[Mesa-dev] [PATCH v3 08/10] i965/pixel_read: Use meta_pbo_GetTexSubImage for PBO ReadPixels

[Jason Ekstrand]

Since the meta path can do strictly more than the blitter path, we just
remove the blitter path entirely.
---
 src/mesa/drivers/dri/i965/intel_pixel_read.c | 130 ++-------------------------
 1 file changed, 6 insertions(+), 124 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_pixel_read.c b/src/mesa/drivers/dri/i965/intel_pixel_read.c
index 688a919..a64a5f4 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel_read.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel_read.c
@@ -1,8 +1,7 @@
 /**************************************************************************
  *
  * Copyright 2003 VMware, Inc.
- * All Rights Reserved.
- *
+ * 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
@@ -35,6 +34,7 @@
 #include "main/readpix.h"
 #include "main/state.h"
 #include "main/glformats.h"
+#include "drivers/common/meta.h"
 
 #include "brw_context.h"
 #include "intel_screen.h"
@@ -47,120 +47,6 @@
 
 #define FILE_DEBUG_FLAG DEBUG_PIXEL
 
-/* For many applications, the new ability to pull the source buffers
- * back out of the GTT and then do the packing/conversion operations
- * in software will be as much of an improvement as trying to get the
- * blitter and/or texture engine to do the work.
- *
- * This step is gated on private backbuffers.
- *
- * Obviously the frontbuffer can't be pulled back, so that is either
- * an argument for blit/texture readpixels, or for blitting to a
- * temporary and then pulling that back.
- *
- * When the destination is a pbo, however, it's not clear if it is
- * ever going to be pulled to main memory (though the access param
- * will be a good hint).  So it sounds like we do want to be able to
- * choose between blit/texture implementation on the gpu and pullback
- * and cpu-based copying.
- *
- * Unless you can magically turn client memory into a PBO for the
- * duration of this call, there will be a cpu-based copying step in
- * any case.
- */
-
-static bool
-do_blit_readpixels(struct gl_context * ctx,
-                   GLint x, GLint y, GLsizei width, GLsizei height,
-                   GLenum format, GLenum type,
-                   const struct gl_pixelstore_attrib *pack, GLvoid * pixels)
-{
-   struct brw_context *brw = brw_context(ctx);
-   struct intel_buffer_object *dst = intel_buffer_object(pack->BufferObj);
-   GLuint dst_offset;
-   drm_intel_bo *dst_buffer;
-   GLint dst_x, dst_y;
-   GLuint dirty;
-
-   DBG("%s\n", __FUNCTION__);
-
-   assert(_mesa_is_bufferobj(pack->BufferObj));
-
-   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
-   struct intel_renderbuffer *irb = intel_renderbuffer(rb);
-
-   /* Currently this function only supports reading from color buffers. */
-   if (!_mesa_is_color_format(format))
-      return false;
-
-   assert(irb != NULL);
-
-   if (ctx->_ImageTransferState ||
-       !_mesa_format_matches_format_and_type(irb->mt->format, format, type,
-                                             false)) {
-      DBG("%s - bad format for blit\n", __FUNCTION__);
-      return false;
-   }
-
-   if (pack->SwapBytes || pack->LsbFirst) {
-      DBG("%s: bad packing params\n", __FUNCTION__);
-      return false;
-   }
-
-   int dst_stride = _mesa_image_row_stride(pack, width, format, type);
-   bool dst_flip = false;
-   /* Mesa flips the dst_stride for pack->Invert, but we want our mt to have a
-    * normal dst_stride.
-    */
-   struct gl_pixelstore_attrib uninverted_pack = *pack;
-   if (pack->Invert) {
-      dst_stride = -dst_stride;
-      dst_flip = true;
-      uninverted_pack.Invert = false;
-   }
-
-   dst_offset = (GLintptr)pixels;
-   dst_offset += _mesa_image_offset(2, &uninverted_pack, width, height,
-				    format, type, 0, 0, 0);
-
-   if (!_mesa_clip_copytexsubimage(ctx,
-				   &dst_x, &dst_y,
-				   &x, &y,
-				   &width, &height)) {
-      return true;
-   }
-
-   dirty = brw->front_buffer_dirty;
-   intel_prepare_render(brw);
-   brw->front_buffer_dirty = dirty;
-
-   dst_buffer = intel_bufferobj_buffer(brw, dst,
-				       dst_offset, height * dst_stride);
-
-   struct intel_mipmap_tree *pbo_mt =
-      intel_miptree_create_for_bo(brw,
-                                  dst_buffer,
-                                  irb->mt->format,
-                                  dst_offset,
-                                  width, height, 1,
-                                  dst_stride);
-
-   if (!intel_miptree_blit(brw,
-                           irb->mt, irb->mt_level, irb->mt_layer,
-                           x, y, _mesa_is_winsys_fbo(ctx->ReadBuffer),
-                           pbo_mt, 0, 0,
-                           0, 0, dst_flip,
-                           width, height, GL_COPY)) {
-      return false;
-   }
-
-   intel_miptree_release(&pbo_mt);
-
-   DBG("%s - DONE\n", __FUNCTION__);
-
-   return true;
-}
-
 void
 intelReadPixels(struct gl_context * ctx,
                 GLint x, GLint y, GLsizei width, GLsizei height,
@@ -172,15 +58,11 @@ intelReadPixels(struct gl_context * ctx,
 
    DBG("%s\n", __FUNCTION__);
 
-   if (_mesa_is_bufferobj(pack->BufferObj)) {
-      /* Using PBOs, so try the BLT based path. */
-      if (do_blit_readpixels(ctx, x, y, width, height, format, type, pack,
-                             pixels)) {
-         return;
-      }
-
+   if (_mesa_meta_pbo_GetTexSubImage(ctx, 2, NULL, x, y, 0, width, height, 1,
+                                     format, type, pixels, pack))
+      return;
+   else
       perf_debug("%s: fallback to CPU mapping in PBO case\n", __FUNCTION__);
-   }
 
    /* glReadPixels() wont dirty the front buffer, so reset the dirty
     * flag after calling intel_prepare_render(). */
-- 
2.2.0