Help!

Hi,
I’m really new to OpenGL, and I ran into a problem I cant seem to fix. I am working out of a book, and one of the chapters in the book is how to initialize an OpenGl session, create a red triangle, and rotate it. I typed in the code exactly from the book (I think) and all I get is the window, but no triangle. Please tell me what is wrong with my code!

Code:
///Triangle.cpp
#define WIN32_LEAN_AND_MEAN
// Includes

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

// Global Variables

float angle = 0.0f;
HDC g_HDC;

// Enable OpenGL

void SetupPixelFormat(HDC hDC)
{
int nPixelFormat;

 static PIXELFORMATDESCRIPTOR pfd = {
      sizeof(PIXELFORMATDESCRIPTOR),
      1,
      PFD_DRAW_TO_WINDOW |
      PFD_SUPPORT_OPENGL |
      PFD_DOUBLEBUFFER,
      PFD_TYPE_RGBA,
      32,
      0, 0, 0, 0, 0, 0,
      0,
      0,
      0,
      0, 0, 0, 0,
      16,
      0,
      0,
      PFD_MAIN_PLANE,
      0,
      0, 0, 0 };
 nPixelFormat = ChoosePixelFormat(hDC, &pfd);

 SetPixelFormat(hDC, nPixelFormat, &pfd);

}

LRESULT CALLBACK
WndProc( HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam )
{
static HDC hDC;
static HGLRC hRC;
char string[] = “Hello World!”;
int height, width;

switch ( message ) {

case WM_CREATE:
hDC = GetDC(hWnd);
g_HDC = hDC;
SetupPixelFormat(hDC);

hRC = wglCreateContext(hDC);
wglMakeCurrent(hDC, hRC);

return 0;
break;

case WM_CLOSE:

wglMakeCurrent(hDC, NULL);
wglDeleteContext(hRC);

PostQuitMessage( 0 );

return 0;
break;

case WM_SIZE:
height = HIWORD(lParam);
width = LOWORD(wParam);

if (height==0)
{
     height=1;
}
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();

gluPerspective(45.0f,(GLfloat)width/(GLfloat)height, 1.0f, 1000.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

return 0;
break;

default:
break;

}

 return (DefWindowProc(hWnd, message, wParam, lParam));

}// WinMain

int WINAPI
WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd )
{
WNDCLASSEX wc;
MSG msg;
BOOL bQuit = FALSE;
HWND hWnd;

// register window class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
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 = NULL;
wc.lpszMenuName = NULL;
wc.lpszClassName = “MyClass”;
wc.hIconSm = LoadIcon(NULL, IDI_WINLOGO);

if (!RegisterClassEx(&wc))
return 0;

// create main window
hWnd = CreateWindowEx(
NULL
“MyClass”,
“Triangle”,
WS_OVERLAPPEDWINDOW | WS_VISIBLE |
WS_SYSMENU | WS_CLIPCHILDREN |
WS_CLIPSIBLINGS,
100, 100,
400, 400,
NULL,
NULL,
hInstance,
NULL );

if (!hWnd)
return 0;

ShowWindow(hWnd, SW_SHOW);
UpdateWindow(hWnd);

// program main loop
while ( !bQuit ) {

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

 // handle or dispatch messages
 if ( msg.message == WM_QUIT )
 {
      bQuit = TRUE;
 }
 else
 {
 // OpenGL animation code
 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 glLoadIdentity();

 angle = angle + 0.1f;
 if (angle >= 360.0f)
      angle = 0.0f;
      glTranslatef(0.0f,0.0f,-5.0f);
      glRotatef(angle, 0.0f, 0.0f, 1.0f);

      glColor3f(1.0f, 0.0f, 0.0f);
      glBegin(GL_TRIANGLES);
           glVertex3f(0.0f, 0.0f, 0.0f);
           glVertex3f(1.0f, 0.0f, 0.0f);
           glVertex3f(1.0f, 1.0f, 0.0f);
      glEnd();

      SwapBuffers(g_HDC);

      TranslateMessage(&msg);
      DispatchMessage(&msg);

 }

}

return msg.wParam;

}

hi dude…
i just gave a fasto look to your code (i am at work and my boss doesn’t really like me having fun on GL forums). However… if i were u i’d try to get rid of the gltranslatef (0,0,-5).

for the little i saw, u don’t have any gluLook at function in your code, so the camera should be stick in the origin, focused on the z axis, positive facing.
I am afraid u are actually drawing the triangle, but outside the screen.
Alternatively u may add AFTER the glLoadIdentity part a nice
gluLookAt (0,0,5,0,0,-5,0,1,0);
so u are quite sure that your camera is aiming on the triangle.
Hope it will solve
Bye The Gunslinger

Hey,
thanks for the help, but it STILL doesnt work! Anyway, here is my GL code right now…

//Begin OpenGl code
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt (0,0,5,0,0,-5,0,1,0);

 angle = angle + 0.1f;
 if (angle >= 360.0f)
      angle = 0.0f;
      glRotatef(angle, 0.0f, 0.0f, 1.0f);

      glColor3f(1.0f, 0.0f, 0.0f);
      glBegin(GL_TRIANGLES);
           glVertex3f(0.0f, 0.0f, 0.0f);
           glVertex3f(1.0f, 0.0f, 0.0f);
           glVertex3f(1.0f, 1.0f, 0.0f);
      glEnd();

      SwapBuffers(g_HDC);

      TranslateMessage(&msg);
      DispatchMessage(&msg);

[This message has been edited by Z (edited 12-17-2003).]

quad:

//Begin OpenGl code
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt (0,0,5,0,0,-5,0,1,0);

angle = angle + 0.1f;
if (angle >= 360.0f)
angle = 0.0f;
glRotatef(angle, 0.0f, 0.0f, 1.0f);

glColor3f(1.0f, 0.0f, 0.0f);
glBegin(GL_TRIANGLES);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(1.0f, 0.0f, 0.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glEnd();

SwapBuffers(g_HDC);

Try to put glPushMatrix()and glPopMatrix();
It will look like…

//Begin OpenGl code
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
gluLookAt (0,0,5,0,0,-5,0,1,0);

angle = angle + 0.1f;
if (angle >= 360.0f)
angle = 0.0f;
glPushMatrix();
glRotatef(angle, 0.0f, 0.0f, 1.0f);

glColor3f(1.0f, 0.0f, 0.0f);
glBegin(GL_TRIANGLES);
glVertex3f(0.0f, 0.0f, 0.0f);
glVertex3f(1.0f, 0.0f, 0.0f);
glVertex3f(1.0f, 1.0f, 0.0f);
glEnd();
glPopMatrix();

SwapBuffers(g_HDC);

still doesnt work! maybe its my compiler… I’m using Dev-C++…
If anyone has any suggestions PLEASE reply!

thanks in advance,
~Z~