using Raylib;
using static Raylib.Raylib;

public partial class Examples
{
    /*******************************************************************************************
    *
    *   raylib [shaders] example - Apply a postprocessing shader to a scene
    *
    *   NOTE: This example requires raylib OpenGL 3.3 or ES2 versions for shaders support,
    *         OpenGL 1.1 does not support shaders, recompile raylib to OpenGL 3.3 version.
    *
    *   NOTE: Shaders used in this example are #version 330 (OpenGL 3.3), to test this example
    *         on OpenGL ES 2.0 platforms (Android, Raspberry Pi, HTML5), use #version 100 shaders
    *         raylib comes with shaders ready for both versions, check raylib/shaders install folder
    *
    *   This example has been created using raylib 1.3 (www.raylib.com)
    *   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
    *
    *   Copyright (c) 2015 Ramon Santamaria (@raysan5)
    *
    ********************************************************************************************/
    
    
        #define GLSL_VERSION            330
    #else   // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB
        #define GLSL_VERSION            100
    
    public const #define MAX_POSTPRO_SHADERS         12

    typedef enum {
        FX_GRAYSCALE = 0,
        FX_POSTERIZATION,
        FX_DREAM_VISION,
        FX_PIXELIZER,
        FX_CROSS_HATCHING,
        FX_CROSS_STITCHING,
        FX_PREDATOR_VIEW,
        FX_SCANLINES,
        FX_FISHEYE,
        FX_SOBEL,
        FX_BLOOM,
        FX_BLUR,
        //FX_FXAA
    } PostproShader;
    
    static const char *postproShaderText[] = {
        "GRAYSCALE",
        "POSTERIZATION",
        "DREAM_VISION",
        "PIXELIZER",
        "CROSS_HATCHING",
        "CROSS_STITCHING",
        "PREDATOR_VIEW",
        "SCANLINES",
        "FISHEYE",
        "SOBEL",
        "BLOOM",
        "BLUR",
        //"FXAA"
    };
    
    public static void Main()
    {
        // Initialization
        //--------------------------------------------------------------------------------------
        int screenWidth = 800;
        int screenHeight = 450;
        
        SetConfigFlags((int)Flag.MSAA_4X_HINT);      // Enable Multi Sampling Anti Aliasing 4x (if available)
    
        InitWindow(screenWidth, screenHeight, "raylib [shaders] example - postprocessing shader");
    
        // Define the camera to look into our 3d world
        Camera camera = {{ 2.0f, 3.0f, 2.0f }, { 0.0f, 1.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, 45.0f, 0 };
        
        Model model = LoadModel("resources/models/church.obj");                 // Load OBJ model
        Texture2D texture = LoadTexture("resources/models/church_diffuse.png"); // Load model texture (diffuse map)
        model.material.maps[MAP_DIFFUSE].texture = texture;                     // Set model diffuse texture
    
        Vector3 position = { 0.0f, 0.0f, 0.0f };                             // Set model position
        
        // Load all postpro shaders
        // NOTE 1: All postpro shader use the base vertex shader (DEFAULT_VERTEX_SHADER)
        // NOTE 2: We load the correct shader depending on GLSL version
        Shader[] shaders = new Shader[MAX_POSTPRO_SHADERS];
        
        // NOTE: Defining 0 (NULL) for vertex shader forces usage of internal default vertex shader
        shaders[FX_GRAYSCALE] = LoadShader(0, FormatText("resources/shaders/glsl%i/grayscale.fs", GLSL_VERSION));
        shaders[FX_POSTERIZATION] = LoadShader(0, FormatText("resources/shaders/glsl%i/posterization.fs", GLSL_VERSION));
        shaders[FX_DREAM_VISION] = LoadShader(0, FormatText("resources/shaders/glsl%i/dream_vision.fs", GLSL_VERSION));
        shaders[FX_PIXELIZER] = LoadShader(0, FormatText("resources/shaders/glsl%i/pixelizer.fs", GLSL_VERSION));
        shaders[FX_CROSS_HATCHING] = LoadShader(0, FormatText("resources/shaders/glsl%i/cross_hatching.fs", GLSL_VERSION));
        shaders[FX_CROSS_STITCHING] = LoadShader(0, FormatText("resources/shaders/glsl%i/cross_stitching.fs", GLSL_VERSION));
        shaders[FX_PREDATOR_VIEW] = LoadShader(0, FormatText("resources/shaders/glsl%i/predator.fs", GLSL_VERSION));
        shaders[FX_SCANLINES] = LoadShader(0, FormatText("resources/shaders/glsl%i/scanlines.fs", GLSL_VERSION));
        shaders[FX_FISHEYE] = LoadShader(0, FormatText("resources/shaders/glsl%i/fisheye.fs", GLSL_VERSION));
        shaders[FX_SOBEL] = LoadShader(0, FormatText("resources/shaders/glsl%i/sobel.fs", GLSL_VERSION));
        shaders[FX_BLOOM] = LoadShader(0, FormatText("resources/shaders/glsl%i/bloom.fs", GLSL_VERSION));
        shaders[FX_BLUR] = LoadShader(0, FormatText("resources/shaders/glsl%i/blur.fs", GLSL_VERSION));
        
        int currentShader = FX_GRAYSCALE;
    
        // Create a RenderTexture2D to be used for render to texture
        RenderTexture2D target = LoadRenderTexture(screenWidth, screenHeight);
        
        // Setup orbital camera
        SetCameraMode(camera, CAMERA_ORBITAL);  // Set an orbital camera mode
    
        SetTargetFPS(60);                       // Set our game to run at 60 frames-per-second
        //--------------------------------------------------------------------------------------
    
        // Main game loop
        while (!WindowShouldClose())            // Detect window close button or ESC key
        {
            // Update
            //----------------------------------------------------------------------------------
            UpdateCamera(&camera);              // Update camera
            
            if (IsKeyPressed((int)Key.RIGHT)) currentShader++;
            else if (IsKeyPressed((int)Key.LEFT)) currentShader--;
            
            if (currentShader >= MAX_POSTPRO_SHADERS) currentShader = 0;
            else if (currentShader < 0) currentShader = MAX_POSTPRO_SHADERS - 1;
            //----------------------------------------------------------------------------------
    
            // Draw
            //----------------------------------------------------------------------------------
            BeginDrawing();
    
                ClearBackground(RAYWHITE);
    
                BeginTextureMode(target);   // Enable drawing to texture
                
                    BeginMode3D(camera);
    
                        DrawModel(model, position, 0.1f, WHITE);   // Draw 3d model with texture
    
                        DrawGrid(10, 1.0f);     // Draw a grid
    
                    EndMode3D();
                    
                EndTextureMode();           // End drawing to texture (now we have a texture available for next passes)
                
                // Render previously generated texture using selected postpro shader
                BeginShaderMode(shaders[currentShader]);
                
                    // NOTE: Render texture must be y-flipped due to default OpenGL coordinates (left-bottom)
                    DrawTextureRec(target.texture, new Rectangle( 0, 0, target.texture.width, -target.texture.height }, (Vector2){ 0, 0 );, WHITE);
                    
                EndShaderMode();
                
                DrawRectangle(0, 9, 580, 30, Fade(LIGHTGRAY, 0.7f));
                
                DrawText("(c) Church 3D model by Alberto Cano", screenWidth - 200, screenHeight - 20, 10, GRAY);
                
                DrawText("CURRENT POSTPRO SHADER:", 10, 15, 20, BLACK);
                DrawText(postproShaderText[currentShader], 330, 15, 20, RED);
                DrawText("< >", 540, 10, 30, DARKBLUE);
                
                DrawFPS(700, 15);
    
            EndDrawing();
            //----------------------------------------------------------------------------------
        }
    
        // De-Initialization
        //--------------------------------------------------------------------------------------
        
        // Unload all postpro shaders
        for (int i = 0; i < MAX_POSTPRO_SHADERS; i++) UnloadShader(shaders[i]);
        
        UnloadTexture(texture);         // Unload texture
        UnloadModel(model);             // Unload model
        UnloadRenderTexture(target);    // Unload render texture
    
        CloseWindow();                  // Close window and OpenGL context
        //--------------------------------------------------------------------------------------
    
        return 0;
    }
        
}