From 6736bcefa6f1bf5f72efb7622f3500515e17661c Mon Sep 17 00:00:00 2001
From: Gordon-F <ishaposhnik@icloud.com>
Date: Wed, 17 Mar 2021 15:37:18 +0300
Subject: [PATCH] [glsl-out] Explicitly set location bindings

---
 src/back/glsl/mod.rs                | 18 ++++++++++++++++--
 tests/out/quad-Fragment.glsl.snap   |  4 ++--
 tests/out/quad-Vertex.glsl.snap     |  6 +++---
 tests/out/shadow-Fragment.glsl.snap |  6 +++---
 tests/out/skybox-Fragment.glsl.snap |  4 ++--
 tests/out/skybox-Vertex.glsl.snap   |  2 +-
 6 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/src/back/glsl/mod.rs b/src/back/glsl/mod.rs
index d9ae2848d7..25a883e90b 100644
--- a/src/back/glsl/mod.rs
+++ b/src/back/glsl/mod.rs
@@ -811,8 +811,22 @@ impl<'a, W: Write> Writer<'a, W> {
                 }
 
                 // Write the storage class
-                write!(self.out, "{} ", if output { "out" } else { "in" })?;
-
+                if self.options.version >= Version::Embedded(310)
+                    || self.options.version >= Version::Desktop(410)
+                {
+                    if let Binding::Location(index, ..) = *binding {
+                        write!(
+                            self.out,
+                            "layout(location = {}) {} ",
+                            index,
+                            if output { "out" } else { "in" }
+                        )?;
+                    } else {
+                        write!(self.out, "{} ", if output { "out" } else { "in" })?;
+                    }
+                } else {
+                    write!(self.out, "{} ", if output { "out" } else { "in" })?;
+                }
                 // Write the type
                 // `write_type` adds no leading or trailing spaces
                 self.write_type(ty)?;
diff --git a/tests/out/quad-Fragment.glsl.snap b/tests/out/quad-Fragment.glsl.snap
index 8773ca4ccf..28e2a75f1d 100644
--- a/tests/out/quad-Fragment.glsl.snap
+++ b/tests/out/quad-Fragment.glsl.snap
@@ -13,8 +13,8 @@ struct VertexOutput {
 
 uniform highp sampler2D _group_0_binding_0;
 
-in vec2 _in_location_0;
-out vec4 _out_location_0;
+layout(location = 0) in vec2 _in_location_0;
+layout(location = 0) out vec4 _out_location_0;
 
 void main() {
     vec2 uv2 = _in_location_0;
diff --git a/tests/out/quad-Vertex.glsl.snap b/tests/out/quad-Vertex.glsl.snap
index c4d67cef93..51a1aa2b03 100644
--- a/tests/out/quad-Vertex.glsl.snap
+++ b/tests/out/quad-Vertex.glsl.snap
@@ -11,9 +11,9 @@ struct VertexOutput {
     vec4 position;
 };
 
-in vec2 _in_location_0;
-in vec2 _in_location_1;
-out vec2 _out_location_0;
+layout(location = 0) in vec2 _in_location_0;
+layout(location = 1) in vec2 _in_location_1;
+layout(location = 0) out vec2 _out_location_0;
 
 void main() {
     vec2 pos = _in_location_0;
diff --git a/tests/out/shadow-Fragment.glsl.snap b/tests/out/shadow-Fragment.glsl.snap
index fa07395965..ff052ae0f8 100644
--- a/tests/out/shadow-Fragment.glsl.snap
+++ b/tests/out/shadow-Fragment.glsl.snap
@@ -22,9 +22,9 @@ readonly buffer Lights_block_1 {
 
 uniform highp sampler2DArrayShadow _group_0_binding_2;
 
-in vec3 _in_location_0;
-in vec4 _in_location_1;
-out vec4 _out_location_0;
+layout(location = 0) in vec3 _in_location_0;
+layout(location = 1) in vec4 _in_location_1;
+layout(location = 0) out vec4 _out_location_0;
 
 float fetch_shadow(uint light_id, vec4 homogeneous_coords) {
     if((homogeneous_coords[3] <= 0.0)) {
diff --git a/tests/out/skybox-Fragment.glsl.snap b/tests/out/skybox-Fragment.glsl.snap
index e08e83c480..532203d3dc 100644
--- a/tests/out/skybox-Fragment.glsl.snap
+++ b/tests/out/skybox-Fragment.glsl.snap
@@ -13,8 +13,8 @@ struct VertexOutput {
 
 uniform highp samplerCube _group_0_binding_1;
 
-in vec3 _in_location_0;
-out vec4 _out_location_0;
+layout(location = 0) in vec3 _in_location_0;
+layout(location = 0) out vec4 _out_location_0;
 
 void main() {
     vec3 uv1 = _in_location_0;
diff --git a/tests/out/skybox-Vertex.glsl.snap b/tests/out/skybox-Vertex.glsl.snap
index 4b71a76fad..3f7c221d58 100644
--- a/tests/out/skybox-Vertex.glsl.snap
+++ b/tests/out/skybox-Vertex.glsl.snap
@@ -16,7 +16,7 @@ uniform Data_block_0 {
     mat4x4 view;
 } _group_0_binding_0;
 
-out vec3 _out_location_0;
+layout(location = 0) out vec3 _out_location_0;
 
 void main() {
     uint vertex_index = uint(gl_VertexID);