quesa-develop

full-screen antialiasing support added

[James W. <ja...@fr...>]

I've added support for full-screen antialiasing via the OpenGL 
multisampling feature.  It is implemented for Mac-Carbon and Windows in 
the OpenGL renderer and derived renderers.  However, it's not quite as 
simple as submitting a kQ3AntiAliasModeMaskFullScreen style object. 
When setting up the draw context, you must provide a multisample-capable 
pixel format (by platform-dependent means) as an object property of type 
kQ3DrawContextPropertyGLPixelFormat.

The extra complication is mostly due to Windows.  On Windows, in order 
to get an appropriate function pointer, you must first get a function 
pointer to wglChoosePixelFormatARB, and in order to get that, you must 
already have an OpenGL context set up.  So the typical routine would 
involve creating a dummy window, getting the function pointer, 
destroying the dummy window, and then proceeding to set up the window 
you really want to use.  I didn't want Quesa to get into the business of 
creating and destroying windows.
-- 
   James W. Walker, Innoventive Software LLC
   <http://www.frameforge3d.com/>

Re: full-screen antialiasing support added

[James W. W. <os...@jw...>]

On Dec 11, 2007, at 4:17 PM, James Walker wrote:

> The extra complication is mostly due to Windows.  On Windows, in order
> to get an appropriate function pointer, you must first get a function
> pointer to wglChoosePixelFormatARB, and in order to get that, you must
> already have an OpenGL context set up.

Oops, that should say "On Windows, in order to get an appropriate  
pixel format, you must..."

> So the typical routine would
> involve creating a dummy window, getting the function pointer,
> destroying the dummy window, and then proceeding to set up the window
> you really want to use.  I didn't want Quesa to get into the  
> business of
> creating and destroying windows.

Re: full-screen antialiasing support added

[Jose' C. <cru...@ce...>]

Il giorno 12/dic/07, alle ore 01:17, James Walker ha scritto:

>
> The extra complication is mostly due to Windows.  On Windows, in order
> to get an appropriate function pointer, you must first get a function
> pointer to wglChoosePixelFormatARB, and in order to get that, you must
> already have an OpenGL context set up.  So the typical routine would
> involve creating a dummy window, getting the function pointer,
> destroying the dummy window, and then proceeding to set up the window
> you really want to use.  I didn't want Quesa to get into the =20
> business of
> creating and destroying windows.


can you please post a code snippet of this, (mostly for documentation =20=

purposes)

Pax et Bonum

# Dott. Jos=E9 Cruanyes Aguilar  -  C.E. Soft srl
#  Pzza. Firenze,4 MILANO  -  XX Settembre 10, CREMONA
#   02,3923101                0372,460602

Re: full-screen antialiasing support added

[James W. <ja...@fr...>]

Jose' Cruanyes wrote:
> Il giorno 12/dic/07, alle ore 01:17, James Walker ha scritto:
> 
>> The extra complication is mostly due to Windows.  On Windows, in order
>> to get an appropriate function pointer, you must first get a function
>> pointer to wglChoosePixelFormatARB, and in order to get that, you must
>> already have an OpenGL context set up.  So the typical routine would
>> involve creating a dummy window, getting the function pointer,
>> destroying the dummy window, and then proceeding to set up the window
>> you really want to use.  I didn't want Quesa to get into the  
>> business of
>> creating and destroying windows.
> 
> 
> can you please post a code snippet of this, (mostly for documentation  
> purposes)

OK... I'm not an expert Windows programmer, so I might be doing more 
work than necessary.

static const char*	kWindowClassName	= "dummy";

static HDC		theDC = NULL;

static PFNWGLGETPIXELFORMATATTRIBIVARBPROC	wglGetPixelFormatAttribivARB 
= NULL;


static PFNWGLCHOOSEPIXELFORMATARBPROC	wglChoosePixelFormatARB = NULL;


static void RegisterWindowClass( HINSTANCE inInstance )
{
	WNDCLASSEX wcex;

	wcex.cbSize        = sizeof(WNDCLASSEX);
	wcex.style         = CS_OWNDC;
	wcex.lpfnWndProc   = (WNDPROC) DefWindowProc;
	wcex.cbClsExtra    = 0;
	wcex.cbWndExtra    = 0;
	wcex.hInstance     = inInstance;
	wcex.hIcon         = LoadIcon(NULL, IDI_WINLOGO);
	wcex.hCursor       = LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground = NULL;
	wcex.lpszMenuName  = NULL;
	wcex.lpszClassName = kWindowClassName;
	wcex.hIconSm       = NULL;

	RegisterClassEx(&wcex);
}

void	SetDummyGLContext()
{
	static HGLRC	glContext = NULL;

	if (glContext == NULL)
	{
		HINSTANCE	theInstance = GetModuleHandle( NULL );
		
		RegisterWindowClass( theInstance );
		
		HWND	theWindow = CreateWindow( kWindowClassName, "XDummy",
										WS_OVERLAPPEDWINDOW |
										WS_CLIPCHILDREN     |
										WS_CLIPSIBLINGS,
										400, 30, 40, 40,
										NULL, NULL, theInstance, NULL );

		theDC = GetDC((HWND) theWindow);
		
		
		PIXELFORMATDESCRIPTOR	pixelFormatDesc;
		
		pixelFormatDesc.nSize      = sizeof(pixelFormatDesc);
	    pixelFormatDesc.nVersion   = 1;
	    pixelFormatDesc.dwFlags    = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |
	    	PFD_DOUBLEBUFFER;
	    pixelFormatDesc.cColorBits = 0;
	    pixelFormatDesc.cDepthBits = 24;
	    pixelFormatDesc.cStencilBits = 8;
	    pixelFormatDesc.iPixelType = PFD_TYPE_RGBA;
		
		int pixelFormat = ChoosePixelFormat( theDC, &pixelFormatDesc );
		
		if (pixelFormat != NULL)
		{
			if (SetPixelFormat( theDC, pixelFormat, &pixelFormatDesc))
			{
				glContext = wglCreateContext( theDC );
			}
		}
	}
	
	if (glContext != NULL)
	{
		wglMakeCurrent( theDC, glContext );
	}
}

static bool HasMultisample()
{
	std::string	theExts(" ");
	theExts += (const char*) glGetString( GL_EXTENSIONS );
	theExts += ' ';
	
	bool	hasExt = theExts.find( " GL_ARB_multisample " ) != std::string::npos;
	
	if (not hasExt)
	{
		// OpenGL 1.3 incorporates multisampling.
		std::string	theVers( (const char*) glGetString( GL_VERSION ) );
		
		if ( (theVers[0] > '1') or (theVers[2] >= '3') )
		{
			hasExt = true;
		}
	}
	
	return hasExt;
}

static bool IsMultisampleFormat( HDC inDC, int inPixelFormat )
{
	bool	isMulti = false;
	
	int	atts[2] = {
		WGL_SAMPLE_BUFFERS_ARB,
		WGL_SAMPLES_ARB
	};
	int	values[2];
	
	if (wglGetPixelFormatAttribivARB( inDC, inPixelFormat, 0, 2,
		atts, values ))
	{
		isMulti = (values[0] > 0) and (values[1] > 0);
	}
	
	return isMulti;
}

static int ChoosePixelFormatARB( HDC hdc, const int *piAttribIList )
{
	UINT	numFormats = -1;
	int		theFormat = 0;
	
	if (wglChoosePixelFormatARB( hdc, piAttribIList, NULL, 1, &theFormat,
					&numFormats ))
	{
		if (numFormats == 0)
		{
			theFormat = 0;
			//DebugMsg("No multisample formats available");
		}
		else
		{
			if (not IsMultisampleFormat( hdc, theFormat ))
			{
				theFormat = 0;	// not sure if this can happen
			}
		}
	}
	else
	{
		DWORD	err = GetLastError();
		char	xmsg[100];
		std::sprintf( xmsg, "wglChoosePixelFormatARB failed with error %X.", 
err );
		DebugMsg(xmsg);
	}
	
	return theFormat;
}


static int ChooseWinMultisampleFormat()
{
	int	theFormat = 0;
	
	SetDummyGLContext();

	if (not HasMultisample())
	{
		return theFormat;
	}
	
	PFNWGLGETEXTENSIONSSTRINGARBPROC	wglGetExtensionsStringARB =
		(PFNWGLGETEXTENSIONSSTRINGARBPROC)
		wglGetProcAddress("wglGetExtensionsStringARB");
	
	if (wglGetExtensionsStringARB != NULL)
	{
		HDC	theDC = GetDummyDC();
		
		std::string	extStr(" ");
		extStr += (char*)wglGetExtensionsStringARB( theDC );
		extStr += ' ';
		
		if (extStr.find( " WGL_ARB_pixel_format " ) != std::string::npos)
		{
			wglChoosePixelFormatARB =
				(PFNWGLCHOOSEPIXELFORMATARBPROC)
				wglGetProcAddress( "wglChoosePixelFormatARB" );
			
			wglGetPixelFormatAttribivARB =
				(PFNWGLGETPIXELFORMATATTRIBIVARBPROC)
				wglGetProcAddress( "wglGetPixelFormatAttribivARB" );
			
			int	atts[] =
			{
				WGL_SAMPLES_ARB, 4,	// keep this first!
				WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
				WGL_DRAW_TO_WINDOW_ARB, GL_TRUE,
				WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
				WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB,
				WGL_SAMPLE_BUFFERS_ARB, 1,
				WGL_DEPTH_BITS_ARB, 24,
				WGL_STENCIL_BITS_ARB, 8,
				0, 0
			};
			
			theFormat = ChoosePixelFormatARB( theDC, atts );
			
			if ( theFormat == 0 )
			{
				atts[1] = 2;	// WGL_SAMPLES_ARB value
				
				theFormat = ChoosePixelFormatARB( theDC, atts );
			}
		}
	}
	
	return theFormat;
}


-- 
   James W. Walker, Innoventive Software LLC
   <http://www.frameforge3d.com/>

Re: full-screen antialiasing support added

[James W. <ja...@fr...>]

Jose' Cruanyes wrote:
> Il giorno 12/dic/07, alle ore 01:17, James Walker ha scritto:
> 
>> The extra complication is mostly due to Windows.  On Windows, in order
>> to get an appropriate function pointer, you must first get a function
>> pointer to wglChoosePixelFormatARB, and in order to get that, you must
>> already have an OpenGL context set up.  So the typical routine would
>> involve creating a dummy window, getting the function pointer,
>> destroying the dummy window, and then proceeding to set up the window
>> you really want to use.  I didn't want Quesa to get into the  
>> business of
>> creating and destroying windows.
> 
> 
> can you please post a code snippet of this, (mostly for documentation  
> purposes)

OK... I'm not an expert Windows programmer, so I might be doing more
work than necessary.

static const char*	kWindowClassName	= "dummy";

static HDC		theDC = NULL;

static PFNWGLGETPIXELFORMATATTRIBIVARBPROC	wglGetPixelFormatAttribivARB
= NULL;


static PFNWGLCHOOSEPIXELFORMATARBPROC	wglChoosePixelFormatARB = NULL;


static void RegisterWindowClass( HINSTANCE inInstance )
{
	WNDCLASSEX wcex;

	wcex.cbSize        = sizeof(WNDCLASSEX);
	wcex.style         = CS_OWNDC;
	wcex.lpfnWndProc   = (WNDPROC) DefWindowProc;
	wcex.cbClsExtra    = 0;
	wcex.cbWndExtra    = 0;
	wcex.hInstance     = inInstance;
	wcex.hIcon         = LoadIcon(NULL, IDI_WINLOGO);
	wcex.hCursor       = LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground = NULL;
	wcex.lpszMenuName  = NULL;
	wcex.lpszClassName = kWindowClassName;
	wcex.hIconSm       = NULL;

	RegisterClassEx(&wcex);
}

void	SetDummyGLContext()
{
	static HGLRC	glContext = NULL;

	if (glContext == NULL)
	{
		HINSTANCE	theInstance = GetModuleHandle( NULL );
		
		RegisterWindowClass( theInstance );
		
		HWND	theWindow = CreateWindow( kWindowClassName, "XDummy",
										WS_OVERLAPPEDWINDOW |
										WS_CLIPCHILDREN     |
										WS_CLIPSIBLINGS,
										400, 30, 40, 40,
										NULL, NULL, theInstance, NULL );

		theDC = GetDC((HWND) theWindow);
		
		
		PIXELFORMATDESCRIPTOR	pixelFormatDesc;
		
		pixelFormatDesc.nSize      = sizeof(pixelFormatDesc);
	    pixelFormatDesc.nVersion   = 1;
	    pixelFormatDesc.dwFlags    = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |
	    	PFD_DOUBLEBUFFER;
	    pixelFormatDesc.cColorBits = 0;
	    pixelFormatDesc.cDepthBits = 24;
	    pixelFormatDesc.cStencilBits = 8;
	    pixelFormatDesc.iPixelType = PFD_TYPE_RGBA;
		
		int pixelFormat = ChoosePixelFormat( theDC, &pixelFormatDesc );
		
		if (pixelFormat != NULL)
		{
			if (SetPixelFormat( theDC, pixelFormat, &pixelFormatDesc))
			{
				glContext = wglCreateContext( theDC );
			}
		}
	}
	
	if (glContext != NULL)
	{
		wglMakeCurrent( theDC, glContext );
	}
}

static bool HasMultisample()
{
	std::string	theExts(" ");
	theExts += (const char*) glGetString( GL_EXTENSIONS );
	theExts += ' ';
	
	bool	hasExt = theExts.find( " GL_ARB_multisample " ) != std::string::npos;
	
	if (not hasExt)
	{
		// OpenGL 1.3 incorporates multisampling.
		std::string	theVers( (const char*) glGetString( GL_VERSION ) );
		
		if ( (theVers[0] > '1') or (theVers[2] >= '3') )
		{
			hasExt = true;
		}
	}
	
	return hasExt;
}

static bool IsMultisampleFormat( HDC inDC, int inPixelFormat )
{
	bool	isMulti = false;
	
	int	atts[2] = {
		WGL_SAMPLE_BUFFERS_ARB,
		WGL_SAMPLES_ARB
	};
	int	values[2];
	
	if (wglGetPixelFormatAttribivARB( inDC, inPixelFormat, 0, 2,
		atts, values ))
	{
		isMulti = (values[0] > 0) and (values[1] > 0);
	}
	
	return isMulti;
}

static int ChoosePixelFormatARB( HDC hdc, const int *piAttribIList )
{
	UINT	numFormats = -1;
	int		theFormat = 0;
	
	if (wglChoosePixelFormatARB( hdc, piAttribIList, NULL, 1, &theFormat,
					&numFormats ))
	{
		if (numFormats == 0)
		{
			theFormat = 0;
			//DebugMsg("No multisample formats available");
		}
		else
		{
			if (not IsMultisampleFormat( hdc, theFormat ))
			{
				theFormat = 0;	// not sure if this can happen
			}
		}
	}
	else
	{
		DWORD	err = GetLastError();
		char	xmsg[100];
		std::sprintf( xmsg, "wglChoosePixelFormatARB failed with error %X.",
err );
		DebugMsg(xmsg);
	}
	
	return theFormat;
}


static int ChooseWinMultisampleFormat()
{
	int	theFormat = 0;
	
	SetDummyGLContext();

	if (not HasMultisample())
	{
		return theFormat;
	}
	
	PFNWGLGETEXTENSIONSSTRINGARBPROC	wglGetExtensionsStringARB =
		(PFNWGLGETEXTENSIONSSTRINGARBPROC)
		wglGetProcAddress("wglGetExtensionsStringARB");
	
	if (wglGetExtensionsStringARB != NULL)
	{
		HDC	theDC = GetDummyDC();
		
		std::string	extStr(" ");
		extStr += (char*)wglGetExtensionsStringARB( theDC );
		extStr += ' ';
		
		if (extStr.find( " WGL_ARB_pixel_format " ) != std::string::npos)
		{
			wglChoosePixelFormatARB =
				(PFNWGLCHOOSEPIXELFORMATARBPROC)
				wglGetProcAddress( "wglChoosePixelFormatARB" );
			
			wglGetPixelFormatAttribivARB =
				(PFNWGLGETPIXELFORMATATTRIBIVARBPROC)
				wglGetProcAddress( "wglGetPixelFormatAttribivARB" );
			
			int	atts[] =
			{
				WGL_SAMPLES_ARB, 4,	// keep this first!
				WGL_DOUBLE_BUFFER_ARB, GL_TRUE,
				WGL_DRAW_TO_WINDOW_ARB, GL_TRUE,
				WGL_SUPPORT_OPENGL_ARB, GL_TRUE,
				WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB,
				WGL_SAMPLE_BUFFERS_ARB, 1,
				WGL_DEPTH_BITS_ARB, 24,
				WGL_STENCIL_BITS_ARB, 8,
				0, 0
			};
			
			theFormat = ChoosePixelFormatARB( theDC, atts );
			
			if ( theFormat == 0 )
			{
				atts[1] = 2;	// WGL_SAMPLES_ARB value
				
				theFormat = ChoosePixelFormatARB( theDC, atts );
			}
		}
	}
	
	return theFormat;
}


-- 
   James W. Walker, Innoventive Software LLC
   <http://www.frameforge3d.com/>