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authorKenneth Graunke <[email protected]>2016-08-02 16:32:52 -0700
committerKenneth Graunke <[email protected]>2016-08-08 14:04:01 -0700
commitf6dc71483abb876386824ba97097089cc0b8f454 (patch)
treefbbf4ee433ede04a14281a038e914a0f48e0e789 /src
parentad32dcf630c387e01f415f98717aad08d20ff9f2 (diff)
meta: Make Meta's BlitFramebuffer() follow the GL 4.4 sRGB rules.
Just avoid whacking GL_FRAMEBUFFER_SRGB altogether, so we respect the application's setting. This appears to work. v2: Update one more comment (requested by Ian). Signed-off-by: Kenneth Graunke <[email protected]> Reviewed-by: Ian Romanick <[email protected]>
Diffstat (limited to 'src')
-rw-r--r--src/mesa/drivers/common/meta_blit.c84
1 files changed, 30 insertions, 54 deletions
diff --git a/src/mesa/drivers/common/meta_blit.c b/src/mesa/drivers/common/meta_blit.c
index d6d3a423040..991d52f21e9 100644
--- a/src/mesa/drivers/common/meta_blit.c
+++ b/src/mesa/drivers/common/meta_blit.c
@@ -606,7 +606,6 @@ blitframebuffer_texture(struct gl_context *ctx,
GLenum filter, GLint flipX, GLint flipY,
GLboolean glsl_version, GLboolean do_depth)
{
- struct save_state *save = &ctx->Meta->Save[ctx->Meta->SaveStackDepth - 1];
int att_index = do_depth ? BUFFER_DEPTH : readFb->_ColorReadBufferIndex;
const struct gl_renderbuffer_attachment *readAtt =
&readFb->Attachment[att_index];
@@ -719,57 +718,32 @@ blitframebuffer_texture(struct gl_context *ctx,
fb_tex_blit.samp_obj = _mesa_meta_setup_sampler(ctx, texObj, target, filter,
srcLevel);
- /* For desktop GL, we do our blits with no net sRGB decode or encode.
- *
- * However, if both the src and dst can be srgb decode/encoded, enable them
- * so that we do any blending (from scaling or from MSAA resolves) in the
- * right colorspace.
- *
- * Our choice of not doing any net encode/decode is from the GL 3.0
- * specification:
- *
- * "Blit operations bypass the fragment pipeline. The only fragment
- * operations which affect a blit are the pixel ownership test and the
- * scissor test."
- *
- * The GL 4.4 specification disagrees and says that the sRGB part of the
- * fragment pipeline applies, but this was found to break applications
- * (such as Left 4 Dead 2).
- *
- * However, for ES 3.0, we follow the specification and perform sRGB
- * decoding and encoding. The specification has always been clear in
- * the ES world, and hasn't changed over time.
- */
if (ctx->Extensions.EXT_texture_sRGB_decode) {
- bool src_srgb = _mesa_get_format_color_encoding(rb->Format) == GL_SRGB;
- if (save->API == API_OPENGLES2 && ctx->Version >= 30) {
- /* From the ES 3.0.4 specification, page 198:
- * "When values are taken from the read buffer, if the value of
- * FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING for the framebuffer
- * attachment corresponding to the read buffer is SRGB (see section
- * 6.1.13), the red, green, and blue components are converted from
- * the non-linear sRGB color space according to equation 3.24.
- *
- * When values are written to the draw buffers, blit operations
- * bypass the fragment pipeline. The only fragment operations which
- * affect a blit are the pixel ownership test, the scissor test,
- * and sRGB conversion (see section 4.1.8)."
- */
- _mesa_set_sampler_srgb_decode(ctx, fb_tex_blit.samp_obj,
- src_srgb ? GL_DECODE_EXT
- : GL_SKIP_DECODE_EXT);
- _mesa_set_framebuffer_srgb(ctx, drawFb->Visual.sRGBCapable);
- } else {
- if (src_srgb && drawFb->Visual.sRGBCapable) {
- _mesa_set_sampler_srgb_decode(ctx, fb_tex_blit.samp_obj,
- GL_DECODE_EXT);
- _mesa_set_framebuffer_srgb(ctx, GL_TRUE);
- } else {
- _mesa_set_sampler_srgb_decode(ctx, fb_tex_blit.samp_obj,
- GL_SKIP_DECODE_EXT);
- /* set_framebuffer_srgb was set by _mesa_meta_begin(). */
- }
- }
+ /* The GL 4.4 spec, section 18.3.1 ("Blitting Pixel Rectangles") says:
+ *
+ * "When values are taken from the read buffer, if FRAMEBUFFER_SRGB
+ * is enabled and the value of FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING
+ * for the framebuffer attachment corresponding to the read buffer
+ * is SRGB (see section 9.2.3), the red, green, and blue components
+ * are converted from the non-linear sRGB color space according to
+ * equation 3.24.
+ *
+ * When values are written to the draw buffers, blit operations
+ * bypass most of the fragment pipeline. The only fragment
+ * operations which affect a blit are the pixel ownership test,
+ * the scissor test, and sRGB conversion (see section 17.3.9)."
+ *
+ * ES 3.0 contains nearly the exact same text, but omits the part
+ * about GL_FRAMEBUFFER_SRGB as that doesn't exist in ES. Mesa
+ * defaults it to on for ES contexts, so we can safely check it.
+ */
+ const bool decode =
+ ctx->Color.sRGBEnabled &&
+ _mesa_get_format_color_encoding(rb->Format) == GL_SRGB;
+
+ _mesa_set_sampler_srgb_decode(ctx, fb_tex_blit.samp_obj,
+ decode ? GL_DECODE_EXT
+ : GL_SKIP_DECODE_EXT);
}
if (!glsl_version) {
@@ -1012,10 +986,12 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
return 0;
}
- /* Only scissor affects blit, but we're doing to set a custom scissor if
- * necessary anyway, so save/clear state.
+ /* Only scissor and FRAMEBUFFER_SRGB affect blit. Leave sRGB alone, but
+ * save restore scissor as we'll set a custom scissor if necessary.
*/
- _mesa_meta_begin(ctx, MESA_META_ALL & ~MESA_META_DRAW_BUFFERS);
+ _mesa_meta_begin(ctx, MESA_META_ALL &
+ ~(MESA_META_DRAW_BUFFERS |
+ MESA_META_FRAMEBUFFER_SRGB));
/* Dithering shouldn't be performed for glBlitFramebuffer */
_mesa_set_enable(ctx, GL_DITHER, GL_FALSE);