#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>
#include <stdio.h>
#include <stdlib.h>

HDC hdc;
HWND hwnd;
WNDCLASS wnd;
HGLRC hglrc;
MSG msg;

LPSTR szClassName = "MyClass";
HINSTANCE hInstance;

LRESULT CALLBACK MyWndProc(HWND, UINT, WPARAM, LPARAM);
void startGL();
void initwindow();
void closewindow();
void draw();


int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR szCmdLine, int iCmdShow)
{
        hInstance = hInst;

        initwindow();
        startGL();

        while(1) {
                if(PeekMessage(&msg, hwnd, 0, 0, PM_REMOVE)) {
                        if(msg.message == WM_QUIT) {
                                break;
                        }

                        TranslateMessage(&msg);
                        DispatchMessage(&msg);
                } else
                        draw();

                Sleep(100);   //crappy way of stopping 10000000000000 loops a second

        }
        closewindow();
        return msg.wParam;
}

void initwindow()
{
        wnd.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC; //CS_OWNDC required for OPEGL - HREDRAW and VREDRAW update the screen on resize.
        wnd.lpfnWndProc = MyWndProc;
        wnd.cbClsExtra = 0;
        wnd.cbWndExtra = 0;
        wnd.hInstance = hInstance;
        wnd.hIcon = LoadIcon(NULL, IDI_APPLICATION); //Icon of the program - default
        wnd.hCursor = LoadCursor(NULL, IDC_ARROW);   //Mouse cursor - default
        wnd.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
        wnd.lpszMenuName = NULL;                     //no menu
        wnd.lpszClassName = szClassName;

        if(!RegisterClass(&wnd)) {
                MessageBox(NULL, "couldn't register class", //cant continue
                           "Error", MB_OK);
                return 0;
        }

        hwnd = CreateWindow(szClassName, "Arcticcu leetpro swagfagets!",WS_OVERLAPPEDWINDOW,
                            CW_USEDEFAULT,CW_USEDEFAULT,
                            1000,1000,NULL,NULL,hInstance,NULL);
        ShowWindow(hwnd, iCmdShow);            //Shows and updates window.
        UpdateWindow(hwnd);
}

void startGL()
{
        hdc = GetDC(hwnd);
        PIXELFORMATDESCRIPTOR pfd = {0};

        pfd.nSize = sizeof( PIXELFORMATDESCRIPTOR );    // just its size
        pfd.nVersion = 1;   // always 1
        pfd.dwFlags = PFD_SUPPORT_OPENGL |  PFD_DOUBLEBUFFER   |  PFD_DRAW_TO_WINDOW;  // openglsupport - doublebuffer support - draw to window not bitmap
        pfd.iPixelType = PFD_TYPE_RGBA ;    // red, green, blue, alpha for each pixel
        pfd.cColorBits = 24;                // 24 bit == 8 bits for red, 8 for green, 8 for blue.
        pfd.cDepthBits = 32;
        int pick;
        pick = ChoosePixelFormat(hdc, &pfd);
        SetPixelFormat(hdc,pick,&pfd);
        hglrc = wglCreateContext(hdc);
        wglMakeCurrent(hdc, hglrc);
}

void closewindow()
{
        wglMakeCurrent(NULL,NULL);  // makes the opengl context not-current
        wglDeleteContext(hglrc);  // deletes the opengl context
        ReleaseDC(hwnd, hdc);     // releases Device context
        CloseWindow(hwnd);          //closes the window, duh
}

void draw()
{
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glMatrixMode(GL_MODELVIEW);             //Basic opengl drawing.. a triangle :P
        glTranslatef(0,0,0);

        glClear(GL_COLOR_BUFFER_BIT);

        glBegin(GL_POLYGON);
        glColor3f(1,0,0);
        glVertex2f(-0.6, -0.75);
        glColor3f(0, 1, 0);
        glVertex2f(0.6, -0.75);
        glColor3f(0, 0, 1);
        glVertex2f(0, 0.75);
        glEnd();
        SwapBuffers(hdc); //Swap the buffers so what was drawn is shown on the screen, must be done on each redraw.
}

LRESULT CALLBACK MyWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
        if(msg == WM_DESTROY) {
                PostQuitMessage(0);
                break;
        }
        if(msg == WM_CLOSE) {
                DestroyWindow(hwnd);
                break;
        }

        return DefWindowProc(hwnd, msg, wParam, lParam);
}