1 files changed, 340 insertions, 0 deletions
diff --git a/packages/ui/src/lib/effects/SaturnEffect.ts b/packages/ui/src/lib/effects/SaturnEffect.ts
new file mode 100644
index 0000000..357da9d
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+++ b/packages/ui/src/lib/effects/SaturnEffect.ts
@@ -0,0 +1,340 @@
+// Optimized Saturn Effect for low-end hardware
+// Uses TypedArrays for memory efficiency and reduced particle density
+
+export class SaturnEffect {
+  private canvas: HTMLCanvasElement;
+  private ctx: CanvasRenderingContext2D;
+  private width: number = 0;
+  private height: number = 0;
+
+  // Data-oriented design for performance
+  // xyz: Float32Array where [i*3, i*3+1, i*3+2] corresponds to x, y, z
+  private xyz: Float32Array | null = null;
+  // types: Uint8Array where 0 = planet, 1 = ring
+  private types: Uint8Array | null = null;
+  private count: number = 0;
+
+  private animationId: number = 0;
+  private angle: number = 0;
+  private scaleFactor: number = 1;
+
+  // Mouse interaction properties
+  private isDragging: boolean = false;
+  private lastMouseX: number = 0;
+  private lastMouseTime: number = 0;
+  private mouseVelocities: number[] = []; // Store recent velocities for averaging
+
+  // Rotation speed control
+  private readonly baseSpeed: number = 0.005; // Original rotation speed
+  private currentSpeed: number = 0.005; // Current rotation speed (can be modified by mouse)
+  private rotationDirection: number = 1; // 1 for clockwise, -1 for counter-clockwise
+  private readonly speedDecayRate: number = 0.992; // How fast speed returns to normal (closer to 1 = slower decay)
+  private readonly minSpeedMultiplier: number = 1; // Minimum speed is baseSpeed
+  private readonly maxSpeedMultiplier: number = 50; // Maximum speed is 50x baseSpeed
+  private isStopped: boolean = false; // Whether the user has stopped the rotation
+
+  constructor(canvas: HTMLCanvasElement) {
+    this.canvas = canvas;
+    this.ctx = canvas.getContext("2d", {
+      alpha: true,
+      desynchronized: false, // default is usually fine, 'desynchronized' can help latency but might flicker
+    })!;
+
+    // Initial resize will set up everything
+    this.resize(window.innerWidth, window.innerHeight);
+    this.initParticles();
+
+    this.animate = this.animate.bind(this);
+    this.animate();
+  }
+
+  // Public methods for external mouse event handling
+  // These can be called from any element that wants to control the Saturn rotation
+
+  handleMouseDown(clientX: number) {
+    this.isDragging = true;
+    this.lastMouseX = clientX;
+    this.lastMouseTime = performance.now();
+    this.mouseVelocities = [];
+  }
+
+  handleMouseMove(clientX: number) {
+    if (!this.isDragging) return;
+
+    const currentTime = performance.now();
+    const deltaTime = currentTime - this.lastMouseTime;
+
+    if (deltaTime > 0) {
+      const deltaX = clientX - this.lastMouseX;
+      const velocity = deltaX / deltaTime; // pixels per millisecond
+
+      // Store recent velocities (keep last 5 for smoothing)
+      this.mouseVelocities.push(velocity);
+      if (this.mouseVelocities.length > 5) {
+        this.mouseVelocities.shift();
+      }
+
+      // Apply direct rotation while dragging
+      this.angle += deltaX * 0.002;
+    }
+
+    this.lastMouseX = clientX;
+    this.lastMouseTime = currentTime;
+  }
+
+  handleMouseUp() {
+    if (this.isDragging && this.mouseVelocities.length > 0) {
+      this.applyFlingVelocity();
+    }
+    this.isDragging = false;
+  }
+
+  handleTouchStart(clientX: number) {
+    this.isDragging = true;
+    this.lastMouseX = clientX;
+    this.lastMouseTime = performance.now();
+    this.mouseVelocities = [];
+  }
+
+  handleTouchMove(clientX: number) {
+    if (!this.isDragging) return;
+
+    const currentTime = performance.now();
+    const deltaTime = currentTime - this.lastMouseTime;
+
+    if (deltaTime > 0) {
+      const deltaX = clientX - this.lastMouseX;
+      const velocity = deltaX / deltaTime;
+
+      this.mouseVelocities.push(velocity);
+      if (this.mouseVelocities.length > 5) {
+        this.mouseVelocities.shift();
+      }
+
+      this.angle += deltaX * 0.002;
+    }
+
+    this.lastMouseX = clientX;
+    this.lastMouseTime = currentTime;
+  }
+
+  handleTouchEnd() {
+    if (this.isDragging && this.mouseVelocities.length > 0) {
+      this.applyFlingVelocity();
+    }
+    this.isDragging = false;
+  }
+
+  private applyFlingVelocity() {
+    // Calculate average velocity from recent samples
+    const avgVelocity =
+      this.mouseVelocities.reduce((a, b) => a + b, 0) / this.mouseVelocities.length;
+
+    // Threshold for considering it a "fling" (pixels per millisecond)
+    const flingThreshold = 0.3;
+    // Threshold for considering the rotation as "stopped" by user
+    const stopThreshold = 0.1;
+
+    if (Math.abs(avgVelocity) > flingThreshold) {
+      // User flung it - start rotating again
+      this.isStopped = false;
+
+      // Determine new direction based on fling direction
+      const newDirection = avgVelocity > 0 ? 1 : -1;
+
+      // If direction changed, update it permanently
+      if (newDirection !== this.rotationDirection) {
+        this.rotationDirection = newDirection;
+      }
+
+      // Calculate speed boost based on fling strength
+      // Map velocity to speed multiplier (stronger fling = faster rotation)
+      const speedMultiplier = Math.min(
+        this.maxSpeedMultiplier,
+        this.minSpeedMultiplier + Math.abs(avgVelocity) * 10,
+      );
+
+      this.currentSpeed = this.baseSpeed * speedMultiplier;
+    } else if (Math.abs(avgVelocity) < stopThreshold) {
+      // User gently released - keep it stopped
+      this.isStopped = true;
+      this.currentSpeed = 0;
+    }
+    // If velocity is between stopThreshold and flingThreshold,
+    // keep current state (don't change isStopped)
+  }
+
+  resize(width: number, height: number) {
+    const dpr = window.devicePixelRatio || 1;
+    this.width = width;
+    this.height = height;
+
+    this.canvas.width = width * dpr;
+    this.canvas.height = height * dpr;
+    this.canvas.style.width = `${width}px`;
+    this.canvas.style.height = `${height}px`;
+
+    this.ctx.scale(dpr, dpr);
+
+    // Dynamic scaling based on screen size
+    const minDim = Math.min(width, height);
+    this.scaleFactor = minDim * 0.45;
+  }
+
+  initParticles() {
+    // Significantly reduced particle count for CPU optimization
+    // Planet: 1800 -> 1000
+    // Rings: 5000 -> 2500
+    // Total approx 3500 vs 6800 previously (approx 50% reduction)
+    const planetCount = 1000;
+    const ringCount = 2500;
+    this.count = planetCount + ringCount;
+
+    // Use TypedArrays for better memory locality
+    this.xyz = new Float32Array(this.count * 3);
+    this.types = new Uint8Array(this.count);
+
+    let idx = 0;
+
+    // 1. Planet
+    for (let i = 0; i < planetCount; i++) {
+      const theta = Math.random() * Math.PI * 2;
+      const phi = Math.acos(Math.random() * 2 - 1);
+      const r = 1.0;
+
+      // x, y, z
+      this.xyz[idx * 3] = r * Math.sin(phi) * Math.cos(theta);
+      this.xyz[idx * 3 + 1] = r * Math.sin(phi) * Math.sin(theta);
+      this.xyz[idx * 3 + 2] = r * Math.cos(phi);
+
+      this.types[idx] = 0; // 0 for planet
+      idx++;
+    }
+
+    // 2. Rings
+    const ringInner = 1.4;
+    const ringOuter = 2.3;
+
+    for (let i = 0; i < ringCount; i++) {
+      const angle = Math.random() * Math.PI * 2;
+      const dist = Math.sqrt(
+        Math.random() * (ringOuter * ringOuter - ringInner * ringInner) + ringInner * ringInner,
+      );
+
+      // x, y, z
+      this.xyz[idx * 3] = dist * Math.cos(angle);
+      this.xyz[idx * 3 + 1] = (Math.random() - 0.5) * 0.05;
+      this.xyz[idx * 3 + 2] = dist * Math.sin(angle);
+
+      this.types[idx] = 1; // 1 for ring
+      idx++;
+    }
+  }
+
+  animate() {
+    this.ctx.clearRect(0, 0, this.width, this.height);
+
+    // Normal blending
+    this.ctx.globalCompositeOperation = "source-over";
+
+    // Update rotation speed - decay towards base speed while maintaining direction
+    if (!this.isDragging && !this.isStopped) {
+      if (this.currentSpeed > this.baseSpeed) {
+        // Gradually decay speed back to base speed
+        this.currentSpeed =
+          this.baseSpeed + (this.currentSpeed - this.baseSpeed) * this.speedDecayRate;
+
+        // Snap to base speed when close enough
+        if (this.currentSpeed - this.baseSpeed < 0.00001) {
+          this.currentSpeed = this.baseSpeed;
+        }
+      }
+
+      // Apply rotation with current speed and direction
+      this.angle += this.currentSpeed * this.rotationDirection;
+    }
+
+    const cx = this.width * 0.6;
+    const cy = this.height * 0.5;
+
+    // Pre-calculate rotation matrices
+    const rotationY = this.angle;
+    const rotationX = 0.4;
+    const rotationZ = 0.15;
+
+    const sinY = Math.sin(rotationY);
+    const cosY = Math.cos(rotationY);
+    const sinX = Math.sin(rotationX);
+    const cosX = Math.cos(rotationX);
+    const sinZ = Math.sin(rotationZ);
+    const cosZ = Math.cos(rotationZ);
+
+    const fov = 1500;
+    const scaleFactor = this.scaleFactor;
+
+    if (!this.xyz || !this.types) return;
+
+    for (let i = 0; i < this.count; i++) {
+      const x = this.xyz[i * 3];
+      const y = this.xyz[i * 3 + 1];
+      const z = this.xyz[i * 3 + 2];
+
+      // Apply Scale
+      const px = x * scaleFactor;
+      const py = y * scaleFactor;
+      const pz = z * scaleFactor;
+
+      // 1. Rotate Y
+      const x1 = px * cosY - pz * sinY;
+      const z1 = pz * cosY + px * sinY;
+      // y1 = py
+
+      // 2. Rotate X
+      const y2 = py * cosX - z1 * sinX;
+      const z2 = z1 * cosX + py * sinX;
+      // x2 = x1
+
+      // 3. Rotate Z
+      const x3 = x1 * cosZ - y2 * sinZ;
+      const y3 = y2 * cosZ + x1 * sinZ;
+      const z3 = z2;
+
+      const scale = fov / (fov + z3);
+
+      if (z3 > -fov) {
+        const x2d = cx + x3 * scale;
+        const y2d = cy + y3 * scale;
+
+        // Size calculation - slightly larger dots to compensate for lower count
+        // Previously Planet 2.0 -> 2.4, Ring 1.3 -> 1.5
+        const type = this.types[i];
+        const sizeBase = type === 0 ? 2.4 : 1.5;
+        const size = sizeBase * scale;
+
+        // Opacity
+        let alpha = scale * scale * scale;
+        if (alpha > 1) alpha = 1;
+        if (alpha < 0.15) continue; // Skip very faint particles for performance
+
+        // Optimization: Planet color vs Ring color
+        if (type === 0) {
+          // Planet: Warm White
+          this.ctx.fillStyle = `rgba(255, 240, 220, ${alpha})`;
+        } else {
+          // Ring: Cool White
+          this.ctx.fillStyle = `rgba(220, 240, 255, ${alpha})`;
+        }
+
+        // Render as squares (fillRect) instead of circles (arc)
+        // This is significantly faster for software rendering and reduces GPU usage.
+        this.ctx.fillRect(x2d, y2d, size, size);
+      }
+    }
+
+    this.animationId = requestAnimationFrame(this.animate);
+  }
+
+  destroy() {
+    cancelAnimationFrame(this.animationId);
+  }
+}