add blue gradient background
Fabien Freling
parent
9083e0e7f1
commit
73cb93cf2d
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@ -1,70 +1,107 @@
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const std = @import("std");
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const sdl = @cImport({
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@cInclude("SDL.h");
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});
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const print = std.debug.print;
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const sdl = @import("sdl.zig");
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const vec3 = @import("vec3.zig");
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const Vec3 = vec3.Vec3;
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const Color = vec3.Color;
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const Point3 = vec3.Point3;
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const Ray = @import("ray.zig").Ray;
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// From: https://github.com/Nelarius/weekend-raytracer-zig/blob/master/src/main.zig
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// See https://github.com/zig-lang/zig/issues/565
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// SDL_video.h:#define SDL_WINDOWPOS_UNDEFINED SDL_WINDOWPOS_UNDEFINED_DISPLAY(0)
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// SDL_video.h:#define SDL_WINDOWPOS_UNDEFINED_DISPLAY(X) (SDL_WINDOWPOS_UNDEFINED_MASK|(X))
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// SDL_video.h:#define SDL_WINDOWPOS_UNDEFINED_MASK 0x1FFF0000u
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const SDL_WINDOWPOS_UNDEFINED = @bitCast(c_int, sdl.SDL_WINDOWPOS_UNDEFINED_MASK);
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const SDL_WINDOWPOS_UNDEFINED = @bitCast(c_int, sdl.c.SDL_WINDOWPOS_UNDEFINED_MASK);
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const win_width = 640;
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const win_height = 320;
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const fps = 60;
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fn rayColor(ray: Ray) Color {
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const unitDirection = vec3.unitVector(ray.direction);
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const t = 0.5 * (unitDirection.y + 1.0);
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const white = Color{ .x = 1.0, .y = 1.0, .z = 1.0 };
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const blue = Color{ .x = 0.5, .y = 0.7, .z = 1.0 };
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return white.mul(1.0 - t).add(blue.mul(t));
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}
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pub fn main() anyerror!void {
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if (sdl.SDL_Init(sdl.SDL_INIT_VIDEO) != 0) {
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std.log.err("Unable to initialize SDL: {}", .{sdl.SDL_GetError()});
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if (sdl.c.SDL_Init(sdl.c.SDL_INIT_VIDEO) != 0) {
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std.log.err("Unable to initialize SDL: {}", .{sdl.c.SDL_GetError()});
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return error.SDLInitializationFailed;
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}
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defer sdl.SDL_Quit();
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defer sdl.c.SDL_Quit();
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const window = sdl.SDL_CreateWindow("Raytracing in One Weekend", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, win_width, win_height, sdl.SDL_WINDOW_OPENGL) orelse {
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std.log.err("Unable to create window: {}", .{sdl.SDL_GetError()});
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// Image
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const aspectRatio: f32 = 16.0 / 9.0;
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const imageWidth = 400;
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const imageHeight = @floatToInt(usize, imageWidth / aspectRatio);
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// Camera
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const viewportHeight = 2.0;
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const viewportWidth = @floatToInt(usize, viewportHeight * aspectRatio);
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const focalLength = 1.0;
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const origin = Vec3{};
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const horizontal = Vec3{ .x = viewportWidth };
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const vertical = Vec3{ .y = viewportHeight };
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const lowerLeftCorner = origin.sub(horizontal.div(2)).sub(vertical.div(2)).sub(Vec3{ .z = focalLength });
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const window = sdl.c.SDL_CreateWindow(
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"Raytracing in One Weekend",
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SDL_WINDOWPOS_UNDEFINED,
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SDL_WINDOWPOS_UNDEFINED,
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imageWidth,
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imageHeight,
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sdl.c.SDL_WINDOW_OPENGL
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) orelse {
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std.log.err("Unable to create window: {}", .{sdl.c.SDL_GetError()});
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return error.SDLInitializationFailed;
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};
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const surface = sdl.SDL_GetWindowSurface(window) orelse {
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std.log.err("Unable to get window surface: {}", .{sdl.SDL_GetError()});
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const surface = sdl.c.SDL_GetWindowSurface(window) orelse {
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std.log.err("Unable to get window surface: {}", .{sdl.c.SDL_GetError()});
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return error.SDLInitializationFailed;
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};
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{
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_ = sdl.SDL_LockSurface(surface);
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_ = sdl.c.SDL_LockSurface(surface);
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var h: usize = 0;
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while (h < win_height) {
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var w: usize = 0;
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while (w < win_width) {
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// std.log.info("w = {}, h = {}", .{ w, h });
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const index = w * 4 + h * @intCast(usize, surface.*.pitch);
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const target_pixel = @ptrToInt(surface.*.pixels) + index;
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@intToPtr(*u32, target_pixel).* = 0xffffffff;
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w += 1;
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var j: usize = 0;
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while (j < imageHeight) {
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var i: usize = 0;
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while (i < imageWidth) {
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const u = @intToFloat(f32, i) / @intToFloat(f32, (imageWidth - 1));
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// SDL coordinate system is flipped compared to the raytracer
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const v = @intToFloat(f32, (imageHeight - 1) - j) / @intToFloat(f32, (imageHeight - 1));
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const r = Ray{
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.origin = origin,
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.direction = lowerLeftCorner.add(horizontal.mul(u).add(vertical.mul(v).sub(origin))),
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};
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const pixelColor = rayColor(r);
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sdl.setSurfacePixel(surface, i, j, pixelColor);
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i += 1;
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}
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h += 1;
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j += 1;
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}
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defer sdl.SDL_UnlockSurface(surface);
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defer sdl.c.SDL_UnlockSurface(surface);
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}
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if (sdl.SDL_UpdateWindowSurface(window) != 0) {
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std.log.err("Error updating window surface: {}", .{sdl.SDL_GetError()});
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if (sdl.c.SDL_UpdateWindowSurface(window) != 0) {
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std.log.err("Error updating window surface: {}", .{sdl.c.SDL_GetError()});
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return error.SDLUpdateWindowFailed;
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}
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var running = true;
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while (running) {
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var event: sdl.SDL_Event = undefined;
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while (sdl.SDL_PollEvent(&event) != 0) {
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var event: sdl.c.SDL_Event = undefined;
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while (sdl.c.SDL_PollEvent(&event) != 0) {
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switch (event.@"type") {
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sdl.SDL_QUIT => {
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sdl.c.SDL_QUIT => {
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running = false;
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},
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else => {},
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}
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}
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sdl.SDL_Delay(1000 / fps);
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sdl.c.SDL_Delay(1000 / fps);
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}
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}
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@ -0,0 +1,11 @@
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const Vec3 = @import("vec3.zig").Vec3;
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const Point3 = @import("vec3.zig").Point3;
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pub const Ray = struct {
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origin: Point3,
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direction: Vec3,
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pub fn at(t: f32) Point3 {
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return origin.add(direction.mul(t));
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}
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};
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@ -0,0 +1,78 @@
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const math = @import("std").math;
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pub const Vec3 = packed struct {
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x: f32 = 0.0,
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y: f32 = 0.0,
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z: f32 = 0.0,
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pub fn add(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.x + v.x,
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.y = u.y + v.y,
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.z = u.z + v.z,
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};
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}
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pub fn sub(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.x - v.x,
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.y = u.y - v.y,
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.z = u.z - v.z,
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};
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}
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pub fn mul(self: Vec3, scalar: f32) Vec3 {
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return Vec3{
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.x = self.x * scalar,
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.y = self.y * scalar,
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.z = self.z * scalar,
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};
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}
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pub fn div(self: Vec3, scalar: f32) Vec3 {
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return Vec3{
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.x = self.x / scalar,
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.y = self.y / scalar,
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.z = self.z / scalar,
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};
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}
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pub fn length(self: Vec3) f32 {
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return math.sqrt(self.x * self.x + self.y * self.y + self.z * self.z);
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}
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pub fn dot(u: Vec3, v: Vec3) f32 {
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return u.x * v.x + u.y * v.y + u.z * v.z;
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}
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pub fn cross(u: Vec3, v: Vec3) Vec3 {
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return Vec3{
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.x = u.y * v.z - u.z * v.y,
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.y = u.z * v.x - u.x * v.z,
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.z = u.x * v.y - u.y * v.x,
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};
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}
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// pub fn unit_vector() Vec3 {
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// return
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// }
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};
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pub fn unitVector(vec: Vec3) Vec3 {
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return vec.div(vec.length());
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}
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pub const Point3 = Vec3;
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pub const Color = Vec3;
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const assert = @import("std").debug.assert;
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fn assert_cmp(actual: f32, expected: f32) void {
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const epsilon: f32 = 1e-5;
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assert(math.fabs(actual - expected) < epsilon);
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}
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test "Vec3.length" {
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const v = Vec3{ .x = 1.0, .y = 1.0, .z = 1.0 };
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assert_cmp(v.length(), 1.7320508);
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}
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