Raylib examples translated from C to Zig https://github.com/raysan5/raylib/tree/master/examples

core_input_mouse.zig

const std = @import("std");

const ray = @cImport({
    @cInclude("raylib.h");
});

pub fn main() void {
    // Initialization
    //--------------------------------------------------------------------------------------
    const screenWidth = 800;
    const screenHeight = 450;

    ray.InitWindow(screenWidth, screenHeight, "raylib [core] example - mouse input");
    defer ray.CloseWindow();

    var ballPosition = ray.Vector2{
        .x = -100.0,
        .y = -100.0,
    };

    var ballColor = ray.DARKBLUE;

    // Set our game to run at 60 frames-per-second
    ray.SetTargetFPS(60);
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!ray.WindowShouldClose()) {
        // Update
        //----------------------------------------------------------------------------------

        // For some reason ballPosition = ray.GetMousePosition();
        // resulted in diagonal movement of the ball,
        // instead I’m using GetMouseX and GetMouseY:
        ballPosition.x = @intToFloat(f32, ray.GetMouseX());
        ballPosition.y = @intToFloat(f32, ray.GetMouseY());

        if (ray.IsMouseButtonPressed(ray.MOUSE_LEFT_BUTTON)) {
            ballColor = ray.MAROON;
        } else if (ray.IsMouseButtonPressed(ray.MOUSE_MIDDLE_BUTTON)) {
            ballColor = ray.LIME;
        } else if (ray.IsMouseButtonPressed(ray.MOUSE_RIGHT_BUTTON)) {
            ballColor = ray.DARKBLUE;
        }
        //----------------------------------------------------------------------------------

        // Draw
        //----------------------------------------------------------------------------------
        ray.BeginDrawing();
        defer ray.EndDrawing();

        ray.ClearBackground(ray.RAYWHITE);
        ray.DrawCircleV(ballPosition, 40, ballColor);

        ray.DrawText("move ball with mouse and click mouse button to change color", 10, 10, 20, ray.DARKGRAY);
        //----------------------------------------------------------------------------------
    }
}

build.zig that links to raylib

const Builder = @import("std").build.Builder;

pub fn build(b: *Builder) void {
    // Standard target options allows 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 release options allow the person running `zig build` to select
    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
    const mode = b.standardReleaseOptions();

    const exe = b.addExecutable("ray", "src/main.zig");

    exe.setTarget(target);
    exe.setBuildMode(mode);
    exe.linkSystemLibrary("raylib");
    exe.install();

    const run_cmd = exe.run();
    run_cmd.step.dependOn(b.getInstallStep());
    if (b.args) |args| {
        run_cmd.addArgs(args);
    }

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

Related Zig issues

• ziglang/zig#3211
• ziglang/zig#1481

const std = @import("std");

const ray = @cImport({
    @cInclude("raylib.h");
});

pub fn main() void {
    const screenWidth = 650;
    const screenHeight = 420;

    ray.InitWindow(screenWidth, screenHeight, "raylib [core] example - mouse input");
    defer ray.CloseWindow();

    var ballPosition = ray.Vector2{
        .x = -100.0,
        .y = -100.0,
    };

    var ballColor = ray.DARKBLUE;

    ray.SetTargetFPS(60);

    while (!ray.WindowShouldClose()) {
        ballPosition = ray.GetMousePosition();

        if (ray.IsMouseButtonPressed(ray.MOUSE_LEFT_BUTTON)) {
            ballColor = ray.MAROON;
        } else if (ray.IsMouseButtonPressed(ray.MOUSE_MIDDLE_BUTTON)) {
            ballColor = ray.LIME;
        } else if (ray.IsMouseButtonPressed(ray.MOUSE_RIGHT_BUTTON)) {
            ballColor = ray.DARKBLUE;
        }

        ray.BeginDrawing();
        defer ray.EndDrawing();

        ray.ClearBackground(ray.RAYWHITE);
        ray.DrawCircleV(ballPosition, 40, ballColor);

        ray.DrawText("move ball with mouse and click mouse button to change color", 10, 10, 20, ray.DARKGRAY);
    }
}

Now (v0.10.0) does what you expect.