let backGrid = null, frontGrid = null; const gridSize = 100; let prevMouseX = null, prevMouseY = null; draw = function() { if (backGrid === null) { backGrid = new Array(gridSize).fill().map(() => new Array(gridSize).fill().map(() => [0, 0, 0, 0])) frontGrid = new Array(gridSize).fill().map(() => new Array(gridSize).fill().map(() => [0, 0, 0, 0])) } if (mouseIsPressed) { if (prevMouseX !== null && prevMouseY !== null) { let dx = mouseX - prevMouseX; let dy = mouseY - prevMouseY; if (dx !== 0 || dy !== 0) { let length = Math.sqrt(dx * dx + dy * dy); injectMass(mouseX, mouseY, dx / length, -(dy / length)); } } prevMouseX = mouseX; prevMouseY = mouseY; } else { prevMouseX = null; prevMouseY = null; } for (let i = 0; i < 4; i++) { updateGrid(); } displayGrid(); let fps = frameRate(); textSize(22); fill('yellow'); text(fps | 0, 5, 25); } function getPixelBilinear(x, y) { const x0 = Math.floor(x); const y0 = Math.floor(y); const x1 = x0 + 1; const y1 = y0 + 1; const ix0 = (x0 + gridSize) % gridSize; const iy0 = (y0 + gridSize) % gridSize; const ix1 = (x1 + gridSize) % gridSize; const iy1 = (y1 + gridSize) % gridSize; const c00 = backGrid[iy0][ix0]; const c10 = backGrid[iy0][ix1]; const c01 = backGrid[iy1][ix0]; const c11 = backGrid[iy1][ix1]; const fx = x - x0; const fy = y - y0; const fx1 = 1 - fx; const fy1 = 1 - fy; const result = [ fx1 * fy1 * c00[0] + fx * fy1 * c10[0] + fx1 * fy * c01[0] + fx * fy * c11[0], fx1 * fy1 * c00[1] + fx * fy1 * c10[1] + fx1 * fy * c01[1] + fx * fy * c11[1], fx1 * fy1 * c00[2] + fx * fy1 * c10[2] + fx1 * fy * c01[2] + fx * fy * c11[2], fx1 * fy1 * c00[3] + fx * fy1 * c10[3] + fx1 * fy * c01[3] + fx * fy * c11[3] ]; return result; } function getCell(x, y) { const pixel = backGrid[(y + gridSize) % gridSize][(x + gridSize) % gridSize]; return getPixelBilinear(x - pixel[0], y - pixel[1]); } function calculate(x, y) { const E = getCell(x, y); const pX = getCell(x + 1, y); const pY = getCell(x, y + 1); const nX = getCell(x - 1, y); const nY = getCell(x, y - 1); let vx = E[0] + (nX[2] - pX[2]) * 0.25; let vy = (E[1] + (nY[2] - pY[2]) * 0.25); // - (E[3]/300.0); const d = ((pX[2] + pY[2] + nX[2] + nY[2]) * 0.25) + (nX[0] - pX[0] + nY[1] - pY[1]) * 0.25; if (x < 3 || y < 3. || gridSize.x - x < 3 || gridSize - y < 3) { vx = 0.0; vy = 0.0; } return [ vx > 1 ? 1 : vx < -1 ? -1 : vx * 0.9992, vy > 1 ? 1 : vy < -1 ? -1 : vy * 0.9992, d > 1 ? 1 : d < 0 ? 0 : d * 0.9992, E[3] > 1 ? 1 : E[3] < 0 ? 0 : E[3] * 0.9992 ]; } function updateGrid() { for (let y = 0; y < gridSize; y++) { for (let x = 0; x < gridSize; x++) { frontGrid[y][x] = calculate(x, y); } } let tmp = backGrid; backGrid = frontGrid; frontGrid = tmp; } function displayGrid() { let cellWidth = width / gridSize; let cellHeight = height / gridSize; noStroke(); isEvenFrame = frameCount % 2 === 0; for (let y = 0; y < gridSize; y++) { for (let x = 0; x < gridSize; x++) { if ((x + y) % 2 === (isEvenFrame ? 0 : 1)) { let cell = backGrid[y][x]; fill(cell[3] * 255, cell[3] * 255, cell[3] * 255); rect(x * cellWidth, height - (y * cellHeight) - cellHeight, cellWidth, cellHeight); } } } } function injectMass(x, y, vx, vy) { let gridX = floor(x / width * gridSize); let gridY = floor(y / height * gridSize); // Inject mass into a 3x3 area around the mouse for (let offsetY = -2; offsetY <= 2; offsetY++) { for (let offsetX = -2; offsetX <= 2; offsetX++) { let cellX = (gridX + offsetX + gridSize) % gridSize; let cellY = gridSize - ((gridY + offsetY + gridSize) % gridSize); backGrid[cellY][cellX][0] = vx; backGrid[cellY][cellX][1] = vy; backGrid[cellY][cellX][3] = 1.0; } } }

Codecasts

Made by awesome people

Recently Published