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free camera

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This commit is contained in:
Fabien Freling 2021-05-27 22:44:29 +02:00
parent 7d830d13d1
commit d6ba8e354c
2 changed files with 37 additions and 12 deletions
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40
in_one_weekend/src/camera.zig
View file

@ -1,23 +1,41 @@
const std = @import("std");
const math = std.math;
const Point3 = @import("vec3.zig").Point3;
const Vec3 = @import("vec3.zig").Vec3;
const Ray = @import("ray.zig").Ray;
fn degreesToRadians(degrees: f32) f32 {
return degrees * math.pi / 180.0;
}
pub const Camera = struct {
origin: Point3,
lowerLeftCorner: Point3,
horizontal: Vec3,
vertical: Vec3,
pub fn init() Camera {
const aspectRatio = 16.0 / 9.0;
const viewportHeight = 2.0;
const viewportWidth = aspectRatio * viewportHeight;
const focalLength = 1.0;
pub fn init(
lookFrom: Point3,
lookAt: Point3,
vup: Vec3,
vfov: f32,
aspectRatio: f32,
) Camera {
const theta = degreesToRadians(vfov);
const h = math.tan(theta / 2);
const origin = Vec3{};
const horizontal = Vec3{ .x = viewportWidth };
const vertical = Vec3{ .y = viewportHeight };
const lowerLeftCorner = origin.sub(horizontal.div(2)).sub(vertical.div(2)).sub(Vec3{ .z = focalLength });
const viewportHeight = 2.0 * h;
const viewportWidth = aspectRatio * viewportHeight;
const w = lookFrom.sub(lookAt).unit();
const u = vup.cross(w).unit();
const v = w.cross(u);
const origin = lookFrom;
const horizontal = u.mul_s(viewportWidth);
const vertical = v.mul_s(viewportHeight);
const lowerLeftCorner = origin.sub(horizontal.div(2)).sub(vertical.div(2)).sub(w);
return Camera {
.origin = origin,
@ -27,10 +45,10 @@ pub const Camera = struct {
};
}
pub fn getRay(self: Camera, u: f32, v: f32) Ray {
pub fn getRay(self: Camera, s: f32, t: f32) Ray {
return Ray{
.origin = self.origin,
.direction = self.lowerLeftCorner.add(self.horizontal.mul_s(u)).add(self.vertical.mul_s(v)).sub(self.origin),
.direction = self.lowerLeftCorner.add(self.horizontal.mul_s(s)).add(self.vertical.mul_s(t)).sub(self.origin),
};
}
};

9
in_one_weekend/src/main.zig
View file

@ -117,12 +117,19 @@ pub fn main() anyerror!void {
Sphere{ .center = Point3{ .x = 0, .y = -100.5, .z = -1 }, .radius = 100, .material = materialGround },
Sphere{ .center = Point3{ .x = 0, .y = 0, .z = -1 }, .radius = 0.5, .material = materialCenter },
Sphere{ .center = Point3{ .x = -1, .y = 0, .z = -1 }, .radius = 0.5, .material = materialLeft },
Sphere{ .center = Point3{ .x = -1, .y = 0, .z = -1 }, .radius = -0.45, .material = materialLeft },
Sphere{ .center = Point3{ .x = 1, .y = 0, .z = -1 }, .radius = 0.5, .material = materialRight },
};
const world = World{ .spheres = spheres[0..spheres.len] };
// Camera
const camera = Camera.init();
const camera = Camera.init(
Point3{ .x = -2, .y = 2, .z = 1 },
Point3{ .x = 0, .y = 0, .z = -1 },
Vec3{ .x = 0, .y = 1, .z = 0 },
20.0,
aspectRatio
);
const window = sdl.c.SDL_CreateWindow(
"Raytracing in One Weekend",