Code:
#include <windows.h>
#include <gl/gl.h>
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);
HINSTANCE hInst;
int WINAPI WinMain(HINSTANCE hThisInst, HINSTANCE hPrevInst, LPSTR lpCmdLine, int nWinMode)
{
WNDCLASS wc;
HWND hWnd;
MSG msg;
int quit = 1;
hInst = hThisInst;
// register window class
wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInst;
wc.hIcon = LoadIcon( NULL, IDI_APPLICATION );
wc.hCursor = LoadCursor( NULL, IDC_ARROW );
wc.hbrBackground = (HBRUSH)GetStockObject( WHITE_BRUSH );
wc.lpszMenuName = NULL;
wc.lpszClassName = "GLSample";
RegisterClass( &wc );
// create main window
hWnd = CreateWindow( "GLSample",
"OpenGL Sample",
WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
0, 0, 800, 600,
NULL, NULL, hInst, NULL );
ShowWindow( hWnd, nWinMode );
UpdateWindow( hWnd );
while( GetMessage( &msg, NULL, 0, 0 ) )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
return msg.wParam;
}
// Window Procedure
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static HDC hDC;
static HGLRC hRC;
static int flag = 1;
switch (message)
{
case WM_CREATE: EnableOpenGL( hWnd, &hDC, &hRC );
return 0;
case WM_PAINT : // OpenGL animation code goes here
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glClear( GL_COLOR_BUFFER_BIT );
if( flag )
{
glBegin( GL_TRIANGLES );
glColor3f( 1.0f, 0.0f, 0.0f ); glVertex2f( 0.0f, 1.0f );
glColor3f( 0.0f, 1.0f, 0.0f ); glVertex2f( 0.87f, -0.5f );
glColor3f( 0.0f, 0.0f, 1.0f ); glVertex2f( -0.87f, -0.5f );
glEnd();
flag = 0;
}
else
{
glBegin( GL_TRIANGLES );
glColor3f( 0.0f, 0.0f, 1.0f ); glVertex2f( 0.0f, 1.0f );
glColor3f( 0.0f, 1.0f, 0.0f ); glVertex2f( 0.87f, -0.5f );
glColor3f( 1.0f, 0.0f, 0.0f ); glVertex2f( -0.87f, -0.5f );
glEnd();
flag = 1;
}
SwapBuffers( hDC );
return 0;
case WM_DESTROY: DisableOpenGL( hWnd, hDC, hRC );
PostQuitMessage(0);
return 0;
default: return DefWindowProc( hWnd, message, wParam, lParam );
}
return 0;
}
// Enable OpenGL
void EnableOpenGL(HWND hWnd, HDC *hDC, HGLRC *hRC)
{
PIXELFORMATDESCRIPTOR pfd;
int format;
// 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;
format = ChoosePixelFormat( *hDC, &pfd );
SetPixelFormat( *hDC, format, &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 );
}