altagos.dev
this repo has no description
added camera and rays
+125
-44
+79
src/camera.zig
+79
src/camera.zig
···
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const std = @import("std");
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const zigimg = @import("zigimg");
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const color = zigimg.color;
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const zm = @import("zmath");
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const log = std.log.scoped(.camera);
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const Camera = @This();
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image_height: usize,
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image_width: usize,
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aspect_ratio: f32,
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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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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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viewport_upper_left: zm.Vec,
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pixel00_loc: zm.Vec,
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image: zigimg.Image,
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pub fn init(allocator: std.mem.Allocator, image_width: usize, aspect_ratio: f32) !Camera {
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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 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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// 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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// 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 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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return Camera{
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.image_width = image_width,
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.image_height = image_height,
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.aspect_ratio = aspect_ratio,
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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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.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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.viewport_upper_left = viewport_upper_left,
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.pixel00_loc = pixel00_loc,
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.image = try zigimg.Image.create(allocator, image_width, image_height, zigimg.PixelFormat.rgba32),
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};
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}
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pub fn setPixel(self: *Camera, x: usize, y: usize, c: color.Rgba32) !void {
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if (x >= self.image_width or y >= self.image_height) return error.OutOfBounds;
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const i = x + self.image_width * y;
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self.image.pixels.rgba32[i] = c;
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}
+19
src/ray.zig
+19
src/ray.zig
···
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const zm = @import("zmath");
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const Ray = @This();
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orig: zm.Vec,
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dir: zm.Vec,
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pub fn init(origin: zm.Vec, direction: zm.Vec) Ray {
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return Ray{
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.orig = origin,
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.dir = direction,
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};
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}
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pub fn color(self: *Ray) zm.Vec {
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const unit_direction = zm.normalize3(self.dir);
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const a = 0.5 * (unit_direction[1] + 1.0);
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return zm.f32x4s(1.0 - a) * zm.f32x4s(1.0) + zm.f32x4s(a) * zm.f32x4(0.5, 0.7, 1.0, 1.0);
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}
+25
-42
src/rayray.zig
+25
-42
src/rayray.zig
···
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const spall = @import("spall");
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const zigimg = @import("zigimg");
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const color = zigimg.color;
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const zm = @import("zmath");
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const Camera = @import("camera.zig");
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const Ray = @import("ray.zig");
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const log = std.log.scoped(.rayray);
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···
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pub fn init(allocator: std.mem.Allocator) !Self {
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return .{
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.allocator = allocator,
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.camera = try Camera.init(allocator, 256 * 10, 256 * 10),
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.camera = try Camera.init(allocator, 400, 16.0 / 9.0),
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};
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}
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···
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defer s.end();
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const rows: usize = try std.Thread.getCpuCount();
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const row_height = @divTrunc(self.camera.height, rows);
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const row_height = @divTrunc(self.camera.image_height, rows);
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const num_threads = blk: {
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if (self.camera.height % rows == 0) {
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if (self.camera.image_height % rows == 0) {
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break :blk rows;
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}
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break :blk rows + 1;
···
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defer self.allocator.free(threads);
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for (0..num_threads) |row| {
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const t = try std.Thread.spawn(.{}, r, .{ &self.camera, row, row_height });
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const t = try std.Thread.spawn(.{}, render_thread, .{ &self.camera, row, row_height });
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threads[row] = t;
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}
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···
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return self.camera.image;
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}
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fn r(cam: *Camera, row: usize, height: usize) void {
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fn render_thread(cam: *Camera, row: usize, height: usize) void {
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spall.init_thread();
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defer spall.deinit_thread();
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const s = spall.trace(@src(), "Render Thread {}", .{row});
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defer s.end();
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for (0..height) |iy| {
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const y = iy + height * row;
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if (y >= cam.height) break;
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for (0..height) |ij| {
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const j = ij + height * row;
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if (j >= cam.image_height) break;
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for (0..cam.width) |x| {
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const col = blk: {
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if (iy <= height - 5) {
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@setRuntimeSafety(false);
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break :blk color.Rgba32.initRgba(
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@intCast(x),
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@intCast(y),
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0,
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255,
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);
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}
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break :blk color.Rgba32.initRgba(0, 0, 255, 255);
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};
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for (0..cam.image_width) |i| {
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const pixel_center = cam.pixel00_loc + (zm.f32x4s(@as(f32, @floatFromInt(i))) * cam.pixel_delta_u) + (zm.f32x4s(@as(f32, @floatFromInt(j))) * cam.pixel_delta_v);
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const ray_direction = pixel_center - cam.camera_center;
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var ray = Ray.init(cam.camera_center, ray_direction);
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const col = vecToRgba(ray.color());
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cam.setPixel(x, y, col) catch break;
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cam.setPixel(i, j, col) catch break;
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}
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}
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}
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};
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pub const Camera = struct {
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width: usize,
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height: usize,
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image: zigimg.Image,
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fn vecToRgba(v: zm.Vec) color.Rgba32 {
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const r: u8 = @intFromFloat(255.999 * v[0]);
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const g: u8 = @intFromFloat(255.999 * v[1]);
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const b: u8 = @intFromFloat(255.999 * v[2]);
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const a: u8 = @intFromFloat(255.999 * v[3]);
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pub fn init(allocator: std.mem.Allocator, width: usize, height: usize) !Camera {
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const img = try zigimg.Image.create(allocator, width, height, zigimg.PixelFormat.rgba32);
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return Camera{
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.width = width,
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.height = height,
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.image = img,
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};
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}
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pub fn setPixel(self: *Camera, x: usize, y: usize, c: color.Rgba32) !void {
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if (x >= self.width or y >= self.height) return error.OutOfBounds;
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const i = x + self.width * y;
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self.image.pixels.rgba32[i] = c;
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}
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};
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return color.Rgba32.initRgba(r, g, b, a);
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}