Feature: TV screen CRT has a warm up and power down sequence

tv-player/src/scene/tv-set.js

@@ -181,7 +181,9 @@ export function turnTvScreenOn() {
 
     state.tvScreen.material = new THREE.ShaderMaterial({
         uniforms: {
-            videoTexture: { value: state.videoTexture }
+            videoTexture: { value: state.videoTexture },
+            u_effect_type: { value: 0.0 },
+            u_effect_strength: { value: 0.0 },
         },
         vertexShader: screenVertexShader,
         fragmentShader: screenFragmentShader,
@@ -189,4 +191,47 @@ export function turnTvScreenOn() {
     });
 
     state.tvScreen.material.needsUpdate = true;
+    setScreenEffect(1); // Trigger warm-up
+}
+
+/**
+ * Controls the warm-up and power-down effects on the TV screen.
+ * @param {number} effectType - 0 normal, 1 for warm-up, 2 for power-down.
+ * @param {function} onComplete - Optional callback when the animation finishes.
+ */
+export function setScreenEffect(effectType, onComplete) {
+    const material = state.tvScreen.material;
+    if (!material.uniforms) return;
+    
+    state.screenEffect.active = true;
+    state.screenEffect.type = effectType;
+    state.screenEffect.startTime = state.clock.getElapsedTime() * 1000;
+    state.screenEffect.onComplete = onComplete;
+}
+
+/**
+ * Updates the screen effect animation. Should be called in the main render loop.
+ */
+export function updateScreenEffect() {
+    if (!state.screenEffect.active) return;
+
+    const material = state.tvScreen.material;
+    if (!material.uniforms) return;
+
+    const elapsedTime = (state.clock.getElapsedTime() * 1000) - state.screenEffect.startTime;
+    const progress = Math.min(elapsedTime / state.screenEffect.duration, 1.0);
+    
+    const easedProgress = state.screenEffect.easing(progress);
+
+    material.uniforms.u_effect_type.value = state.screenEffect.type;
+    material.uniforms.u_effect_strength.value = easedProgress;
+
+    if (progress >= 1.0) {
+        state.screenEffect.active = false;
+        material.uniforms.u_effect_strength.value = (state.screenEffect.type === 2) ? 1.0 : 0.0; // Final state
+        if (state.screenEffect.onComplete) {
+            state.screenEffect.onComplete();
+        }
+        material.uniforms.u_effect_type.value = 0.0; // Reset effect type
+    }
 }