OpenGL: Add uniform for translation.

1 files changed, 13 insertions, 4 deletions

diff --git a/rust/opengl/src/main.rs b/rust/opengl/src/main.rs
index 667339b..ff24d1e 100644
--- a/rust/opengl/src/main.rs
+++ b/rust/opengl/src/main.rs
@@ -31,8 +31,11 @@ fn main() {
     let vertex_shader_src = r#"
         #version 140
         in vec2 position;
+        uniform float t;
         void main() {
-            gl_Position = vec4(position, 0.0, 1.0);
+            vec2 p = position;
+            p.x += t;
+            gl_Position = vec4(p, 0.0, 1.0);
         }
     "#;
 
@@ -40,16 +43,22 @@ fn main() {
         #version 140
         out vec4 color;
         void main() {
-            color = vec4(1.0, 0.0, 0.0, 1.0);
+            color = vec4(0.7, 0.3, 0.2, 1.0);
         }
     "#;
 
     let program = glium::Program::from_source(&display, vertex_shader_src, fragment_shader_src, None).unwrap();
 
+    let mut t: f32 = -0.5;
     loop {
+        t += 0.002;
+        if t > 0.5 {
+            t = -0.5;
+        }
+
         let mut target = display.draw();
-        target.clear_color(0.0, 0.0, 1.0, 1.0);
-        target.draw(&vertex_buffer, &indices, &program, &glium::uniforms::EmptyUniforms,
+        target.clear_color(0.3, 0.3, 0.2, 1.0);
+        target.draw(&vertex_buffer, &indices, &program, &uniform! { t: t },
                     &Default::default()).unwrap();
         target.finish().unwrap();