From 7c8fbb43772cc8a5efd2ceca071d553cc55d7e45 Mon Sep 17 00:00:00 2001
From: Frizi <frizi09@gmail.com>
Date: Tue, 15 Jun 2021 12:02:31 +0200
Subject: [PATCH] [glsl-in] support more math functions and builitns

---
 src/front/glsl/functions.rs | 5 ++++-
 src/front/glsl/variables.rs | 9 +++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/front/glsl/functions.rs b/src/front/glsl/functions.rs
index 9e7655e4bb..9bddc953db 100644
--- a/src/front/glsl/functions.rs
+++ b/src/front/glsl/functions.rs
@@ -270,7 +270,7 @@ impl Program<'_> {
 
                         Ok(Some(ctx.add_expression(expr, body)))
                     }
-                    "pow" | "dot" | "max" => {
+                    "pow" | "dot" | "max" | "min" | "reflect" | "cross" => {
                         if args.len() != 2 {
                             return Err(ErrorKind::wrong_function_args(name, 2, args.len(), meta));
                         }
@@ -280,6 +280,9 @@ impl Program<'_> {
                                     "pow" => MathFunction::Pow,
                                     "dot" => MathFunction::Dot,
                                     "max" => MathFunction::Max,
+                                    "min" => MathFunction::Min,
+                                    "reflect" => MathFunction::Reflect,
+                                    "cross" => MathFunction::Cross,
                                     _ => unreachable!(),
                                 },
                                 arg: args[0].0,
diff --git a/src/front/glsl/variables.rs b/src/front/glsl/variables.rs
index fc54c5daff..9636281cef 100644
--- a/src/front/glsl/variables.rs
+++ b/src/front/glsl/variables.rs
@@ -115,6 +115,15 @@ impl Program<'_> {
                 false,
                 PrologueStage::COMPUTE,
             ),
+            "gl_FrontFacing" => add_builtin(
+                TypeInner::Scalar {
+                    kind: ScalarKind::Bool,
+                    width: 1,
+                },
+                BuiltIn::FrontFacing,
+                false,
+                PrologueStage::FRAGMENT,
+            ),
             _ => Ok(None),
         }
     }