function setup_pumpkin(canvas_id, clearbtn_id, form_id, pattern_field_id, grid_size) { const canvas = document.getElementById(canvas_id); const ctx = canvas.getContext('2d'); const img = new Image(); img.src = '/static/pumpkin.png'; const GRID_SIZE = grid_size; const CELL_SIZE = canvas.width / GRID_SIZE; img.onload = () => { ctx.drawImage(img, 0, 0, canvas.width, canvas.height); drawGrid(); }; let drawing = false; let currentPattern = []; canvas.addEventListener('mousedown', () => { drawing = true; }); canvas.addEventListener('mouseup', () => { drawing = false; }); canvas.addEventListener('mousemove', draw); canvas.addEventListener('click', (e) => {draw(e, true)}); function draw(e, force=false) { if (!drawing && !force) return; var rect = canvas.getBoundingClientRect(); var x = e.clientX - rect.left; var y = e.clientY - rect.top; var gridX = Math.floor(x / CELL_SIZE); var gridY = Math.floor(y / CELL_SIZE); var cellX = gridX * CELL_SIZE + CELL_SIZE / 3; var cellY = gridY * CELL_SIZE + CELL_SIZE / 3; var pixel = ctx.getImageData(cellX, cellY, 1, 1).data; if (pixel[0] >= 254 && (pixel[1] >= 124 && pixel[1] <= 126)) { var key = `${gridX},${gridY}`; if (!currentPattern.includes(key)) { currentPattern.push(key); ctx.fillStyle = 'black'; ctx.fillRect(cellX - CELL_SIZE / 3, cellY - CELL_SIZE / 3, CELL_SIZE, CELL_SIZE); } } } function drawGrid() { ctx.strokeStyle = 'rgba(0, 0, 0, 0.6)'; ctx.lineWidth = 1; for (let i = 0; i <= GRID_SIZE; i++) { const pos = i * CELL_SIZE; ctx.beginPath(); ctx.moveTo(pos, 0); ctx.lineTo(pos, canvas.height); ctx.stroke(); ctx.beginPath() ctx.moveTo(0, pos); ctx.lineTo(canvas.width, pos); ctx.stroke() } } document.getElementById(clearbtn_id).addEventListener('click', clearCanvas); function clearCanvas() { drawing = false; // Fix hold staying after clear ctx.clearRect(0, 0, canvas.width, canvas.height); ctx.drawImage(img, 0, 0, canvas.width, canvas.height); drawGrid() currentPattern = []; } document.getElementById(form_id).addEventListener('submit', function(event) { document.getElementById(pattern_field_id).value = JSON.stringify(currentPattern); }); }