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Objects only appearing white in OpenGL?


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#1 Varien   Members   -  Reputation: 109

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Posted 20 May 2012 - 11:09 AM

I've just gotten started in 3D programming, and have tried learning as much as I can, and it's been working pretty well. The issue I'm having is, as the title suggests, any objects I try and instantiate in my test environment are only appearing white. This isn't an issue I used to have. In the last tutorial I followed, it covered texture mapping, and everything worked fine, I had a cube that had textures mapped to its' surfaces, and all was right with the world. Only after I followed the next tutorial in the series, here: http://nehe.gamedev...._control/15002/, did I have this problem (NOTE: the "LoadGLTextures()" int in the tutorial is outdated! Using SOIL is a much easier alternative that the person who wrote the tutorial even asks you to use in the texture mapping tutorial). I'm not sure what I added to cause the objects to appear white, but it has to be something in that tutorial I linked.

Now, I've looked all through that tutorial, and I can't see anything that I added that would have caused this. I even copy/pasted the tutorials' code into my project to test it, then deleted it afterwards, and there was still nothing but a white cube being displayed.

Does ANYONE know how to fix this?

Code:
#include <windows.h>
#include <stdio.h>
#include <SDL\gl.h>  
#include <SDL\glu.h>
#include <SDL\glaux.h>
#include <SDL\SOIL.h>
HDC   hDC=NULL;
HGLRC  hRC=NULL;
HWND  hWnd=NULL;
HINSTANCE hInstance;
bool keys[256];
bool active=TRUE;
bool fullscreen=TRUE;
bool light;
bool lp, fp;
GLfloat xrot;
GLfloat yrot;
GLfloat xspeed;
GLfloat yspeed;
GLfloat z=-5.0f;
GLfloat LightAmbient[]={0.5f,0.5f,0.5f,1.0f};
GLfloat LightDiffuse[]={1.0f,1.0f,1.0f,1.0f};
GLfloat LightPosition[]={0.0f,0.0f,2.0f,1.0f};
GLuint filter;
GLuint texture[3];
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int LoadGLTextures(){
	texture[0]=SOIL_load_OGL_texture("Resources/Crate.bmp",SOIL_LOAD_AUTO,SOIL_CREATE_NEW_ID,SOIL_FLAG_INVERT_Y);
	if(texture[0]==0){return false;}
	glGenTextures(3,&texture[0]);
glBindTexture(GL_TEXTURE_2D, texture[0]);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
  glBindTexture(GL_TEXTURE_2D, texture[1]);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);

  glBindTexture(GL_TEXTURE_2D, texture[2]);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
  glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);

  
	return true;
	}
GLvoid ReSizeGLScene(GLsizei width, GLsizei height){
	if (height==0){height=1;}
	glViewport(0,0,width,height);
glMatrixMode(GL_PROJECTION);	
glLoadIdentity();
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
glMatrixMode(GL_MODELVIEW);	  
glLoadIdentity();	  
}
int InitGL(GLvoid){
	if(!LoadGLTextures()){return false;}
	glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);	
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);  
glClearDepth(1.0f);	  
glEnable(GL_DEPTH_TEST);	
glDepthFunc(GL_LEQUAL);	  
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);
glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);
glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);
glEnable(GL_LIGHT1);
return true;		
}
int DrawGLScene(GLvoid){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
	glTranslatef(0.0f,0.0f,z);
	glRotatef(xrot,1.0f,0.0f,0.0f);
	glRotatef(yrot,0.0f,1.0f,0.0f);
  
	glBindTexture(GL_TEXTURE_2D, texture[filter]);
	glBegin(GL_QUADS);
	  glNormal3f( 0.0f, 0.0f, 1.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
  // Back Face
  glNormal3f( 0.0f, 0.0f,-1.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
  // Top Face
  glNormal3f( 0.0f, 1.0f, 0.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
  // Bottom Face
  glNormal3f( 0.0f,-1.0f, 0.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
  // Right face
  glNormal3f( 1.0f, 0.0f, 0.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
  // Left Face
  glNormal3f(-1.0f, 0.0f, 0.0f);
  glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
  glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
  glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
  glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
	glEnd();
  
	xrot+=xspeed;
	yrot+=yspeed;
return true;		
}
GLvoid KillGLWindow(GLvoid){
if(fullscreen)		
{ChangeDisplaySettings(NULL,0);	
  ShowCursor(TRUE);}
if(hRC)		
{if(!wglMakeCurrent(NULL,NULL)){
   MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);}
		if (!wglDeleteContext(hRC)){
   MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);}
  hRC=NULL;}
	if(hDC && !ReleaseDC(hWnd,hDC))	
{MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
  hDC=NULL;}
	if (hWnd && !DestroyWindow(hWnd))	
{MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
  hWnd=NULL;}
	if(!UnregisterClass("OpenGL",hInstance)){
  MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
  hInstance=NULL;}}

BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag){
GLuint  PixelFormat;  
WNDCLASS wc;	
DWORD  dwExStyle;  
DWORD  dwStyle;  
RECT  WindowRect;  
WindowRect.left=(long)0;  
WindowRect.right=(long)width;
WindowRect.top=(long)0;  
WindowRect.bottom=(long)height;
fullscreen=fullscreenflag;  
hInstance   = GetModuleHandle(NULL);  
wc.style   = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wc.lpfnWndProc  = (WNDPROC) WndProc;	
wc.cbClsExtra  = 0;	  
wc.cbWndExtra  = 0;		
wc.hInstance  = hInstance;	
wc.hIcon   = LoadIcon(NULL, IDI_WINLOGO);
wc.hCursor   = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = NULL;	  
wc.lpszMenuName  = NULL;	  
wc.lpszClassName = "OpenGL";	  
if (!RegisterClass(&wc)){
  MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return FALSE;}

if (fullscreen){
  DEVMODE dmScreenSettings;	  
  memset(&dmScreenSettings,0,sizeof(dmScreenSettings));
  dmScreenSettings.dmSize=sizeof(dmScreenSettings);
  dmScreenSettings.dmPelsWidth = width;  
  dmScreenSettings.dmPelsHeight = height;  
  dmScreenSettings.dmBitsPerPel = bits;	
  dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;
  if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL){
   if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By\nYour Video Card. Use Windowed Mode Instead?","NeHe GL",MB_YESNO|MB_ICONEXCLAMATION)==IDYES){
	fullscreen=FALSE;}
   else{
	MessageBox(NULL,"Program Will Now Close.","ERROR",MB_OK|MB_ICONSTOP);
	return false;}}}
if (fullscreen){
  dwExStyle=WS_EX_APPWINDOW;	  
  dwStyle=WS_POPUP;		
  ShowCursor(FALSE);}
else{
  dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;  
  dwStyle=WS_OVERLAPPEDWINDOW;}
AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);
// Create The Window
if (!(hWnd=CreateWindowEx( dwExStyle,	
		"OpenGL",	  
		title,	  
		dwStyle |	
		WS_CLIPSIBLINGS |	
		WS_CLIPCHILDREN,  
		0, 0,	  
		WindowRect.right-WindowRect.left,
		WindowRect.bottom-WindowRect.top,
		NULL,	  
		NULL,	  
		hInstance,	  
		NULL))){
  KillGLWindow();	  
  MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return FALSE;}
static PIXELFORMATDESCRIPTOR pfd={
  sizeof(PIXELFORMATDESCRIPTOR),	// Size Of This Pixel Format Descriptor
  1,		   // Version Number
  PFD_DRAW_TO_WINDOW |	  // Format Must Support Window
  PFD_SUPPORT_OPENGL |	  // Format Must Support OpenGL
  PFD_DOUBLEBUFFER,	   // Must Support Double Buffering
  PFD_TYPE_RGBA,		// Request An RGBA Format
  bits,		  // Select Our Color Depth
  0, 0, 0, 0, 0, 0,	   // Color Bits Ignored
  0,		   // No Alpha Buffer
  0,		   // Shift Bit Ignored
  0,		   // No Accumulation Buffer
  0, 0, 0, 0,		 // Accumulation Bits Ignored
  16,		   // 16Bit Z-Buffer (Depth Buffer)
  0,		   // No Stencil Buffer
  0,		   // No Auxiliary Buffer
  PFD_MAIN_PLANE,		// Main Drawing Layer
  0,		   // Reserved
  0, 0, 0		  // Layer Masks Ignored
};

if (!(hDC=GetDC(hWnd))){
  KillGLWindow();	  
  MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return false;}
if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd))){
  KillGLWindow();	  
  MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return false;}
if(!SetPixelFormat(hDC,PixelFormat,&pfd)){
  KillGLWindow();	  
  MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return false;}
if (!(hRC=wglCreateContext(hDC))){
  KillGLWindow();	  
  MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return false;}
if(!wglMakeCurrent(hDC,hRC)){
  KillGLWindow();	  
  MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return false;}
ShowWindow(hWnd,SW_SHOW);	
SetForegroundWindow(hWnd);	
SetFocus(hWnd);		
ReSizeGLScene(width, height);	
if (!InitGL()){
  KillGLWindow();	  
  MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
  return FALSE;}
return true;}
LRESULT CALLBACK WndProc(HWND hWnd,UINT uMsg,WPARAM wParam,LPARAM lParam){
switch (uMsg){
  case WM_ACTIVATE:{
   if (!HIWORD(wParam)){
	active=TRUE;}
   else{
	active=FALSE;}
   return 0;}
  case WM_SYSCOMMAND:{
   switch (wParam){
	case SC_SCREENSAVE:	
	case SC_MONITORPOWER:  
	return 0;}
   break;}
  case WM_CLOSE:{
   PostQuitMessage(0);	
   return 0;}
  case WM_KEYDOWN:{
			 keys[wParam] = TRUE;	
   return 0;}
  case WM_KEYUP:{
   keys[wParam] = FALSE;	
   return 0;}
  case WM_SIZE:{
   ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));
   return 0;}}

return DefWindowProc(hWnd,uMsg,wParam,lParam);
}
int WINAPI WinMain( HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow){  
	MSG  msg;	  
BOOL done=FALSE;  
if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO){fullscreen=FALSE;}
if (!CreateGLWindow("OpenGL Game Testing Framework",640,480,16,fullscreen)){return 0;}
while(!done){if (PeekMessage(&msg,NULL,0,0,PM_REMOVE)){
   if (msg.message==WM_QUIT){done=TRUE;}
   else{TranslateMessage(&msg);  
		DispatchMessage(&msg);}}
	  else{if (active){if (keys[VK_ESCAPE]){
	 done=TRUE;}
   else{DrawGLScene();  
		SwapBuffers(hDC);
				if (keys['L'] && !lp){
					lp=TRUE;
	 light=!light;
	 if (!light){glDisable(GL_LIGHTING);}
	 else{glEnable(GL_LIGHTING);}}
	if (!keys['L']){lp=FALSE;}
  
				 if(keys['F']&&!fp){fp=true;
									filter+=1;
									if(filter>2){filter=0;}}
				 if(!keys['F']){fp=false;}
				 if(keys[VK_PRIOR]){z-=0.02f;}
				 if(keys[VK_NEXT]){z+=0.02f;}
				 if(keys[VK_UP]){xspeed-=0.01f;}
				 if(keys[VK_DOWN]){xspeed+=0.01f;}
				 if(keys[VK_RIGHT]){yspeed+=0.01f;}
				 if(keys[VK_LEFT]){yspeed-=0.01f;}
				 if(keys['Q']){xspeed=0.0f;
							   yspeed=0.0f;}
				 }}
   if (keys[VK_F1])	
   {keys[VK_F1]=FALSE;  
	KillGLWindow();	
	fullscreen=!fullscreen;  
	if (!CreateGLWindow("OpenGL Game Testing Framework",640,480,16,fullscreen)){return 0;}}}}
KillGLWindow();		
return (msg.wParam);	  
}

Edited by Varien, 20 May 2012 - 12:51 PM.


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#2 Varien   Members   -  Reputation: 109

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Posted 20 May 2012 - 12:50 PM

Problem solved.

When I was just about to give up on finding the error for now, I found out it had issues with the glGenTextures() command, it won't work for my version of the tutorials' project seeing as he passes as parameter to the section glGenTextures() is in, causing it to create 3 different textures stored in texture[0], texture[1], and texture[2]. Mine doesn't pass any of those parameters, but instead only stores "Crate.bmp" into textures[0], so when it's overwritten by glGenTextures(), it's overwritten with a blank mesh. Bit of an obscure error, but at least I fixed it.




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