Supporting gl_PointCoord (#2180)

gfx-rs · Dec 21, 2022 · 8e1b052 · 8e1b052
1 parent 37be4df
commit 8e1b052
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Showing 8 changed files with 25 additions and 1 deletion.
diff --git a/src/back/glsl/mod.rs b/src/back/glsl/mod.rs
@@ -3723,6 +3723,7 @@ const fn glsl_built_in(
         Bi::VertexIndex => "uint(gl_VertexID)",
         // fragment
         Bi::FragDepth => "gl_FragDepth",
+        Bi::PointCoord => "gl_PointCoord",
         Bi::FrontFacing => "gl_FrontFacing",
         Bi::PrimitiveIndex => "uint(gl_PrimitiveID)",
         Bi::SampleIndex => "gl_SampleID",

diff --git a/src/back/hlsl/conv.rs b/src/back/hlsl/conv.rs
@@ -177,7 +177,7 @@ impl crate::BuiltIn {
             Self::BaseInstance | Self::BaseVertex | Self::WorkGroupSize => {
                 return Err(Error::Unimplemented(format!("builtin {:?}", self)))
             }
-            Self::ViewIndex => {
+            Self::ViewIndex | Self::PointCoord => {
                 return Err(Error::Custom(format!("Unsupported builtin {:?}", self)))
             }
         })

diff --git a/src/back/msl/mod.rs b/src/back/msl/mod.rs
@@ -391,6 +391,7 @@ impl ResolvedBinding {
                     Bi::VertexIndex => "vertex_id",
                     // fragment
                     Bi::FragDepth => "depth(any)",
+                    Bi::PointCoord => "point_coord",
                     Bi::FrontFacing => "front_facing",
                     Bi::PrimitiveIndex => "primitive_id",
                     Bi::SampleIndex => "sample_id",

diff --git a/src/back/spv/writer.rs b/src/back/spv/writer.rs
@@ -1231,6 +1231,7 @@ impl Writer {
                     Bi::VertexIndex => BuiltIn::VertexIndex,
                     // fragment
                     Bi::FragDepth => BuiltIn::FragDepth,
+                    Bi::PointCoord => BuiltIn::PointCoord,
                     Bi::FrontFacing => BuiltIn::FrontFacing,
                     Bi::PrimitiveIndex => {
                         self.require_any(

diff --git a/src/front/glsl/variables.rs b/src/front/glsl/variables.rs
@@ -128,6 +128,16 @@ impl Parser {
                 mutable: false,
                 storage: StorageQualifier::Input,
             },
+            "gl_PointCoord" => BuiltInData {
+                inner: TypeInner::Vector {
+                    size: VectorSize::Bi,
+                    kind: ScalarKind::Float,
+                    width: 4,
+                },
+                builtin: BuiltIn::PointCoord,
+                mutable: false,
+                storage: StorageQualifier::Input,
+            },
             "gl_GlobalInvocationID"
             | "gl_NumWorkGroups"
             | "gl_WorkGroupSize"

diff --git a/src/front/spv/convert.rs b/src/front/spv/convert.rs
@@ -137,6 +137,7 @@ pub(super) fn map_builtin(word: spirv::Word, invariant: bool) -> Result<crate::B
         Some(Bi::VertexIndex) => crate::BuiltIn::VertexIndex,
         // fragment
         Some(Bi::FragDepth) => crate::BuiltIn::FragDepth,
+        Some(Bi::PointCoord) => crate::BuiltIn::PointCoord,
         Some(Bi::FrontFacing) => crate::BuiltIn::FrontFacing,
         Some(Bi::PrimitiveId) => crate::BuiltIn::PrimitiveIndex,
         Some(Bi::SampleId) => crate::BuiltIn::SampleIndex,

diff --git a/src/lib.rs b/src/lib.rs
@@ -340,6 +340,7 @@ pub enum BuiltIn {
     VertexIndex,
     // fragment
     FragDepth,
+    PointCoord,
     FrontFacing,
     PrimitiveIndex,
     SampleIndex,

diff --git a/src/valid/interface.rs b/src/valid/interface.rs
@@ -177,6 +177,15 @@ impl VaryingContext<'_> {
                                 width,
                             },
                     ),
+                    Bi::PointCoord => (
+                        self.stage == St::Fragment && !self.output,
+                        *ty_inner
+                            == Ti::Vector {
+                                size: Vs::Bi,
+                                kind: Sk::Float,
+                                width,
+                            },
+                    ),
                     Bi::Position { .. } => (
                         match self.stage {
                             St::Vertex => self.output,