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01-03-2004, 05:23 PM
Hi, I'm currently using the latest stable release (not the beta) of Dev-C++ and I'm trying to teach myself OpenGl, now for some reason when i create the window, I am only getting the background and not the actual things that I draw with OpenGL. I'm working with the template included in Dev-C++. If anyone could help me or tell me what's wrong with my code (or maybe its just WinXP?? wouldn't surprise me...) I would be grateful & have attached the code below..


-Enemy Of Reality





// 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( &amp;wc );

// create main window
hWnd = CreateWindow(
"GLSample", "OpenGL Sample",
WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
0, 0, 1200, 800,
NULL, NULL, hInstance, NULL );

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

// program main loop
while ( !bQuit ) {

// check for messages
if ( PeekMessage( &amp;msg, NULL, 0, 0, PM_REMOVE ) ) {

// handle or dispatch messages
if ( msg.message == WM_QUIT ) {
bQuit = TRUE;
} else {
TranslateMessage( &amp;msg );
DispatchMessage( &amp;msg );
}

} else {

// OpenGL animation code goes here

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(-1.5f,0.0f,-6.0f);
glBegin(GL_TRIANGLES); // Drawing Using Triangles
glColor3f(1.0f,0.0f,0.0f);
glVertex3f( 0.0f, 1.0f, 0.0f); // Top
glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
glEnd();

}

}

// 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( &amp;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, &amp;pfd );
SetPixelFormat( *hDC, iFormat, &amp;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 );
}

JRW
01-03-2004, 06:43 PM
[QUOTE]Originally posted by EnemyofReality:
[B]Hi, I'm currently using the latest stable release (not the beta) of Dev-C++ and I'm trying to teach myself OpenGl,


...

Try adding

SwapBuffers(hDC) after glEnd

comment out glTranslatef(-1.5f,0.0f,-6.0f); after glLoadIdentity

[This message has been edited by JRW (edited 01-03-2004).]

Hull
01-03-2004, 07:35 PM
I dont see any WM_PAINT message handling.

Add this to your globals:

static PAINTSTRUCT ps;

Add this to your windowproc

case WM_PAINT:
BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
break;

01-07-2004, 07:02 PM
um, where excatly do I add the stuff for the message handling?? you said window proc... but there's multiple of those, do i add to both, or just one and where do i add it to the beginning or the end, or the middle?

^C++
01-08-2004, 02:04 AM
To correct this error You should use Direct3D instead of OpenGL. This is a solution of Your problem. Good luck!

ZbuffeR
01-08-2004, 02:13 AM
Moderator please ?

fishybawb
01-08-2004, 02:33 AM
Add Hull's code to the function that starts:

// Window Procedure
LRESULT CALLBACK WndProc( HWND hWnd, UINT message,WPARAM wParam, LPARAM lParam )
{
switch ( message )
{
case WM_CREATE:
return 0;
...


[This message has been edited by fishybawb (edited 01-08-2004).]