From ec03b316b4dc5d56b8510cc5aeb0f71a4fdada18 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 15 Dec 2010 11:54:38 -0800
Subject: [PATCH] intel: Try to sanely check that formats match for
 CopyTexImage.

Before, we were going off of a couple of known (hopeful) matches
between internalFormats and the cpp of the read buffer.  Instead, we
can now just look at the gl_format of the two to see if they match.
We should avoid bad blits that might have been possible before, but
also allow different internalFormats to work without having to
enumerate each one.
---
 src/mesa/drivers/dri/intel/intel_tex_copy.c | 60 +++++++--------------
 1 file changed, 20 insertions(+), 40 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_tex_copy.c b/src/mesa/drivers/dri/intel/intel_tex_copy.c
index 381ad14dcbf..c4a3364ceba 100644
--- a/src/mesa/drivers/dri/intel/intel_tex_copy.c
+++ b/src/mesa/drivers/dri/intel/intel_tex_copy.c
@@ -50,44 +50,20 @@
  * Do the best we can using the blitter.  A future project is to use
  * the texture engine and fragment programs for these copies.
  */
-static const struct intel_region *
-get_teximage_source(struct intel_context *intel, GLenum internalFormat)
+static struct intel_renderbuffer *
+get_teximage_readbuffer(struct intel_context *intel, GLenum internalFormat)
 {
-   struct intel_renderbuffer *irb;
-
    DBG("%s %s\n", __FUNCTION__,
        _mesa_lookup_enum_by_nr(internalFormat));
 
    switch (internalFormat) {
    case GL_DEPTH_COMPONENT:
    case GL_DEPTH_COMPONENT16:
-      irb = intel_get_renderbuffer(intel->ctx.ReadBuffer, BUFFER_DEPTH);
-      if (irb && irb->region && irb->region->cpp == 2)
-         return irb->region;
-      return NULL;
    case GL_DEPTH24_STENCIL8_EXT:
    case GL_DEPTH_STENCIL_EXT:
-      irb = intel_get_renderbuffer(intel->ctx.ReadBuffer, BUFFER_DEPTH);
-      if (irb && irb->region && irb->region->cpp == 4)
-         return irb->region;
-      return NULL;
-   case 4:
-   case GL_RGBA:
-   case GL_RGBA8:
-      irb = intel_renderbuffer(intel->ctx.ReadBuffer->_ColorReadBuffer);
-      /* We're required to set alpha to 1.0 in this case, but we can't
-       * do that with the blitter, so fall back.  We could use the 3D
-       * engine or do two passes with the blitter, but it doesn't seem
-       * worth it for this case. */
-      if (irb->Base._BaseFormat == GL_RGB)
-	 return NULL;
-      return irb->region;
-   case 3:
-   case GL_RGB:
-   case GL_RGB8:
-      return intel_readbuf_region(intel);
+      return intel_get_renderbuffer(intel->ctx.ReadBuffer, BUFFER_DEPTH);
    default:
-      return NULL;
+      return intel_renderbuffer(intel->ctx.ReadBuffer->_ColorReadBuffer);
    }
 }
 
@@ -101,20 +77,24 @@ do_copy_texsubimage(struct intel_context *intel,
                     GLint x, GLint y, GLsizei width, GLsizei height)
 {
    struct gl_context *ctx = &intel->ctx;
-   const struct intel_region *src;
+   struct intel_renderbuffer *irb;
 
    intel_prepare_render(intel);
-   src = get_teximage_source(intel, internalFormat);
-   if (!intelImage->mt || !src || !src->buffer) {
+
+   irb = get_teximage_readbuffer(intel, internalFormat);
+   if (!intelImage->mt || !irb) {
       if (unlikely(INTEL_DEBUG & DEBUG_FALLBACKS))
 	 fprintf(stderr, "%s fail %p %p (0x%08x)\n",
-		 __FUNCTION__, intelImage->mt, src, internalFormat);
+		 __FUNCTION__, intelImage->mt, irb, internalFormat);
       return GL_FALSE;
    }
 
-   if (intelImage->mt->cpp != src->cpp) {
-      fallback_debug("%s fail %d vs %d cpp\n",
-		     __FUNCTION__, intelImage->mt->cpp, src->cpp);
+   if (intelImage->base.TexFormat != irb->Base.Format) {
+      if (unlikely(INTEL_DEBUG & DEBUG_FALLBACKS))
+	 fprintf(stderr, "%s mismatched formats %s, %s\n",
+		 __FUNCTION__,
+		 _mesa_get_format_name(intelImage->base.TexFormat),
+		 _mesa_get_format_name(irb->Base.Format));
       return GL_FALSE;
    }
 
@@ -140,24 +120,24 @@ do_copy_texsubimage(struct intel_context *intel,
       if (ctx->ReadBuffer->Name == 0) {
 	 /* Flip vertical orientation for system framebuffers */
 	 y = ctx->ReadBuffer->Height - (y + height);
-	 src_pitch = -src->pitch;
+	 src_pitch = -irb->region->pitch;
       } else {
 	 /* reading from a FBO, y is already oriented the way we like */
-	 src_pitch = src->pitch;
+	 src_pitch = irb->region->pitch;
       }
 
       /* blit from src buffer to texture */
       if (!intelEmitCopyBlit(intel,
 			     intelImage->mt->cpp,
 			     src_pitch,
-			     src->buffer,
+			     irb->region->buffer,
 			     0,
-			     src->tiling,
+			     irb->region->tiling,
 			     intelImage->mt->region->pitch,
 			     dst_bo,
 			     0,
 			     intelImage->mt->region->tiling,
-			     src->draw_x + x, src->draw_y + y,
+			     irb->region->draw_x + x, irb->region->draw_y + y,
 			     image_x + dstx, image_y + dsty,
 			     width, height,
 			     GL_COPY)) {
-- 
2.30.2