2 files changed, 29 insertions(+), 12 deletions(-)

M camera.ha
M main.ha

@@ 1,3 1,5 @@
+use math;
+
 export type camera = struct {
 	origin: vector,
 	plane_origin: vector,


@@ 5,6 7,28 @@ export type camera = struct {
 	vertical: vector,
 };
 
+export fn make_camera(
+	from: vector,
+	to: vector,
+	vup: vector,
+	vfov: f64,
+	ar: f64
+) camera = {
+	let height = 2.0 * math::tanf64(vfov * math::PI / 360.0);
+	let width = ar * height;
+
+	let w = unit(diff(from, to)), u = unit(cross(vup, w)), v = cross(w, u);
+
+	let c = camera {
+		origin = from,
+		horizontal = scale(u, width),
+		vertical = scale(v, height),
+		...
+	};
+	c.plane_origin = neg(sum(scale(sum(c.horizontal, c.vertical), 0.5), w));
+	return c;
+};
+
 export fn get_ray_for(c: *const camera, u: f64, v: f64) ray = ray {
 	origin = c.origin,
 	direction = sum(

@@ 5,8 5,8 @@ use time;
 
 fn init_scene() *hittable = {
 	let ground = alloc(make_lambertian(&C(0.8, 0.8, 0.0)));
-	let center = alloc(make_dielectric(1.5));
-	let left = alloc(make_dielectric(1.2));
+	let center = alloc(make_lambertian(&C(0.1, 0.2, 0.5)));
+	let left = alloc(make_dielectric(1.5));
 	let right = alloc(make_metal(&C(0.8, 0.6, 0.2), 1.0));
 	let a = alloc(multi([]));
 	append(a.arr, [


@@ 14,6 14,7 @@ fn init_scene() *hittable = {
 		alloc(make_sphere(V(0.0, 0.0, -1.0), 0.5, center)),
 		alloc(make_sphere(V(1.0, -0.7, -1.0), 0.3, center)),
 		alloc(make_sphere(V(-1.0, 0.0, -1.0), 0.5, left)),
+		alloc(make_sphere(V(-1.0, 0.0, -1.0), -0.45, left)),
 		alloc(make_sphere(V(1.0, 0.0, -1.0), 0.5, right)),
 	]...);
 	return a;


@@ 48,16 49,8 @@ export fn main() void = {
 	let samples = 50u32;
 	let max_bounce = 50u;
 
-	let focus = V(0.0, 0.0, 1.0);
-	let horizontal = V(4.0, 0.0, 0.0);
-	let vertical = V(0.0, 3.0, 0.0);
-	let corner = diff(scale(sum(horizontal, vertical), -0.5), focus);
-	let c = camera {
-		origin = V(0.0, 0.0, 0.0),
-		plane_origin = corner,
-		horizontal = horizontal,
-		vertical = vertical,
-	};
+	let c = make_camera(V(-2.0, -2.0, 1.0), V(0.0, 0.0, -1.0), V(0.0, 1.0, 0.0),
+		20.0, 4.0/3.0);
 
 	let scene = init_scene();