From 32205e3097d2ae447e545eba3a1210df075f7c73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Capucho?= <jcapucho7@gmail.com>
Date: Mon, 3 Jan 2022 22:08:00 +0000
Subject: [PATCH] glsl-out: write array initializers

---
 src/back/glsl/mod.rs                  | 34 ++++++++++++++++++++++++++-
 tests/out/glsl/access.foo.Vertex.glsl |  2 +-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/back/glsl/mod.rs b/src/back/glsl/mod.rs
index eee1b34c2e..09cb1d7f0b 100644
--- a/src/back/glsl/mod.rs
+++ b/src/back/glsl/mod.rs
@@ -90,6 +90,16 @@ impl crate::StorageClass {
             _ => false,
         }
     }
+
+    /// Whether a variable with this storage class can be initialized
+    fn initializable(&self) -> bool {
+        match *self {
+            crate::StorageClass::WorkGroup
+            | crate::StorageClass::Uniform
+            | crate::StorageClass::Storage { .. } => false,
+            _ => true,
+        }
+    }
 }
 
 //Note: similar to `back/spv/helpers.rs`
@@ -941,7 +951,7 @@ impl<'a, W: Write> Writer<'a, W> {
             self.write_array_size(size)?;
         }
 
-        if is_value_init_supported(self.module, global.ty) {
+        if global.class.initializable() && is_value_init_supported(self.module, global.ty) {
             write!(self.out, " = ")?;
             if let Some(init) = global.init {
                 self.write_constant(init)?;
@@ -2770,6 +2780,25 @@ impl<'a, W: Write> Writer<'a, W> {
                 self.write_zero_init_scalar(crate::ScalarKind::Float)?;
                 write!(self.out, ")")?;
             }
+            TypeInner::Array { base, size, .. } => {
+                let count = match size
+                    .to_indexable_length(self.module)
+                    .expect("Bad array size")
+                {
+                    proc::IndexableLength::Known(count) => count,
+                    proc::IndexableLength::Dynamic => return Ok(()),
+                };
+                self.write_type(base)?;
+                self.write_array_size(size)?;
+                write!(self.out, "(")?;
+                for _ in 1..count {
+                    self.write_zero_init_value(base)?;
+                    write!(self.out, ", ")?;
+                }
+                // write last parameter without comma and space
+                self.write_zero_init_value(base)?;
+                write!(self.out, ")")?;
+            }
             _ => {} // TODO:
         }
 
@@ -3054,6 +3083,9 @@ fn glsl_storage_format(format: crate::StorageFormat) -> &'static str {
 fn is_value_init_supported(module: &crate::Module, ty: Handle<crate::Type>) -> bool {
     match module.types[ty].inner {
         TypeInner::Scalar { .. } | TypeInner::Vector { .. } | TypeInner::Matrix { .. } => true,
+        TypeInner::Array { base, size, .. } => {
+            size != crate::ArraySize::Dynamic && is_value_init_supported(module, base)
+        }
         _ => false,
     }
 }
diff --git a/tests/out/glsl/access.foo.Vertex.glsl b/tests/out/glsl/access.foo.Vertex.glsl
index 9b24f67403..efac041484 100644
--- a/tests/out/glsl/access.foo.Vertex.glsl
+++ b/tests/out/glsl/access.foo.Vertex.glsl
@@ -20,7 +20,7 @@ float read_from_private(inout float foo_2) {
 void main() {
     uint vi = uint(gl_VertexID);
     float foo_1 = 0.0;
-    int c[5];
+    int c[5] = int[5](0, 0, 0, 0, 0);
     float baz = foo_1;
     foo_1 = 1.0;
     mat4x4 matrix = _group_0_binding_0_vs.matrix;