/*******************************************************************************************
*
*   raylib [audio] example - Module playing (streaming)
*
*   NOTE: This example requires OpenAL Soft library installed
*
*   This example has been created using raylib 1.5 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Copyright (c) 2016 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

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

#define MAX_CIRCLES 32

//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
typedef struct {
    Vector2 position;
    float radius;
    float alpha;
    float speed;
    Color color;
} CircleWave;

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

float timePlayed = 0.0f;

Color colors[14] = { ORANGE, RED, GOLD, LIME, BLUE, VIOLET, BROWN, LIGHTGRAY, PINK,
                     YELLOW, GREEN, SKYBLUE, PURPLE, BEIGE };

// Creates ome circles for visual effect
CircleWave circles[MAX_CIRCLES];

Shader shader;
RenderTexture2D target;

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

//----------------------------------------------------------------------------------
// Main Enry Point
//----------------------------------------------------------------------------------
int main()
{
    // Initialization
    //--------------------------------------------------------------------------------------
    InitWindow(screenWidth, screenHeight, "raylib [audio] example - module playing (streaming)");

    InitAudioDevice();              // Initialize audio device
    
    for (int i = MAX_CIRCLES - 1; i >= 0; i--)
    {
        circles[i].alpha = 0.0f;
        circles[i].radius = GetRandomValue(10, 40);
        circles[i].position.x = GetRandomValue(circles[i].radius, screenWidth - circles[i].radius);
        circles[i].position.y = GetRandomValue(circles[i].radius, screenHeight - circles[i].radius);
        circles[i].speed = (float)GetRandomValue(1, 100)/20000.0f;
        circles[i].color = colors[GetRandomValue(0, 13)];
    }
    
    // Load postprocessing bloom shader
    shader = LoadShader("resources/shaders/glsl100/base.vs", 
                        "resources/shaders/glsl100/bloom.fs");

    // Create a RenderTexture2D to be used for render to texture
    target = LoadRenderTexture(screenWidth, screenHeight);

    PlayMusicStream(0, "resources/audio/2t2m_spa.xm");         // Play module stream
    
#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
    UnloadRenderTexture(target);    // Unload render texture
    
    CloseAudioDevice();     // Close audio device (music streaming is automatically stopped)

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

    return 0;
}

//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
void UpdateDrawFrame(void)
{
    // Update
    //----------------------------------------------------------------------------------
    for (int i = MAX_CIRCLES - 1; i >= 0; i--)
    {
        circles[i].alpha += circles[i].speed;
        circles[i].radius += circles[i].speed*10.0f;
        
        if (circles[i].alpha > 1.0f) circles[i].speed *= -1;
        
        if (circles[i].alpha <= 0.0f)
        {
            circles[i].alpha = 0.0f;
            circles[i].radius = GetRandomValue(10, 40);
            circles[i].position.x = GetRandomValue(circles[i].radius, screenWidth - circles[i].radius);
            circles[i].position.y = GetRandomValue(circles[i].radius, screenHeight - circles[i].radius);
            circles[i].color = colors[GetRandomValue(0, 13)];
            circles[i].speed = (float)GetRandomValue(1, 100)/20000.0f;
        }
    }

    // Get timePlayed scaled to bar dimensions
    timePlayed = (GetMusicTimePlayed(0)/GetMusicTimeLength(0)*(screenWidth - 40))*2;
    
    UpdateMusicStream(0);        // Update music buffer with new stream data
    //----------------------------------------------------------------------------------

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

        ClearBackground(BLACK);
        
        BeginTextureMode(target);   // Enable drawing to texture

            for (int i = MAX_CIRCLES - 1; i >= 0; i--)
            {
                DrawCircleV(circles[i].position, circles[i].radius, Fade(circles[i].color, circles[i].alpha));
            }
            
        EndTextureMode();           // End drawing to texture (now we have a texture available for next passes)
        
        BeginShaderMode(shader);

            // NOTE: Render texture must be y-flipped due to default OpenGL coordinates (left-bottom)
            DrawTextureRec(target.texture, (Rectangle){ 0, 0, target.texture.width, -target.texture.height }, (Vector2){ 0, 0 }, WHITE);
            
        EndShaderMode();

        // Draw time bar
        DrawRectangle(20, screenHeight - 20 - 12, screenWidth - 40, 12, LIGHTGRAY);
        DrawRectangle(20, screenHeight - 20 - 12, (int)timePlayed, 12, MAROON);
        DrawRectangleLines(20, screenHeight - 20 - 12, screenWidth - 40, 12, WHITE);

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