X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fmain%2Freadpix.c;h=ca4b9431bbe4934a6bc05f1c93295b8c96928ca6;hb=92163482bda87216764edc0beca3ca090678038d;hp=cb4d02daf81b9a8ce03f0dcd70472f85dd60e281;hpb=ce9118c7f053e68102e215c7cf57a6d1b68d5955;p=mesa.git

diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index cb4d02daf81..ca4b9431bbe 100644
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -1,6 +1,5 @@
 /*
  * Mesa 3-D graphics library
- * Version:  7.1
  *
  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
  *
@@ -17,13 +16,15 @@
  * 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.
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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 "glheader.h"
 #include "imports.h"
+#include "blend.h"
 #include "bufferobj.h"
 #include "context.h"
 #include "enums.h"
@@ -38,14 +39,217 @@
 #include "state.h"
 #include "glformats.h"
 #include "fbobject.h"
+#include "format_utils.h"
+#include "pixeltransfer.h"
 
 
 /**
- * Tries to implement glReadPixels() of GL_DEPTH_COMPONENT using memcpy of the
- * mapping.
+ * Return true if the conversion L=R+G+B is needed.
  */
 static GLboolean
-fast_read_depth_pixels( struct gl_context *ctx,
+need_rgb_to_luminance_conversion(mesa_format texFormat, GLenum format)
+{
+   GLenum baseTexFormat = _mesa_get_format_base_format(texFormat);
+
+   return (baseTexFormat == GL_RG ||
+           baseTexFormat == GL_RGB ||
+           baseTexFormat == GL_RGBA) &&
+          (format == GL_LUMINANCE || format == GL_LUMINANCE_ALPHA);
+}
+
+
+/**
+ * Return transfer op flags for this ReadPixels operation.
+ */
+static GLbitfield
+get_readpixels_transfer_ops(const struct gl_context *ctx, mesa_format texFormat,
+                            GLenum format, GLenum type, GLboolean uses_blit)
+{
+   GLbitfield transferOps = ctx->_ImageTransferState;
+
+   if (format == GL_DEPTH_COMPONENT ||
+       format == GL_DEPTH_STENCIL ||
+       format == GL_STENCIL_INDEX) {
+      return 0;
+   }
+
+   /* Pixel transfer ops (scale, bias, table lookup) do not apply
+    * to integer formats.
+    */
+   if (_mesa_is_enum_format_integer(format)) {
+      return 0;
+   }
+
+   if (uses_blit) {
+      /* For blit-based ReadPixels packing, the clamping is done automatically
+       * unless the type is float. */
+      if (_mesa_get_clamp_read_color(ctx) &&
+          (type == GL_FLOAT || type == GL_HALF_FLOAT)) {
+         transferOps |= IMAGE_CLAMP_BIT;
+      }
+   }
+   else {
+      /* For CPU-based ReadPixels packing, the clamping must always be done
+       * for non-float types, */
+      if (_mesa_get_clamp_read_color(ctx) ||
+          (type != GL_FLOAT && type != GL_HALF_FLOAT)) {
+         transferOps |= IMAGE_CLAMP_BIT;
+      }
+   }
+
+   /* If the format is unsigned normalized, we can ignore clamping
+    * because the values are already in the range [0,1] so it won't
+    * have any effect anyway.
+    */
+   if (_mesa_get_format_datatype(texFormat) == GL_UNSIGNED_NORMALIZED &&
+       !need_rgb_to_luminance_conversion(texFormat, format)) {
+      transferOps &= ~IMAGE_CLAMP_BIT;
+   }
+
+   return transferOps;
+}
+
+
+/**
+ * Return true if memcpy cannot be used for ReadPixels.
+ *
+ * If uses_blit is true, the function returns true if a simple 3D engine blit
+ * cannot be used for ReadPixels packing.
+ *
+ * NOTE: This doesn't take swizzling and format conversions between
+ *       the readbuffer and the pixel pack buffer into account.
+ */
+GLboolean
+_mesa_readpixels_needs_slow_path(const struct gl_context *ctx, GLenum format,
+                                 GLenum type, GLboolean uses_blit)
+{
+   struct gl_renderbuffer *rb =
+         _mesa_get_read_renderbuffer_for_format(ctx, format);
+   GLenum srcType;
+
+   ASSERT(rb);
+
+   /* There are different rules depending on the base format. */
+   switch (format) {
+   case GL_DEPTH_STENCIL:
+      return !_mesa_has_depthstencil_combined(ctx->ReadBuffer) ||
+             ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f ||
+             ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
+             ctx->Pixel.MapStencilFlag;
+
+   case GL_DEPTH_COMPONENT:
+      return ctx->Pixel.DepthScale != 1.0f || ctx->Pixel.DepthBias != 0.0f;
+
+   case GL_STENCIL_INDEX:
+      return ctx->Pixel.IndexShift || ctx->Pixel.IndexOffset ||
+             ctx->Pixel.MapStencilFlag;
+
+   default:
+      /* Color formats. */
+      if (need_rgb_to_luminance_conversion(rb->Format, format)) {
+         return GL_TRUE;
+      }
+
+      /* Conversion between signed and unsigned integers needs masking
+       * (it isn't just memcpy). */
+      srcType = _mesa_get_format_datatype(rb->Format);
+
+      if ((srcType == GL_INT &&
+           (type == GL_UNSIGNED_INT ||
+            type == GL_UNSIGNED_SHORT ||
+            type == GL_UNSIGNED_BYTE)) ||
+          (srcType == GL_UNSIGNED_INT &&
+           (type == GL_INT ||
+            type == GL_SHORT ||
+            type == GL_BYTE))) {
+         return GL_TRUE;
+      }
+
+      /* And finally, see if there are any transfer ops. */
+      return get_readpixels_transfer_ops(ctx, rb->Format, format, type,
+                                         uses_blit) != 0;
+   }
+   return GL_FALSE;
+}
+
+
+static GLboolean
+readpixels_can_use_memcpy(const struct gl_context *ctx, GLenum format, GLenum type,
+                          const struct gl_pixelstore_attrib *packing)
+{
+   struct gl_renderbuffer *rb =
+         _mesa_get_read_renderbuffer_for_format(ctx, format);
+
+   ASSERT(rb);
+
+   if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_FALSE)) {
+      return GL_FALSE;
+   }
+
+   /* The base internal format and the base Mesa format must match. */
+   if (rb->_BaseFormat != _mesa_get_format_base_format(rb->Format)) {
+      return GL_FALSE;
+   }
+
+   /* The Mesa format must match the input format and type. */
+   if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
+                                             packing->SwapBytes)) {
+      return GL_FALSE;
+   }
+
+   return GL_TRUE;
+}
+
+
+static GLboolean
+readpixels_memcpy(struct gl_context *ctx,
+                  GLint x, GLint y,
+                  GLsizei width, GLsizei height,
+                  GLenum format, GLenum type,
+                  GLvoid *pixels,
+                  const struct gl_pixelstore_attrib *packing)
+{
+   struct gl_renderbuffer *rb =
+         _mesa_get_read_renderbuffer_for_format(ctx, format);
+   GLubyte *dst, *map;
+   int dstStride, stride, j, texelBytes;
+
+   /* Fail if memcpy cannot be used. */
+   if (!readpixels_can_use_memcpy(ctx, format, type, packing)) {
+      return GL_FALSE;
+   }
+
+   dstStride = _mesa_image_row_stride(packing, width, format, type);
+   dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
+					   format, type, 0, 0);
+
+   ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
+			       &map, &stride);
+   if (!map) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+      return GL_TRUE;  /* don't bother trying the slow path */
+   }
+
+   texelBytes = _mesa_get_format_bytes(rb->Format);
+
+   /* memcpy*/
+   for (j = 0; j < height; j++) {
+      memcpy(dst, map, width * texelBytes);
+      dst += dstStride;
+      map += stride;
+   }
+
+   ctx->Driver.UnmapRenderbuffer(ctx, rb);
+   return GL_TRUE;
+}
+
+
+/**
+ * Optimized path for conversion of depth values to GL_DEPTH_COMPONENT,
+ * GL_UNSIGNED_INT.
+ */
+static GLboolean
+read_uint_depth_pixels( struct gl_context *ctx,
 			GLint x, GLint y,
 			GLsizei width, GLsizei height,
 			GLenum type, GLvoid *pixels,
@@ -65,10 +269,6 @@ fast_read_depth_pixels( struct gl_context *ctx,
    if (_mesa_get_format_datatype(rb->Format) != GL_UNSIGNED_NORMALIZED)
       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);
 
@@ -82,12 +282,7 @@ fast_read_depth_pixels( struct gl_context *ctx,
 					   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);
-      }
+      _mesa_unpack_uint_z_row(rb->Format, width, map, (GLuint *)dst);
 
       map += stride;
       dst += dstStride;
@@ -123,8 +318,10 @@ read_depth_pixels( struct gl_context *ctx,
    ASSERT(x + width <= (GLint) rb->Width);
    ASSERT(y + height <= (GLint) rb->Height);
 
-   if (fast_read_depth_pixels(ctx, x, y, width, height, type, pixels, packing))
+   if (type == GL_UNSIGNED_INT &&
+       read_uint_depth_pixels(ctx, x, y, width, height, type, pixels, packing)) {
       return;
+   }
 
    dstStride = _mesa_image_row_stride(packing, width, GL_DEPTH_COMPONENT, type);
    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
@@ -210,196 +407,217 @@ read_stencil_pixels( struct gl_context *ctx,
    ctx->Driver.UnmapRenderbuffer(ctx, rb);
 }
 
-
-/**
- * Try to do glReadPixels of RGBA data using a simple memcpy or swizzle.
- * \return GL_TRUE if successful, GL_FALSE otherwise (use the slow path)
+/*
+ * Read R, G, B, A, RGB, L, or LA pixels.
  */
-static GLboolean
-fast_read_rgba_pixels_memcpy( struct gl_context *ctx,
-			      GLint x, GLint y,
-			      GLsizei width, GLsizei height,
-			      GLenum format, GLenum type,
-			      GLvoid *pixels,
-			      const struct gl_pixelstore_attrib *packing,
-			      GLbitfield transferOps )
+static void
+read_rgba_pixels( struct gl_context *ctx,
+                  GLint x, GLint y,
+                  GLsizei width, GLsizei height,
+                  GLenum format, GLenum type, GLvoid *pixels,
+                  const struct gl_pixelstore_attrib *packing )
 {
-   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
+   GLbitfield transferOps;
+   bool dst_is_integer, dst_is_luminance, needs_rebase;
+   int dst_stride, src_stride, rb_stride;
+   uint32_t dst_format, src_format;
    GLubyte *dst, *map;
-   int dstStride, stride, j, texelBytes;
-   GLboolean swizzle_rb = GL_FALSE, copy_xrgb = GL_FALSE;
-
-   /* XXX we could check for other swizzle/special cases here as needed */
-   if (rb->Format == MESA_FORMAT_RGBA8888_REV &&
-       format == GL_BGRA &&
-       type == GL_UNSIGNED_INT_8_8_8_8_REV &&
-       !ctx->Pack.SwapBytes) {
-      swizzle_rb = GL_TRUE;
-   }
-   else if (rb->Format == MESA_FORMAT_XRGB8888 &&
-       format == GL_BGRA &&
-       type == GL_UNSIGNED_INT_8_8_8_8_REV &&
-       !ctx->Pack.SwapBytes) {
-      copy_xrgb = GL_TRUE;
-   }
-   else if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
-                                                  ctx->Pack.SwapBytes))
-      return GL_FALSE;
-
-   /* If the format is unsigned normalized then we can ignore clamping
-    * because the values are already in the range [0,1] so it won't
-    * have any effect anyway.
-    */
-   if (_mesa_get_format_datatype(rb->Format) == GL_UNSIGNED_NORMALIZED)
-      transferOps &= ~IMAGE_CLAMP_BIT;
+   mesa_format rb_format;
+   bool needs_rgba;
+   void *rgba, *src;
+   bool src_is_uint = false;
+   uint8_t rebase_swizzle[4];
+   struct gl_framebuffer *fb = ctx->ReadBuffer;
+   struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
 
-   if (transferOps)
-      return GL_FALSE;
+   if (!rb)
+      return;
 
-   dstStride = _mesa_image_row_stride(packing, width, format, type);
+   transferOps = get_readpixels_transfer_ops(ctx, rb->Format, format, type,
+                                             GL_FALSE);
+   /* Describe the dst format */
+   dst_is_integer = _mesa_is_enum_format_integer(format);
+   dst_stride = _mesa_image_row_stride(packing, width, format, type);
+   dst_format = _mesa_format_from_format_and_type(format, type);
+   dst_is_luminance = format == GL_LUMINANCE ||
+                      format == GL_LUMINANCE_ALPHA ||
+                      format == GL_LUMINANCE_INTEGER_EXT ||
+                      format == GL_LUMINANCE_ALPHA_INTEGER_EXT;
    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
-					   format, type, 0, 0);
+                                           format, type, 0, 0);
 
+   /* Map the source render buffer */
    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
-			       &map, &stride);
+                               &map, &rb_stride);
    if (!map) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
-      return GL_TRUE;  /* don't bother trying the slow path */
+      return;
    }
+   rb_format = _mesa_get_srgb_format_linear(rb->Format);
 
-   texelBytes = _mesa_get_format_bytes(rb->Format);
-
-   if (swizzle_rb) {
-      /* swap R/B */
-      for (j = 0; j < height; j++) {
-         int i;
-         for (i = 0; i < width; i++) {
-            GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
-            GLuint pixel = map4[i];
-            dst4[i] = (pixel & 0xff00ff00)
-                   | ((pixel & 0x00ff0000) >> 16)
-                   | ((pixel & 0x000000ff) << 16);
-         }
-         dst += dstStride;
-         map += stride;
-      }
-   } else if (copy_xrgb) {
-      /* convert xrgb -> argb */
-      for (j = 0; j < height; j++) {
-         GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
-         int i;
-         for (i = 0; i < width; i++) {
-            dst4[i] = map4[i] | 0xff000000;  /* set A=0xff */
-         }
-         dst += dstStride;
-         map += stride;
-      }
+   /*
+    * Depending on the base formats involved in the conversion we might need to
+    * rebase some values, so for these formats we compute a rebase swizzle.
+    */
+   if (rb->_BaseFormat == GL_LUMINANCE || rb->_BaseFormat == GL_INTENSITY) {
+      needs_rebase = true;
+      rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
+      rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
+      rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
+      rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_ONE;
+   } else if (rb->_BaseFormat == GL_LUMINANCE_ALPHA) {
+      needs_rebase = true;
+      rebase_swizzle[0] = MESA_FORMAT_SWIZZLE_X;
+      rebase_swizzle[1] = MESA_FORMAT_SWIZZLE_ZERO;
+      rebase_swizzle[2] = MESA_FORMAT_SWIZZLE_ZERO;
+      rebase_swizzle[3] = MESA_FORMAT_SWIZZLE_W;
+   } else if (_mesa_get_format_base_format(rb_format) != rb->_BaseFormat) {
+      needs_rebase =
+         _mesa_compute_rgba2base2rgba_component_mapping(rb->_BaseFormat,
+                                                        rebase_swizzle);
    } else {
-      /* just memcpy */
-      for (j = 0; j < height; j++) {
-         memcpy(dst, map, width * texelBytes);
-         dst += dstStride;
-         map += stride;
-      }
+      needs_rebase = false;
    }
 
-   ctx->Driver.UnmapRenderbuffer(ctx, rb);
-
-   return GL_TRUE;
-}
-
-static void
-slow_read_rgba_pixels( struct gl_context *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;
-   const gl_format rbFormat = _mesa_get_srgb_format_linear(rb->Format);
-   void *rgba;
-   GLubyte *dst, *map;
-   int dstStride, stride, j;
-   GLboolean dst_is_integer = _mesa_is_enum_format_integer(format);
-   GLboolean dst_is_uint = _mesa_is_format_unsigned(rbFormat);
-
-   dstStride = _mesa_image_row_stride(packing, width, format, type);
-   dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
-					   format, type, 0, 0);
-
-   ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
-			       &map, &stride);
-   if (!map) {
-      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
-      return;
-   }
+   /* Since _mesa_format_convert does not handle transferOps we need to handle
+    * them before we call the function. This requires to convert to RGBA float
+    * first so we can call _mesa_apply_rgba_transfer_ops. If the dst format is
+    * integer transferOps do not apply.
+    *
+    * Converting to luminance also requires converting to RGBA first, so we can
+    * then compute luminance values as L=R+G+B. Notice that this is different
+    * from GetTexImage, where we compute L=R.
+    */
+   assert(!transferOps || (transferOps && !dst_is_integer));
 
-   rgba = malloc(width * MAX_PIXEL_BYTES);
-   if (!rgba)
-      goto done;
+   needs_rgba = transferOps || dst_is_luminance;
+   rgba = NULL;
+   if (needs_rgba) {
+      uint32_t rgba_format;
+      int rgba_stride;
+      bool need_convert;
 
-   for (j = 0; j < height; j++) {
+      /* Convert to RGBA float or int/uint depending on the type of the src */
       if (dst_is_integer) {
-	 _mesa_unpack_uint_rgba_row(rbFormat, width, map, (GLuint (*)[4]) rgba);
-         _mesa_rebase_rgba_uint(width, (GLuint (*)[4]) rgba,
-                                rb->_BaseFormat);
-         if (dst_is_uint) {
-            _mesa_pack_rgba_span_from_uints(ctx, width, (GLuint (*)[4]) rgba, format,
-                                            type, dst);
+         src_is_uint = _mesa_is_format_unsigned(rb_format);
+         if (src_is_uint) {
+            rgba_format = RGBA32_UINT;
+            rgba_stride = width * 4 * sizeof(GLuint);
          } else {
-            _mesa_pack_rgba_span_from_ints(ctx, width, (GLint (*)[4]) rgba, format,
-                                           type, dst);
+            rgba_format = RGBA32_INT;
+            rgba_stride = width * 4 * sizeof(GLint);
          }
       } else {
-	 _mesa_unpack_rgba_row(rbFormat, width, map, (GLfloat (*)[4]) rgba);
-         _mesa_rebase_rgba_float(width, (GLfloat (*)[4]) rgba,
-                                 rb->_BaseFormat);
-	 _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba, format,
-                                    type, dst, packing, transferOps);
+         rgba_format = RGBA32_FLOAT;
+         rgba_stride = width * 4 * sizeof(GLfloat);
       }
-      dst += dstStride;
-      map += stride;
-   }
-
-   free(rgba);
 
-done:
-   ctx->Driver.UnmapRenderbuffer(ctx, rb);
-}
-
-/*
- * Read R, G, B, A, RGB, L, or LA pixels.
- */
-static void
-read_rgba_pixels( struct gl_context *ctx,
-                  GLint x, GLint y,
-                  GLsizei width, GLsizei height,
-                  GLenum format, GLenum type, GLvoid *pixels,
-                  const struct gl_pixelstore_attrib *packing )
-{
-   GLbitfield transferOps = ctx->_ImageTransferState;
-   struct gl_framebuffer *fb = ctx->ReadBuffer;
-   struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
+      /* If we are lucky and the dst format matches the RGBA format we need to
+       * convert to, then we can convert directly into the dst buffer and avoid
+       * the final conversion/copy from the rgba buffer to the dst buffer.
+       */
+      if (dst_format == rgba_format) {
+         need_convert = false;
+         rgba = dst;
+      } else {
+         need_convert = true;
+         rgba = malloc(height * rgba_stride);
+         if (!rgba) {
+            _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+            goto done_unmap;
+         }
+      }
 
-   if (!rb)
-      return;
+      /* Convert to RGBA now */
+      _mesa_format_convert(rgba, rgba_format, rgba_stride,
+                           map, rb_format, rb_stride,
+                           width, height,
+                           needs_rebase ? rebase_swizzle : NULL);
+
+      /* Handle transfer ops if necessary */
+      if (transferOps)
+         _mesa_apply_rgba_transfer_ops(ctx, transferOps, width * height, rgba);
+
+      /* If we had to rebase, we have already taken care of that */
+      needs_rebase = false;
+
+      /* If we were lucky and our RGBA conversion matches the dst format, then
+       * we are done.
+       */
+      if (!need_convert)
+         goto done_swap;
+
+      /* Otherwise, we need to convert from RGBA to dst next */
+      src = rgba;
+      src_format = rgba_format;
+      src_stride = rgba_stride;
+   } else {
+      /* No RGBA conversion needed, convert directly to dst */
+      src = map;
+      src_format = rb_format;
+      src_stride = rb_stride;
+   }
 
-   if ((ctx->Color._ClampReadColor == GL_TRUE || type != GL_FLOAT) &&
-       !_mesa_is_enum_format_integer(format)) {
-      transferOps |= IMAGE_CLAMP_BIT;
+   /* Do the conversion.
+    *
+    * If the dst format is Luminance, we need to do the conversion by computing
+    * L=R+G+B values.
+    */
+   if (!dst_is_luminance) {
+      _mesa_format_convert(dst, dst_format, dst_stride,
+                           src, src_format, src_stride,
+                           width, height,
+                           needs_rebase ? rebase_swizzle : NULL);
+   } else if (!dst_is_integer) {
+      /* Compute float Luminance values from RGBA float */
+      int luminance_stride, luminance_bytes;
+      void *luminance;
+      uint32_t luminance_format;
+
+      luminance_stride = width * sizeof(GL_FLOAT);
+      if (format == GL_LUMINANCE_ALPHA)
+         luminance_stride *= 2;
+      luminance_bytes = height * luminance_stride;
+      luminance = malloc(luminance_bytes);
+      if (!luminance) {
+         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
+         free(rgba);
+         goto done_unmap;
+      }
+      _mesa_pack_luminance_from_rgba_float(width * height, src,
+                                           luminance, format, transferOps);
+
+      /* Convert from Luminance float to dst (this will hadle type conversion
+       * from float to the type of dst if necessary)
+       */
+      luminance_format = _mesa_format_from_format_and_type(format, GL_FLOAT);
+      _mesa_format_convert(dst, dst_format, dst_stride,
+                           luminance, luminance_format, luminance_stride,
+                           width, height, NULL);
+   } else {
+      _mesa_pack_luminance_from_rgba_integer(width * height, src, !src_is_uint,
+                                             dst, format, type);
    }
 
-   /* Try the optimized paths first. */
-   if (fast_read_rgba_pixels_memcpy(ctx, x, y, width, height,
-                                    format, type, pixels, packing,
-                                    transferOps)) {
-      return;
+   if (rgba)
+      free(rgba);
+
+done_swap:
+   /* Handle byte swapping if required */
+   if (packing->SwapBytes) {
+      GLint swapSize = _mesa_sizeof_packed_type(type);
+      if (swapSize == 2 || swapSize == 4) {
+         int swapsPerPixel = _mesa_bytes_per_pixel(format, type) / swapSize;
+         assert(_mesa_bytes_per_pixel(format, type) % swapSize == 0);
+         if (swapSize == 2)
+            _mesa_swap2((GLushort *) dst, width * height * swapsPerPixel);
+         else if (swapSize == 4)
+            _mesa_swap4((GLuint *) dst, width * height * swapsPerPixel);
+      }
    }
 
-   slow_read_rgba_pixels(ctx, x, y, width, height,
-			 format, type, pixels, packing, transferOps);
+done_unmap:
+   ctx->Driver.UnmapRenderbuffer(ctx, rb);
 }
 
 /**
@@ -421,8 +639,8 @@ fast_read_depth_stencil_pixels(struct gl_context *ctx,
    if (rb != stencilRb)
       return GL_FALSE;
 
-   if (rb->Format != MESA_FORMAT_Z24_S8 &&
-       rb->Format != MESA_FORMAT_S8_Z24)
+   if (rb->Format != MESA_FORMAT_S8_UINT_Z24_UNORM &&
+       rb->Format != MESA_FORMAT_Z24_UNORM_S8_UINT)
       return GL_FALSE;
 
    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
@@ -649,6 +867,14 @@ _mesa_readpixels(struct gl_context *ctx,
       pixels = _mesa_map_pbo_dest(ctx, &clippedPacking, pixels);
 
       if (pixels) {
+         /* Try memcpy first. */
+         if (readpixels_memcpy(ctx, x, y, width, height, format, type,
+                               pixels, packing)) {
+            _mesa_unmap_pbo_dest(ctx, &clippedPacking);
+            return;
+         }
+
+         /* Otherwise take the slow path. */
          switch (format) {
          case GL_STENCIL_INDEX:
             read_stencil_pixels(ctx, x, y, width, height, type, pixels,
@@ -694,6 +920,8 @@ read_pixels_es3_error_check(GLenum format, GLenum type,
 
    switch (format) {
    case GL_RGBA:
+      if (type == GL_FLOAT && data_type == GL_FLOAT)
+         return GL_NO_ERROR; /* EXT_color_buffer_float */
       if (type == GL_UNSIGNED_BYTE && data_type == GL_UNSIGNED_NORMALIZED)
          return GL_NO_ERROR;
       if (internalFormat == GL_RGB10_A2 &&
@@ -729,8 +957,8 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
    struct gl_renderbuffer *rb;
 
    GET_CURRENT_CONTEXT(ctx);
-   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 
+   FLUSH_VERTICES(ctx, 0);
    FLUSH_CURRENT(ctx, 0);
 
    if (MESA_VERBOSE & VERBOSE_API)
@@ -771,7 +999,12 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
     * combination is, and Mesa can handle anything valid.  Just work instead.
     */
    if (_mesa_is_gles(ctx)) {
-      if (ctx->Version < 30) {
+      if (ctx->API == API_OPENGLES2 &&
+          _mesa_is_color_format(format) &&
+          _mesa_get_color_read_format(ctx) == format &&
+          _mesa_get_color_read_type(ctx) == type) {
+         err = GL_NO_ERROR;
+      } else if (ctx->Version < 30) {
          err = _mesa_es_error_check_format_and_type(format, type, 2);
          if (err == GL_NO_ERROR) {
             if (type == GL_FLOAT || type == GL_HALF_FLOAT_OES) {
@@ -845,7 +1078,7 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
    }
 
    if (_mesa_is_bufferobj(ctx->Pack.BufferObj) &&
-       _mesa_bufferobj_mapped(ctx->Pack.BufferObj)) {
+       _mesa_check_disallowed_mapping(ctx->Pack.BufferObj)) {
       /* buffer is mapped - that's an error */
       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
       return;