From 13c9b28e8a1e61032ae651b5b2f685dfbd1f5867 Mon Sep 17 00:00:00 2001
From: Kjetil Orbekk <kjetil.orbekk@gmail.com>
Date: Wed, 6 Jul 2016 22:12:49 -0400
Subject: 1.5. Output parameter from fragment shader.

---
 rust/opengl/src/main.rs | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/rust/opengl/src/main.rs b/rust/opengl/src/main.rs
index d7b3a52..29ee2ec 100644
--- a/rust/opengl/src/main.rs
+++ b/rust/opengl/src/main.rs
@@ -29,21 +29,25 @@ fn main() {
     let vertex_shader_src = r#"
         #version 140
         in vec2 position;
+        out vec2 my_attr;
         uniform mat4 trans;
         void main() {
+            my_attr = position;
             gl_Position = trans * vec4(position, 0.0, 1.0);
         }
     "#;
 
     let fragment_shader_src = r#"
         #version 140
+        in vec2 my_attr;
         out vec4 color;
         void main() {
-            color = vec4(0.7, 0.3, 0.2, 1.0);
+            color = vec4(my_attr, 0.0, 1.0);
         }
     "#;
 
-    let program = glium::Program::from_source(&display, vertex_shader_src, fragment_shader_src, None).unwrap();
+    let program = glium::Program::from_source(
+        &display, vertex_shader_src, fragment_shader_src, None).unwrap();
 
     let mut t: f32 = -0.5;
     loop {
@@ -62,7 +66,7 @@ fn main() {
         };
 
         let mut target = display.draw();
-        target.clear_color(0.3, 0.3, 0.2, 1.0);
+        target.clear_color(0.0, 0.0, 0.0, 1.0);
         target.draw(&vertex_buffer, &indices, &program, &uniforms,
                     &Default::default()).unwrap();
         target.finish().unwrap();
-- 
cgit v1.2.3