From 4e549ddb500cf677b6fa16d9ebdfa67cc23da097 Mon Sep 17 00:00:00 2001 From: Marek Olšák Date: Tue, 7 Jan 2014 22:00:20 +0100 Subject: st/mesa: use sRGB formats for MSAA resolving if destination is sRGB Copied from the i965 driver, including the big comment. Cc: 9.2 10.0 --- src/mesa/state_tracker/st_cb_blit.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/src/mesa/state_tracker/st_cb_blit.c b/src/mesa/state_tracker/st_cb_blit.c index a236a08e95..82c2e38e57 100644 --- a/src/mesa/state_tracker/st_cb_blit.c +++ b/src/mesa/state_tracker/st_cb_blit.c @@ -43,6 +43,34 @@ #include "util/u_format.h" +static void +st_adjust_blit_for_msaa_resolve(struct pipe_blit_info *blit) +{ + /* Even though we do multisample resolves at the time of the blit, OpenGL + * specification defines them as if they happen at the time of rendering, + * which means that the type of averaging we do during the resolve should + * only depend on the source format; the destination format should be + * ignored. But, specification doesn't seem to be strict about it. + * + * It has been observed that mulitisample resolves produce slightly better + * looking images when averaging is done using destination format. NVIDIA's + * proprietary OpenGL driver also follows this approach. + * + * When multisampling, if the source and destination formats are equal + * (aside from the color space), we choose to blit in sRGB space to get + * this higher quality image. + */ + if (blit->src.resource->nr_samples > 1 && + blit->dst.resource->nr_samples <= 1) { + blit->dst.format = blit->dst.resource->format; + + if (util_format_is_srgb(blit->dst.resource->format)) + blit->src.format = util_format_srgb(blit->src.resource->format); + else + blit->src.format = util_format_linear(blit->src.resource->format); + } +} + static void st_BlitFramebuffer(struct gl_context *ctx, GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, @@ -192,6 +220,8 @@ st_BlitFramebuffer(struct gl_context *ctx, blit.src.box.z = srcAtt->Zoffset + srcAtt->CubeMapFace; blit.src.format = util_format_linear(srcObj->pt->format); + st_adjust_blit_for_msaa_resolve(&blit); + st->pipe->blit(st->pipe, &blit); } } @@ -227,6 +257,8 @@ st_BlitFramebuffer(struct gl_context *ctx, blit.src.box.z = srcSurf->u.tex.first_layer; blit.src.format = util_format_linear(srcSurf->format); + st_adjust_blit_for_msaa_resolve(&blit); + st->pipe->blit(st->pipe, &blit); } } -- cgit v1.2.3