mesa: Move OES_read_format support from drivers into the core.

The assertion is that the correct read type to be using is the native
type of the underlying read renderbuffer.  For some fallback paths, this
may be worse than GL_RGBA/GL_UNSIGNED_BYTE for reads today, but it gets
all drivers the expected GL_BGRA/GL_UNSIGNED_BYTE for ARGB8888 or
GL_BGR//GL_UNSIGNED_SHORT_5_6_5_REV for rgb565 with no work.

This fixes the intel (and other) DRI drivers to report read formats that
should hit blit PBO readpixels paths.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/mesa/main/framebuffer.c b/src/mesa/main/framebuffer.c
index 154dedacd50..d958dbf7d48 100644
--- a/src/mesa/main/framebuffer.c
+++ b/src/mesa/main/framebuffer.c
@@ -969,3 +969,29 @@ _mesa_dest_buffer_exists(GLcontext *ctx, GLenum format)
    /* OK */
    return GL_TRUE;
 }
+
+GLenum
+_mesa_get_color_read_format(GLcontext *ctx)
+{
+   switch (ctx->ReadBuffer->_ColorReadBuffer->Format) {
+   case MESA_FORMAT_ARGB8888:
+      return GL_BGRA;
+   case MESA_FORMAT_RGB565:
+      return GL_BGR;
+   default:
+      return GL_RGBA;
+   }
+}
+
+GLenum
+_mesa_get_color_read_type(GLcontext *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;
+   }
+}