HeadlightBlocker/pixel_pattern_blur_simulator.html at main · nolanhergert/HeadlightBlocker · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <title>Pixel Pattern Blur Simulator</title>
  <style>
    body {
      font-family: sans-serif;
      background: #111;
      color: #eee;
      margin: 0;
      padding: 16px;
    }
    .controls {
      display: grid;
      grid-template-columns: repeat(1, 1fr);
      gap: 12px;
      margin-bottom: 12px;
    }
    label {
      font-size: 14px;
    }
    canvas {
      border: 1px solid #444;
      image-rendering: pixelated;
    }
    select, input {
      width: 256px;
    }
    select {
      height: 40px;
    }
  </style>
</head>
<body>
  <h2>Pixel Pattern Blur Simulator</h2>

  <div class="controls">
    <label>
      Pattern </br>
      <select id="pattern">

        <option value="grid">Square Grid</option>
        <option value="stagger">Row Stagger</option>
        <option value="hexagonal">Hexagonal Grid</option>
        <option value="sine">Sinusoidal</option>
        <option value="blue">Blue Noise Voronoi</option>
        <option value="hexagonalblue">Hexagonal + Temporarily White Noise Voronoi</option>

      </select>
    </label>

    <label>
      Pixel Pitch (px)</br>
      <input type="range" id="pitch" min="6" max="40" value="12" oninput="this.nextElementSibling.value = this.value" />
      <output>12</output>
    </label>

    <label>
      Gap Width (px)</br>
      <input type="range" id="gap" min="1" max="8" value="3" oninput="this.nextElementSibling.value = this.value" />
      <output>3</output>
    </label>

    <p></p>

    <label>
      Sine Amplitude (px)</br>
      <input type="range" id="amp" min="0" max="5" value="2" step="0.1"oninput="this.nextElementSibling.value = this.value" />
      <output>2</output>
    </label>

    <label>
      Sine Wavelength (px)</br>
      <input type="range" id="wave" min="1" max="200" value="20" oninput="this.nextElementSibling.value = this.value" />
      <output>20</output>
    </label>

    <label>
      Sine Phase Offset (px)</br>
      <input type="range" id="phase" min="0" max="10" value="4" step="0.1" oninput="this.nextElementSibling.value = this.value" />
      <output>4</output>
    </label>

    <label>
      Blue noise allowed diameter deviation (%)</br>
      <input type="range" id="voronoiDeviation" min="0" max="100" value="5" step="5" oninput="this.nextElementSibling.value = this.value" />
      <output>5</output>
    </label>
    <p></p>

    <label style="font-weight: bold;">
      Blur Radius (px)</br>
      <input type="range" id="blur" min="0" max="40" value="25" step="1" oninput="this.nextElementSibling.value = this.value" />
      <output>25</output>
    </label>
  </div>

  <canvas id="src" width="256" height="256"></canvas>
  <canvas id="dst" width="256" height="256"></canvas>

  <script>
    const src = document.getElementById('src');
    const dst = document.getElementById('dst');
    const sctx = src.getContext('2d');
    const dctx = dst.getContext('2d');

    const controls = document.querySelectorAll('input, select');
    controls.forEach(c => c.addEventListener('input', (event) => {
      //console.log(`Input changed: ${event.target.id}, New Value: ${event.target.value}`);
      render(event.target.id);
    }));

    function drawSinusoid(startX, startY, length, amplitude, frequency, phaseOffset, strokeWidth, direction) {

      sctx.lineWidth = strokeWidth;
      sctx.beginPath();

      if (direction === 'horizontal') {
        for (let i = 0; i <= length; i += 0.5) {
          const x = startX + i;
          const y = startY + amplitude * Math.sin(frequency * i + phaseOffset);
          if (i === 0) {
            sctx.moveTo(x, y);
          } else {
            sctx.lineTo(x, y);
          }
        }
      } else { // vertical
        for (let i = 0; i <= length; i += 0.5) {
          const x = startX + amplitude * Math.sin(frequency * i + phaseOffset);
          const y = startY + i;
          if (i === 0) {
            sctx.moveTo(x, y);
          } else {
            sctx.lineTo(x, y);
          }
        }
      }

      sctx.stroke();
    }

    function thresholdImageData(sctx) {      // Get the image data from the canvas
      const imageData = sctx.getImageData(0, 0, src.width, src.height);
      const data = imageData.data;

      // Apply thresholding to make the sinusoid either black or white
      for (let i = 0; i < data.length; i += 4) {
        const brightness = 0.299 * data[i] + 0.587 * data[i + 1] + 0.114 * data[i + 2];
        const threshold = 128; // Adjust this value as needed
        const value = brightness > threshold ? 255 : 0;

        data[i] = value;     // Red
        data[i + 1] = value; // Green
        data[i + 2] = value; // Blue
      }

      // Put the modified image data back onto the canvas
      sctx.putImageData(imageData, 0, 0);
    }


    function applyBoxBlur(ctx, radius) {
      if (radius <= 0) return;

      // Get the image data
      const imageData = ctx.getImageData(0, 0, ctx.canvas.width, ctx.canvas.height);
      const width = imageData.width;
      const height = imageData.height;
      const data = imageData.data;

      // Create output buffer
      const output = new Uint8ClampedArray(data.length);

      const radiusCeil = Math.ceil(radius);
      const radiusSquared = radius * radius;

      // Single pass radial blur
      for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
          let r = 0, g = 0, b = 0, a = 0;
          let count = 0;

          // Sample pixels in a circular pattern
          for (let ky = -radiusCeil; ky <= radiusCeil; ky++) {
            for (let kx = -radiusCeil; kx <= radiusCeil; kx++) {
              // Check if within circle
              const distSquared = kx * kx + ky * ky;
              if (distSquared <= radiusSquared) {
                const sx = x + kx;
                const sy = y + ky;

                if (sx >= 0 && sx < width && sy >= 0 && sy < height) {
                  const idx = (sy * width + sx) * 4;
                  r += data[idx];
                  g += data[idx + 1];
                  b += data[idx + 2];
                  a += data[idx + 3];
                  count++;
                }
              }
            }
          }

          const idx = (y * width + x) * 4;
          output[idx] = r / count;
          output[idx + 1] = g / count;
          output[idx + 2] = b / count;
          output[idx + 3] = a / count;
        }
      }

      // Put the blurred data back
      const outputImageData = new ImageData(output, width, height);
      ctx.putImageData(outputImageData, 0, 0);
    }


    /**
     * Draw a hexagon centered at (cx, cy) with a given radius
     * @param {CanvasRenderingContext2D} ctx - The canvas context
     * @param {number} cx - Center x coordinate
     * @param {number} cy - Center y coordinate
     * @param {number} radius - Radius from center to vertex
     */
    function drawHexagon(ctx, cx, cy, radius) {
      ctx.beginPath();
      for (let i = 0; i < 6; i++) {
        const angle = (Math.PI / 3) * i + Math.PI / 6;
        const x = cx + radius * Math.cos(angle);
        const y = cy + radius * Math.sin(angle);
        if (i === 0) {
          ctx.moveTo(x, y);
        } else {
          ctx.lineTo(x, y);
        }
      }
      ctx.closePath();
      ctx.fill();
    }

    function generateHexagonCenters(pitch) {
      let centers = [];
      const rowHeight = pitch;
      const colWidth = pitch * Math.sqrt(3) / 2;
      for (let row = 0; row * rowHeight < src.height + pitch; row++) {
        const y = row * rowHeight;
        for (let col = 0; col * colWidth < src.width + pitch; col++) {
          const yOffset = (col % 2) * (pitch / 2);
          const x = col * colWidth;
          centers.push({x: x, y: y + yOffset});
        }
      }
      return centers;
    }

    /**
     * Generate blue noise distributed points using Poisson disk sampling
     * @param {number} width - Canvas width
     * @param {number} height - Canvas height
     * @param {number} pitch - Average spacing between points
     * @param {number} deviationPercent - Percentage deviation allowed
     * @returns {Array} Array of {x, y} points
     */
    function generateBlueNoiseCenters(width, height, pitch, deviationPercent) {
      const points = [];
      const minDist = pitch * (1 - deviationPercent / 100);
      const maxDist = pitch * (1 + deviationPercent / 100);
      const cellSize = minDist / Math.sqrt(2);
      const cols = Math.ceil(width / cellSize);
      const rows = Math.ceil(height / cellSize);
      const grid = new Array(cols * rows).fill(-1);
      const active = [];
      const k = 300; // Number of attempts before rejection

      // Helper function to get grid index
      function gridIndex(x, y) {
        const col = Math.floor(x / cellSize);
        const row = Math.floor(y / cellSize);
        if (col < 0 || col >= cols || row < 0 || row >= rows) return -1;
        return row * cols + col;
      }

      // Helper function to check if point is valid
      function isValid(x, y) {
        if (x < 0 || x >= width || y < 0 || y >= height) return false;

        const gidx = gridIndex(x, y);
        if (gidx === -1) return false;

        // Check neighboring cells
        const col = Math.floor(x / cellSize);
        const row = Math.floor(y / cellSize);

        for (let r = Math.max(0, row - 2); r <= Math.min(rows - 1, row + 2); r++) {
          for (let c = Math.max(0, col - 2); c <= Math.min(cols - 1, col + 2); c++) {
            const neighborIdx = r * cols + c;
            const pointIdx = grid[neighborIdx];

            if (pointIdx !== -1) {
              const dx = x - points[pointIdx].x;
              const dy = y - points[pointIdx].y;
              const dist = Math.sqrt(dx * dx + dy * dy);

              if (dist < minDist) {
                return false;
              }
            }
          }
        }

        return true;
      }

      // Start with a random point
      const startX = Math.random() * width;
      const startY = Math.random() * height;
      points.push({x: startX, y: startY});
      active.push(0);
      grid[gridIndex(startX, startY)] = 0;

      // Process active list
      while (active.length > 0) {
        const randomIdx = Math.floor(Math.random() * active.length);
        const pointIdx = active[randomIdx];
        const point = points[pointIdx];
        let found = false;

        for (let i = 0; i < k; i++) {
          // Generate random point around the current point
          const angle = Math.random() * 2 * Math.PI;
          const radius = minDist + Math.random() * (maxDist - minDist);
          const newX = point.x + radius * Math.cos(angle);
          const newY = point.y + radius * Math.sin(angle);

          if (isValid(newX, newY)) {
            const newIdx = points.length;
            points.push({x: newX, y: newY});
            active.push(newIdx);
            grid[gridIndex(newX, newY)] = newIdx;
            found = true;
            break;
          }
        }

        if (!found) {
          active.splice(randomIdx, 1);
        }
      }

      return points;
    }

    /**
     * Draw pixels with blue noise centers and Voronoi edges
     * @param {CanvasRenderingContext2D} ctx - The canvas context to draw on
     * @param {number} gapWidth - Width of the gap between pixels (in pixels)
     */
    function drawVoronoi(ctx, points, gapWidth) {
      const width = ctx.canvas.width;
      const height = ctx.canvas.height;

      // Draw Voronoi cells for each pixel
      const imageData = ctx.createImageData(width, height);
      const data = imageData.data;

      // For each pixel in the canvas, find the nearest point
      for (let y = 0; y < height; y++) {
        for (let x = 0; x < width; x++) {
          const idx = (y * width + x) * 4;

          // Find nearest point
          let minDist = Infinity;
          let nearestIdx = -1;

          for (let i = 0; i < points.length; i++) {
            const dx = x - points[i].x;
            const dy = y - points[i].y;
            const dist = Math.sqrt(dx * dx + dy * dy);

            if (dist < minDist) {
              minDist = dist;
              nearestIdx = i;
            }
          }

          // Check if we're near the edge of the Voronoi cell (gap)
          let secondMinDist = Infinity;
          for (let i = 0; i < points.length; i++) {
            if (i === nearestIdx) continue;
            const dx = x - points[i].x;
            const dy = y - points[i].y;
            const dist = Math.sqrt(dx * dx + dy * dy);

            if (dist < secondMinDist) {
              secondMinDist = dist;
            }
          }

          // If the difference between nearest and second-nearest is small, we're at an edge
          const edgeThreshold = gapWidth / 2;
          const isEdge = (secondMinDist - minDist) < edgeThreshold;

          // Set pixel color (white for cell, black for edge/gap)
          const value = isEdge ? 255 : 0;
          data[idx] = value;     // R
          data[idx + 1] = value; // G
          data[idx + 2] = value; // B
          data[idx + 3] = 255;   // A
        }
      }

      // Draw the blue noise center points
      points.forEach(point => {
        const x = Math.round(point.x);
        const y = Math.round(point.y);
        const idx = (y * width + x) * 4;
        data[idx] = 255;     // R
        data[idx + 1] = 255;   // G
        data[idx + 2] = 255;   // B
        data[idx + 3] = 255; // A
      });


      ctx.putImageData(imageData, 0, 0);
    }


    function render(updatedId) {
      const pitch = +document.getElementById('pitch').value;
      const gap = +document.getElementById('gap').value;
      const blur = +document.getElementById('blur').value;
      const amp = +document.getElementById('amp').value;
      const wave = +document.getElementById('wave').value;
      const phase = +document.getElementById('phase').value;
      const voronoiDeviation = +document.getElementById('voronoiDeviation').value;
      const pat = document.getElementById('pattern').value;


      if (updatedId !== 'blur') {
        if (pat === 'sine') {
          sctx.fillStyle = '#000';
          sctx.fillRect(0, 0, src.width, src.height);
          sctx.strokeStyle = '#fff';
          for (let x = 0; x <= src.width; x += pitch) {
            drawSinusoid(x, 0, 256, amp, (2 * Math.PI) / wave, (x/pitch) * phase, gap, 'vertical');
          }
          for (let y = 0; y <= src.height; y += pitch) {
            drawSinusoid(0, y, 256, amp, (2 * Math.PI) / wave, (y/pitch) * phase, gap, 'horizontal');
          }
        } else if (pat === 'hexagonal') {
          const centers = generateHexagonCenters(pitch);
          drawVoronoi(sctx, centers, gap);

        } else if (pat === 'blue') {
          let centers = generateBlueNoiseCenters(src.width, src.height, pitch, voronoiDeviation);
          drawVoronoi(sctx, centers, gap);
        } else if (pat === 'hexagonalblue') {
          let centers = generateHexagonCenters(pitch);
          // Introduce some noise to hex centers
          centers = centers.map(c => {
            const angle = Math.random() * 2 * Math.PI;
            const radius = (Math.random() - 0.5) * (pitch * voronoiDeviation / 100);
            return {
              x: c.x + radius * Math.cos(angle),
              y: c.y + radius * Math.sin(angle)
            };
          });
          drawVoronoi(sctx, centers, gap);
        } else {
          sctx.fillStyle = '#fff';
          sctx.fillRect(0, 0, src.width, src.height);
          sctx.fillStyle = '#000';
          for (let y = 1; y < src.height; y += pitch) {
            let xoff = 1;
            if (pat === 'stagger' && ((y-1) / pitch) % 2) xoff = pitch / 2;

            for (let x = -pitch; x < src.width + pitch; x += pitch) {
              let gx = x + xoff;
              let gy = y;
                sctx.fillRect(gx, gy, pitch - gap, pitch - gap);
            }
          }
        }
        thresholdImageData(sctx);
      }
      dctx.clearRect(0, 0, dst.width, dst.height);
      dctx.drawImage(src, 0, 0);
      applyBoxBlur(dctx, blur);
    }

    render();


  </script>
</body>
</html>