This behaviour was changed in 1e5b09f42f694687ac. The commit message for that says it is just a “tidy up” so my assumption is that the behaviour change was a mistake. It’s a little hard to decipher looking at the diff, but the previous code before that patch was:
if (builtin == SpvBuiltInFragCoord || builtin == SpvBuiltInSamplePosition) nir_var->data.origin_upper_left = b->origin_upper_left; if (builtin == SpvBuiltInFragCoord) nir_var->data.pixel_center_integer = b->pixel_center_integer; After the patch the code was: case SpvBuiltInSamplePosition: nir_var->data.origin_upper_left = b->origin_upper_left; /* fallthrough */ case SpvBuiltInFragCoord: nir_var->data.pixel_center_integer = b->pixel_center_integer; break; Before the patch origin_upper_left affected both builtins and pixel_center_integer only affected FragCoord. After the patch origin_upper_left only affects SamplePosition and pixel_center_integer affects both variables. This patch tries to restore the previous behaviour by changing the code to: case SpvBuiltInFragCoord: nir_var->data.pixel_center_integer = b->pixel_center_integer; /* fallthrough */ case SpvBuiltInSamplePosition: nir_var->data.origin_upper_left = b->origin_upper_left; break; This change will be important for ARB_gl_spirv which is meant to support OriginLowerLeft. --- src/compiler/spirv/vtn_variables.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c index 9679ff6526c..fd8ab7f247a 100644 --- a/src/compiler/spirv/vtn_variables.c +++ b/src/compiler/spirv/vtn_variables.c @@ -1419,11 +1419,11 @@ apply_var_decoration(struct vtn_builder *b, nir_variable *nir_var, case SpvBuiltInTessLevelInner: nir_var->data.compact = true; break; - case SpvBuiltInSamplePosition: - nir_var->data.origin_upper_left = b->origin_upper_left; - /* fallthrough */ case SpvBuiltInFragCoord: nir_var->data.pixel_center_integer = b->pixel_center_integer; + /* fallthrough */ + case SpvBuiltInSamplePosition: + nir_var->data.origin_upper_left = b->origin_upper_left; break; default: break; -- 2.14.3 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev