From 890ccedf5e2ef00a49d30d471f9cecb46d206474 Mon Sep 17 00:00:00 2001
From: Michael Hills <mhills@gmail.com>
Date: Sun, 23 Aug 2020 14:19:36 +1000
Subject: [PATCH] Switch over to shaderc-rs for glsl to spirv compilation

---
 crates/bevy_render/Cargo.toml           |  2 +-
 crates/bevy_render/src/shader/shader.rs | 36 +++++++++++++++++--------
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/crates/bevy_render/Cargo.toml b/crates/bevy_render/Cargo.toml
index 5d7c1324ef8bd..3ad36f0cb8987 100644
--- a/crates/bevy_render/Cargo.toml
+++ b/crates/bevy_render/Cargo.toml
@@ -24,7 +24,7 @@ bevy_window = { path = "../bevy_window", version = "0.1" }
 
 # rendering
 spirv-reflect = "0.2.3"
-bevy-glsl-to-spirv = "0.1.7"
+shaderc = "0.6.2"
 image = { version = "0.23", default-features = false }
 
 # misc
diff --git a/crates/bevy_render/src/shader/shader.rs b/crates/bevy_render/src/shader/shader.rs
index f963c0c90aa55..96d2d7c1183af 100644
--- a/crates/bevy_render/src/shader/shader.rs
+++ b/crates/bevy_render/src/shader/shader.rs
@@ -1,7 +1,6 @@
 use super::ShaderLayout;
 use bevy_asset::Handle;
-use bevy_glsl_to_spirv::compile;
-use std::{io::Read, marker::Copy};
+use std::marker::Copy;
 
 /// The stage of a shader
 #[derive(Hash, Eq, PartialEq, Copy, Clone, Debug)]
@@ -11,12 +10,12 @@ pub enum ShaderStage {
     Compute,
 }
 
-impl Into<bevy_glsl_to_spirv::ShaderType> for ShaderStage {
-    fn into(self) -> bevy_glsl_to_spirv::ShaderType {
+impl Into<shaderc::ShaderKind> for ShaderStage {
+    fn into(self) -> shaderc::ShaderKind {
         match self {
-            ShaderStage::Vertex => bevy_glsl_to_spirv::ShaderType::Vertex,
-            ShaderStage::Fragment => bevy_glsl_to_spirv::ShaderType::Fragment,
-            ShaderStage::Compute => bevy_glsl_to_spirv::ShaderType::Compute,
+            ShaderStage::Vertex => shaderc::ShaderKind::Vertex,
+            ShaderStage::Fragment => shaderc::ShaderKind::Fragment,
+            ShaderStage::Compute => shaderc::ShaderKind::Compute,
         }
     }
 }
@@ -26,10 +25,25 @@ fn glsl_to_spirv(
     stage: ShaderStage,
     shader_defs: Option<&[String]>,
 ) -> Vec<u32> {
-    let mut output = compile(glsl_source, stage.into(), shader_defs).unwrap();
-    let mut spv_bytes = Vec::new();
-    output.read_to_end(&mut spv_bytes).unwrap();
-    bytes_to_words(&spv_bytes)
+    let mut compiler = shaderc::Compiler::new().unwrap();
+    let mut options = shaderc::CompileOptions::new().unwrap();
+    if let Some(shader_defs) = shader_defs {
+        for def in shader_defs.iter() {
+            options.add_macro_definition(def, None);
+        }
+    }
+
+    let binary_result = compiler
+        .compile_into_spirv(
+            glsl_source,
+            stage.into(),
+            "shader.glsl",
+            "main",
+            Some(&options),
+        )
+        .unwrap();
+
+    binary_result.as_binary().to_vec()
 }
 
 fn bytes_to_words(bytes: &[u8]) -> Vec<u32> {