raylib-zig/examples/core/input_mouse_wheel.zig

//
// input_mouse_wheel
// Zig version: 
// Author: Nikolas Wipper
// Date: 2020-02-16
//

const rl = @import("raylib");

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

    rl.InitWindow(screenWidth, screenHeight, "raylib-zig [core] example - basic window");

    var boxPositionY: f32 = screenHeight / 2 - 40;
    var scrollSpeed: f32 = 4;            // Scrolling speed in pixels

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

    // Main game loop
    while (!rl.WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        boxPositionY -= (rl.GetMouseWheelMove() * scrollSpeed);
        //----------------------------------------------------------------------------------

        // Draw
        //----------------------------------------------------------------------------------
        rl.BeginDrawing();

            rl.ClearBackground(rl.WHITE);

            rl.DrawRectangle(screenWidth/2 - 40, @floatToInt(c_int, boxPositionY), 80, 80, rl.MAROON);

            rl.DrawText("Use mouse wheel to move the cube up and down!", 10, 10, 20, rl.GRAY);
            rl.DrawText(rl.TextFormat("Box position Y: %03i", @floatToInt(c_int, boxPositionY)), 10, 40, 20, rl.LIGHTGRAY);

        rl.EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    rl.CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------
}