height, format, type, 0, 0);
+      const GLint srcStride = _mesa_image_row_stride(&unpack, width,
+                                                     format, type);
+      if (simpleZoom) {
+         GLint row;
+         for (row = 0; row < drawHeight; row++) {
+            rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, src, NULL);
+            src += srcStride;
+            destY += yStep;
+         }
+      }
+      else {
+         /* with zooming */
+         GLint row;
+         for (row = 0; row < drawHeight; row++) {
+            span.x = destX;
+            span.y = destY;
+            span.end = drawWidth;
+            span.array->ChanType = rbType;
+            _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span, src);
+            src += srcStride;
+            destY++;
+         }
+         span.array->ChanType = CHAN_TYPE;
+      }
+      return GL_TRUE;
+   }
+
+   /* Remaining cases haven't been tested with alignment != 1 */
+   if (userUnpack->Alignment != 1)
+      return GL_FALSE;
+
+   if (format == GL_LUMINANCE && type == CHAN_TYPE && rbType == CHAN_TYPE) {
+      const GLchan *src = (const GLchan *) pixels
+         + (unpack.SkipRows * unpack.RowLength + unpack.SkipPixels);
+      if (simpleZoom) {
+         /* no zooming */
+         GLint row;
+         ASSERT(drawWidth <= MAX_WIDTH);
+         for (row = 0; row < drawHeight; row++) {
+            GLchan rgb[MAX_WIDTH][3];
+            GLint i;
+            for (i = 0;i<drawWidth;i++) {
+               rgb[i][0] = src[i];
+               rgb[i][1] = src[i];
+               rgb[i][2] = src[i];
+            }
+            rb->PutRowRGB(ctx, rb, drawWidth, destX, destY, rgb, NULL);
+            src += unpack.RowLength;
+            destY += yStep;
+         }
+      }
+      else {
+         /* with zooming */
+         GLint row;
+         ASSERT(drawWidth <= MAX_WIDTH);
+         for (row = 0; row < drawHeight; row++) {
+            GLchan rgb[MAX_WIDTH][3];
+            GLint i;
+            for (i = 0;i<drawWidth;i++) {
+               rgb[i][0] = src[i];
+               rgb[i][1] = src[i];
+               rgb[i][2] = src[i];
+            }
+            span.x = destX;
+            span.y = destY;
+            span.end = drawWidth;
+            _swrast_write_zoomed_rgb_span(ctx, imgX, imgY, &span, rgb);
+            src += unpack.RowLength;
+            destY++;
+         }
+      }
+      return GL_TRUE;
+   }
+
+   if (format == GL_LUMINANCE_ALPHA && type == CHAN_TYPE && rbType == CHAN_TYPE) {
+      const GLchan *src = (const GLchan *) pixels
+         + (unpack.SkipRows * unpack.RowLength + unpack.SkipPixels)*2;
+      if (simpleZoom) {
+         GLint row;
+         ASSERT(drawWidth <= MAX_WIDTH);
+         for (row = 0; row < drawHeight; row++) {
+            GLint i;
+            const GLchan *ptr = src;
+            for (i = 0;i<drawWidth;i++) {
+               span.array->rgba[i][0] = *ptr;
+               span.array->rgba[i][1] = *ptr;
+               span.array->rgba[i][2] = *ptr++;
+               span.array->rgba[i][3] = *ptr++;
+            }
+            rb->PutRow(ctx, rb, drawWidth, destX, destY,
+                       span.array->rgba, NULL);
+            src += unpack.RowLength*2;
+            destY += yStep;
+         }
+      }
+      else {
+         /* with zooming */
+         GLint row;
+         ASSERT(drawWidth <= MAX_WIDTH);
+         for (row = 0; row < drawHeight; row++) {
+            const GLchan *ptr = src;
+            GLint i;
+            for (i = 0;i<drawWidth;i++) {
+               span.array->rgba[i][0] = *ptr;
+               span.array->rgba[i][1] = *ptr;
+               span.array->rgba[i][2] = *ptr++;
+               span.array->rgba[i][3] = *ptr++;
+            }
+            span.x = destX;
+            span.y = destY;
+            span.end = drawWidth;
+            _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
+                                           span.array->rgba);
+            src += unpack.RowLength*2;
+            destY++;
+         }
+      }
+      return GL_TRUE;
+   }
+
+   if (format == GL_COLOR_INDEX && type == GL_UNSIGNED_BYTE) {
+      const GLubyte *src = (const GLubyte *) pixels
+         + unpack.SkipRows * unpack.RowLength + unpack.SkipPixels;
+      if (ctx->Visual.rgbMode && rbType == GL_UNSIGNED_BYTE) {
+         /* convert ubyte/CI data to ubyte/RGBA */
+         if (simpleZoom) {
+            GLint row;
+            for (row = 0; row < drawHeight; row++) {
+               ASSERT(drawWidth <= MAX_WIDTH);
+               _mesa_map_ci8_to_rgba8(ctx, drawWidth, src,
+                                      span.array->rgba8);
+               rb->PutRow(ctx, rb, drawWidth, destX, destY,
+                          span.array->rgba8, NULL);
+               src += unpack.RowLength;
+               destY += yStep;
+            }
+         }
+         else {
+            /* ubyte/CI to ubyte/RGBA with zooming */
+            GLint row;
+            for (row = 0; row < drawHeight; row++) {
+               ASSERT(drawWidth <= MAX_WIDTH);
+               _mesa_map_ci8_to_rgba8(ctx, drawWidth, src,
+                                      span.array->rgba8);
+               span.x = destX;
+               span.y = destY;
+               span.end = drawWidth;
+               _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span,
+                                              span.array->rgba8);
+               src += unpack.RowLength;
+               destY++;
+            }
+         }
+         return GL_TRUE;
+      }
+      else if (!ctx->Visual.rgbMode && rbType == GL_UNSIGNED_INT) {
+         /* write CI data to CI frame buffer */
+         GLint row;
+         if (simpleZoom) {
+            for (row = 0; row < drawHeight; row++) {
+               GLuint index32[MAX_WIDTH];
+               GLint col;
+               for (col = 0; col < drawWidth; col++)
+                  index32[col] = src[col];
+               rb->PutRow(ctx, rb, drawWidth, destX, destY, index32, NULL);
+               src += unpack.RowLength;
+               destY += yStep;
+            }
+            return GL_TRUE;
+         }
+      }
+   }
+
+   /* can't handle this pixel format and/or data type */
+   return GL_FALSE;
+}
+
+
+
+/*
+ * Draw color index image.
+ */
+static void
+draw_index_pixels( GLcontext *ctx, GLint x, GLint y,
+                   GLsizei width, GLsizei height,
+                   GLenum type,
+                   const struct gl_pixelstore_attrib *unpack,
+                   const GLvoid *pixels )
+{
+   const GLint imgX = x, imgY = y;
+   const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
+   GLint row, skipPixels;
+   SWspan span;
+
+   INIT_SPAN(span, GL_BITMAP);
+   span.arrayMask = SPAN_INDEX;
+   _swrast_span_default_attribs(ctx, &span);
+
+   /*
+    * General solution
+    */
+   skipPixels = 0;
+   while (skipPixels < width) {
+      const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
+      ASSERT(spanWidth <= MAX_WIDTH);
+      for (row = 0; row < height; row++) {
+         const GLvoid *source = _mesa_image_address2d(unpack, pixels,
+                                                      width, height,
+                                                      GL_COLOR_INDEX, type,
+                                                      row, skipPixels);
+         _mesa_unpack_index_span(ctx, spanWidth, GL_UNSIGNED_INT,
+                                 span.array->index, type, source, unpack,
+                                 ctx->_ImageTransferState);
+
+         /* These may get changed during writing/clipping */
+         span.x = x + skipPixels;
+         span.y = y + row;
+         span.end = spanWidth;
+         
+         if (zoom)
+            _swrast_write_zoomed_index_span(ctx, imgX, imgY, &span);
+         else
+            _swrast_write_index_span(ctx, &span);
+      }
+      skipPixels += spanWidth;
+   }
+}
+
+
+
+/*
+ * Draw stencil image.
+ */
+static void
+draw_stencil_pixels( GLcontext *ctx, GLint x, GLint y,
+                     GLsizei width, GLsizei height,
+                     GLenum type,
+                     const struct gl_pixelstore_attrib *unpack,
+                     const GLvoid *pixels )
+{
+   const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
+   GLint skipPixels;
+
+   /* if width > MAX_WIDTH, have to process image in chunks */
+   skipPixels = 0;
+   while (skipPixels < width) {
+      const GLint spanX = x + skipPixels;
+      const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
+      GLint row;
+      for (row = 0; row < height; row++) {
+         const GLint spanY = y + row;
+         GLstencil values[MAX_WIDTH];
+         GLenum destType = (sizeof(GLstencil) == sizeof(GLubyte))
+                         ? GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT;
+         const GLvoid *source = _mesa_image_address2d(unpack, pixels,
+                                                      width, height,
+                                                      GL_COLOR_INDEX, type,
+                                                      row, skipPixels);
+         _mesa_unpack_stencil_span(ctx, spanWidth, destType, values,
+                                   type, source, unpack,
+                                   ctx->_ImageTransferState);
+         if (zoom) {
+            _swrast_write_zoomed_stencil_span(ctx, x, y, spanWidth,
+                                              spanX, spanY, values);
+         }
+         else {
+            _swrast_write_stencil_span(ctx, spanWidth, spanX, spanY, values);
+         }
+      }
+      skipPixels += spanWidth;
+   }
+}
+
+
+/*
+ * Draw depth image.
+ */
+static void
+draw_depth_pixels( GLcontext *ctx, GLint x, GLint y,
+                   GLsizei width, GLsizei height,
+                   GLenum type,
+                   const struct gl_pixelstore_attrib *unpack,
+                   const GLvoid *pixels )
+{
+   const GLboolean scaleOrBias
+      = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
+   const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
+   SWspan span;
+
+   INIT_SPAN(span, GL_BITMAP);
+   span.arrayMask = SPAN_Z;
+   _swrast_span_default_attribs(ctx, &span);
+
+   if (type == GL_UNSIGNED_SHORT
+       && ctx->DrawBuffer->Visual.depthBits == 16
+       && !scaleOrBias
+       && !zoom
+       && ctx->Visual.rgbMode
+       && width <= MAX_WIDTH
+       && !unpack->SwapBytes) {
+      /* Special case: directly write 16-bit depth values */
+      GLint row;
+      for (row = 0; row < height; row++) {
+         const GLushort *zSrc = (const GLushort *)
+            _mesa_image_address2d(unpack, pixels, width, height,
+                                  GL_DEPTH_COMPONENT, type, row, 0);
+         GLint i;
+         for (i = 0; i < width; i++)
+            span.array->z[i] = zSrc[i];
+         span.x = x;
+         span.y = y + row;
+         span.end = width;
+         _swrast_write_rgba_span(ctx, &span);
+      }
+   }
+   else if (type == GL_UNSIGNED_INT
+            && !scaleOrBias
+            && !zoom
+            && ctx->Visual.rgbMode
+            && width <= MAX_WIDTH
+            && !unpack->SwapBytes) {
+      /* Special case: shift 32-bit values down to Visual.depthBits */
+      const GLint shift = 32 - ctx->DrawBuffer->Visual.depthBits;
+      GLint row;
+      for (row = 0; row < height; row++) {
+         const GLuint *zSrc = (const GLuint *)
+            _mesa_image_address2d(unpack, pixels, width, height,
+                                  GL_DEPTH_COMPONENT, type, row, 0);
+         if (shift == 0) {
+            _mesa_memcpy(span.array->z, zSrc, width * sizeof(GLuint));
+         }
+         else {
+            GLint col;
+            for (col = 0; col < width; col++)
+               span.array->z[col] = zSrc[col] >> shift;
+         }
+         span.x = x;
+         span.y = y + row;
+         span.end = width;
+         _swrast_write_rgba_span(ctx, &span);
+      }
+   }
+   else {
+      /* General case */
+      const GLuint depthMax = ctx->DrawBuffer->_DepthMax;
+      GLint skipPixels = 0;
+
+      /* in case width > MAX_WIDTH do the copy in chunks */
+      while (skipPixels < width) {
+         const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
+         GLint row;
+         ASSERT(span.end <= MAX_WIDTH);
+         for (row = 0; row < height; row++) {
+            const GLvoid *zSrc = _mesa_image_address2d(unpack,
+                                                      pixels, width, height,
+                                                      GL_DEPTH_COMPONENT, type,
+                                                      row, skipPixels);
+
+            /* Set these for each row since the _swrast_write_* function may
+             * change them while clipping.
+             */
+            span.x = x + skipPixels;
+            span.y = y + row;
+            span.end = spanWidth;
+
+            _mesa_unpack_depth_span(ctx, spanWidth,
+                                    GL_UNSIGNED_INT, span.array->z, depthMax,
+                                    type, zSrc, unpack);
+            if (zoom) {
+               _swrast_write_zoomed_depth_span(ctx, x, y, &span);
+            }
+            else if (ctx->Visual.rgbMode) {
+               _swrast_write_rgba_span(ctx, &span);
+            }
+            else {
+               _swrast_write_index_span(ctx, &span);
+            }
+         }
+         skipPixels += spanWidth;
+      }
+   }
+}
+
+
+
+/**
+ * Draw RGBA image.
+ */
+static void
+draw_rgba_pixels( GLcontext *ctx, GLint x, GLint y,
+                  GLsizei width, GLsizei height,
+                  GLenum format, GLenum type,
+                  const struct gl_pixelstore_attrib *unpack,
+                  const GLvoid *pixels )
+{
+   const GLint imgX = x, imgY = y;
+   const GLboolean zoom = ctx->Pixel.ZoomX!=1.0 || ctx->Pixel.ZoomY!=1.0;
+   GLfloat *convImage = NULL;
+   GLbitfield transferOps = ctx->_ImageTransferState;
+   SWspan span;
+
+   /* Try an optimized glDrawPixels first */
+   if (fast_draw_rgba_pixels(ctx, x, y, width, height, format, type,
+                             unpack, pixels)) {
+      return;
+   }
+
+   INIT_SPAN(span, GL_BITMAP);
+   _swrast_span_default_attribs(ctx, &span);
+   span.arrayMask = SPAN_RGBA;
+   span.arrayAttribs = FRAG_BIT_COL0; /* we're fill in COL0 attrib values */
+
+   if (ctx->Pixel.Convolution2DEnabled || ctx->Pixel.Separable2DEnabled) {
+      /* Convolution has to be handled specially.  We'll create an
+       * intermediate image, applying all pixel transfer operations
+       * up to convolution.  Then we'll convolve the image.  Then
+       * we'll proceed with the rest of the transfer operations and
+       * rasterize the image.
+       */
+      GLint row;
+      GLfloat *dest, *tmpImage;
+
+      tmpImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
+      if (!tmpImage) {
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glDrawPixels");
+         return;
+      }
+      convImage = (GLfloat *) _mesa_malloc(width * height * 4 * sizeof(GLfloat));
+      if (!convImage) {
+         _mesa_free(tmpImage);
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glDrawPixels");
+         return;
+      }
+
+      /* Unpack the image and apply transfer ops up to convolution */
+      dest = tmpImage;
+      for (row = 0; row < height; row++) {
+         const GLvoid *source = _mesa_image_address2d(unpack,
+                                  pixels, width, height, format, type, row, 0);
+         _mesa_unpack_color_span_float(ctx, width, GL_RGBA, (GLfloat *) dest,
+                                     format, type, source, unpack,
+                                     transferOps & IMAGE_PRE_CONVOLUTION_BITS);
+         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);
+
+      /* continue transfer ops and draw the convolved image */
+      unpack = &ctx->DefaultPacking;
+      pixels = convImage;
+      format = GL_RGBA;
+      type = GL_FLOAT;
+      transferOps &= IMAGE_POST_CONVOLUTION_BITS;
+   }
+   else if (ctx->Pixel.Convolution1DEnabled) {
+      /* we only want to apply 1D convolution to glTexImage1D */
+      transferOps &= ~(IMAGE_CONVOLUTION_BIT |
+                       IMAGE_POST_CONVOLUTION_SCALE_BIAS);
+   }
+
+   if (ctx->DrawBuffer->_NumColorDrawBuffers > 0 &&
+       ctx->DrawBuffer->_ColorDrawBuffers[0]->DataType != GL_FLOAT &&
+       ctx->Color.ClampFragmentColor != GL_FALSE) {
+      /* need to clamp colors before applying fragment ops */
+      transferOps |= IMAGE_CLAMP_BIT;
+   }
+
+   /*
+    * General solution
+    */
+   {
+      const GLboolean sink = (ctx->Pixel.MinMaxEnabled && ctx->MinMax.Sink)
+         || (ctx->Pixel.HistogramEnabled && ctx->Histogram.Sink);
+      const GLbitfield interpMask = span.interpMask;
+      const GLbitfield arrayMask = span.arrayMask;
+      const GLint srcStride
+         = _mesa_image_row_stride(unpack, width, format, type);
+      GLint skipPixels = 0;
+      /* use span array for temp color storage */
+      GLfloat *rgba = (GLfloat *) span.array->attribs[FRAG_ATTRIB_COL0];
+
+      /* if the span is wider than MAX_WIDTH we have to do it in chunks */
+      while (skipPixels < width) {
+         const GLint spanWidth = MIN2(width - skipPixels, MAX_WIDTH);
+         const GLubyte *source
+            = (const GLubyte *) _mesa_image_address2d(unpack, pixels,
+                                                      width, height, format,
+                                                      type, 0, skipPixels);
+         GLint row;
+
+         for (row = 0; row < height; row++) {
+            /* get image row as float/RGBA */
+            _mesa_unpack_color_span_float(ctx, spanWidth, GL_RGBA, rgba,
+                                     format, type, source, unpack,
+                                     transferOps);
+            /* draw the span */
+            if (!sink) {
+               /* Set these for each row since the _swrast_write_* functions
+                * may change them while clipping/rendering.
+                */
+               span.array->ChanType = GL_FLOAT;
+               span.x = x + skipPixels;
+               span.y = y + row;
+               span.end = spanWidth;
+               span.arrayMask = arrayMask;
+               span.interpMask = interpMask;
+               if (zoom) {
+                  _swrast_write_zoomed_rgba_span(ctx, imgX, imgY, &span, rgba);
+               }
+               else {
+                  _swrast_write_rgba_span(ctx, &span);
+               }
+            }
+
+            source += srcStride;
+         } /* for row */
+
+         skipPixels += spanWidth;
+      } /* while skipPixels < width */
+
+      /* XXX this is ugly/temporary, to undo above change */
+      span.array->ChanType = CHAN_TYPE;
+   }
+
+   if (convImage) {
+      _mesa_free(convImage);
+   }
+}
+
+
+/**
+ * This is a bit different from drawing GL_DEPTH_COMPONENT pixels.
+ * The only per-pixel operations that apply are depth scale/bias,
+ * stencil offset/shift, GL_DEPTH_WRITEMASK and GL_STENCIL_WRITEMASK,
+ * and pixel zoom.
+ * Also, only the depth buffer and stencil buffers are touched, not the
+ * color buffer(s).
+ */
+static void
+draw_depth_stencil_pixels(GLcontext *ctx, GLint x, GLint y,
+                          GLsizei width, GLsizei height, GLenum type,
+                          const struct gl_pixelstore_attrib *unpack,
+                          const GLvoid *pixels)
+{
+   const GLint imgX = x, imgY = y;
+   const GLboolean scaleOrBias
+      = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
+   const GLuint depthMax = ctx->DrawBuffer->_DepthMax;
+   const GLuint stencilMask = ctx->Stencil.WriteMask[0];
+   const GLuint stencilType = (STENCIL_BITS == 8) ? 
+      GL_UNSIGNED_BYTE : GL_UNSIGNED_SHORT;
+   const GLboolean zoom = ctx->Pixel.ZoomX != 1.0 || ctx->Pixel.ZoomY != 1.0;
+   struct gl_renderbuffer *depthRb, *stencilRb;
+   struct gl_pixelstore_attrib clippedUnpack = *unpack;
+
+   if (!zoom) {
+      if (!_mesa_clip_drawpixels(ctx, &x, &y, &width, &height,
+                                 &clippedUnpack)) {
+         /* totally clipped */
+         return;
+      }
+   }
+   
+   depthRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
+   stencilRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
+   ASSERT(depthRb);
+   ASSERT(stencilRb);
+
+   if (depthRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
+       stencilRb->_BaseFormat == GL_DEPTH_STENCIL_EXT &&
+       depthRb == stencilRb &&
+       !scaleOrBias &&
+       !zoom &&
+       ctx->Depth.Mask &&
+       (stencilMask & 0xff) == 0xff) {
+      /* This is the ideal case.
+       * Drawing GL_DEPTH_STENCIL pixels into a combined depth/stencil buffer.
+       * Plus, no pixel transfer ops, zooming, or masking needed.
+       */
+      GLint i;
+      for (i = 0; i < height; i++) {
+         const GLuint *src = (const GLuint *) 
+            _mesa_image_address2d(&clippedUnpack, pixels, width, height,
+                                  GL_DEPTH_STENCIL_EXT, type, i, 0);
+         depthRb->PutRow(ctx, depthRb, width, x, y + i, src, NULL);
+      }
+   }
+   else {
+      /* sub-optimal cases:
+       * Separate depth/stencil buffers, or pixel transfer ops required.
+       */
+      /* XXX need to handle very wide images (skippixels) */
+      GLint i;
+
+      depthRb = ctx->DrawBuffer->_DepthBuffer;
+      stencilRb = ctx->DrawBuffer->_StencilBuffer;
+
+      for (i = 0; i < height; i++) {
+         const GLuint *depthStencilSrc = (const GLuint *)
+            _mesa_image_address2d(&clippedUnpack, pixels, width, height,
+                                  GL_DEPTH_STENCIL_EXT, type, i, 0);
+
+         if (ctx->Depth.Mask) {
+            if (!scaleOrBias && ctx->DrawBuffer->Visual.depthBits == 24) {
+               /* fast path 24-bit zbuffer */
+               GLuint zValues[MAX_WIDTH];
+               GLint j;
+               ASSERT(depthRb->DataType == GL_UNSIGNED_INT);
+               for (j = 0; j < width; j++) {
+                  zValues[j] = depthStencilSrc[j] >> 8;
+               }
+               if (zoom)
+                  _swrast_write_zoomed_z_span(ctx, imgX, imgY, width,
+                                              x, y + i, zValues);
+               else
+                  depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
+            }
+            else if (!scaleOrBias && ctx->DrawBuffer->Visual.depthBits == 16) {
+               /* fast path 16-bit zbuffer */
+               GLushort zValues[MAX_WIDTH];
+               GLint j;
+               ASSERT(depthRb->DataType == GL_UNSIGNED_SHORT);
+               for (j = 0; j < width; j++) {
+                  zValues[j] = depthStencilSrc[j] >> 16;
+               }
+               if (zoom)
+                  _swrast_write_zoomed_z_span(ctx, imgX, imgY, width,
+                                              x, y + i, zValues);
+               else
+                  depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
+            }
+            else {
+               /* general case */
+               GLuint zValues[MAX_WIDTH];  /* 16 or 32-bit Z value storage */
+               _mesa_unpack_depth_span(ctx, width,
+                                       depthRb->DataType, zValues, depthMax,
+                                       type, depthStencilSrc, &clippedUnpack);
+               if (zoom) {
+                  _swrast_write_zoomed_z_span(ctx, imgX, imgY, width, x,
+                                              y + i, zValues);
+               }
+               else {
+                  depthRb->PutRow(ctx, depthRb, width, x, y + i, zValues,NULL);
+               }
+            }
+         }
+
+         if (stencilMask != 0x0) {
+            GLstencil stencilValues[MAX_WIDTH];
+            /* get stencil values, with shift/offset/mapping */
+            _mesa_unpack_stencil_span(ctx, width, stencilType, stencilValues,
+                                      type, depthStencilSrc, &clippedUnpack,
+                                      ctx->_ImageTransferState);
+            if (zoom)
+               _swrast_write_zoomed_stencil_span(ctx, imgX, imgY, width,
+                                                  x, y + i, stencilValues);
+            else
+               _swrast_write_stencil_span(ctx, width, x, y + i, stencilValues);
+         }
+      }
+   }
+}
+
+
+/**
+ * Execute software-based glDrawPixels.
+ * By time we get here, all error checking will have been done.
+ */
+void
+_swrast_DrawPixels( GLcontext *ctx,
+		    GLint x, GLint y,
+		    GLsizei width, GLsizei height,
+		    GLenum format, GLenum type,
+		    const struct gl_pixelstore_attrib *unpack,
+		    const GLvoid *pixels )
+{
+   SWcontext *swrast = SWRAST_CONTEXT(ctx);
+   GLboolean save_vp_override = ctx->VertexProgram._Overriden;
+
+   /* We are creating fragments directly, without going through vertex
+    * programs.
+    *
+    * This override flag tells the fragment processing code that its input
+    * comes from a non-standard source, and it may therefore not rely on
+    * optimizations that assume e.g. constant color if there is no color
+    * vertex array.
+    */
+   _mesa_set_vp_override(ctx, GL_TRUE);
+
+   swrast_render_start(ctx);
+
+   if (ctx->NewState)
+      _mesa_update_state(ctx);
+
+   if (swrast->NewState)
+      _swrast_validate_derived( ctx );
+
+    pixels = _mesa_map_pbo_source(ctx, unpack, pixels);
+    if (!pixels) {
+       swrast_render_finish(ctx);
+       _mesa_set_vp_override(ctx, save_vp_override);
+       return;
+    }
+
+   switch (format) {
+   case GL_STENCIL_INDEX:
+      draw_stencil_pixels( ctx, x, y, width, height, type, unpack, pixels );
+      break;
+   case GL_DEPTH_COMPONENT:
+      draw_depth_pixels( ctx, x, y, width, height, type, unpack, pixels );
+      break;
+   case GL_COLOR_INDEX:
+      if (ctx->Visual.rgbMode)
+	 draw_rgba_pixels(ctx, x,y, width, height, format, type, unpack, pixels);
+      else
+	 draw_index_pixels(ctx, x, y, width, height, type, unpack, pixels);
+      break;
+   case GL_RED:
+   case GL_GREEN:
+   case GL_BLUE:
+   case GL_ALPHA:
+   case GL_LUMINANCE:
+   case GL_LUMINANCE_ALPHA:
+   case GL_RGB:
+   case GL_BGR:
+   case GL_RGBA:
+   case GL_BGRA:
+   case GL_ABGR_EXT:
+      draw_rgba_pixels(ctx, x, y, width, height, format, type, unpack, pixels);
+      break;
+   case GL_DEPTH_STENCIL_EXT:
+      draw_depth_stencil_pixels(ctx, x, y, width, height,
+                                type, unpack, pixels);
+      break;
+   default:
+      _mesa_problem(ctx, "unexpected format in _swrast_DrawPixels");
+      /* don't return yet, clean-up */
+   }
+
+   swrast_render_finish(ctx);
+   _mesa_set_vp_override(ctx, save_vp_override);
+
+   _mesa_unmap_pbo_source(ctx, unpack);
+}