X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fmain%2Fframebuffer.c;h=63da71c95b4bd9609173f099e432bed07431da2c;hb=2fa6012f6a0b02de6093cbccba3bf4432f072e57;hp=dc79b8ca61ad763b4de571cdb379172843e1e2b7;hpb=940ca2e837efe45caae1cf1d9665f6736347705d;p=mesa.git

diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index dc79b8ca61a..63da71c95b4 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -35,6 +35,8 @@
 #include "buffers.h"
 #include "context.h"
 #include "depthstencil.h"
+#include "enums.h"
+#include "formats.h"
 #include "macros.h"
 #include "mtypes.h"
 #include "fbobject.h"
@@ -73,7 +75,6 @@ compute_depth_max(struct gl_framebuffer *fb)
    fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
 }
 
-
 /**
  * Create and initialize a gl_framebuffer object.
  * This is intended for creating _window_system_ framebuffers, not generic
@@ -82,12 +83,12 @@ compute_depth_max(struct gl_framebuffer *fb)
  * \sa _mesa_new_framebuffer
  */
 struct gl_framebuffer *
-_mesa_create_framebuffer(const GLvisual *visual)
+_mesa_create_framebuffer(const struct gl_config *visual)
 {
    struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
    assert(visual);
    if (fb) {
-      _mesa_initialize_framebuffer(fb, visual);
+      _mesa_initialize_window_framebuffer(fb, visual);
    }
    return fb;
 }
@@ -101,22 +102,14 @@ _mesa_create_framebuffer(const GLvisual *visual)
  * \sa _mesa_create_framebuffer
  */
 struct gl_framebuffer *
-_mesa_new_framebuffer(GLcontext *ctx, GLuint name)
+_mesa_new_framebuffer(struct gl_context *ctx, GLuint name)
 {
    struct gl_framebuffer *fb;
    (void) ctx;
    assert(name != 0);
    fb = CALLOC_STRUCT(gl_framebuffer);
    if (fb) {
-      fb->Name = name;
-      fb->RefCount = 1;
-      fb->_NumColorDrawBuffers = 1;
-      fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
-      fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
-      fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
-      fb->_ColorReadBufferIndex = BUFFER_COLOR0;
-      fb->Delete = _mesa_destroy_framebuffer;
-      _glthread_INIT_MUTEX(fb->Mutex);
+      _mesa_initialize_user_framebuffer(fb, name);
    }
    return fb;
 }
@@ -125,15 +118,16 @@ _mesa_new_framebuffer(GLcontext *ctx, GLuint name)
 /**
  * Initialize a gl_framebuffer object.  Typically used to initialize
  * window system-created framebuffers, not user-created framebuffers.
- * \sa _mesa_create_framebuffer
+ * \sa _mesa_initialize_user_framebuffer
  */
 void
-_mesa_initialize_framebuffer(struct gl_framebuffer *fb, const GLvisual *visual)
+_mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
+				     const struct gl_config *visual)
 {
    assert(fb);
    assert(visual);
 
-   _mesa_bzero(fb, sizeof(struct gl_framebuffer));
+   memset(fb, 0, sizeof(struct gl_framebuffer));
 
    _glthread_INIT_MUTEX(fb->Mutex);
 
@@ -165,6 +159,30 @@ _mesa_initialize_framebuffer(struct gl_framebuffer *fb, const GLvisual *visual)
 }
 
 
+/**
+ * Initialize a user-created gl_framebuffer object.
+ * \sa _mesa_initialize_window_framebuffer
+ */
+void
+_mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
+{
+   assert(fb);
+   assert(name);
+
+   memset(fb, 0, sizeof(struct gl_framebuffer));
+
+   fb->Name = name;
+   fb->RefCount = 1;
+   fb->_NumColorDrawBuffers = 1;
+   fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
+   fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
+   fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
+   fb->_ColorReadBufferIndex = BUFFER_COLOR0;
+   fb->Delete = _mesa_destroy_framebuffer;
+   _glthread_INIT_MUTEX(fb->Mutex);
+}
+
+
 /**
  * Deallocate buffer and everything attached to it.
  * Typically called via the gl_framebuffer->Delete() method.
@@ -174,7 +192,7 @@ _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
 {
    if (fb) {
       _mesa_free_framebuffer_data(fb);
-      _mesa_free(fb);
+      free(fb);
    }
 }
 
@@ -263,7 +281,7 @@ _mesa_reference_framebuffer(struct gl_framebuffer **ptr,
  * without a currently bound rendering context.
  */
 void
-_mesa_resize_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
+_mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
                          GLuint width, GLuint height)
 {
    GLuint i;
@@ -281,7 +299,6 @@ _mesa_resize_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
          struct gl_renderbuffer *rb = att->Renderbuffer;
          /* only resize if size is changing */
          if (rb->Width != width || rb->Height != height) {
-            /* could just as well pass rb->_ActualFormat here */
             if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
                ASSERT(rb->Width == width);
                ASSERT(rb->Height == height);
@@ -342,7 +359,7 @@ _mesa_resize_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
  * from device drivers (as was done in the past).
  */
 void
-_mesa_resizebuffers( GLcontext *ctx )
+_mesa_resizebuffers( struct gl_context *ctx )
 {
    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 
@@ -355,7 +372,7 @@ _mesa_resizebuffers( GLcontext *ctx )
 
    if (ctx->WinSysDrawBuffer) {
       GLuint newWidth, newHeight;
-      GLframebuffer *buffer = ctx->WinSysDrawBuffer;
+      struct gl_framebuffer *buffer = ctx->WinSysDrawBuffer;
 
       assert(buffer->Name == 0);
 
@@ -372,7 +389,7 @@ _mesa_resizebuffers( GLcontext *ctx )
    if (ctx->WinSysReadBuffer
        && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
       GLuint newWidth, newHeight;
-      GLframebuffer *buffer = ctx->WinSysReadBuffer;
+      struct gl_framebuffer *buffer = ctx->WinSysReadBuffer;
 
       assert(buffer->Name == 0);
 
@@ -412,7 +429,7 @@ _mesa_ResizeBuffersMESA( void )
  * window-system framebuffes.
  */
 static void
-update_framebuffer_size(GLcontext *ctx, struct gl_framebuffer *fb)
+update_framebuffer_size(struct gl_context *ctx, struct gl_framebuffer *fb)
 {
    GLuint minWidth = ~0, minHeight = ~0;
    GLuint i;
@@ -447,7 +464,7 @@ update_framebuffer_size(GLcontext *ctx, struct gl_framebuffer *fb)
  * \param ctx  the GL context.
  */
 void
-_mesa_update_draw_buffer_bounds(GLcontext *ctx)
+_mesa_update_draw_buffer_bounds(struct gl_context *ctx)
 {
    struct gl_framebuffer *buffer = ctx->DrawBuffer;
 
@@ -505,11 +522,12 @@ _mesa_update_draw_buffer_bounds(GLcontext *ctx)
  * integer Z values.
  */
 void
-_mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
+_mesa_update_framebuffer_visual(struct gl_context *ctx,
+				struct gl_framebuffer *fb)
 {
    GLuint i;
 
-   _mesa_bzero(&fb->Visual, sizeof(fb->Visual));
+   memset(&fb->Visual, 0, sizeof(fb->Visual));
    fb->Visual.rgbMode = GL_TRUE; /* assume this */
 
 #if 0 /* this _might_ be needed */
@@ -519,51 +537,52 @@ _mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
    }
 #endif
 
-   /* find first RGB or CI renderbuffer */
+   /* find first RGB renderbuffer */
    for (i = 0; i < BUFFER_COUNT; i++) {
       if (fb->Attachment[i].Renderbuffer) {
          const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
-         if (rb->_BaseFormat == GL_RGBA || rb->_BaseFormat == GL_RGB) {
-            fb->Visual.redBits = rb->RedBits;
-            fb->Visual.greenBits = rb->GreenBits;
-            fb->Visual.blueBits = rb->BlueBits;
-            fb->Visual.alphaBits = rb->AlphaBits;
+         const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
+         const gl_format fmt = rb->Format;
+
+         if (_mesa_is_legal_color_format(ctx, baseFormat)) {
+            fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
+            fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
+            fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
+            fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
             fb->Visual.rgbBits = fb->Visual.redBits
                + fb->Visual.greenBits + fb->Visual.blueBits;
             fb->Visual.floatMode = GL_FALSE;
             fb->Visual.samples = rb->NumSamples;
             break;
          }
-         else if (rb->_BaseFormat == GL_COLOR_INDEX) {
-            fb->Visual.indexBits = rb->IndexBits;
-            fb->Visual.rgbMode = GL_FALSE;
-            break;
-         }
       }
    }
 
    if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
+      const struct gl_renderbuffer *rb =
+         fb->Attachment[BUFFER_DEPTH].Renderbuffer;
+      const gl_format fmt = rb->Format;
       fb->Visual.haveDepthBuffer = GL_TRUE;
-      fb->Visual.depthBits
-         = fb->Attachment[BUFFER_DEPTH].Renderbuffer->DepthBits;
+      fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
    }
 
    if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
+      const struct gl_renderbuffer *rb =
+         fb->Attachment[BUFFER_STENCIL].Renderbuffer;
+      const gl_format fmt = rb->Format;
       fb->Visual.haveStencilBuffer = GL_TRUE;
-      fb->Visual.stencilBits
-         = fb->Attachment[BUFFER_STENCIL].Renderbuffer->StencilBits;
+      fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
    }
 
    if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
+      const struct gl_renderbuffer *rb =
+         fb->Attachment[BUFFER_ACCUM].Renderbuffer;
+      const gl_format fmt = rb->Format;
       fb->Visual.haveAccumBuffer = GL_TRUE;
-      fb->Visual.accumRedBits
-         = fb->Attachment[BUFFER_ACCUM].Renderbuffer->RedBits;
-      fb->Visual.accumGreenBits
-         = fb->Attachment[BUFFER_ACCUM].Renderbuffer->GreenBits;
-      fb->Visual.accumBlueBits
-         = fb->Attachment[BUFFER_ACCUM].Renderbuffer->BlueBits;
-      fb->Visual.accumAlphaBits
-         = fb->Attachment[BUFFER_ACCUM].Renderbuffer->AlphaBits;
+      fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
+      fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
+      fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
+      fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
    }
 
    compute_depth_max(fb);
@@ -581,7 +600,7 @@ _mesa_update_framebuffer_visual(struct gl_framebuffer *fb)
  * \param attIndex  indicates the renderbuffer to possibly wrap
  */
 void
-_mesa_update_depth_buffer(GLcontext *ctx,
+_mesa_update_depth_buffer(struct gl_context *ctx,
                           struct gl_framebuffer *fb,
                           GLuint attIndex)
 {
@@ -592,11 +611,11 @@ _mesa_update_depth_buffer(GLcontext *ctx,
 
    depthRb = fb->Attachment[attIndex].Renderbuffer;
 
-   if (depthRb && depthRb->_ActualFormat == GL_DEPTH24_STENCIL8_EXT) {
+   if (depthRb && _mesa_is_format_packed_depth_stencil(depthRb->Format)) {
       /* The attached depth buffer is a GL_DEPTH_STENCIL renderbuffer */
       if (!fb->_DepthBuffer
           || fb->_DepthBuffer->Wrapped != depthRb
-          || fb->_DepthBuffer->_BaseFormat != GL_DEPTH_COMPONENT) {
+          || _mesa_get_format_base_format(fb->_DepthBuffer->Format) != GL_DEPTH_COMPONENT) {
          /* need to update wrapper */
          struct gl_renderbuffer *wrapper
             = _mesa_new_z24_renderbuffer_wrapper(ctx, depthRb);
@@ -622,7 +641,7 @@ _mesa_update_depth_buffer(GLcontext *ctx,
  * \param attIndex  indicates the renderbuffer to possibly wrap
  */
 void
-_mesa_update_stencil_buffer(GLcontext *ctx,
+_mesa_update_stencil_buffer(struct gl_context *ctx,
                             struct gl_framebuffer *fb,
                             GLuint attIndex)
 {
@@ -633,11 +652,11 @@ _mesa_update_stencil_buffer(GLcontext *ctx,
 
    stencilRb = fb->Attachment[attIndex].Renderbuffer;
 
-   if (stencilRb && stencilRb->_ActualFormat == GL_DEPTH24_STENCIL8_EXT) {
+   if (stencilRb && _mesa_is_format_packed_depth_stencil(stencilRb->Format)) {
       /* The attached stencil buffer is a GL_DEPTH_STENCIL renderbuffer */
       if (!fb->_StencilBuffer
           || fb->_StencilBuffer->Wrapped != stencilRb
-          || fb->_StencilBuffer->_BaseFormat != GL_STENCIL_INDEX) {
+          || _mesa_get_format_base_format(fb->_StencilBuffer->Format) != GL_STENCIL_INDEX) {
          /* need to update wrapper */
          struct gl_renderbuffer *wrapper
             = _mesa_new_s8_renderbuffer_wrapper(ctx, stencilRb);
@@ -703,7 +722,7 @@ _mesa_update_stencil_buffer(GLcontext *ctx,
  * writing colors.
  */
 static void
-update_color_draw_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
+update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
 {
    GLuint output;
 
@@ -727,7 +746,7 @@ update_color_draw_buffers(GLcontext *ctx, struct gl_framebuffer *fb)
  * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
  */
 static void
-update_color_read_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
+update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 {
    (void) ctx;
    if (fb->_ColorReadBufferIndex == -1 ||
@@ -762,7 +781,7 @@ update_color_read_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
  * glRenderbufferStorageEXT.
  */
 static void
-update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
+update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 {
    if (fb->Name == 0) {
       /* This is a window-system framebuffer */
@@ -804,10 +823,14 @@ update_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
  * Update state related to the current draw/read framebuffers.
  */
 void
-_mesa_update_framebuffer(GLcontext *ctx)
+_mesa_update_framebuffer(struct gl_context *ctx)
 {
-   struct gl_framebuffer *drawFb = ctx->DrawBuffer;
-   struct gl_framebuffer *readFb = ctx->ReadBuffer;
+   struct gl_framebuffer *drawFb;
+   struct gl_framebuffer *readFb;
+
+   assert(ctx);
+   drawFb = ctx->DrawBuffer;
+   readFb = ctx->ReadBuffer;
 
    update_framebuffer(ctx, drawFb);
    if (readFb != drawFb)
@@ -823,7 +846,7 @@ _mesa_update_framebuffer(GLcontext *ctx)
  * \return GL_TRUE if buffer exists, GL_FALSE otherwise
  */
 GLboolean
-_mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
+_mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
 {
    const struct gl_renderbuffer_attachment *att = ctx->ReadBuffer->Attachment;
 
@@ -845,39 +868,53 @@ _mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
    case GL_LUMINANCE:
    case GL_LUMINANCE_ALPHA:
    case GL_INTENSITY:
+   case GL_RG:
    case GL_RGB:
    case GL_BGR:
    case GL_RGBA:
    case GL_BGRA:
    case GL_ABGR_EXT:
    case GL_COLOR_INDEX:
+   case GL_RED_INTEGER_EXT:
+   case GL_GREEN_INTEGER_EXT:
+   case GL_BLUE_INTEGER_EXT:
+   case GL_ALPHA_INTEGER_EXT:
+   case GL_RGB_INTEGER_EXT:
+   case GL_RGBA_INTEGER_EXT:
+   case GL_BGR_INTEGER_EXT:
+   case GL_BGRA_INTEGER_EXT:
+   case GL_LUMINANCE_INTEGER_EXT:
+   case GL_LUMINANCE_ALPHA_INTEGER_EXT:
       if (ctx->ReadBuffer->_ColorReadBuffer == NULL) {
          return GL_FALSE;
       }
-      ASSERT(ctx->ReadBuffer->_ColorReadBuffer->RedBits > 0 ||
-             ctx->ReadBuffer->_ColorReadBuffer->IndexBits > 0);
+      ASSERT(_mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_RED_BITS) > 0 ||
+             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_ALPHA_BITS) > 0 ||
+             _mesa_get_format_bits(ctx->ReadBuffer->_ColorReadBuffer->Format, GL_INDEX_BITS) > 0);
       break;
    case GL_DEPTH:
    case GL_DEPTH_COMPONENT:
       if (!att[BUFFER_DEPTH].Renderbuffer) {
          return GL_FALSE;
       }
-      ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+      /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
       break;
    case GL_STENCIL:
    case GL_STENCIL_INDEX:
       if (!att[BUFFER_STENCIL].Renderbuffer) {
          return GL_FALSE;
       }
-      ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+      /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
       break;
    case GL_DEPTH_STENCIL_EXT:
       if (!att[BUFFER_DEPTH].Renderbuffer ||
           !att[BUFFER_STENCIL].Renderbuffer) {
          return GL_FALSE;
       }
+      /*
       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+      */
       break;
    default:
       _mesa_problem(ctx,
@@ -896,7 +933,7 @@ _mesa_source_buffer_exists(GLcontext *ctx, GLenum format)
  * XXX could do some code merging w/ above function.
  */
 GLboolean
-_mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
+_mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
 {
    const struct gl_renderbuffer_attachment *att = ctx->DrawBuffer->Attachment;
 
@@ -924,6 +961,16 @@ _mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
    case GL_BGRA:
    case GL_ABGR_EXT:
    case GL_COLOR_INDEX:
+   case GL_RED_INTEGER_EXT:
+   case GL_GREEN_INTEGER_EXT:
+   case GL_BLUE_INTEGER_EXT:
+   case GL_ALPHA_INTEGER_EXT:
+   case GL_RGB_INTEGER_EXT:
+   case GL_RGBA_INTEGER_EXT:
+   case GL_BGR_INTEGER_EXT:
+   case GL_BGRA_INTEGER_EXT:
+   case GL_LUMINANCE_INTEGER_EXT:
+   case GL_LUMINANCE_ALPHA_INTEGER_EXT:
       /* Nothing special since GL_DRAW_BUFFER could be GL_NONE. */
       /* Could assert that colorbuffer has RedBits > 0 */
       break;
@@ -932,22 +979,24 @@ _mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
       if (!att[BUFFER_DEPTH].Renderbuffer) {
          return GL_FALSE;
       }
-      ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
+      /*ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);*/
       break;
    case GL_STENCIL:
    case GL_STENCIL_INDEX:
       if (!att[BUFFER_STENCIL].Renderbuffer) {
          return GL_FALSE;
       }
-      ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+      /*ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);*/
       break;
    case GL_DEPTH_STENCIL_EXT:
       if (!att[BUFFER_DEPTH].Renderbuffer ||
           !att[BUFFER_STENCIL].Renderbuffer) {
          return GL_FALSE;
       }
+      /*
       ASSERT(att[BUFFER_DEPTH].Renderbuffer->DepthBits > 0);
       ASSERT(att[BUFFER_STENCIL].Renderbuffer->StencilBits > 0);
+      */
       break;
    default:
       _mesa_problem(ctx,
@@ -959,3 +1008,77 @@ _mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
    /* OK */
    return GL_TRUE;
 }
+
+
+/**
+ * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES query.
+ */
+GLenum
+_mesa_get_color_read_format(struct gl_context *ctx)
+{
+   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
+   case MESA_FORMAT_ARGB8888:
+      return GL_BGRA;
+   case MESA_FORMAT_RGB565:
+      return GL_BGR;
+   default:
+      return GL_RGBA;
+   }
+}
+
+
+/**
+ * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES query.
+ */
+GLenum
+_mesa_get_color_read_type(struct gl_context *ctx)
+{
+   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
+   case MESA_FORMAT_ARGB8888:
+      return GL_UNSIGNED_BYTE;
+   case MESA_FORMAT_RGB565:
+      return GL_UNSIGNED_SHORT_5_6_5_REV;
+   default:
+      return GL_UNSIGNED_BYTE;
+   }
+}
+
+
+/**
+ * Print framebuffer info to stderr, for debugging.
+ */
+void
+_mesa_print_framebuffer(const struct gl_framebuffer *fb)
+{
+   GLuint i;
+
+   fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
+   fprintf(stderr, "  Size: %u x %u  Status: %s\n", fb->Width, fb->Height,
+           _mesa_lookup_enum_by_nr(fb->_Status));
+   fprintf(stderr, "  Attachments:\n");
+
+   for (i = 0; i < BUFFER_COUNT; i++) {
+      const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
+      if (att->Type == GL_TEXTURE) {
+         const struct gl_texture_image *texImage;
+         fprintf(stderr,
+                 "  %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
+                 i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
+                 att->Zoffset, att->Complete);
+         texImage = att->Texture->Image[att->CubeMapFace][att->TextureLevel];
+         fprintf(stderr, "       Size: %u x %u x %u  Format %s\n",
+                 texImage->Width, texImage->Height, texImage->Depth,
+                 _mesa_get_format_name(texImage->TexFormat));
+      }
+      else if (att->Type == GL_RENDERBUFFER) {
+         fprintf(stderr, "  %2d: Renderbuffer %u, complete %d\n",
+                 i, att->Renderbuffer->Name, att->Complete);
+         fprintf(stderr, "       Size: %u x %u  Format %s\n",
+                 att->Renderbuffer->Width, att->Renderbuffer->Height,
+                 _mesa_get_format_name(att->Renderbuffer->Format));
+      }
+      else {
+         fprintf(stderr, "  %2d: none\n", i);
+      }
+   }
+}