win_glimp.c

quakeIII源码这个不用我多说吧

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
/*
** WIN_GLIMP.C
**
** This file contains ALL Win32 specific stuff having to do with the
** OpenGL refresh.  When a port is being made the following functions
** must be implemented by the port:
**
** GLimp_EndFrame
** GLimp_Init
** GLimp_LogComment
** GLimp_Shutdown
**
** Note that the GLW_xxx functions are Windows specific GL-subsystem
** related functions that are relevant ONLY to win_glimp.c
*/
#include <assert.h>
#include "../renderer/tr_local.h"
#include "../qcommon/qcommon.h"
#include "resource.h"
#include "glw_win.h"
#include "win_local.h"

extern void WG_CheckHardwareGamma( void );
extern void WG_RestoreGamma( void );

typedef enum {
	RSERR_OK,

	RSERR_INVALID_FULLSCREEN,
	RSERR_INVALID_MODE,

	RSERR_UNKNOWN
} rserr_t;

#define TRY_PFD_SUCCESS		0
#define TRY_PFD_FAIL_SOFT	1
#define TRY_PFD_FAIL_HARD	2

#define	WINDOW_CLASS_NAME	"Quake 3: Arena"

static void		GLW_InitExtensions( void );
static rserr_t	GLW_SetMode( const char *drivername, 
							 int mode, 
							 int colorbits, 
							 qboolean cdsFullscreen );

static qboolean s_classRegistered = qfalse;

//
// function declaration
//
void	 QGL_EnableLogging( qboolean enable );
qboolean QGL_Init( const char *dllname );
void     QGL_Shutdown( void );

//
// variable declarations
//
glwstate_t glw_state;

cvar_t	*r_allowSoftwareGL;		// don't abort out if the pixelformat claims software
cvar_t	*r_maskMinidriver;		// allow a different dll name to be treated as if it were opengl32.dll



/*
** GLW_StartDriverAndSetMode
*/
static qboolean GLW_StartDriverAndSetMode( const char *drivername, 
										   int mode, 
										   int colorbits,
										   qboolean cdsFullscreen )
{
	rserr_t err;

	err = GLW_SetMode( drivername, r_mode->integer, colorbits, cdsFullscreen );

	switch ( err )
	{
	case RSERR_INVALID_FULLSCREEN:
		ri.Printf( PRINT_ALL, "...WARNING: fullscreen unavailable in this mode\n" );
		return qfalse;
	case RSERR_INVALID_MODE:
		ri.Printf( PRINT_ALL, "...WARNING: could not set the given mode (%d)\n", mode );
		return qfalse;
	default:
		break;
	}
	return qtrue;
}

/*
** ChoosePFD
**
** Helper function that replaces ChoosePixelFormat.
*/
#define MAX_PFDS 256

static int GLW_ChoosePFD( HDC hDC, PIXELFORMATDESCRIPTOR *pPFD )
{
	PIXELFORMATDESCRIPTOR pfds[MAX_PFDS+1];
	int maxPFD = 0;
	int i;
	int bestMatch = 0;

	ri.Printf( PRINT_ALL, "...GLW_ChoosePFD( %d, %d, %d )\n", ( int ) pPFD->cColorBits, ( int ) pPFD->cDepthBits, ( int ) pPFD->cStencilBits );

	// count number of PFDs
	if ( glConfig.driverType > GLDRV_ICD )
	{
		maxPFD = qwglDescribePixelFormat( hDC, 1, sizeof( PIXELFORMATDESCRIPTOR ), &pfds[0] );
	}
	else
	{
		maxPFD = DescribePixelFormat( hDC, 1, sizeof( PIXELFORMATDESCRIPTOR ), &pfds[0] );
	}
	if ( maxPFD > MAX_PFDS )
	{
		ri.Printf( PRINT_WARNING, "...numPFDs > MAX_PFDS (%d > %d)\n", maxPFD, MAX_PFDS );
		maxPFD = MAX_PFDS;
	}

	ri.Printf( PRINT_ALL, "...%d PFDs found\n", maxPFD - 1 );

	// grab information
	for ( i = 1; i <= maxPFD; i++ )
	{
		if ( glConfig.driverType > GLDRV_ICD )
		{
			qwglDescribePixelFormat( hDC, i, sizeof( PIXELFORMATDESCRIPTOR ), &pfds[i] );
		}
		else
		{
			DescribePixelFormat( hDC, i, sizeof( PIXELFORMATDESCRIPTOR ), &pfds[i] );
		}
	}

	// look for a best match
	for ( i = 1; i <= maxPFD; i++ )
	{
		//
		// make sure this has hardware acceleration
		//
		if ( ( pfds[i].dwFlags & PFD_GENERIC_FORMAT ) != 0 ) 
		{
			if ( !r_allowSoftwareGL->integer )
			{
				if ( r_verbose->integer )
				{
					ri.Printf( PRINT_ALL, "...PFD %d rejected, software acceleration\n", i );
				}
				continue;
			}
		}

		// verify pixel type
		if ( pfds[i].iPixelType != PFD_TYPE_RGBA )
		{
			if ( r_verbose->integer )
			{
				ri.Printf( PRINT_ALL, "...PFD %d rejected, not RGBA\n", i );
			}
			continue;
		}

		// verify proper flags
		if ( ( ( pfds[i].dwFlags & pPFD->dwFlags ) & pPFD->dwFlags ) != pPFD->dwFlags ) 
		{
			if ( r_verbose->integer )
			{
				ri.Printf( PRINT_ALL, "...PFD %d rejected, improper flags (%x instead of %x)\n", i, pfds[i].dwFlags, pPFD->dwFlags );
			}
			continue;
		}

		// verify enough bits
		if ( pfds[i].cDepthBits < 15 )
		{
			continue;
		}
		if ( ( pfds[i].cStencilBits < 4 ) && ( pPFD->cStencilBits > 0 ) )
		{
			continue;
		}

		//
		// selection criteria (in order of priority):
		// 
		//  PFD_STEREO
		//  colorBits
		//  depthBits
		//  stencilBits
		//
		if ( bestMatch )
		{
			// check stereo
			if ( ( pfds[i].dwFlags & PFD_STEREO ) && ( !( pfds[bestMatch].dwFlags & PFD_STEREO ) ) && ( pPFD->dwFlags & PFD_STEREO ) )
			{
				bestMatch = i;
				continue;
			}
			
			if ( !( pfds[i].dwFlags & PFD_STEREO ) && ( pfds[bestMatch].dwFlags & PFD_STEREO ) && ( pPFD->dwFlags & PFD_STEREO ) )
			{
				bestMatch = i;
				continue;
			}

			// check color
			if ( pfds[bestMatch].cColorBits != pPFD->cColorBits )
			{
				// prefer perfect match
				if ( pfds[i].cColorBits == pPFD->cColorBits )
				{
					bestMatch = i;
					continue;
				}
				// otherwise if this PFD has more bits than our best, use it
				else if ( pfds[i].cColorBits > pfds[bestMatch].cColorBits )
				{
					bestMatch = i;
					continue;
				}
			}

			// check depth
			if ( pfds[bestMatch].cDepthBits != pPFD->cDepthBits )
			{
				// prefer perfect match
				if ( pfds[i].cDepthBits == pPFD->cDepthBits )
				{
					bestMatch = i;
					continue;
				}
				// otherwise if this PFD has more bits than our best, use it
				else if ( pfds[i].cDepthBits > pfds[bestMatch].cDepthBits )
				{
					bestMatch = i;
					continue;
				}
			}

			// check stencil
			if ( pfds[bestMatch].cStencilBits != pPFD->cStencilBits )
			{
				// prefer perfect match
				if ( pfds[i].cStencilBits == pPFD->cStencilBits )
				{
					bestMatch = i;
					continue;
				}
				// otherwise if this PFD has more bits than our best, use it
				else if ( ( pfds[i].cStencilBits > pfds[bestMatch].cStencilBits ) && 
					 ( pPFD->cStencilBits > 0 ) )
				{
					bestMatch = i;
					continue;
				}
			}
		}
		else
		{
			bestMatch = i;
		}
	}
	
	if ( !bestMatch )
		return 0;

	if ( ( pfds[bestMatch].dwFlags & PFD_GENERIC_FORMAT ) != 0 )
	{
		if ( !r_allowSoftwareGL->integer )
		{
			ri.Printf( PRINT_ALL, "...no hardware acceleration found\n" );
			return 0;
		}
		else
		{
			ri.Printf( PRINT_ALL, "...using software emulation\n" );
		}
	}
	else if ( pfds[bestMatch].dwFlags & PFD_GENERIC_ACCELERATED )
	{
		ri.Printf( PRINT_ALL, "...MCD acceleration found\n" );
	}
	else
	{
		ri.Printf( PRINT_ALL, "...hardware acceleration found\n" );
	}

	*pPFD = pfds[bestMatch];

	return bestMatch;
}

/*
** void GLW_CreatePFD
**
** Helper function zeros out then fills in a PFD
*/
static void GLW_CreatePFD( PIXELFORMATDESCRIPTOR *pPFD, int colorbits, int depthbits, int stencilbits, qboolean stereo )
{
    PIXELFORMATDESCRIPTOR src = 
	{
		sizeof(PIXELFORMATDESCRIPTOR),	// size of this pfd
		1,								// version number
		PFD_DRAW_TO_WINDOW |			// support window
		PFD_SUPPORT_OPENGL |			// support OpenGL
		PFD_DOUBLEBUFFER,				// double buffered
		PFD_TYPE_RGBA,					// RGBA type
		24,								// 24-bit 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, 					// accum bits ignored
		24,								// 24-bit z-buffer	
		8,								// 8-bit stencil buffer
		0,								// no auxiliary buffer
		PFD_MAIN_PLANE,					// main layer
		0,								// reserved
		0, 0, 0							// layer masks ignored
    };

	src.cColorBits = colorbits;
	src.cDepthBits = depthbits;
	src.cStencilBits = stencilbits;

	if ( stereo )
	{
		ri.Printf( PRINT_ALL, "...attempting to use stereo\n" );
		src.dwFlags |= PFD_STEREO;
		glConfig.stereoEnabled = qtrue;
	}
	else
	{
		glConfig.stereoEnabled = qfalse;
	}

	*pPFD = src;
}

/*
** GLW_MakeContext
*/
static int GLW_MakeContext( PIXELFORMATDESCRIPTOR *pPFD )
{
	int pixelformat;

	//
	// don't putz around with pixelformat if it's already set (e.g. this is a soft
	// reset of the graphics system)
	//
	if ( !glw_state.pixelFormatSet )
	{
		//
		// choose, set, and describe our desired pixel format.  If we're
		// using a minidriver then we need to bypass the GDI functions,
		// otherwise use the GDI functions.
		//
		if ( ( pixelformat = GLW_ChoosePFD( glw_state.hDC, pPFD ) ) == 0 )
		{
			ri.Printf( PRINT_ALL, "...GLW_ChoosePFD failed\n");
			return TRY_PFD_FAIL_SOFT;
		}
		ri.Printf( PRINT_ALL, "...PIXELFORMAT %d selected\n", pixelformat );

		if ( glConfig.driverType > GLDRV_ICD )
		{
			qwglDescribePixelFormat( glw_state.hDC, pixelformat, sizeof( *pPFD ), pPFD );
			if ( qwglSetPixelFormat( glw_state.hDC, pixelformat, pPFD ) == FALSE )
			{
				ri.Printf ( PRINT_ALL, "...qwglSetPixelFormat failed\n");
				return TRY_PFD_FAIL_SOFT;
			}
		}
		else
		{
			DescribePixelFormat( glw_state.hDC, pixelformat, sizeof( *pPFD ), pPFD );

			if ( SetPixelFormat( glw_state.hDC, pixelformat, pPFD ) == FALSE )
			{
				ri.Printf (PRINT_ALL, "...SetPixelFormat failed\n", glw_state.hDC );
				return TRY_PFD_FAIL_SOFT;
			}
		}

		glw_state.pixelFormatSet = qtrue;
	}

	//
	// startup the OpenGL subsystem by creating a context and making it current
	//
	if ( !glw_state.hGLRC )
	{
		ri.Printf( PRINT_ALL, "...creating GL context: " );
		if ( ( glw_state.hGLRC = qwglCreateContext( glw_state.hDC ) ) == 0 )
		{
			ri.Printf (PRINT_ALL, "failed\n");

			return TRY_PFD_FAIL_HARD;
		}
		ri.Printf( PRINT_ALL, "succeeded\n" );

		ri.Printf( PRINT_ALL, "...making context current: " );
		if ( !qwglMakeCurrent( glw_state.hDC, glw_state.hGLRC ) )
		{
			qwglDeleteContext( glw_state.hGLRC );
			glw_state.hGLRC = NULL;
			ri.Printf (PRINT_ALL, "failed\n");
			return TRY_PFD_FAIL_HARD;
		}
		ri.Printf( PRINT_ALL, "succeeded\n" );
	}

	return TRY_PFD_SUCCESS;
}


/*
** GLW_InitDriver
**
** - get a DC if one doesn't exist
** - create an HGLRC if one doesn't exist
*/
static qboolean GLW_InitDriver( const char *drivername, int colorbits )
{
	int		tpfd;
	int		depthbits, stencilbits;
	static PIXELFORMATDESCRIPTOR pfd;		// save between frames since 'tr' gets cleared

	ri.Printf( PRINT_ALL, "Initializing OpenGL driver\n" );

	//
	// get a DC for our window if we don't already have one allocated
	//
	if ( glw_state.hDC == NULL )
	{
		ri.Printf( PRINT_ALL, "...getting DC: " );

		if ( ( glw_state.hDC = GetDC( g_wv.hWnd ) ) == NULL )
		{
			ri.Printf( PRINT_ALL, "failed\n" );
			return qfalse;
		}
		ri.Printf( PRINT_ALL, "succeeded\n" );
	}

	if ( colorbits == 0 )
	{
		colorbits = glw_state.desktopBitsPixel;
	}

	//
	// implicitly assume Z-buffer depth == desktop color depth
	//
	if ( r_depthbits->integer == 0 ) {
		if ( colorbits > 16 ) {
			depthbits = 24;
		} else {
			depthbits = 16;
		}
	} else {
		depthbits = r_depthbits->integer;
	}

	//
	// do not allow stencil if Z-buffer depth likely won't contain it
	//
	stencilbits = r_stencilbits->integer;
	if ( depthbits < 24 )
	{
		stencilbits = 0;
	}

	//
	// make two attempts to set the PIXELFORMAT
	//

	//
	// first attempt: r_colorbits, depthbits, and r_stencilbits
	//
	if ( !glw_state.pixelFormatSet )
	{
		GLW_CreatePFD( &pfd, colorbits, depthbits, stencilbits, r_stereo->integer );
		if ( ( tpfd = GLW_MakeContext( &pfd ) ) != TRY_PFD_SUCCESS )
		{
			if ( tpfd == TRY_PFD_FAIL_HARD )
			{
				ri.Printf( PRINT_WARNING, "...failed hard\n" );
				return qfalse;
			}

			//
			// punt if we've already tried the desktop bit depth and no stencil bits
			//
			if ( ( r_colorbits->integer == glw_state.desktopBitsPixel ) &&
				 ( stencilbits == 0 ) )
			{
				ReleaseDC( g_wv.hWnd, glw_state.hDC );
				glw_state.hDC = NULL;

				ri.Printf( PRINT_ALL, "...failed to find an appropriate PIXELFORMAT\n" );

				return qfalse;
			}

			//
			// second attempt: desktop's color bits and no stencil
			//
			if ( colorbits > glw_state.desktopBitsPixel )
			{
				colorbits = glw_state.desktopBitsPixel;
			}
			GLW_CreatePFD( &pfd, colorbits, depthbits, 0, r_stereo->integer );
			if ( GLW_MakeContext( &pfd ) != TRY_PFD_SUCCESS )
			{
				if ( glw_state.hDC )
				{
					ReleaseDC( g_wv.hWnd, glw_state.hDC );
					glw_state.hDC = NULL;
				}

				ri.Printf( PRINT_ALL, "...failed to find an appropriate PIXELFORMAT\n" );

				return qfalse;
			}
		}

		/*
		** report if stereo is desired but unavailable
		*/