altagos.dev
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moveable camera
+42
-10
src/camera.zig
+42
-10
src/camera.zig
···
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const zm = @import("zmath");
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pub const Ray = @import("ray.zig");
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const util = @import("util.zig");
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const log = std.log.scoped(.camera);
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···
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aspect_ratio: f32,
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samples_per_pixel: usize,
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max_depth: usize,
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vfov: f32 = 90,
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look_from: zm.Vec = zm.f32x4s(0),
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look_at: zm.Vec = zm.f32x4(0, 0, -1, 0),
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vup: zm.Vec = zm.f32x4(0, 1, 0, 0),
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};
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image_height: usize,
···
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samples_per_pixel: usize,
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max_depth: usize,
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vfov: f32,
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look_from: zm.Vec,
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look_at: zm.Vec,
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vup: zm.Vec,
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focal_lenght: f32,
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viewport_height: f32,
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viewport_width: f32,
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camera_center: zm.Vec,
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center: zm.Vec,
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viewport_u: zm.Vec,
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viewport_v: zm.Vec,
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pixel_delta_u: zm.Vec,
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pixel_delta_v: zm.Vec,
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u: zm.Vec,
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v: zm.Vec,
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w: zm.Vec,
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viewport_upper_left: zm.Vec,
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pixel00_loc: zm.Vec,
···
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const image_height = @as(usize, @intFromFloat(@as(f32, @floatFromInt(image_width)) / aspect_ratio));
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if (image_height < 1) return error.ImageWidthLessThanOne;
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const focal_lenght: f32 = 1.0;
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const viewport_height: f32 = 2.0;
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const vfov = opts.vfov;
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const look_from = opts.look_from;
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const look_at = opts.look_at;
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const vup = opts.vup;
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const center = look_from;
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const focal_lenght: f32 = zm.length3(look_from - look_at)[0];
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const theta = util.degreesToRadians(opts.vfov);
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const h = @tan(theta / 2);
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const viewport_height: f32 = 2 * h * focal_lenght;
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const viewport_width = viewport_height * (@as(f32, @floatFromInt(image_width)) / @as(f32, @floatFromInt(image_height)));
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const camera_center = zm.f32x4s(0.0);
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const w = zm.normalize3(look_from - look_at);
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const u = zm.normalize3(zm.cross3(vup, w));
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const v = zm.cross3(w, u);
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// Calculate the vectors across the horizontal and down the vertical viewport edges.
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const viewport_u = zm.f32x4(viewport_width, 0, 0, 0);
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const viewport_v = zm.f32x4(0, -viewport_height, 0, 0);
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const viewport_u = zm.f32x4s(viewport_width) * u;
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const viewport_v = zm.f32x4s(viewport_height) * -v;
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// Calculate the horizontal and vertical delta vectors from pixel to pixel.
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const pixel_delta_u = viewport_u / zm.f32x4s(@as(f32, @floatFromInt(image_width)));
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const pixel_delta_v = viewport_v / zm.f32x4s(@as(f32, @floatFromInt(image_height)));
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// Calculate the location of the upper left pixel.
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const viewport_upper_left = camera_center - zm.f32x4(0, 0, focal_lenght, 0) - viewport_u / zm.f32x4s(2.0) - viewport_v / zm.f32x4s(2.0);
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const viewport_upper_left = center - zm.f32x4s(focal_lenght) * w - viewport_u / zm.f32x4s(2.0) - viewport_v / zm.f32x4s(2.0);
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const pixel00_loc = viewport_upper_left + zm.f32x4s(0.5) * (pixel_delta_u + pixel_delta_v);
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log.debug("image_width: {}, image_height: {}, aspect_ratio: {d:.2}, focal_lenght: {d:.1}", .{ image_width, image_height, aspect_ratio, focal_lenght });
···
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.samples_per_pixel = opts.samples_per_pixel,
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.max_depth = opts.max_depth,
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.vfov = vfov,
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.look_from = look_from,
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.look_at = look_at,
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.vup = vup,
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.focal_lenght = focal_lenght,
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.viewport_height = viewport_height,
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.viewport_width = viewport_width,
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.camera_center = camera_center,
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.center = center,
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.viewport_u = viewport_u,
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.viewport_v = viewport_v,
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.pixel_delta_u = pixel_delta_u,
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.pixel_delta_v = pixel_delta_v,
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.u = u,
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.v = v,
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.w = w,
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.viewport_upper_left = viewport_upper_left,
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.pixel00_loc = pixel00_loc,
···
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const pixel_center = self.pixel00_loc + (zm.f32x4s(@as(f32, @floatFromInt(i))) * self.pixel_delta_u) + (zm.f32x4s(@as(f32, @floatFromInt(j))) * self.pixel_delta_v);
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const pixel_sample = pixel_center + self.pixelSamplesSq();
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const ray_direction = pixel_sample - self.camera_center;
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return Ray.init(self.camera_center, ray_direction);
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const ray_direction = pixel_sample - self.center;
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return Ray.init(self.center, ray_direction);
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}
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pub fn setPixel(self: *Camera, x: usize, y: usize, c: color.Rgba32) !void {
+4
-1
src/main.zig
+4
-1
src/main.zig
···
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var world = HittableList.init(allocator);
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(0, -100.5, -1, 0), .radius = 100, .mat = &material_ground }));
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(0, 0, -1, 0), .radius = 0.5, .mat = &material_center }));
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(0, 0, -1.2, 0), .radius = 0.5, .mat = &material_center }));
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(-1, 0, -1, 0), .radius = 0.5, .mat = &material_left }));
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(-1, 0, -1, 0), .radius = 0.4, .mat = &material_bubble }));
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try world.add(Hittable.sphere(Sphere{ .center = zm.f32x4(1, 0, -1, 0), .radius = 0.5, .mat = &material_right }));
···
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.image_width = 400,
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.samples_per_pixel = 100,
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.max_depth = 50,
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.vfov = 20,
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.look_from = zm.f32x4(-2, 2, 1, 0),
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.look_at = zm.f32x4(0, 0, -1, 0),
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});
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defer raytracer.deinit();
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+6
-2
src/util.zig
+6
-2
src/util.zig
···
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const std = @import("std");
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const random = std.crypto.random;
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const random = @import("std").crypto.random;
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const math = @import("std").math;
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const zm = @import("zmath");
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pub inline fn degreesToRadians(degrees: f32) f32 {
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return degrees * math.pi / 180.0;
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}
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/// Returns a random real in [0,1).
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pub inline fn randomF32() f32 {