Encapsulate rendering program setup

app-proto/src/display.rs

@@ -27,6 +27,45 @@ fn compile_shader(
     shader
 }
 
+fn create_program_with_shaders(
+    context: &WebGl2RenderingContext,
+    vertex_shader_source: &str,
+    fragment_shader_source: &str
+) -> WebGlProgram {
+    // compile the shaders
+    let vertex_shader = compile_shader(
+        &context,
+        WebGl2RenderingContext::VERTEX_SHADER,
+        vertex_shader_source,
+    );
+    let fragment_shader = compile_shader(
+        &context,
+        WebGl2RenderingContext::FRAGMENT_SHADER,
+        fragment_shader_source,
+    );
+    
+    // create the program and attach the shaders
+    let program = context.create_program().unwrap();
+    context.attach_shader(&program, &vertex_shader);
+    context.attach_shader(&program, &fragment_shader);
+    context.link_program(&program);
+    
+    /* DEBUG */
+    // report whether linking succeeded
+    let link_status = context
+        .get_program_parameter(&program, WebGl2RenderingContext::LINK_STATUS)
+        .as_bool()
+        .unwrap();
+    let link_msg = if link_status {
+        "Linked successfully"
+    } else {
+        "Linking failed"
+    };
+    console::log_1(&JsValue::from(link_msg));
+    
+    program
+}
+
 fn get_uniform_array_locations<const N: usize>(
     context: &WebGl2RenderingContext,
     program: &WebGlProgram,
@@ -186,31 +225,12 @@ pub fn Display() -> View {
             .dyn_into::<WebGl2RenderingContext>()
             .unwrap();
         
-        // compile and attach the vertex and fragment shaders
+        // create and use the rendering program
-        let vertex_shader = compile_shader(
+        let program = create_program_with_shaders(
             &ctx,
-            WebGl2RenderingContext::VERTEX_SHADER,
             include_str!("identity.vert"),
+            include_str!("inversive.frag")
         );
-        let fragment_shader = compile_shader(
-            &ctx,
-            WebGl2RenderingContext::FRAGMENT_SHADER,
-            include_str!("inversive.frag"),
-        );
-        let program = ctx.create_program().unwrap();
-        ctx.attach_shader(&program, &vertex_shader);
-        ctx.attach_shader(&program, &fragment_shader);
-        ctx.link_program(&program);
-        let link_status = ctx
-            .get_program_parameter(&program, WebGl2RenderingContext::LINK_STATUS)
-            .as_bool()
-            .unwrap();
-        let link_msg = if link_status {
-            "Linked successfully"
-        } else {
-            "Linking failed"
-        };
-        console::log_1(&JsValue::from(link_msg));
         ctx.use_program(Some(&program));
         
         /* DEBUG */