Only draw frames when necessary

src/Frame.js

@@ -58,6 +58,9 @@ class Frame {
 	 * @param {number} canvasPixelSize
 	 */
 	draw(ctx, direction, canvasPixelSize, species) {
+		// Clear the canvas before drawing the new frame
+		ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+		
 		const pixels = this.getPixels(species?.tags[0]);
 		for (let y = 0; y < pixels.length; y++) {
 			const row = pixels[y];

src/anim.js

@@ -11,12 +11,49 @@ class Anim {
 		this.frames = frames;
 		this.durations = durations;
 		this.loop = loop;
+		this.lastFrameIndex = -1;
+		this.lastDirection = null;
+		this.lastTimeStart = null;
 	}
 
 	getAnimationDuration() {
 		return this.durations.reduce((a, b) => a + b, 0);
 	}
 
+	/**
+	 * Get the current frame index based on elapsed time
+	 * @param {number} time The elapsed time since animation start
+	 * @returns {number} The index of the current frame
+	 */
+	getCurrentFrameIndex(time) {
+		let totalDuration = 0;
+		for (let i = 0; i < this.durations.length; i++) {
+			totalDuration += this.durations[i];
+			if (time < totalDuration) {
+				return i;
+			}
+		}
+		return this.frames.length - 1;
+	}
+
+	/**
+	 * Clear the cached frame state
+	 */
+	#clearCache() {
+		this.lastFrameIndex = -1;
+		this.lastDirection = null;
+	}
+
+	/**
+	 * Check if the frame needs to be redrawn
+	 * @param {number} frameIndex The current frame index
+	 * @param {number} direction The current direction
+	 * @returns {boolean} Whether the frame needs to be redrawn
+	 */
+	#shouldRedraw(frameIndex, direction) {
+		return frameIndex !== this.lastFrameIndex || direction !== this.lastDirection;
+	}
+
 	/**
 	 * @param {CanvasRenderingContext2D} ctx
 	 * @param {number} direction
@@ -26,22 +63,29 @@ class Anim {
 	 * @returns {boolean} Whether the animation is complete
 	 */
 	draw(ctx, direction, timeStart, canvasPixelSize, species) {
+		// Reset cache if animation was restarted
+		if (this.lastTimeStart !== timeStart) {
+			this.#clearCache();
+			this.lastTimeStart = timeStart;
+		}
+
 		let time = Date.now() - timeStart;
 		const duration = this.getAnimationDuration();
+		
 		if (this.loop) {
 			time %= duration;
 		}
-		let totalDuration = 0;
-		for (let i = 0; i < this.durations.length; i++) {
-			totalDuration += this.durations[i];
-			if (time < totalDuration) {
-				this.frames[i].draw(ctx, direction, canvasPixelSize, species);
-				return false;
-			}
+
+		const currentFrameIndex = this.getCurrentFrameIndex(time);
+		
+		if (this.#shouldRedraw(currentFrameIndex, direction)) {
+			this.frames[currentFrameIndex].draw(ctx, direction, canvasPixelSize, species);
+			this.lastFrameIndex = currentFrameIndex;
+			this.lastDirection = direction;
 		}
-		// Draw the last frame if the animation is complete
-		this.frames[this.frames.length - 1].draw(ctx, direction, canvasPixelSize, species);
-		return true;
+		
+		// Return whether animation is complete (for non-looping animations)
+		return !this.loop && time >= duration;
 	}
 }
 

src/birb.js

@@ -125,7 +125,6 @@ export class Birb {
 	 * @returns {boolean} Whether the animation has completed (for non-looping animations)
 	 */
 	draw(species) {
-		this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
 		const anim = this.animations[this.currentAnimation];
 		return anim.draw(this.ctx, this.direction, this.animStart, this.canvasPixelSize, species);
 	}

src/frame.js

@@ -58,6 +58,9 @@ class Frame {
 	 * @param {number} canvasPixelSize
 	 */
 	draw(ctx, direction, canvasPixelSize, species) {
+		// Clear the canvas before drawing the new frame
+		ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
+		
 		const pixels = this.getPixels(species?.tags[0]);
 		for (let y = 0; y < pixels.length; y++) {
 			const row = pixels[y];