added starfalls / shooting stars

global/globalScript.js

@@ -31,6 +31,11 @@ function randomInt(min, max) {
 }
 
 
+function randomBool(probablity) {
+  return Math.random() <= probablity
+}
+
+
 function clampNearest(n, mul) {
   if(n > 0)
     return Math.ceil(n / mul) * mul;

global/pxDensity.js

@@ -1,12 +1,15 @@
 let pxDensity = parseFloat(getComputedStyle(document.body).getPropertyValue("--pxDensity"))
 let pxDensityDefined = false
 
-let densityWidth = document.documentElement.clientWidth / 256
-let densityHeight = document.documentElement.clientHeight / 164
+let pxWidth = 256
+let pxHeight = 164
+
+let densityWidth = document.documentElement.clientWidth / pxWidth
+let densityHeight = document.documentElement.clientHeight / pxHeight
 
 function calcPixelDensity() {
-  densityWidth = document.documentElement.clientWidth / 256
-  densityHeight = document.documentElement.clientHeight / 164
+  densityWidth = document.documentElement.clientWidth / pxWidth
+  densityHeight = document.documentElement.clientHeight / pxHeight
 
   let widest = Math.max(densityWidth, densityHeight)
 

index.html

@@ -35,9 +35,12 @@
     <img src="/assets/backgrounds/bgGradient_256x164.png" class="bgGradient">
     
     <img src="/assets/backgrounds/starNoise_512x512.png" draggable="false" id="starNoise">
+
+    <canvas id="starfallCanvas"></canvas>
+
     <img src="/assets/synthwaveSun_40x40.png" draggable="false" class="synthSun">
 
-    <div id="canvasContainer"></div>
+    <div id="synthwaveCanvas"></div>
     <div id="navBarContainer"></div>
   </div>
 
@@ -61,6 +64,7 @@
   <!-- local -->
   <script src="script.js"></script>
   <script src="synthwaveEffect.js"></script>
+  <script src="starfall.js"></script>
 </body>
 
 </html>

script.js

@@ -4,6 +4,9 @@ function loadingScreenSynthwave() {
   setLoadingProgress("Adding stars...")
   addStars()
 
+  setLoadingProgress("Starting starfall animation...")
+  startStarfall()
+
   setLoadingProgress("Starting synthwave animation...")
   defShaderMaterial()
   preAnimateSynthwave(25)
@@ -21,3 +24,12 @@ function addStars() {
   starNoise.style.top = `round(calc(${randX}px * var(--pxDensity)), var(--pxDensityPx))`
   starNoise.style.left = `round(calc(${randY}px * var(--pxDensity)), var(--pxDensityPx))`
 }
+
+
+function onResizeSynthwave() {
+  renderer.setSize(window.innerWidth, window.innerHeight)
+  composer.setSize(window.innerWidth, window.innerHeight)
+  camera.aspect = window.innerWidth / window.innerHeight
+  camera.updateProjectionMatrix()
+  if (shaderMaterial) { updateShaderMatPxDensity() }
+}

starfall.js

@@ -0,0 +1,112 @@
+const starfallCanvas = document.getElementById("starfallCanvas")
+starfallCanvas.width = window.innerWidth
+starfallCanvas.height = window.innerHeight
+
+const starfallCtx = starfallCanvas.getContext("2d")
+
+
+class Starfall {
+  constructor() {
+    this.pos = {x: 0, y: 0}
+    this.vel = {x: 0, y: 0}
+  }
+
+  generate() {
+    const dir = randomBool(0.5)
+    this.pos.x = dir ? -50 : pxWidth + 50
+    this.pos.y = randomInt(-starfallCanvas.height / 2, starfallCanvas.height / 2)
+    this.vel.x = dir ? randomFloat(3, 6) : randomFloat(-6, -3)
+    this.vel.y = randomFloat(0.25, 1)
+  }
+
+  draw() {
+    // very expensive but idk how to make it less expensive
+    drawPixelLine(
+      this.pos.x,
+      this.pos.y,
+      this.pos.x - (this.vel.x * 5),
+      this.pos.y - (this.vel.y * 5)
+    )
+  }
+
+  stepAnimation() {
+    this.pos.x += this.vel.x
+    this.pos.y += this.vel.y
+  }
+}
+
+
+function drawPixelLine(fromX, fromY, toX, toY) {
+  const pxInflate = 0.1;
+
+  const dx = Math.abs(toX - fromX);
+  const dy = Math.abs(toY - fromY);
+  const sx = fromX < toX ? 1 : -1;
+  const sy = fromY < toY ? 1 : -1;
+  let err = dx - dy;
+
+  let x = fromX;
+  let y = fromY;
+
+  starfallCtx.beginPath();
+
+  const steps = Math.max(dx, dy);
+
+  for (let i = 0; i <= steps; i++) {
+    const alpha = i == 0 ? 1 : 0.1 * (1 - i / steps)
+    starfallCtx.fillStyle = `rgba(255, 255, 255, ${alpha})`;
+
+    starfallCtx.rect(
+      clampNearest(x * pxDensity, pxDensity) - 0.5,
+      clampNearest(y * pxDensity, pxDensity) - 0.5,
+      pxInflate + pxDensity,
+      pxInflate + pxDensity
+    );
+
+    const e2 = 2 * err;
+    if (e2 > -dy) {
+      err -= dy;
+      x += sx;
+    }
+    if (e2 < dx) {
+      err += dx;
+      y += sy;
+    }
+
+    starfallCtx.fill();
+  }
+}
+
+
+let allStarfalls = []
+
+function animateStarfalls() {
+  if (!isAnimating) { return }
+
+  starfallCtx.clearRect(0, 0, starfallCanvas.width, starfallCanvas.height)
+
+  let shouldGenerate = randomBool(0.01)
+
+  if (shouldGenerate) {
+    let newStarfall = new Starfall()
+    newStarfall.generate()
+    allStarfalls.push(newStarfall)
+  }
+
+  for (let starfall of allStarfalls) {
+    if (starfall.pos.x < -50 || starfall.pos.x > pxWidth + 50) {
+      allStarfalls.splice(allStarfalls.indexOf(starfall), 1)
+      continue
+    }
+
+    starfall.stepAnimation()
+    starfall.draw()
+  }
+}
+
+
+function startStarfall() {
+  animateStarfalls()
+
+  requestAnimationFrame(startStarfall)
+}