commit 2109bb5bf83c79c9c0de774e0fd3c777f8f3e54d
Author: Marto <marto@marto.si>
Date:   Wed Feb 12 20:55:26 2025 +0100

    initial commit

diff --git a/build.zig b/build.zig
new file mode 100644
index 0000000..c22fcb0
--- /dev/null
+++ b/build.zig
@@ -0,0 +1,47 @@
+const std = @import("std");
+const rlz = @import("raylib-zig");
+
+pub fn build(b: *std.Build) !void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+    
+    const raylib_dep = b.dependency("raylib-zig", .{
+        .target = target,
+        .optimize = optimize,
+    });
+
+    const raylib = raylib_dep.module("raylib");
+    const raylib_artifact = raylib_dep.artifact("raylib");
+
+    //web exports are completely separate
+    if (target.query.os_tag == .emscripten) {
+        const exe_lib = try rlz.emcc.compileForEmscripten(b, "integral-display-calculation", "src/main.zig", target, optimize);
+
+        exe_lib.linkLibrary(raylib_artifact);
+        exe_lib.root_module.addImport("raylib", raylib);
+
+        // Note that raylib itself is not actually added to the exe_lib output file, so it also needs to be linked with emscripten.
+        const link_step = try rlz.emcc.linkWithEmscripten(b, &[_]*std.Build.Step.Compile{ exe_lib, raylib_artifact });
+        //this lets your program access files like "resources/my-image.png":
+        link_step.addArg("--embed-file");
+        link_step.addArg("resources/");
+
+        b.getInstallStep().dependOn(&link_step.step);
+        const run_step = try rlz.emcc.emscriptenRunStep(b);
+        run_step.step.dependOn(&link_step.step);
+        const run_option = b.step("run", "Run integral-display-calculation");
+        run_option.dependOn(&run_step.step);
+        return;
+    }
+
+    const exe = b.addExecutable(.{ .name = "integral-display-calculation", .root_source_file = b.path("src/main.zig"), .optimize = optimize, .target = target });
+
+    exe.linkLibrary(raylib_artifact);
+    exe.root_module.addImport("raylib", raylib);
+
+    const run_cmd = b.addRunArtifact(exe);
+    const run_step = b.step("run", "Run integral-display-calculation");
+    run_step.dependOn(&run_cmd.step);
+
+    b.installArtifact(exe);
+}
diff --git a/build.zig.zon b/build.zig.zon
new file mode 100644
index 0000000..de8f467
--- /dev/null
+++ b/build.zig.zon
@@ -0,0 +1,11 @@
+.{
+    .name = "integral-display-calculation",
+    .version = "0.0.1",
+    .dependencies = .{
+        .@"raylib-zig" = .{
+            .url = "git+https://github.com/Not-Nik/raylib-zig?ref=devel#5004bb2316fc34a416644f3910c8c79dd08d7c63",
+            .hash = "1220223e9881fc9510eeb30fc2ee73fb49ee645bf1859cc46a92b649d35ecfd3351a",
+        },
+    },
+    .paths = .{""},
+}
diff --git a/src/main.zig b/src/main.zig
new file mode 100644
index 0000000..4d49e31
--- /dev/null
+++ b/src/main.zig
@@ -0,0 +1,69 @@
+const rl = @import("raylib");
+const std = @import("std");
+const math = @import("math.zig");
+
+const SCREENWIDTH = 1920;
+const SCREENHEIGHT = 1080;
+
+pub fn main() !void {
+    rl.setConfigFlags(.{ .msaa_4x_hint = true });
+    rl.initWindow(SCREENWIDTH, SCREENHEIGHT, "Koordinatni sistem");
+    defer rl.closeWindow();
+
+    rl.setTargetFPS(60);
+
+    while (!rl.windowShouldClose()) {
+        rl.beginDrawing();
+        defer rl.endDrawing();
+
+        rl.clearBackground(rl.Color.white);
+        drawAxis();
+        // markAxis();
+        plotGraph(0.01);
+    }
+}
+
+fn drawAxis() void {
+    const endy_on_abscis: i32 = @divTrunc(SCREENHEIGHT, 2);
+    const endx_on_ordinat: i32 = @divTrunc(SCREENWIDTH, 2);
+    // x
+    rl.drawLine(0, endy_on_abscis, SCREENWIDTH, endy_on_abscis, rl.Color.black);
+    // y
+    rl.drawLine(endx_on_ordinat, 0, endx_on_ordinat, SCREENHEIGHT, rl.Color.black);
+}
+
+// todo in the future we will do calculations only once and just repeat displaying
+fn plotGraph(diff: f32) void {
+    // diff is currently 0.01
+    const thickness = 2.5;
+    var x_value: f32 = -SCREENWIDTH / 2;
+
+    while (x_value <= SCREENWIDTH) : (x_value += diff) {
+        const cur_pos = adjustForGridSystem(rl.Vector2{
+            .x = x_value,
+            .y = getY(x_value),
+        });
+
+        const next_pos = adjustForGridSystem(rl.Vector2{
+            .x = x_value + diff,
+            .y = getY(x_value + diff),
+        });
+
+        rl.drawLineEx(cur_pos, next_pos, thickness, rl.Color.dark_blue);
+    }
+}
+
+fn getY(x: f32) f32 {
+    const a = math.abs(x) - 2;
+    const b = 1;
+    return @divTrunc(a, b);
+}
+
+fn adjustForGridSystem(input_vector: rl.Vector2) rl.Vector2 {
+    const new_vector = rl.Vector2{
+        .x = input_vector.x + SCREENWIDTH / 2,
+        .y = -input_vector.y + SCREENHEIGHT / 2,
+    };
+
+    return new_vector;
+}
diff --git a/src/math.zig b/src/math.zig
new file mode 100644
index 0000000..6aa5294
--- /dev/null
+++ b/src/math.zig
@@ -0,0 +1,27 @@
+pub fn abs(a: f32) f32 {
+    if (a < 0) {
+        return -a;
+    }
+
+    return a;
+}
+
+pub fn pow(a: f32, b: i32) f32 {
+    var res: f32 = 1.0;
+    var n: usize = undefined;
+    var f: f32 = undefined;
+
+    if (b < 0) {
+        f = 1 / a;
+        n = @intCast(-b);
+    } else {
+        f = a;
+        n = @intCast(b);
+    }
+
+    for (0..n) |_| {
+        res *= f;
+    }
+
+    return res;
+}