Add ellipse drawing

window.ts

@@ -194,6 +194,44 @@ export const outlineCircle = (x: number, y: number, r: number, color: number) =>
 	}
 }
 
+export const fillEllipse = (x0: number, y0: number, x1: number, y1: number, color: number) => {
+	const x = 0.5*(x0 + x1);
+	const y = 0.5*(y0 + y1);
+	const rx = Math.abs(x0-x1)/2;
+	const ry = Math.abs(y0-y1)/2;
+	const left = Math.floor(x-rx-1);
+	const top = Math.floor(y-ry-1);
+	for (let i = left; i <= Math.ceil(x+rx+1); i ++) {
+		for (let j = top; j <= Math.ceil(y+ry+1); j ++) {
+			if (Math.sqrt(((x-i)/rx)**2 + ((y-j)/ry)**2) <= 1+(1/(rx+ry))) {
+				setPixelColor(i, j, color);
+			}
+		}
+	}
+}
+
+export const outlineEllipse = (x0: number, y0: number, x1: number, y1: number, color: number) => {
+	const x = 0.5*(x0 + x1);
+	const y = 0.5*(y0 + y1);
+	const rx = Math.abs(x0-x1)/2;
+	const ry = Math.abs(y0-y1)/2;
+	const left = Math.floor(x-rx-1);
+	const top = Math.floor(y-ry-1);
+	const inR = (d: number) => d <= 1+1/(rx+ry);
+	for (let i = left; i <= Math.ceil(x+rx+1); i ++) {
+		for (let j = top; j <= Math.ceil(y+ry+1); j ++) {
+			const d = Math.sqrt(((x-i)/rx)**2 + ((y-j)/ry)**2);
+			if (inR(d)) {
+				const dh = Math.sqrt(((x-(i+Math.sign(i-x)))/rx)**2 + ((y-j)/ry)**2);
+				const dv = Math.sqrt(((x-i)/rx)**2 + ((y-(j+Math.sign(j-y)))/ry)**2);
+				if (!inR(dh) || !inR(dv)) {
+					setPixelColor(i, j, color);
+				}
+			}
+		}
+	}
+}
+
 export const fillRectRaw = (x: number, y: number, w: number, h: number, color: number) => {
 	setPixelsInRectRaw(x, y, w, Array(w*h).fill(color));
 }