diff --git a/src/ShaderWorker.ts b/src/ShaderWorker.ts
index a935979..2deeb49 100644
--- a/src/ShaderWorker.ts
+++ b/src/ShaderWorker.ts
@@ -56,6 +56,7 @@ class ShaderWorker {
   private imageDataCache: LRUCache<string, ImageData> = new LRUCache(PERFORMANCE.IMAGE_DATA_CACHE_SIZE);
   private compilationCache: LRUCache<string, ShaderFunction> = new LRUCache(PERFORMANCE.COMPILATION_CACHE_SIZE);
   private colorTables: Map<string, Uint8Array> = new Map();
+  private feedbackBuffer: Float32Array | null = null;
 
   constructor() {
     self.onmessage = (e: MessageEvent<WorkerMessage>) => {
@@ -156,6 +157,15 @@ class ShaderWorker {
           'y',
           't',
           'i',
+          'r',
+          'a',
+          'u',
+          'v',
+          'c',
+          'f',
+          'd',
+          'n',
+          'b',
           'mouseX',
           'mouseY',
           'mousePressed',
@@ -295,6 +305,11 @@ class ShaderWorker {
     const data = imageData.data;
     const startTime = performance.now();
     const maxRenderTime = PERFORMANCE.MAX_RENDER_TIME_MS;
+    
+    // Initialize feedback buffer if needed
+    if (!this.feedbackBuffer || this.feedbackBuffer.length !== width * height) {
+      this.feedbackBuffer = new Float32Array(width * height);
+    }
 
     try {
       // Use tiled rendering for better timeout handling
@@ -392,11 +407,34 @@ class ShaderWorker {
         const actualY = y + yOffset;
 
         try {
+          // Calculate additional coordinate variables
+          const u = x / fullWidth;
+          const v = actualY / fullHeight;
+          const centerX = fullWidth / 2;
+          const centerY = fullHeight / 2;
+          const radius = Math.sqrt((x - centerX) ** 2 + (actualY - centerY) ** 2);
+          const angle = Math.atan2(actualY - centerY, x - centerX);
+          const maxDistance = Math.sqrt(centerX ** 2 + centerY ** 2);
+          const normalizedDistance = radius / maxDistance;
+          const frameCount = Math.floor(time * 60);
+          const manhattanDistance = Math.abs(x - centerX) + Math.abs(actualY - centerY);
+          const noise = (Math.sin(x * 0.1) * Math.cos(actualY * 0.1) + 1) * 0.5;
+          const feedbackValue = this.feedbackBuffer ? this.feedbackBuffer[pixelIndex] || 0 : 0;
+          
           const value = this.compiledFunction!(
             x,
             actualY,
             time,
             pixelIndex,
+            radius,
+            angle,
+            u,
+            v,
+            normalizedDistance,
+            frameCount,
+            manhattanDistance,
+            noise,
+            feedbackValue,
             message.mouseX || 0,
             message.mouseY || 0,
             message.mousePressed ? 1 : 0,
@@ -436,6 +474,11 @@ class ShaderWorker {
           data[i + 1] = g;
           data[i + 2] = b;
           data[i + 3] = 255;
+          
+          // Update feedback buffer with current processed value
+          if (this.feedbackBuffer) {
+            this.feedbackBuffer[pixelIndex] = safeValue;
+          }
         } catch (error) {
           data[i] = 0;
           data[i + 1] = 0;
diff --git a/src/components/HelpPopup.tsx b/src/components/HelpPopup.tsx
index 03c6b7f..d96db3f 100644
--- a/src/components/HelpPopup.tsx
+++ b/src/components/HelpPopup.tsx
@@ -58,6 +58,30 @@ export function HelpPopup() {
           <p>
             <strong>i</strong> - Pixel index
           </p>
+          <p>
+            <strong>r</strong> - Distance from center
+          </p>
+          <p>
+            <strong>a</strong> - Angle from center (radians)
+          </p>
+          <p>
+            <strong>u, v</strong> - Normalized coordinates (0.0 to 1.0)
+          </p>
+          <p>
+            <strong>c</strong> - Normalized center distance (0.0 to 1.0)
+          </p>
+          <p>
+            <strong>f</strong> - Frame count (discrete timing)
+          </p>
+          <p>
+            <strong>d</strong> - Manhattan distance from center
+          </p>
+          <p>
+            <strong>n</strong> - Noise value (0.0 to 1.0)
+          </p>
+          <p>
+            <strong>b</strong> - Previous frame's value (feedback)
+          </p>
           <p>
             <strong>mouseX, mouseY</strong> - Mouse position (0.0 to 1.0)
           </p>
diff --git a/src/components/ShaderCanvas.tsx b/src/components/ShaderCanvas.tsx
index caf6f02..f1b5713 100644
--- a/src/components/ShaderCanvas.tsx
+++ b/src/components/ShaderCanvas.tsx
@@ -74,13 +74,7 @@ export function ShaderCanvas() {
   // Handle animation
   useEffect(() => {
     if (shaderRef.current) {
-      const hasTime = shader.code.includes('t');
-      if (hasTime) {
-        shaderRef.current.startAnimation();
-      } else {
-        shaderRef.current.stopAnimation();
-        shaderRef.current.render(false);
-      }
+      shaderRef.current.startAnimation();
     }
   }, [shader.code]);