Pass uniform for elapsed

gloom-rs/report/exercise2.md

@@ -40,3 +40,6 @@ OpenGL does a simple interpolation between the vertex colors, and assigns a colo
 ![](./images/transparent_triangles.png)
 
 Here we have drawn three partially overlapping triangles drawn in the order "red - green - blue" with red having the highest z-index (furthest back), followed by green and finally blue. All triangles are rendered with alpha = 0.4
+
+TODO TASK 2B)
+

gloom-rs/shaders/simple.vert

@@ -2,18 +2,19 @@
 
 layout(location=0) in vec3 position;
 layout(location=1) in vec4 vertex_colors;
+uniform float elapsed;
 out vec4 fragment_colors;
 
-// this matrix mirrors over the x-axis and the y-axis simultaneously
-const mat4 flip = mat4(
-    vec4(-1.0f,  0.0f,  0.0f,  0.0f),  // column 0
-    vec4( 0.0f, -1.0f,  0.0f,  0.0f),  // column 1
-    vec4( 0.0f,  0.0f,  1.0f,  0.0f),  // column 2
-    vec4( 0.0f,  0.0f,  0.0f,  1.0f)   // column 3
-);
 
 void main()
 {
-    gl_Position = flip * vec4(position, 1.0f);
+    // this matrix mirrors over the x-axis and the y-axis simultaneously
+    mat4 ID_MAT = mat4(
+        vec4( 1.0f,  0.0f,  0.0f,  0.0f),  // column 0
+        vec4( 0.0f,  elapsed,  0.0f,  0.0f),  // column 1
+        vec4( 0.0f,  0.0f,  1.0f,  0.0f),  // column 2
+        vec4( 0.0f,  0.0f,  0.0f,  1.0f)   // column 3
+    );
+    gl_Position = ID_MAT * vec4(position, 1.0f);
     fragment_colors = vertex_colors;
 }

gloom-rs/src/main.rs

@@ -217,6 +217,7 @@ fn main() {
         let vao_id = unsafe { create_vao(&vertices, &indices, &colors) };
 
 
+
         // == // Set up your shaders here
 
         // Basic usage of shader helper:
@@ -296,7 +297,9 @@ fn main() {
                 // Clear the color and depth buffers
                 gl::ClearColor(0.035, 0.046, 0.078, 1.0); // night sky
                 gl::Clear(gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT);
-
+                
+                let loc = simple_shader.get_uniform_location("elapsed");
+                gl::Uniform1f(loc, elapsed.sin());
                 gl::DrawElements(gl::TRIANGLES, indices.len() as i32, gl::UNSIGNED_INT, ptr::null());
             }