raylib-cs/Examples/Shapes/EasingsBoxAnim.cs

/*******************************************************************************************
*
*   raylib [shapes] example - easings box anim
*
*   This example has been created using raylib 2.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Copyright (c) 2014-2019 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

using System.Numerics;
using static Raylib_cs.Raylib;
using Examples.Shared;

namespace Examples.Shapes;

public class EasingsBoxAnim
{
    public static int Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        const int screenWidth = 800;
        const int screenHeight = 450;

        InitWindow(screenWidth, screenHeight, "raylib [shapes] example - easings box anim");

        // Box variables to be animated with easings
        Rectangle rec = new(GetScreenWidth() / 2, -100, 100, 100);
        float rotation = 0.0f;
        float alpha = 1.0f;

        int state = 0;
        int framesCounter = 0;

        SetTargetFPS(60);
        //--------------------------------------------------------------------------------------

        // Main game loop
        while (!WindowShouldClose())
        {
            // Update
            //----------------------------------------------------------------------------------
            switch (state)
            {
                // Move box down to center of screen
                case 0:
                    framesCounter += 1;

                    // NOTE: Remember that 3rd parameter of easing function refers to
                    // desired value variation, do not confuse it with expected final value!
                    rec.Y = Easings.EaseElasticOut(framesCounter, -100, GetScreenHeight() / 2 + 100, 120);

                    if (framesCounter >= 120)
                    {
                        framesCounter = 0;
                        state = 1;
                    }
                    break;
                // Scale box to an horizontal bar
                case 1:
                    framesCounter += 1;
                    rec.Height = Easings.EaseBounceOut(framesCounter, 100, -90, 120);
                    rec.Width = Easings.EaseBounceOut(framesCounter, 100, GetScreenWidth(), 120);

                    if (framesCounter >= 120)
                    {
                        framesCounter = 0;
                        state = 2;
                    }
                    break;
                // Rotate horizontal bar rectangle
                case 2:
                    framesCounter += 1;
                    rotation = Easings.EaseQuadOut(framesCounter, 0.0f, 270.0f, 240);

                    if (framesCounter >= 240)
                    {
                        framesCounter = 0;
                        state = 3;
                    }
                    break;
                // Increase bar size to fill all screen
                case 3:
                    framesCounter += 1;
                    rec.Height = Easings.EaseCircOut(framesCounter, 10, GetScreenWidth(), 120);

                    if (framesCounter >= 120)
                    {
                        framesCounter = 0;
                        state = 4;
                    }
                    break;
                // Fade out animation
                case 4:
                    framesCounter++;
                    alpha = Easings.EaseSineOut(framesCounter, 1.0f, -1.0f, 160);

                    if (framesCounter >= 160)
                    {
                        framesCounter = 0;
                        state = 5;
                    }
                    break;
                default:
                    break;
            }

            // Reset animation at any moment
            if (IsKeyPressed(KeyboardKey.KEY_SPACE))
            {
                rec = new Rectangle(GetScreenWidth() / 2, -100, 100, 100);
                rotation = 0.0f;
                alpha = 1.0f;
                state = 0;
                framesCounter = 0;
            }
            //----------------------------------------------------------------------------------

            // Draw
            //----------------------------------------------------------------------------------
            BeginDrawing();
            ClearBackground(Color.RAYWHITE);

            DrawRectanglePro(
                rec,
                new Vector2(rec.Width / 2, rec.Height / 2),
                rotation,
                ColorAlpha(Color.BLACK, alpha)
            );
            DrawText("PRESS [SPACE] TO RESET BOX ANIMATION!", 10, GetScreenHeight() - 25, 20, Color.LIGHTGRAY);

            EndDrawing();
            //----------------------------------------------------------------------------------
        }

        // De-Initialization
        //--------------------------------------------------------------------------------------
        CloseWindow();
        //--------------------------------------------------------------------------------------

        return 0;
    }
}