/*******************************************************************************************
*
*   raylib [shaders] example - Basic lighting: Blinn-Phong
*
*   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) 2014 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

#define SHININESS_SPEED 1.0f
#define LIGHT_SPEED 0.25f

int main()
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 800;
    const int screenHeight = 450;
    
    SetConfigFlags(FLAG_MSAA_4X_HINT);
    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - basic lighting");
    
    // Camera initialization
    Camera camera = {{ 8.0f, 8.0f, 8.0f }, { 0.0f, 3.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }};
    
    // Model initialization
    Vector3 position = { 0.0f, 0.0f, 0.0f };
    Model model = LoadModel("resources/model/dwarf.obj");
    Shader shader = LoadShader("resources/shaders/phong.vs", "resources/shaders/phong.fs");
    SetModelShader(&model, shader);
    
    // Shader locations initialization
    int lIntensityLoc = GetShaderLocation(shader, "light_intensity");
    int lAmbientLoc = GetShaderLocation(shader, "light_ambientColor");
    int lDiffuseLoc = GetShaderLocation(shader, "light_diffuseColor");
    int lSpecularLoc = GetShaderLocation(shader, "light_specularColor");
    int lSpecIntensityLoc = GetShaderLocation(shader, "light_specIntensity");
    
    int mAmbientLoc = GetShaderLocation(shader, "mat_ambientColor");
    int mSpecularLoc = GetShaderLocation(shader, "mat_specularColor");
    int mGlossLoc = GetShaderLocation(shader, "mat_glossiness");
    
    // Camera and light vectors shader locations
    int cameraLoc = GetShaderLocation(shader, "cameraPos");
    int lightLoc = GetShaderLocation(shader, "lightPos");
    
    // Light and material definitions
    Light light;
    Material matBlinn;
    
    // Light initialization
    light.position = (Vector3){ 4.0f, 2.0f, 0.0f };
    light.direction = (Vector3){ 5.0f, 1.0f, 1.0f };
    light.intensity = 1.0f;
    light.diffuse = WHITE;
    light.ambient = (Color){ 150, 75, 0, 255 };
    light.specular = WHITE;
    light.specIntensity = 1.0f;
    
    // Material initialization
    matBlinn.diffuse = WHITE;
    matBlinn.ambient = (Color){ 50, 50, 50, 255 };
    matBlinn.specular = WHITE;
    matBlinn.glossiness = 50.0f;
    
    // Setup camera
    SetCameraMode(CAMERA_FREE);             // Set camera mode
    SetCameraPosition(camera.position);     // Set internal camera position to match our camera position
    SetCameraTarget(camera.target);         // Set internal camera target to match our camera target
    
    SetTargetFPS(60);
    //--------------------------------------------------------------------------------------
    
    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        UpdateCamera(&camera);      // Update camera position
        
        // Glossiness input control
        if(IsKeyDown(KEY_UP)) matBlinn.glossiness += SHININESS_SPEED;
        else if(IsKeyDown(KEY_DOWN))
        {
            matBlinn.glossiness -= SHININESS_SPEED;
            if( matBlinn.glossiness < 0) matBlinn.glossiness = 0.0f;
        }
        
        // Light X movement
        if (IsKeyDown(KEY_D)) light.position.x += LIGHT_SPEED;
        else if(IsKeyDown(KEY_A)) light.position.x -= LIGHT_SPEED;
        
        // Light Y movement
        if (IsKeyDown(KEY_LEFT_SHIFT)) light.position.y += LIGHT_SPEED;
        else if (IsKeyDown(KEY_LEFT_CONTROL)) light.position.y -= LIGHT_SPEED;

        // Light Z movement
        if (IsKeyDown(KEY_S)) light.position.z += LIGHT_SPEED;
        else if (IsKeyDown(KEY_W)) light.position.z -= LIGHT_SPEED;
        
        // Send light values to shader
        SetShaderValue(shader, lIntensityLoc, &light.intensity, 1);
        SetShaderValue(shader, lAmbientLoc, ColorToFloat(light.ambient), 3);
        SetShaderValue(shader, lDiffuseLoc, ColorToFloat(light.diffuse), 3);
        SetShaderValue(shader, lSpecularLoc, ColorToFloat(light.specular), 3);
        SetShaderValue(shader, lSpecIntensityLoc, &light.specIntensity, 1);
        
        // Send material values to shader
        SetShaderValue(shader, mAmbientLoc, ColorToFloat(matBlinn.ambient), 3);
        SetShaderValue(shader, mSpecularLoc, ColorToFloat(matBlinn.specular), 3);
        SetShaderValue(shader, mGlossLoc, &matBlinn.glossiness, 1);
        
        // Send camera and light transform values to shader
        SetShaderValue(shader, cameraLoc, VectorToFloat(camera.position), 3);
        SetShaderValue(shader, lightLoc, VectorToFloat(light.position), 3);
        //----------------------------------------------------------------------------------
        
        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();
        
            ClearBackground(RAYWHITE);
            
            Begin3dMode(camera);
                
                DrawModel(model, position, 4.0f, matBlinn.diffuse);
                DrawSphere(light.position, 0.5f, GOLD);
                
                DrawGrid(20, 1.0f);
                
            End3dMode();
            
            DrawFPS(10, 10);                // Draw FPS
            
        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadShader(shader);
    UnloadModel(model);

    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------
    
    return 0;
}