2 files changed, 76 insertions(+), 1 deletions(-)

M color.ha
M image.ha

@@ 24,6 24,19 @@ export fn torgb(c: color, scale: f64) rgb = rgb {
 	b = (clamp(sqrtf64(c.b * scale), 0.0, 0.9999) * 256f64): int: u8,
 };
 
+export fn fromrgb(c: rgb) color = {
+	let c = color {
+		r = c.r: i32: f64 / 256f64,
+		g = c.g: i32: f64 / 256f64,
+		b = c.b: i32: f64 / 256f64,
+	};
+	return color {
+		r = c.r * c.r,
+		g = c.g * c.g,
+		b = c.b * c.b,
+	};
+};
+
 export fn lerp(c1: *const color, c2: *const color, t: f64) color = color {
 	r = (1.0 - t) * c1.r + t * c2.r,
 	g = (1.0 - t) * c1.g + t * c2.g,


@@ 38,4 51,3 @@ export fn sum_color(c1: *const color, c2: *const color) color = color {
 
 export fn equal(c1: color, c2: color) bool =
 	c1.r == c2.r && c1.g == c2.g && c1.b == c2.b;
-

@@ 1,11 1,18 @@
+use bufio;
 use fmt;
 use io;
+use strconv;
+use strings;
 
 def MAGIC: str = "P6";
 def MAXVAL: u16 = 255;
 
 export type image = [][]color;
 
+export type invalid = !void;
+
+export type error = !(invalid | io::error);
+
 export fn image_create(width: size, height: size, init: color) image = {
 	let img: image = alloc([[]...], height);
 	for (let i = 0z; i < height; i += 1) {


@@ 35,6 42,62 @@ export fn write(h: io::handle, img: image, samples: u32) (size | io::error) = {
 	return ln;
 };
 
+fn tonl(h: io::handle) ([]u8 | error) = match (bufio::scantok(h, '\n': u32: u8)?) {
+case io::EOF =>
+	yield invalid;
+case let buf: []u8 =>
+	yield buf;
+};
+
+export fn read(f: io::handle) (image | error) = {
+	let magic = strings::fromutf8(tonl(f)?);
+	if (magic != MAGIC) {
+		return invalid;
+	};
+	let w = match (strconv::stoz(strings::fromutf8(tonl(f)?))) {
+	case let sz: size =>
+		yield sz;
+	case =>
+		return invalid;
+	};
+	let h = match (strconv::stoz(strings::fromutf8(tonl(f)?))) {
+	case let sz: size=>
+		yield sz;
+	case =>
+		return invalid;
+	};
+	match (strconv::stou(strings::fromutf8(tonl(f)?))) {
+	case let u: uint =>
+		if (u != MAXVAL) {
+			return invalid;
+		};
+	case =>
+		return invalid;
+	};
+
+	let img: image = alloc([[]...], h);
+	for (let i = h - 1; i < h; i -= 1) {
+		img[i] = alloc([color { ... }...], w);
+		for (let j = 0z; j < w; j += 1) {
+			let buf: [3]u8 = [0...];
+			match (io::read(f, buf)?) {
+			case let sz: size =>
+				if (sz != 3) {
+					return invalid;
+				};
+				img[i][j] = fromrgb(rgb {
+					r = buf[0],
+					g = buf[1],
+					b = buf[2],
+				});
+			case io::EOF =>
+				return invalid;
+			};
+		};
+	};
+	return img;
+};
+
 @test fn image_create() void = {
 	let grey = C(0.5, 0.5, 0.5);
 	let img = image_create(10, 20, grey);