Added image loading routines and a triangular lattice sampler

canvas/image-loading.js

@@ -31,8 +31,18 @@ function setup() {
 setup();
 
 
+const { load_image_from_src, Image_Data_Sampler, Bitfield_Image_Sampler } = await import('../lib/image-functions.js');
 
-const { load_image_from_src, Image_Data_Sampler } = await import('../lib/image-functions.js');
+/*
+//Convert
 const sampler = new Image_Data_Sampler(await load_image_from_src("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABHNCSVQICAgIfAhkiAAAAFVJREFUOE9jZGBg+A/EZAMmsnVCNQ4DA1hAXvn/HxGOjIyMJAULC0gzsiZ0PiHTwC5AB8guQpdD52M1gJA3YK4E0SwgxZSEASjERlMieryQyKc4MwEA45UXJyonWOMAAAAASUVORK5CYII="));
-
 console.log(sampler.encode_as_bitfield());
+*/
+
+//Load
+const sampler = Bitfield_Image_Sampler.from_string('16,16,AAAAAAAAAAAAAA4AEQDx/xGgDqAAAAAAAAAAAAAAAAA=');
+sampler.pixel_map((x, y, value) => {
+	C.beginPath();
+	C.arc(x * 0.1 - sampler.width * .05, sampler.height * .05 - y * 0.1, value ? 0.05 : 0.02, 0, Math.PI * 2);
+	C.fill();
+});

canvas/triangular-lattice-sampler.js

@@ -0,0 +1,90 @@
+//Create useful variables
+const aspect = W / H;
+const scale = aspect >= 1 ? H / 2 : W / 2;
+
+function setup() {
+	const [W, H] = [400, 400];
+	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=');
+console.log(sampler);
+
+const s = 0.2;
+for (let y = -10; y < 10; y++) {
+    const xo = y & 1 ? s * .5 : 0;
+    const sxo = 0;
+    //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';
+		C.lineWidth = 1 / scale;
+
+		// 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();
+	}
+}