[Mesa-dev] [PATCH 3/3] i965: Export format comparison for blitting between miptrees

[Chris Wilson]

Since the introduction of

commit 536003c11e4cb1172c540932ce3cce06f03bf44e
Author: Boyan Ding <boyan.j.ding at gmail.com>
Date:   Wed Mar 25 19:36:54 2015 +0800

    i965: Add XRGB8888 format to intel_screen_make_configs

winsys buffers no longer have an alpha channel. This causes
_mesa_format_matches_format_and_type() to reject previously working BGRA
uploads from using the BLT fast path. Instead of using the generic
routine for matching formats exactly, export the slightly more relaxed
check from intel_miptree_blit() which importantly allows the blitter
routine to apply a small number of format conversions.

References: https://bugs.freedesktop.org/show_bug.cgi?id=90839
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jason Ekstrand <jason at jlekstrand.net>
Cc: Alexander Monakov <amonakov at gmail.com>
Cc: Kristian Høgsberg <krh at bitplanet.net>
Cc: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/intel_blit.c       |  4 ++--
 src/mesa/drivers/dri/i965/intel_blit.h       |  2 ++
 src/mesa/drivers/dri/i965/intel_pixel_draw.c | 11 +++++++++--
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_blit.c b/src/mesa/drivers/dri/i965/intel_blit.c
index 02666dc..b691525 100644
--- a/src/mesa/drivers/dri/i965/intel_blit.c
+++ b/src/mesa/drivers/dri/i965/intel_blit.c
@@ -138,7 +138,7 @@ static int blt_pitch(struct intel_mipmap_tree *mt)
    return pitch;
 }
 
-static bool blt_compatible_formats(mesa_format src, mesa_format dst)
+bool intel_miptree_blit_compatible_formats(mesa_format src, mesa_format dst)
 {
    /* The BLT doesn't handle sRGB conversion */
    assert(src == _mesa_get_srgb_format_linear(src));
@@ -205,7 +205,7 @@ intel_miptree_blit(struct brw_context *brw,
     * the X channel don't matter), and XRGB8888 to ARGB8888 by setting the A
     * channel to 1.0 at the end.
     */
-   if (!blt_compatible_formats(src_format, dst_format)) {
+   if (!intel_miptree_blit_compatible_formats(src_format, dst_format)) {
       perf_debug("%s: Can't use hardware blitter from %s to %s, "
                  "falling back.\n", __func__,
                  _mesa_get_format_name(src_format),
diff --git a/src/mesa/drivers/dri/i965/intel_blit.h b/src/mesa/drivers/dri/i965/intel_blit.h
index f563939..2287c37 100644
--- a/src/mesa/drivers/dri/i965/intel_blit.h
+++ b/src/mesa/drivers/dri/i965/intel_blit.h
@@ -46,6 +46,8 @@ intelEmitCopyBlit(struct brw_context *brw,
                               GLshort w, GLshort h,
 			      GLenum logicop );
 
+bool intel_miptree_blit_compatible_formats(mesa_format src, mesa_format dst);
+
 bool intel_miptree_blit(struct brw_context *brw,
                         struct intel_mipmap_tree *src_mt,
                         int src_level, int src_slice,
diff --git a/src/mesa/drivers/dri/i965/intel_pixel_draw.c b/src/mesa/drivers/dri/i965/intel_pixel_draw.c
index 4ecefc8..d68cbb6 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel_draw.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel_draw.c
@@ -28,6 +28,7 @@
 #include "main/glheader.h"
 #include "main/enums.h"
 #include "main/image.h"
+#include "main/glformats.h"
 #include "main/mtypes.h"
 #include "main/condrender.h"
 #include "main/fbobject.h"
@@ -76,8 +77,14 @@ do_blit_drawpixels(struct gl_context * ctx,
    struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
    struct intel_renderbuffer *irb = intel_renderbuffer(rb);
 
-   if (!_mesa_format_matches_format_and_type(irb->mt->format, format, type,
-                                             false)) {
+   mesa_format src_format = _mesa_format_from_format_and_type(format, type);
+   mesa_format dst_format = irb->mt->format;
+
+   /* We can safely discard sRGB encode/decode for the DrawPixels interface */
+   src_format = _mesa_get_srgb_format_linear(src_format);
+   dst_format = _mesa_get_srgb_format_linear(dst_format);
+
+   if (!intel_miptree_blit_compatible_formats(src_format, dst_format)) {
       DBG("%s: bad format for blit\n", __func__);
       return false;
    }
-- 
2.1.4