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| author | Paul Berry <stereotype441@gmail.com> | 2012-07-26 18:01:28 -0700 |
|---|---|---|
| committer | Paul Berry <stereotype441@gmail.com> | 2012-08-01 12:45:15 -0700 |
| commit | 97fc89c6cbaa3b5ef7f678d2dc2c7d5bbba05315 (patch) | |
| tree | 357d9e09d8b56536aad4bdc80e0779e4f3df41a3 /src/mesa/drivers/dri/i965/gen7_sf_state.c | |
| parent | d5c918f6adb2f7f72a759607c8f76e7616656c13 (diff) | |
i965/msaa: Treat GL_SAMPLES=1 as equivalent to GL_SAMPLES=0.
EXT_framebuffer_multisample is a required subpart of
ARB_framebuffer_object, which means that we must support it even on
platforms that don't support MSAA. Fortunately
EXT_framebuffer_multisample allows for this by allowing GL_MAX_SAMPLES
to be set to 1.
This leads to a tricky quirk in the GL spec: since
GlRenderbufferStorageMultisamples() accepts any value for its
"samples" parameter up to and including GL_MAX_SAMPLES, that means
that on platforms that don't support MSAA, GL_SAMPLES is allowed to be
set to either 0 or 1. On platforms that do support MSAA, GL_SAMPLES=1
is not used; 0 means no MSAA, and 2 or higher means MSAA.
In other words, GL_SAMPLES needs to be interpreted as follows:
=0 no MSAA (possible on all platforms)
=1 no MSAA (only possible on platforms where MSAA unsupported)
>1 MSAA (only possible on platforms where MSAA supported)
This patch modifies all MSAA-related code to choose between
multisampling and single-sampling based on the condition (GL_SAMPLES >
1) instead of (GL_SAMPLES > 0) so that GL_SAMPLES=1 will be treated as
"no MSAA".
Note that since GL_SAMPLES=1 implies GL_SAMPLE_BUFFERS=1, we can no
longer use GL_SAMPLE_BUFFERS to distinguish between MSAA and non-MSAA
rendering.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Diffstat (limited to 'src/mesa/drivers/dri/i965/gen7_sf_state.c')
| -rw-r--r-- | src/mesa/drivers/dri/i965/gen7_sf_state.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/mesa/drivers/dri/i965/gen7_sf_state.c b/src/mesa/drivers/dri/i965/gen7_sf_state.c index 2d258d2f1be..871a8b753a3 100644 --- a/src/mesa/drivers/dri/i965/gen7_sf_state.c +++ b/src/mesa/drivers/dri/i965/gen7_sf_state.c @@ -161,7 +161,7 @@ upload_sf_state(struct brw_context *brw) float point_size; /* _NEW_BUFFERS */ bool render_to_fbo = _mesa_is_user_fbo(brw->intel.ctx.DrawBuffer); - bool multisampled_fbo = ctx->DrawBuffer->Visual.sampleBuffers; + bool multisampled_fbo = ctx->DrawBuffer->Visual.samples > 1; dw1 = GEN6_SF_STATISTICS_ENABLE | GEN6_SF_VIEWPORT_TRANSFORM_ENABLE; |