From 4a8b395cf27220dc35c09607bd5d48f272dc930c Mon Sep 17 00:00:00 2001
From: Emile Clark-Boman <eclarkboman@gmail.com>
Date: Sat, 31 Jan 2026 11:14:12 +1000
Subject: [PATCH] fetch vertex shader source

---
 www/js/webgl-demo.js | 60 ++++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 25 deletions(-)

diff --git a/www/js/webgl-demo.js b/www/js/webgl-demo.js
index 9f46772..9acbf13 100644
--- a/www/js/webgl-demo.js
+++ b/www/js/webgl-demo.js
@@ -3,8 +3,8 @@ import { drawScene } from "./draw-scene.js";
 
 main();
 
-/* TODO: Avoid using alerts! Check return values instead,
- * TODO: or create/use a Result like object.
+/* XXX: TODO: Avoid using alerts! Check return values instead,
+ * XXX: TODO: or create/use a Result like object.
  */
 
 // Initialize a shader program, so WebGL knows how to draw our data
@@ -37,7 +37,7 @@ function loadShader(gl, type, source) {
 
   // Send the source to the shader object
   gl.shaderSource(shader, source);
-  
+
   // Compile the shader program
   gl.compileShader(shader);
 
@@ -75,31 +75,41 @@ function main() {
       }
     `;
 
-  const fsSource = `
-      // is highp wasteful for this shader?
-      #ifdef GL_FRAGMENT_PRECISION_HIGH
-        precision highp float;
-      #else
-        precision mediump float;
-      #endif
+  // const fsSource = `
+  //     // is highp wasteful for this shader?
+  //     #ifdef GL_FRAGMENT_PRECISION_HIGH
+  //       precision highp float;
+  //     #else
+  //       precision mediump float;
+  //     #endif
 
-      // shadertoy-like parameters
-      // uniform vec2 uResolution; 
-      uniform float uTime;
-  
-      void main() {
-        vec2 uv = gl_FragCoord.xy/vec2(300, 300).xy;
+  //     // shadertoy-like parameters
+  //     // uniform vec2 uResolution; 
+  //     uniform float uTime;
 
-        // Time varying pixel color
-        vec3 col = 0.5 + 0.5*cos(uTime+uv.xyx+vec3(0,2,4));
+  //     void main() {
+  //       vec2 uv = gl_FragCoord.xy/vec2(300, 300).xy;
+
+  //       // Time varying pixel color
+  //       vec3 col = 0.5 + 0.5*cos(uTime+uv.xyx+vec3(0,2,4));
+
+  //       // Output to screen
+  //       gl_FragColor = vec4(col,1.0);
+
+  //       // gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
+  //     }
+  //   `;
+  const fsSource = (async () => {
+    const res = await fetch("../shaders/segfault.glsl");
+    if (!res.ok) {
+      const error = `Failed to load fragment shader source ${url}: ${res.status}`;
+      alert(error);
+      throw new Error(error);
+    }
+
+    return await res.text()
+  })();
 
-        // Output to screen
-        gl_FragColor = vec4(col,1.0);
-  
-        // gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
-      }
-    `;
-  
   const shaderProgram = initShaderProgram(gl, vsSource, fsSource);
 
   // Collect all the info needed to use the shader program.