small shader tweak

Author: AkinAguda

crates/web/src/utility/webgl/constants.rs

@@ -28,10 +28,13 @@ pub const VERTEX_SHADER_2: &str = r#"
 
 pub const FRAGMENT_SHADER_1: &str = r#"
   precision mediump float;
+  
+  uniform vec2 u_resolution;
   varying float v_density;
 
   void main() {
-    gl_FragColor = vec4(v_density * v_density, v_density * 0.0, v_density * 1.0, 1.0);
+    vec2 uv = gl_FragCoord.xy / u_resolution;
+    gl_FragColor = vec4(v_density * uv.x, v_density * uv.y, v_density, 1.0);
   }
 "#;
 

crates/web/src/utility/webgl/functions.rs

@@ -279,6 +279,10 @@ pub fn initialise_webgl(canvas: &web_sys::HtmlCanvasElement, nw: f32, nh: f32) -
         .get_uniform_location(&rtc_program, "u_imageProjection")
         .unwrap();
 
+    let resolution_uniform_location = context
+        .get_uniform_location(&rtt_program, "u_resolution")
+        .unwrap();
+
     let position_buffer = context.create_buffer().unwrap();
 
     let density_buffer = context.create_buffer().unwrap();
@@ -304,6 +308,11 @@ pub fn initialise_webgl(canvas: &web_sys::HtmlCanvasElement, nw: f32, nh: f32) -
         &texture_position_projection_matrix,
     );
 
+    context.uniform2fv_with_f32_array(
+        Some(&resolution_uniform_location),
+        &vec![nw as f32, nh as f32],
+    );
+
     context.use_program(Some(&rtc_program));
 
     #[rustfmt::skip]