/*******************************************************************************************
*
*   raylib [shaders] example - Texture Waves
*
*   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 2.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Example contributed by Anata (@anatagawa) and reviewed by Ramon Santamaria (@raysan5)
*
*   Copyright (c) 2019 Anata (@anatagawa) and Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

#if defined(PLATFORM_WEB)
    #include <emscripten/emscripten.h>
#endif

#if defined(PLATFORM_DESKTOP)
    #define GLSL_VERSION            330
#else   // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB
    #define GLSL_VERSION            100
#endif

//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
const int screenWidth = 800;
const int screenHeight = 450;

// NOTE: Textures MUST be loaded after Window initialization (OpenGL context is required)

Texture2D texture = { 0 };
Shader shader = { 0 };

int secondsLoc = 0;
int freqXLoc = 0;
int freqYLoc = 0;
int ampXLoc = 0;
int ampYLoc = 0;
int speedXLoc = 0;
int speedYLoc = 0;

// Shader uniform values that can be updated at any time
float freqX = 25.0f;
float freqY = 25.0f;
float ampX = 5.0f;
float ampY = 5.0f;
float speedX = 8.0f;
float speedY = 8.0f;

float seconds = 0.0f;

//----------------------------------------------------------------------------------
// Module Functions Declaration
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void);     // Update and Draw one frame

//----------------------------------------------------------------------------------
// Program Main Entry Point
//----------------------------------------------------------------------------------
int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - texture waves");

    // Load space texture to apply shaders
    texture = LoadTexture("resources/space.png");

    // Load shader and setup location points and values
    shader = LoadShader(0, FormatText("resources/shaders/glsl%i/wave.fs", GLSL_VERSION));

    secondsLoc = GetShaderLocation(shader, "secondes");
    freqXLoc = GetShaderLocation(shader, "freqX");
    freqYLoc = GetShaderLocation(shader, "freqY");
    ampXLoc = GetShaderLocation(shader, "ampX");
    ampYLoc = GetShaderLocation(shader, "ampY");
    speedXLoc = GetShaderLocation(shader, "speedX");
    speedYLoc = GetShaderLocation(shader, "speedY");

    float screenSize[2] = { (float)GetScreenWidth(), (float)GetScreenHeight() };
    SetShaderValue(shader, GetShaderLocation(shader, "size"), &screenSize, UNIFORM_VEC2);
    SetShaderValue(shader, freqXLoc, &freqX, UNIFORM_FLOAT);
    SetShaderValue(shader, freqYLoc, &freqY, UNIFORM_FLOAT);
    SetShaderValue(shader, ampXLoc, &ampX, UNIFORM_FLOAT);
    SetShaderValue(shader, ampYLoc, &ampY, UNIFORM_FLOAT);
    SetShaderValue(shader, speedXLoc, &speedX, UNIFORM_FLOAT);
    SetShaderValue(shader, speedYLoc, &speedY, UNIFORM_FLOAT);

#if defined(PLATFORM_WEB)
    emscripten_set_main_loop(UpdateDrawFrame, 0, 1);
#else
    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        UpdateDrawFrame();
    }
#endif

    // De-Initialization
    //--------------------------------------------------------------------------------------
    UnloadShader(shader);         // Unload shader
    UnloadTexture(texture);       // Unload texture

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

    return 0;
}

//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void)
{
    // Update
    //----------------------------------------------------------------------------------
    seconds += GetFrameTime();

    SetShaderValue(shader, secondsLoc, &seconds, UNIFORM_FLOAT);
    //----------------------------------------------------------------------------------

    // Draw
    //----------------------------------------------------------------------------------
    BeginDrawing();

        ClearBackground(RAYWHITE);

        BeginShaderMode(shader);

            DrawTexture(texture, 0, 0, WHITE);
            DrawTexture(texture, texture.width, 0, WHITE);

        EndShaderMode();

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