/*******************************************************************************************
*
*   raylib [textures] example - image text
*
*   Example complexity rating: [★★☆☆] 2/4
*
*   Example originally created with raylib 1.8, last time updated with raylib 4.0
*
*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
*   BSD-like license that allows static linking with closed source software
*
*   Copyright (c) 2017-2025 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

using System.Numerics;
using static Raylib_cs.Raylib;

namespace Examples.Textures;

public partial class ImageText : IExample
{
    private const int screenWidth = 800;
    private const int screenHeight = 450;

    public string Name => "Textures / Image Text";

    public string Title => "raylib [textures] example - image text";

    private Font font;
    private Texture2D texture;
    private Vector2 position;
    private bool showFont;

    public void Init()
    {
        var parrots = LoadImage("resources/parrots.png"); // Load image in CPU memory (RAM)

        // TTF Font loading with custom generation parameters
        font = LoadFontEx("resources/fonts/KAISG.ttf", 64, null, 0);

        // Draw over image using custom font
        ImageDrawTextEx(
            ref parrots,
            font,
            "[Parrots font drawing]",
            new Vector2(20, 20),
            font.BaseSize,
            0,
            Color.Red
        );

        texture = LoadTextureFromImage(parrots);  // Image converted to texture, uploaded to GPU memory (VRAM)
        UnloadImage(parrots);   // Once image has been converted to texture and uploaded to VRAM, it can be unloaded from RAM

        position = new(
            screenWidth / 2 - texture.Width / 2,
            screenHeight / 2 - texture.Height / 2 - 20
        );

        showFont = false;
    }

    public void Update()
    {
        // Update
        //----------------------------------------------------------------------------------
        if (IsKeyDown(KeyboardKey.Space))
        {
            showFont = true;
        }
        else
        {
            showFont = false;
        }
        //----------------------------------------------------------------------------------

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

        if (!showFont)
        {
            // Draw texture with text already drawn inside
            DrawTextureV(texture, position, Color.White);

            // Draw text directly using sprite font
            Vector2 textPosition = new(position.X + 20, position.Y + 20 + 280);
            DrawTextEx(font, "[Parrots font drawing]", textPosition, font.BaseSize, 0, Color.White);
        }
        else
        {
            DrawTexture(font.Texture, screenWidth / 2 - font.Texture.Width / 2, 50, Color.Black);
        }

        DrawText("PRESS SPACE to SHOW FONT ATLAS USED", 290, 420, 10, Color.DarkGray);

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

    public void Unload()
    {
        UnloadTexture(texture);     // Texture unloading

        UnloadFont(font);           // Unload custom font
    }

    public static int Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        InitWindow(screenWidth, screenHeight, "raylib [textures] example - image text");

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

        var game = new ImageText();
        game.Init();

        // Main game loop
        while (!WindowShouldClose())    // Detect window close button or ESC key
        {
            game.Update();
        }

        game.Unload();

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

        return 0;
    }
}