Basic drawing

2026-08-08 16:10:51 +05:30 · 2026-08-08 16:10:51 +05:30 · c79c0a84b3
commit c79c0a84b3
parent fbcac3646d
3 changed files with 133 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@ -4,3 +4,5 @@
 *.sass.map
 *.scss.map

+test/
+dprint.json
--- a/app.js
+++ b/app.js
@ -0,0 +1,91 @@
+const canvas = document.getElementById("canvas");
+const ctx = canvas.getContext("2d");
+
+const widthInput = document.getElementById("width");
+const heightInput = document.getElementById("height");
+const resizeButton = document.getElementById("resize");
+
+const colorInput = document.getElementById("color");
+const brushInput = document.getElementById("brush");
+
+let color = colorInput.value;
+let size = Number(brushInput.value);
+let painting = false;
+
+function resize() {
+    canvas.width = Number(widthInput.value);
+    canvas.height = Number(heightInput.value);
+
+    ctx.fillStyle = "#ffffff";
+    ctx.fillRect(0, 0, canvas.width, canvas.height);
+}
+
+function wrap(value, size) {
+    return ((value % size) + size) % size;
+}
+
+function paint(x, y) {
+    x = wrap(x, canvas.width);
+    y = wrap(y, canvas.height);
+
+    const radius = size / 2;
+
+    ctx.fillStyle = color;
+
+    for (const dx of [-canvas.width, 0, canvas.width]) {
+        for (const dy of [-canvas.height, 0, canvas.height]) {
+            ctx.beginPath();
+            ctx.arc(x + dx, y + dy, radius, 0, Math.PI * 2);
+            ctx.fill();
+        }
+    }
+}
+
+function pointerPosition(event) {
+    const rect = canvas.getBoundingClientRect();
+
+    return {
+        x: (event.clientX - rect.left) * canvas.width / rect.width,
+        y: (event.clientY - rect.top) * canvas.height / rect.height,
+    };
+}
+
+canvas.addEventListener("pointerdown", event => {
+    painting = true;
+    canvas.setPointerCapture(event.pointerId);
+
+    const { x, y } = pointerPosition(event);
+    paint(x, y);
+});
+
+canvas.addEventListener("pointermove", event => {
+    if (!painting)
+        return;
+
+    const { x, y } = pointerPosition(event);
+    paint(x, y);
+});
+
+canvas.addEventListener("pointerup", event => {
+    painting = false;
+    canvas.releasePointerCapture(event.pointerId);
+});
+
+canvas.addEventListener("pointercancel", () => {
+    painting = false;
+});
+
+colorInput.addEventListener("input", () => {
+    color = colorInput.value;
+});
+
+brushInput.addEventListener("input", () => {
+    if (brushInput.value < 1)
+        brushInput.value = 1;
+
+    size = Number(brushInput.value);
+});
+
+resizeButton.addEventListener("click", resize);
+
+resize();
--- a/index.html
+++ b/index.html
@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Tile Painter</title>
+</head>
+<body>
+
+    <div>
+        <label>
+            Width
+            <input id="width" type="number" value="512" min="1">
+        </label>
+
+        <label>
+            Height
+            <input id="height" type="number" value="512" min="1">
+        </label>
+
+        <button id="resize">Resize</button>
+    </div>
+
+    <div>
+        <label>
+            Color
+            <input id="color" type="color" value="#000000">
+        </label>
+
+		<label>
+			Brush
+			<input id="brush" type="number" min="1" value="32">
+		</label>
+    </div>
+
+    <canvas id="canvas"></canvas>
+
+    <script src="app.js"></script>
+</body>
+</html>