Variant of the Olive.c example flag_jp.c 🇯🇵 in Zig ⚡, this time generating the Swedish flag 🇸🇪

.gitignore

zig-out
.zig-cache

build.zig

const std = @import("std");

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    const exe = b.addExecutable(.{
        .name = "olive-flag-se",
        .root_source_file = b.path("main.zig"),
        .target = target,
        .optimize = optimize,
    });

    const olive = b.dependency("olive", .{});

    exe.addCSourceFile(.{ .file = olive.path("olive.c") });
    exe.addIncludePath(olive.path("."));

    const stb = b.dependency("stb", .{});

    exe.addCSourceFile(.{ .file = b.path("stb_image_write.c") });
    exe.addIncludePath(stb.path("."));

    exe.linkLibC();

    b.installArtifact(exe);

    const run_cmd = b.addRunArtifact(exe);

    run_cmd.step.dependOn(b.getInstallStep());

    const run_step = b.step("run", "Run the app");
    run_step.dependOn(&run_cmd.step);
}

build.zig.zon

.{
    .name = "olive-flag-se",
    .version = "0.0.0",
    .dependencies = .{
        .olive = .{
            .url = "https://github.com/tsoding/olive.c/archive/refs/heads/master.zip",
            .hash = "12208a1706b00a5fcdd12775f5b3457ebdd3daea3d49d298894b962058b6b393e2f8",
        },
        .stb = .{
            .url = "https://github.com/nothings/stb/archive/refs/heads/master.zip",
            .hash = "1220aefdc5ff6261afb86675b54f987d9e86c575049b2050ee8f23d49c954ff4970a",
        },
    },
    .paths = .{
        "build.zig",
        "build.zig.zon",
        "src",
    },
}

flag_se.png

main.zig

const std = @import("std");
const olive = @import("olive.zig");
const stbi = @import("stbi.zig");

pub fn main() u8 {
    const WIDTH = 1600;
    const HEIGHT = 1000;

    // https://www.norden.org/en/information/swedish-flag
    const BLUE = 0xFF9B5500;
    const YELLOW = 0xFF00CEFF;

    return swedishFlag(WIDTH, HEIGHT, BLUE, YELLOW, "flag_se.png");
}

pub fn swedishFlag(comptime w: usize, comptime h: usize, blue: u32, yellow: u32, file_path: [*c]const u8) u8 {
    var pixels: [w * h]u32 = std.mem.zeroes([w * h]u32);

    const oc: olive.Canvas = olive.canvas(pixels[0..], w, h, w);
    const SIZE = h / 10;

    olive.fill(oc, blue);
    olive.rect(oc, 5 * SIZE, 0, 2 * SIZE, h, yellow);
    olive.rect(oc, 0, 4 * SIZE, w, 2 * SIZE, yellow);

    const stride_bytes = @sizeOf(u32) * w;

    if (stbi.write_png(file_path, w, h, 4, pixels[0..], stride_bytes) == 0) {
        _ = stbi.c.fprintf(stbi.c.stderr, "ERROR: could not write %s\n", file_path);
        return 1;
    }

    return 0;
}

olive.zig

const c = @cImport({
    @cDefine("OLIVEC_IMPLEMENTATION", "");
    @cInclude("olive.c");
});

pub const Canvas = c.Olivec_Canvas;
pub const canvas = c.olivec_canvas;
pub const fill = c.olivec_fill;
pub const rect = c.olivec_rect;

stb_image_write.c

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

stbi.zig

pub const c = @cImport({
    @cDefine("STB_IMAGE_WRITE_IMPLEMENTATION", "");
    @cInclude("stb_image_write.h");
});

pub const write_png = c.stbi_write_png;

Flag specs: https://www.norden.org/en/information/swedish-flag

Inspired by this example: https://github.com/tsoding/olive.c?tab=readme-ov-file#quick-example-flag-of-japan