Am 22.09.2016 um 17:40 schrieb Emil Velikov: > Hi Nicholas, > > On 26 August 2016 at 00:31, Nicholas Bishop <nbis...@neverware.com> wrote: >> From: Nicholas Bishop <nicholasbis...@gmail.com> >> >> On Intel Pineview M hardware, the i915 gallium driver doesn't output >> the correct gl_FragCoord. It seems to always have an X coord of 0.0 >> and a Y coord of the window's height in pixels, e.g. 600.0f or such. >> >> I believe this is a regression caused in part by this commit: >> afa035031ff9e0c07a2297d864e46c76f7bfff58 >> >> The old behavior used the output at index zero, while the new behavior >> uses actual zeroes. In the case of gl_FragCoord the output at index >> zero happened to be the correct one, so the behavior appeared correct >> although the code already had a bug. >> >> Fixed by checking for I915_SEMANTIC_POS when setting up texCoords. If >> the generic_mapping is I915_SEMANTIC_POS, look for the >> TGSI_SEMANTIC_POSITION instead of a TGSI_SEMANTIC_GENERIC output. >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugs.freedesktop.org_show-5Fbug.cgi-3Fid-3D97477&d=CwIFaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=Mt7V3FvGsInekgNmMd2jOoCYRJDl4If-uvNtbOhGkRQ&s=JlfHHRDgBQvDfacPpT-qFUmY4drEprImNSdf1L6ch3c&e= >> >> --- >> src/gallium/drivers/i915/i915_state_derived.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/src/gallium/drivers/i915/i915_state_derived.c >> b/src/gallium/drivers/i915/i915_state_derived.c >> index 177b854..dbfbc84 100644 >> --- a/src/gallium/drivers/i915/i915_state_derived.c >> +++ b/src/gallium/drivers/i915/i915_state_derived.c >> @@ -145,7 +145,12 @@ static void calculate_vertex_layout(struct i915_context >> *i915) >> uint hwtc; >> if (texCoords[i]) { >> hwtc = TEXCOORDFMT_4D; >> - src = draw_find_shader_output(i915->draw, TGSI_SEMANTIC_GENERIC, >> fs->generic_mapping[i]); >> + if (fs->generic_mapping[i] == I915_SEMANTIC_POS) { >> + src = draw_find_shader_output(i915->draw, >> TGSI_SEMANTIC_POSITION, 0); >> + } >> + else { >> + src = draw_find_shader_output(i915->draw, >> TGSI_SEMANTIC_GENERIC, fs->generic_mapping[i]); >> + } > > Personally I'm unfamiliar with the i915g driver, so I've Cc'd Roland > (the author of the commit 'breaking' this) and Stéphane (the author of > this driver). > > Gents, any input on the above ?
Oh, I wasn't aware I broke this... This looks to me like before my patch there i915g was indeed just relying on draw code redirecting undefined inputs to 0, which near certainly was unspecified behavior. I don't really know i915g, but this looks like it should be correct. Reviewed-by: Roland Scheidegger <srol...@vmware.com> > > That said, please drop the unneeded brackets and add the following > line in the commit message for v2. > Cc: mesa-sta...@lists.freedesktop.org > > Thanks, > Emil > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
