Added unfinished interactive triangular lattice and a vibe coded gradient editor

canvas/interactive-triangular-lattice.js

@@ -0,0 +1,112 @@
+{ // Wrapping in new local scope so we can override constants
+const oldCanvas = document.getElementById('canvas');
+const canvas = oldCanvas.cloneNode(true);
+oldCanvas.parentNode.replaceChild(canvas, oldCanvas);
+const C = canvas.getContext('2d');
+
+
+//Create useful variables
+function setup() {
+	const [W, H] = [400, 400];
+    const aspect = W / H;
+    const scale = aspect >= 1 ? H / 2 : W / 2;
+	canvas.width = W;
+	canvas.height = H;
+
+	// Reset transform
+	C.setTransform(1, 0, 0, 1, 0, 0);
+
+	// Clear canvas
+	C.clearRect(0, 0, W, H);
+
+	// Reset common properties
+	C.globalCompositeOperation = 'source-over';
+	C.fillStyle = 'rgba(255,200,100,1)';
+	C.strokeStyle = 'rgba(0,0,0,1)';
+
+
+	// Set up transform to map -1,-1..1,1 to canvas with aspect fit
+	const offsetX = W / 2;
+	const offsetY = H / 2;
+
+	//Apply transform
+	C.translate(offsetX, offsetY);
+	C.scale(scale, scale);
+
+	// Set 1 pixel wide lines
+	C.lineWidth = 1 / scale;
+}
+
+
+setup();
+
+
+
+const { Bitfield_Image_Sampler } = await import('../lib/image-functions.js');
+//Load
+const sampler = Bitfield_Image_Sampler.from_string('16,16,AAAAAAAAAAAAAA4AEQDx/xGgDqAAAAAAAAAAAAAAAAA=');
+
+const s = 0.08;
+for (let y = -10; y < 10; y++) {
+    const xo = y & 1 ? -0.5*s : 0;
+    const sxo = (y >> 1);
+    //const sxo = y & 1 ? 1 : 0;
+	for (let x = -10; x < 10; x++) {
+		const p0 = [xo + (x + .5) * s, y * s];
+		const p1 = [xo + (x + 1.5) * s, y * s];
+		const p2 = [xo + (x + 1) * s, (y + 1) * s];
+		const p3 = [xo + (x + 0) * s, (y + 1) * s];
+
+		// Filled parallelogram
+		C.beginPath();
+		C.moveTo(...p0);
+		C.lineTo(...p1);
+		C.lineTo(...p2);
+		C.lineTo(...p3);
+		C.closePath();
+
+		if (sampler.sample(sxo + x + 8, 8 + y)) {
+			C.fillStyle = `#cf8`;
+		} else {
+			C.fillStyle = `#f88`;
+		}
+
+		C.fill();
+
+		// Triangle lines
+		C.strokeStyle = '#000';
+
+		// Outline parallelogram
+		C.beginPath();
+		C.moveTo(...p0);
+		C.lineTo(...p1);
+		C.lineTo(...p2);
+		C.lineTo(...p3);
+		C.closePath();
+		C.stroke();
+
+		// Diagonal from p0 to p2
+		C.beginPath();
+		C.moveTo(...p0);
+		C.lineTo(...p2);
+		C.stroke();
+	}
+}
+
+canvas.addEventListener('mousemove', (e) => {
+	const rect = canvas.getBoundingClientRect();
+	const viewX = e.clientX - rect.left;
+	const viewY = e.clientY - rect.top;
+
+	// Get the current transform matrix
+	const m = C.getTransform(); // DOMMatrix
+	const inv = m.invertSelf();  // In-place inverse
+
+	const worldX = inv.a * viewX + inv.c * viewY + inv.e;
+	const worldY = inv.b * viewX + inv.d * viewY + inv.f;
+
+	// Store or use the world coords
+	console.log('World:', worldX, worldY);
+});
+
+}