// ----------------------------------------------------------------------------------------------------------------------------

#include <windows.h>

#ifndef WM_MOUSWHEEL
    #define WM_MOUSWHEEL 0x020A
#endif

#include "string.h"
#include "glmath.h"

#pragma comment(lib, "winmm.lib")

#pragma warning(disable : 4996)

// ----------------------------------------------------------------------------------------------------------------------------

class complex
{
public:
    double r, i;

public:
    complex();
    ~complex();

public:
    complex(double r, double i);

public:
    double abs();

public:
    friend complex operator + (const complex &a, const complex &b);
    friend complex operator * (const complex &a, const complex &b);
};

// ----------------------------------------------------------------------------------------------------------------------------

class CSoftwareRenderer
{
private:
    int Width, Height;

private:
    BYTE *ColorBuffer;
    int ColorBufferWidth, ColorBufferHeight;
    BITMAPINFO ColorBufferInfo;

private:
    int Pitch;

public:
    CSoftwareRenderer();
    ~CSoftwareRenderer();

public:
    int GetPitch();

public:
    void Clear();
    void SetPixel(int i, BYTE r, BYTE g, BYTE b);

public:
    void Viewport(int Width, int Height);
    void SwapBuffers(HDC hDC);
};

// ----------------------------------------------------------------------------------------------------------------------------

class CFractalRenderer : public CSoftwareRenderer
{
private:
    int LastX, LastY, LastClickedX, LastClickedY;

private:
    int Width, Height, WMH;

private:
    double cx, cy, d, aspect;

private:
    int maxmaxn, maxn, n;

private:
    complex *zs, *cs;
    int *ns;
    bool *diverges, *colored;

private:
    vec3 *Colors;
    int ColorsCount;

public:
    CFractalRenderer();
    ~CFractalRenderer();

public:
    int GetN();
    int GetMaxN();

public:
    bool Init();
    void Render(float FrameTime);
    void Resize(int Width, int Height);
    void Destroy();

public:
    void RandomizeColors();

public:
    void OnKeyDown(UINT Key);
    void OnLButtonDown(int X, int Y);
    void OnLButtonUp(int X, int Y);
    void OnMouseMove(int X, int Y);
    void OnMouseWheel(short zDelta);
    void OnRButtonDown(int X, int Y);
    void OnRButtonUp(int X, int Y);
};

// ----------------------------------------------------------------------------------------------------------------------------

class CFractalView
{
private:
    char *Title;
    int Width, Height;
    HWND hWnd;
    HDC hDC;

private:
    CFractalRenderer FractalRenderer;

public:
    CFractalView();
    ~CFractalView();

public:
    bool Create(HINSTANCE hInstance, char *Title, int Width, int Height);
    void Show(bool Maximized = false);
    void MsgLoop();
    void Destroy();

public:
    void OnKeyDown(UINT Key);
    void OnLButtonDown(int X, int Y);
    void OnLButtonUp(int X, int Y);
    void OnMouseMove(int X, int Y);
    void OnMouseWheel(short zDelta);
    void OnPaint();
    void OnRButtonDown(int X, int Y);
    void OnRButtonUp(int X, int Y);
    void OnSize(int Width, int Height);
};

// ----------------------------------------------------------------------------------------------------------------------------

LRESULT CALLBACK WndProc(HWND hWnd, UINT uiMsg, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR sCmdLine, int iShow);

// ----------------------------------------------------------------------------------------------------------------------------

// ----------------------------------------------------------------------------------------------------------------------------

#include "fractal.h"

// ----------------------------------------------------------------------------------------------------------------------------

CString ErrorLog, ModuleDirectory;

// ----------------------------------------------------------------------------------------------------------------------------

complex::complex()
{
    r = 0.0;
    i = 0.0;
}

complex::~complex()
{
}

complex::complex(double r, double i)
{
    this->r = r;
    this->i = i;
}

double complex::abs()
{
    return sqrt(r * r + i * i);
}

complex operator + (const complex &a, const complex &b)
{
    return complex(a.r + b.r, a.i + b.i);
}

complex operator * (const complex &a, const complex &b)
{
    return complex(a.r * b.r - a.i * b.i, a.r * b.i + a.i * b.r);
}

// ----------------------------------------------------------------------------------------------------------------------------

CSoftwareRenderer::CSoftwareRenderer()
{
    Width = 0;
    Height = 0;

    ColorBuffer = NULL;
    ColorBufferWidth = 0;
    ColorBufferHeight = 0;
}

CSoftwareRenderer::~CSoftwareRenderer()
{
    if(ColorBuffer != NULL)
    {
        delete [] ColorBuffer;
    }
}

int CSoftwareRenderer::GetPitch()
{
    return Pitch;
}

void CSoftwareRenderer::Clear()
{
    if(ColorBuffer != NULL)
    {
        memset(ColorBuffer, 0, ColorBufferWidth * ColorBufferHeight * 3);
    }
}

void CSoftwareRenderer::SetPixel(int i, BYTE r, BYTE g, BYTE b)
{
    ColorBuffer[i++] = b;
    ColorBuffer[i++] = g;
    ColorBuffer[i++] = r;
}

void CSoftwareRenderer::Viewport(int Width, int Height)
{
    this->Width = Width;
    this->Height = Height;

    if(ColorBuffer != NULL)
    {
        delete [] ColorBuffer;
        ColorBuffer = NULL;
    }

    if(Width > 0 && Height > 0)
    {
        ColorBufferWidth = Width;
        ColorBufferHeight = Height;

        int WidthMod4 = Width % 4;

        if(WidthMod4 > 0)
        {
            ColorBufferWidth += 4 - WidthMod4;
        }

        Pitch = (ColorBufferWidth - Width) * 3;

        ColorBuffer = new BYTE[ColorBufferWidth * ColorBufferHeight * 3];

        memset(&ColorBufferInfo, 0, sizeof(BITMAPINFO));
        ColorBufferInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
        ColorBufferInfo.bmiHeader.biPlanes = 1;
        ColorBufferInfo.bmiHeader.biBitCount = 24;
        ColorBufferInfo.bmiHeader.biCompression = BI_RGB;
        ColorBufferInfo.bmiHeader.biWidth = ColorBufferWidth;
        ColorBufferInfo.bmiHeader.biHeight = ColorBufferHeight;
    }
}

void CSoftwareRenderer::SwapBuffers(HDC hDC)
{
    if(ColorBuffer != NULL)
    {
        StretchDIBits(hDC, 0, 0, Width, Height, 0, 0, Width, Height, ColorBuffer, &ColorBufferInfo, DIB_RGB_COLORS, SRCCOPY);
    }
}

// ----------------------------------------------------------------------------------------------------------------------------

CFractalRenderer::CFractalRenderer()
{
    cx = -0.5;
    cy = 0.0;
    d = 1.5;

    maxmaxn = 8192;
    maxn = maxmaxn / 32;
    n = 0;

    zs = NULL;
    cs = NULL;
    ns = NULL;
    diverges = NULL;
}

CFractalRenderer::~CFractalRenderer()
{
}

int CFractalRenderer::GetN()
{
    return n;
}

int CFractalRenderer::GetMaxN()
{
    return maxn;
}

bool CFractalRenderer::Init()
{
    ColorsCount = 128;

    Colors = new vec3[ColorsCount];

    RandomizeColors();

    return true;
}

void CFractalRenderer::Render(float FrameTime)
{
    if(n < maxn)
    {
        if(n == 0)
        {
            Clear();

            int i = 0;

            for(int y = 0; y < Height; y++)
            {
                for(int x = 0; x < Width; x++)
                {
                    // zs[i] = complex(0.0, 0.0);

                    zs[i].r = 0.0;
                    zs[i].i = 0.0;

                    // cs[i] = complex(cx + ((double)x / (double)Width * 2.0 - 1.0) * d * aspect, cy + ((double)y / (double)Height * 2.0 - 1.0) * d);

                    cs[i].r = cx + ((double)x / (double)Width * 2.0 - 1.0) * d * aspect;
                    cs[i].i = cy + ((double)y / (double)Height * 2.0 - 1.0) * d;

                    ns[i] = 0;

                    diverges[i] = false;

                    colored[i] = false;

                    i++;
                }
            }
        }

        DWORD Time = GetTickCount();

        while(n < maxn && GetTickCount() - Time < 250)
        {
            for(int i = 0; i < WMH; i++)
            {
                if(!diverges[i])
                {
                    // zs[i] = zs[i] * zs[i] + cs[i];

                    double zr = zs[i].r, zi = zs[i].i, cr = cs[i].r, ci = cs[i].i;

                    zs[i].r = zr * zr - zi * zi + cr;
                    zs[i].i = 2.0 * zr * zi + ci;

                    ns[i] = n;

                    // diverges[i] = zs[i].abs() > 2.0;

                    zr = zs[i].r;
                    zi = zs[i].i;

                    diverges[i] = zr * zr + zi * zi > 4.0;
                }
            }

            n++;
        }
    }

    int i = 0, ii = 0;

    for(int y = 0; y < Height; y++)
    {
        for(int x = 0; x < Width; x++)
        {
            if(diverges[i] && !colored[i])
            {
                float cf = (float)(ColorsCount - 2) * (float)ns[i] / (float)maxmaxn;

                int c1 = (int)cf, c2 = c1 + 1;

                cf -= (float)c1;

                vec3 Color = mix(Colors[c1], Colors[c2], cf);

                SetPixel(ii, (BYTE)Color.r, (BYTE)Color.g, (BYTE)Color.b);

                colored[i] = true;
            }

            i++;
            ii += 3;
        }

        ii += GetPitch();
    }
}

void CFractalRenderer::Resize(int Width, int Height)
{
    this->Width = Width;
    this->Height = Height;

    WMH = Width * Height;

    Viewport(Width, Height);

    aspect = (double)Width / (double)Height;

    if(zs != NULL)
    {
        delete [] zs;
        zs = NULL;
    }

    if(cs != NULL)
    {
        delete [] cs;
        cs = NULL;
    }

    if(ns != NULL)
    {
        delete [] ns;
        ns = NULL;
    }

    if(diverges != NULL)
    {
        delete [] diverges;
        diverges = NULL;
    }

    if(colored != NULL)
    {
        delete [] colored;
        colored = NULL;
    }

    if(Width > 0 && Height > 0)
    {
        zs = new complex[WMH];
        cs = new complex[WMH];
        ns = new int[WMH];
        diverges = new bool[WMH];
        colored = new bool[WMH];
    }

    n = 0;
}

void CFractalRenderer::Destroy()
{
    if(zs != NULL)
    {
        delete [] zs;
    }

    if(cs != NULL)
    {
        delete [] cs;
    }

    if(ns != NULL)
    {
        delete [] ns;
    }

    if(diverges != NULL)
    {
        delete [] diverges;
    }

    if(colored != NULL)
    {
        delete [] colored;
    }

    delete Colors;
}

void CFractalRenderer::RandomizeColors()
{
    for(int i = 0; i < ColorsCount; i++)
    {
        Colors[i].r = 255.0f * (float)rand() / (float)RAND_MAX;
        Colors[i].g = 255.0f * (float)rand() / (float)RAND_MAX;
        Colors[i].b = 255.0f * (float)rand() / (float)RAND_MAX;
    }

    Colors[0] *= 0.125f;

    for(int i = 0; i < WMH; i++)
    {
        colored[i] = false;
    }
}

void CFractalRenderer::OnKeyDown(UINT Key)
{
    switch(Key)
    {
        case VK_F1:
            RandomizeColors();
            break;

        case '1':
            n = 0;
            maxn = maxmaxn / 512;
            break;

        case '2':
            n = 0;
            maxn = maxmaxn / 256;
            break;

        case '3':
            n = 0;
            maxn = maxmaxn / 128;
            break;

        case '4':
            n = 0;
            maxn = maxmaxn / 64;
            break;

        case '5':
            n = 0;
            maxn = maxmaxn / 32;
            break;

        case '6':
            n = 0;
            maxn = maxmaxn / 16;
            break;

        case '7':
            n = 0;
            maxn = maxmaxn / 8;
            break;

        case '8':
            n = 0;
            maxn = maxmaxn / 4;
            break;

        case '9':
            n = 0;
            maxn = maxmaxn / 2;
            break;

        case '0':
            n = 0;
            maxn = maxmaxn;
            break;

        case 'R':
            cx = -0.5;
            cy = 0.0;
            d = 1.5;
            n = 0;
            break;
    }
}

void CFractalRenderer::OnLButtonDown(int X, int Y)
{
    LastClickedX = X;
    LastClickedY = Y;
}

void CFractalRenderer::OnLButtonUp(int X, int Y)
{
    if(X == LastClickedX && Y == LastClickedY)
    {
        cx += (X - Width / 2) * d * 2.0 / (double)Width * aspect;
        cy += (Height / 2 - Y) * d * 2.0 / (double)Height;

        d *= 0.5;

        n = 0;
    }
}

void CFractalRenderer::OnMouseMove(int X, int Y)
{
    if(GetKeyState(VK_LBUTTON) & 0x80)
    {
        cx += (LastX - X) * d * 2.0 / (double)Width * aspect;
        cy += (Y - LastY) * d * 2.0 / (double)Height;

        n = 0;
    }

    LastX = X;
    LastY = Y;
}

void CFractalRenderer::OnMouseWheel(short zDelta)
{
    if(zDelta > 0)
    {
        d *= 0.5;
        n = 0;
    }

    if(zDelta < 0)
    {
        d *= 2.0;
        n = 0;
    }
}

void CFractalRenderer::OnRButtonDown(int X, int Y)
{
    LastClickedX = X;
    LastClickedY = Y;
}

void CFractalRenderer::OnRButtonUp(int X, int Y)
{
    if(X == LastClickedX && Y == LastClickedY)
    {
        cx += (X - Width / 2) * d * 2.0 / (double)Width * aspect;
        cy += (Height / 2 - Y) * d * 2.0 / (double)Height;

        d *= 2.0;

        n = 0;
    }
}

// ----------------------------------------------------------------------------------------------------------------------------

CFractalView::CFractalView()
{
    char *moduledirectory = new char[256];
    GetModuleFileName(GetModuleHandle(NULL), moduledirectory, 256);
    *(strrchr(moduledirectory, '\\') + 1) = 0;
    ModuleDirectory = moduledirectory;
    delete [] moduledirectory;
}

CFractalView::~CFractalView()
{
}

bool CFractalView::Create(HINSTANCE hInstance, char *Title, int Width, int Height)
{
    WNDCLASSEX WndClassEx;

    memset(&WndClassEx, 0, sizeof(WNDCLASSEX));

    WndClassEx.cbSize = sizeof(WNDCLASSEX);
    WndClassEx.style = CS_OWNDC | CS_HREDRAW | CS_VREDRAW;
    WndClassEx.lpfnWndProc = WndProc;
    WndClassEx.hInstance = hInstance;
    WndClassEx.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    WndClassEx.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
    WndClassEx.hCursor = LoadCursor(NULL, IDC_ARROW);
    WndClassEx.lpszClassName = "Win32OpenGLWindow";

    if(RegisterClassEx(&WndClassEx) == 0)
    {
        ErrorLog.Set("RegisterClassEx failed!");
        return false;
    }

    this->Title = Title;

    this->Width = Width;
    this->Height = Height;

    DWORD Style = WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN;

    if((hWnd = CreateWindowEx(WS_EX_APPWINDOW, WndClassEx.lpszClassName, Title, Style, 0, 0, Width, Height, NULL, NULL, hInstance, NULL)) == NULL)
    {
        ErrorLog.Set("CreateWindowEx failed!");
        return false;
    }

    if((hDC = GetDC(hWnd)) == NULL)
    {
        ErrorLog.Set("GetDC failed!");
        return false;
    }

    return FractalRenderer.Init();
}

void CFractalView::Show(bool Maximized)
{
    RECT dRect, wRect, cRect;

    GetWindowRect(GetDesktopWindow(), &dRect);
    GetWindowRect(hWnd, &wRect);
    GetClientRect(hWnd, &cRect);

    wRect.right += Width - cRect.right;
    wRect.bottom += Height - cRect.bottom;

    wRect.right -= wRect.left;
    wRect.bottom -= wRect.top;

    wRect.left = dRect.right / 2 - wRect.right / 2;
    wRect.top = dRect.bottom / 2 - wRect.bottom / 2;

    MoveWindow(hWnd, wRect.left, wRect.top, wRect.right, wRect.bottom, FALSE);

    ShowWindow(hWnd, Maximized ? SW_SHOWMAXIMIZED : SW_SHOWNORMAL);
}

void CFractalView::MsgLoop()
{
    MSG Msg;

    while(GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
}

void CFractalView::Destroy()
{
    FractalRenderer.Destroy();

    DestroyWindow(hWnd);
}

void CFractalView::OnKeyDown(UINT Key)
{
    FractalRenderer.OnKeyDown(Key);
}

void CFractalView::OnLButtonDown(int X, int Y)
{
    FractalRenderer.OnLButtonDown(X, Y);
}

void CFractalView::OnLButtonUp(int X, int Y)
{
    FractalRenderer.OnLButtonUp(X, Y);
}

void CFractalView::OnMouseMove(int X, int Y)
{
    FractalRenderer.OnMouseMove(X, Y);
}

void CFractalView::OnMouseWheel(short zDelta)
{
    FractalRenderer.OnMouseWheel(zDelta);
}

void CFractalView::OnPaint()
{
    PAINTSTRUCT ps;

    BeginPaint(hWnd, &ps);

    static DWORD LastFPSTime = GetTickCount(), LastFrameTime = LastFPSTime;
    static int FPS = 0;

    DWORD Time = GetTickCount();

    float FrameTime = (Time - LastFrameTime) * 0.001f;

    LastFrameTime = Time;

    if(Time - LastFPSTime > 1000)
    {
        CString Text = Title;

        Text.Append(" - %dx%d", Width, Height);
        Text.Append(", FPS: %d", FPS);
        Text.Append(" - %d / %d", FractalRenderer.GetN(), FractalRenderer.GetMaxN());

        SetWindowText(hWnd, Text);

        LastFPSTime = Time;
        FPS = 0;
    }
    else
    {
        FPS++;
    }

    FractalRenderer.Render(FrameTime);

    FractalRenderer.SwapBuffers(hDC);

    EndPaint(hWnd, &ps);

    InvalidateRect(hWnd, NULL, FALSE);
}

void CFractalView::OnRButtonDown(int X, int Y)
{
    FractalRenderer.OnRButtonDown(X, Y);
}

void CFractalView::OnRButtonUp(int X, int Y)
{
    FractalRenderer.OnRButtonUp(X, Y);
}

void CFractalView::OnSize(int Width, int Height)
{
    this->Width = Width;
    this->Height = Height;

    FractalRenderer.Resize(Width, Height);
}

// ----------------------------------------------------------------------------------------------------------------------------

CFractalView FractalView;

// ----------------------------------------------------------------------------------------------------------------------------

LRESULT CALLBACK WndProc(HWND hWnd, UINT uiMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uiMsg)
    {
        case WM_CLOSE:
            PostQuitMessage(0);
            break;

        case WM_KEYDOWN:
            FractalView.OnKeyDown((UINT)wParam);
            break;

        case WM_LBUTTONDOWN:
            FractalView.OnLButtonDown(LOWORD(lParam), HIWORD(lParam));
            break;

        case WM_LBUTTONUP:
            FractalView.OnLButtonUp(LOWORD(lParam), HIWORD(lParam));
            break;

        case WM_MOUSEMOVE:
            FractalView.OnMouseMove(LOWORD(lParam), HIWORD(lParam));
            break;

        case WM_MOUSWHEEL:
            FractalView.OnMouseWheel(HIWORD(wParam));
            break;

        case WM_PAINT:
            FractalView.OnPaint();
            break;

        case WM_RBUTTONDOWN:
            FractalView.OnRButtonDown(LOWORD(lParam), HIWORD(lParam));
            break;

        case WM_RBUTTONUP:
            FractalView.OnRButtonUp(LOWORD(lParam), HIWORD(lParam));
            break;

        case WM_SIZE:
            FractalView.OnSize(LOWORD(lParam), HIWORD(lParam));
            break;

        default:
            return DefWindowProc(hWnd, uiMsg, wParam, lParam);
    }

    return 0;
}

// ----------------------------------------------------------------------------------------------------------------------------

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR sCmdLine, int iShow)
{
    if(FractalView.Create(hInstance, "Fractal", 800, 600))
    {
        FractalView.Show();
        FractalView.MsgLoop();
    }
    else
    {
        MessageBox(NULL, ErrorLog, "Error", MB_OK | MB_ICONERROR);
    }

    FractalView.Destroy();

    return 0;
}

// ----------------------------------------------------------------------------------------------------------------------------