/**************************
 * Includes
 *
 **************************/

#include <windows.h>
#include <gl/gl.h>


/**************************
 * Function Declarations
 *
 **************************/

LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
                          WPARAM wParam, LPARAM lParam);
void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC);
void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC);


/**************************
 * WinMain
 *
 **************************/

int WINAPI WinMain (HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpCmdLine,
                    int iCmdShow) {
    WNDCLASS wc;
    HWND hWnd;
    HDC hDC;
    HGLRC hRC;
    MSG msg;
    BOOL bQuit = FALSE;
    float theta = 0.0f;

    /* register window class */
    wc.style = CS_OWNDC;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wc.hCursor = LoadCursor (NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = "GLSample";
    RegisterClass (&wc);

    /* create main window */
    hWnd = CreateWindow (
               "GLSample", "MY openGL",
               WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
               0, 0, 256, 256,
               NULL, NULL, hInstance, NULL);

    /* enable OpenGL for the window */
    EnableOpenGL (hWnd, &hDC, &hRC);

    /* program main loop */
    while (!bQuit) {
        /* check for messages */
        if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) {
            /* handle or dispatch messages */
            if (msg.message == WM_QUIT) {
                bQuit = TRUE;
            } else {
                TranslateMessage (&msg);
                DispatchMessage (&msg);
            }
        } else {
            /* OpenGL animation code goes here */
            for(float i=1.0; i<=1; i+=0.01) {

                glPushMatrix ();
                glBegin (GL_TRIANGLES);
                glColor3f (i,i, i);
                glVertex2f ((0-i), i);
                glColor3f (i, i, i);
                glVertex2f (i, i);
                glColor3f (i, i, i);
                glVertex2f ( i,(0-i));
                glEnd ();
                glPopMatrix ();
                glPushMatrix ();
                glBegin (GL_TRIANGLES);
                glColor3f (i, i, i);
                glVertex2f ((0-i), i);
                glColor3f (i, i, i);
                glVertex2f ( (0-i),(0-i));
                glColor3f (i, i, i);
                glVertex2f ( i,(0-i));
                glEnd ();
                glPopMatrix ();
                SwapBuffers (hDC);
                Sleep (1);
            }
            for(int i=1; i<=360; i++) {
                if(i<=90){
                    float x1=1.0/90*i*0.5;
                    float y1=1.0/90*(90-i)*0.5;
                    float x2=1.0/90*(i+1)*0.5;
                    float y2=1.0/90*(90-(i+1))*0.5;
                    glPushMatrix ();
                    glBegin (GL_TRIANGLES);
                    glColor3f (1.0f,0.0f, 0.0f);
                    glVertex2f (x1,y1);
                    glColor3f (1.0f,0.0f, 0.0f);
                    glVertex2f (x2,y2);
                    glColor3f (1.0f,0.0f, 0.0f);
                    glVertex2f (0,0);

                glEnd ();
                glPopMatrix ();
                SwapBuffers (hDC);
                }
            }
        }
    }

    /* shutdown OpenGL */
    DisableOpenGL (hWnd, hDC, hRC);

    /* destroy the window explicitly */
    DestroyWindow (hWnd);

    return msg.wParam;
}


/********************
 * Window Procedure
 *
 ********************/

LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
                          WPARAM wParam, LPARAM lParam) {

    switch (message) {
        case WM_CREATE:
            return 0;
        case WM_CLOSE:
            PostQuitMessage (0);
            return 0;

        case WM_DESTROY:
            return 0;

        case WM_KEYDOWN:
            switch (wParam) {
                case VK_ESCAPE:
                    PostQuitMessage(0);
                    return 0;
            }
            return 0;

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


/*******************
 * Enable OpenGL
 *
 *******************/

void EnableOpenGL (HWND hWnd, HDC *hDC, HGLRC *hRC) {
    PIXELFORMATDESCRIPTOR pfd;
    int iFormat;

    /* get the device context (DC) */
    *hDC = GetDC (hWnd);

    /* set the pixel format for the DC */
    ZeroMemory (&pfd, sizeof (pfd));
    pfd.nSize = sizeof (pfd);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW |
                  PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 16;
    pfd.iLayerType = PFD_MAIN_PLANE;
    iFormat = ChoosePixelFormat (*hDC, &pfd);
    SetPixelFormat (*hDC, iFormat, &pfd);

    /* create and enable the render context (RC) */
    *hRC = wglCreateContext( *hDC );
    wglMakeCurrent( *hDC, *hRC );

}


/******************
 * Disable OpenGL
 *
 ******************/

void DisableOpenGL (HWND hWnd, HDC hDC, HGLRC hRC) {
    wglMakeCurrent (NULL, NULL);
    wglDeleteContext (hRC);
    ReleaseDC (hWnd, hDC);
}
c++****