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This commit is contained in:
Martin Vrhovšek
2026-01-23 21:16:06 +01:00
commit ac81ff714a
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/.zig-cache
/.idea
/zig-out

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const std = @import("std");
// Although this function looks imperative, it does not perform the build
// directly and instead it mutates the build graph (`b`) that will be then
// executed by an external runner. The functions in `std.Build` implement a DSL
// for defining build steps and express dependencies between them, allowing the
// build runner to parallelize the build automatically (and the cache system to
// know when a step doesn't need to be re-run).
pub fn build(b: *std.Build) void {
// Standard target options allow the person running `zig build` to choose
// what target to build for. Here we do not override the defaults, which
// means any target is allowed, and the default is native. Other options
// for restricting supported target set are available.
const target = b.standardTargetOptions(.{});
// Standard optimization options allow the person running `zig build` to select
// between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
// set a preferred release mode, allowing the user to decide how to optimize.
const optimize = b.standardOptimizeOption(.{});
// It's also possible to define more custom flags to toggle optional features
// of this build script using `b.option()`. All defined flags (including
// target and optimize options) will be listed when running `zig build --help`
// in this directory.
// This creates a module, which represents a collection of source files alongside
// some compilation options, such as optimization mode and linked system libraries.
// Zig modules are the preferred way of making Zig code available to consumers.
// addModule defines a module that we intend to make available for importing
// to our consumers. We must give it a name because a Zig package can expose
// multiple modules and consumers will need to be able to specify which
// module they want to access.
// const mod = b.addModule("rasteriser", .{
// // The root source file is the "entry point" of this module. Users of
// // this module will only be able to access public declarations contained
// // in this file, which means that if you have declarations that you
// // intend to expose to consumers that were defined in other files part
// // of this module, you will have to make sure to re-export them from
// // the root file.
// .root_source_file = b.path("src/root.zig"),
// // Later on we'll use this module as the root module of a test executable
// // which requires us to specify a target.
// .target = target,
// });
const raylib_dep = b.dependency("raylib_zig", .{
.target = target,
.optimize = optimize,
});
const raylib = raylib_dep.module("raylib");
const raylib_artifact = raylib_dep.artifact("raylib");
// Here we define an executable. An executable needs to have a root module
// which needs to expose a `main` function. While we could add a main function
// to the module defined above, it's sometimes preferable to split business
// logic and the CLI into two separate modules.
//
// If your goal is to create a Zig library for others to use, consider if
// it might benefit from also exposing a CLI tool. A parser library for a
// data serialization format could also bundle a CLI syntax checker, for example.
//
// If instead your goal is to create an executable, consider if users might
// be interested in also being able to embed the core functionality of your
// program in their own executable in order to avoid the overhead involved in
// subprocessing your CLI tool.
//
// If neither case applies to you, feel free to delete the declaration you
// don't need and to put everything under a single module.
const exe = b.addExecutable(.{
.name = "rasteriser",
.root_module = b.createModule(.{
// b.createModule defines a new module just like b.addModule but,
// unlike b.addModule, it does not expose the module to consumers of
// this package, which is why in this case we don't have to give it a name.
.root_source_file = b.path("src/main.zig"),
// Target and optimization levels must be explicitly wired in when
// defining an executable or library (in the root module), and you
// can also hardcode a specific target for an executable or library
// definition if desireable (e.g. firmware for embedded devices).
.target = target,
.optimize = optimize,
// List of modules available for import in source files part of the
// root module.
.imports = &.{
// Here "rasteriser" is the name you will use in your source code to
// import this module (e.g. `@import("rasteriser")`). The name is
// repeated because you are allowed to rename your imports, which
// can be extremely useful in case of collisions (which can happen
// importing modules from different packages).
// .{ .name = "rasteriser", .module = mod },
.{ .name = "raylib", .module = raylib},
},
}),
});
exe.linkLibrary(raylib_artifact);
// This declares intent for the executable to be installed into the
// install prefix when running `zig build` (i.e. when executing the default
// step). By default the install prefix is `zig-out/` but can be overridden
// by passing `--prefix` or `-p`.
b.installArtifact(exe);
// This creates a top level step. Top level steps have a name and can be
// invoked by name when running `zig build` (e.g. `zig build run`).
// This will evaluate the `run` step rather than the default step.
// For a top level step to actually do something, it must depend on other
// steps (e.g. a Run step, as we will see in a moment).
const run_step = b.step("run", "Run the app");
// This creates a RunArtifact step in the build graph. A RunArtifact step
// invokes an executable compiled by Zig. Steps will only be executed by the
// runner if invoked directly by the user (in the case of top level steps)
// or if another step depends on it, so it's up to you to define when and
// how this Run step will be executed. In our case we want to run it when
// the user runs `zig build run`, so we create a dependency link.
const run_cmd = b.addRunArtifact(exe);
run_step.dependOn(&run_cmd.step);
// By making the run step depend on the default step, it will be run from the
// installation directory rather than directly from within the cache directory.
run_cmd.step.dependOn(b.getInstallStep());
// This allows the user to pass arguments to the application in the build
// command itself, like this: `zig build run -- arg1 arg2 etc`
if (b.args) |args| {
run_cmd.addArgs(args);
}
// Creates an executable that will run `test` blocks from the provided module.
// Here `mod` needs to define a target, which is why earlier we made sure to
// set the releative field.
// const mod_tests = b.addTest(.{
// .root_module = mod,
// });
// A run step that will run the test executable.
// const run_mod_tests = b.addRunArtifact(mod_tests);
// Creates an executable that will run `test` blocks from the executable's
// root module. Note that test executables only test one module at a time,
// hence why we have to create two separate ones.
const exe_tests = b.addTest(.{
.root_module = exe.root_module,
});
// A run step that will run the second test executable.
const run_exe_tests = b.addRunArtifact(exe_tests);
// A top level step for running all tests. dependOn can be called multiple
// times and since the two run steps do not depend on one another, this will
// make the two of them run in parallel.
const test_step = b.step("test", "Run tests");
// test_step.dependOn(&run_mod_tests.step);
test_step.dependOn(&run_exe_tests.step);
// Just like flags, top level steps are also listed in the `--help` menu.
//
// The Zig build system is entirely implemented in userland, which means
// that it cannot hook into private compiler APIs. All compilation work
// orchestrated by the build system will result in other Zig compiler
// subcommands being invoked with the right flags defined. You can observe
// these invocations when one fails (or you pass a flag to increase
// verbosity) to validate assumptions and diagnose problems.
//
// Lastly, the Zig build system is relatively simple and self-contained,
// and reading its source code will allow you to master it.
}

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.{
// This is the default name used by packages depending on this one. For
// example, when a user runs `zig fetch --save <url>`, this field is used
// as the key in the `dependencies` table. Although the user can choose a
// different name, most users will stick with this provided value.
//
// It is redundant to include "zig" in this name because it is already
// within the Zig package namespace.
.name = .rasteriser,
// This is a [Semantic Version](https://semver.org/).
// In a future version of Zig it will be used for package deduplication.
.version = "0.0.0",
// Together with name, this represents a globally unique package
// identifier. This field is generated by the Zig toolchain when the
// package is first created, and then *never changes*. This allows
// unambiguous detection of one package being an updated version of
// another.
//
// When forking a Zig project, this id should be regenerated (delete the
// field and run `zig build`) if the upstream project is still maintained.
// Otherwise, the fork is *hostile*, attempting to take control over the
// original project's identity. Thus it is recommended to leave the comment
// on the following line intact, so that it shows up in code reviews that
// modify the field.
.fingerprint = 0xde5064b97e2d76b, // Changing this has security and trust implications.
// Tracks the earliest Zig version that the package considers to be a
// supported use case.
.minimum_zig_version = "0.15.2",
// This field is optional.
// Each dependency must either provide a `url` and `hash`, or a `path`.
// `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
// Once all dependencies are fetched, `zig build` no longer requires
// internet connectivity.
.dependencies = .{
.raylib_zig = .{
.url = "git+https://github.com/raylib-zig/raylib-zig?ref=devel#7d4761b878f43671024ce197f721827b5355a67e",
.hash = "raylib_zig-5.6.0-dev-KE8REGlNBQDR7NML06VBtT7gP3VZNY70E5WohAxzqrNn",
},
},
.paths = .{
"build.zig",
"build.zig.zon",
"src",
// For example...
//"LICENSE",
//"README.md",
},
}

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const std = @import("std");
const rl = @import("raylib");
const structures = @import("structures/structures.zig");
pub fn main() !void {
const screen = .{.width = 800, .height = 600};
rl.initWindow(screen.width, screen.height, "Rasteriser");
defer rl.closeWindow();
rl.setTargetFPS(60);
const point_a = rl.Vector2 {.x = 50, .y = 550}; // A
const point_b = rl.Vector2 {.x = 750, .y = 550}; // B
const point_c = rl.Vector2 {.x = 400, .y = 100}; // C
var triangle = structures.Triangle.new(point_a, point_b, point_c);
const range = triangle.getCoordsLimit();
while (!rl.windowShouldClose()) {
rl.beginDrawing();
defer rl.endDrawing();
rl.clearBackground(.gray);
for (range.y.min..range.y.max+1) |y| {
for (range.x.min..range.x.max+1) |x| {
const point = rl.Vector2 {
.x = @floatFromInt(x),
.y = @floatFromInt(y),
};
const colour = triangle.pixelColour(point) orelse continue;
rl.drawPixelV(point, colour);
}
}
}
}

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/// Tracks minimum and maximum possible x/y coordinate of the triangle (or any other object we wish to render)
pub const MinMaxLimit = struct{
x: struct{min: usize, max: usize},
y: struct{min: usize, max: usize},
};

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const rl = @import("raylib");
const BaseStructures = @import("base_structs.zig");
pub const Triangle = struct {
point_a: rl.Vector2,
point_b: rl.Vector2,
point_c: rl.Vector2,
/// Constructor
pub fn new(point_a: rl.Vector2, point_b: rl.Vector2, point_c: rl.Vector2) Triangle {
return .{
.point_a = point_a,
.point_b = point_b,
.point_c = point_c,
};
}
/// Calculates the pixel colour or returns null if the pixle is not within the triangle
pub fn pixelColour(self: *Triangle, point: rl.Vector2) ?rl.Color {
const acp = edgeFunction(self.point_a, self.point_c, point);
const cbp = edgeFunction(self.point_c, self.point_b, point);
const apb = edgeFunction(self.point_a, point, self.point_b);
if (acp < 0 or cbp < 0 or apb < 0) return null;
// normalize values
const abc = edgeFunction(self.point_a, self.point_c, self.point_b);
// a red, b blue, c green
const weight_a = cbp / abc;
const weight_b = acp / abc;
const weight_c = apb / abc;
const colour_a = rl.Vector3 {
.x = @floatFromInt(rl.Color.red.r),
.y = @floatFromInt(rl.Color.red.g),
.z = @floatFromInt(rl.Color.red.b),
};
const colour_b = rl.Vector3 {
.x = @floatFromInt(rl.Color.blue.r),
.y = @floatFromInt(rl.Color.blue.g),
.z = @floatFromInt(rl.Color.blue.b),
};
const colour_c = rl.Vector3 {
.x = @floatFromInt(rl.Color.green.r),
.y = @floatFromInt(rl.Color.green.g),
.z = @floatFromInt(rl.Color.green.b),
};
// craft colours
const r = colour_a.x * weight_a + colour_b.x * weight_b + colour_c.x * weight_c;
const g = colour_a.y * weight_a + colour_b.y * weight_b + colour_c.y * weight_c;
const b = colour_a.z * weight_a + colour_b.z * weight_b + colour_c.z * weight_c;
return .{
.r = @intFromFloat(r),
.g = @intFromFloat(g),
.b = @intFromFloat(b),
.a = 255,
};
}
/// Calculates point's orientation
fn edgeFunction(a: rl.Vector2, b: rl.Vector2, c: rl.Vector2) f32 {
return (b.x - a.x) * (c.y - a.y) - (b.y - a.y) * (c.x - a.x);
}
/// Returns what the triangle's minimum and maximum x and y are
pub fn getCoordsLimit(self: *Triangle) BaseStructures.MinMaxLimit {
return .{
.x = .{
.min = @intFromFloat(@min(self.point_a.x, self.point_b.x, self.point_c.x)),
.max = @intFromFloat(@max(self.point_a.x, self.point_b.x, self.point_c.x)),
},
.y = .{
.min = @intFromFloat(@min(self.point_a.y, self.point_b.y, self.point_c.y)),
.max = @intFromFloat(@max(self.point_a.y, self.point_b.y, self.point_c.y)),
}
};
}
};

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pub const Triangle = @import("internal/triangle.zig").Triangle;
pub const BaseStr = @import("internal/base_structs.zig");