win_glimp.c

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/*
===========================================================================
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
        */
        if ( !( pfd.dwFlags & PFD_STEREO ) && ( r_stereo->integer != 0 ) ) 
        {
            ri.Printf( PRINT_ALL, "...failed to select stereo pixel format\n" );
            glConfig.stereoEnabled = qfalse;
        }
    }

    /*
    ** store PFD specifics 
    */
    glConfig.colorBits = ( int ) pfd.cColorBits;
    glConfig.depthBits = ( int ) pfd.cDepthBits;
    glConfig.stencilBits = ( int ) pfd.cStencilBits;

    return qtrue;
}

/*
** GLW_CreateWindow
**
** Responsible for creating the Win32 window and initializing the OpenGL driver.
*/
#define WINDOW_STYLE    (WS_OVERLAPPED|WS_BORDER|WS_CAPTION|WS_VISIBLE)
static qboolean GLW_CreateWindow( const char *drivername, int width, int height, int colorbits, qboolean cdsFullscreen )
{
    RECT            r;
    cvar_t          *vid_xpos, *vid_ypos;
    int             stylebits;
    int             x, y, w, h;
    int             exstyle;

    //
    // register the window class if necessary
    //
    if ( !s_classRegistered )
    {
        WNDCLASS wc;

        memset( &wc, 0, sizeof( wc ) );

        wc.style         = 0;
        wc.lpfnWndProc   = (WNDPROC) glw_state.wndproc;
        wc.cbClsExtra    = 0;
        wc.cbWndExtra    = 0;
        wc.hInstance     = g_wv.hInstance;
        wc.hIcon         = LoadIcon( g_wv.hInstance, MAKEINTRESOURCE(IDI_ICON1));
        wc.hCursor       = LoadCursor (NULL,IDC_ARROW);
        wc.hbrBackground = (void *)COLOR_GRAYTEXT;
        wc.lpszMenuName  = 0;
        wc.lpszClassName = WINDOW_CLASS_NAME;

        if ( !RegisterClass( &wc ) )
        {
            ri.Error( ERR_FATAL, "GLW_CreateWindow: could not register window class" );
        }
        s_classRegistered = qtrue;
        ri.Printf( PRINT_ALL, "...registered window class\n" );
    }

    //
    // create the HWND if one does not already exist
    //
    if ( !g_wv.hWnd )
    {
        //
        // compute width and height
        //
        r.left = 0;
        r.top = 0;
        r.right  = width;
        r.bottom = height;

        if ( cdsFullscreen || !Q_stricmp( _3DFX_DRIVER_NAME, drivername ) )
        {
            exstyle = WS_EX_TOPMOST;
            stylebits = WS_POPUP|WS_VISIBLE|WS_SYSMENU;
        }
        else
        {
            exstyle = 0;
            stylebits = WINDOW_STYLE|WS_SYSMENU;
            AdjustWindowRect (&r, stylebits, FALSE);
        }

        w = r.right - r.left;
        h = r.bottom - r.top;

        if ( cdsFullscreen || !Q_stricmp( _3DFX_DRIVER_NAME, drivername ) )
        {
            x = 0;
            y = 0;
        }
        else
        {
            vid_xpos = ri.Cvar_Get ("vid_xpos", "", 0);
            vid_ypos = ri.Cvar_Get ("vid_ypos", "", 0);
            x = vid_xpos->integer;
            y = vid_ypos->integer;

            // adjust window coordinates if necessary 
            // so that the window is completely on screen
            if ( x < 0 )
                x = 0;
            if ( y < 0 )
                y = 0;

            if ( w < glw_state.desktopWidth &&
                 h < glw_state.desktopHeight )
            {
                if ( x + w > glw_state.desktopWidth )
                    x = ( glw_state.desktopWidth - w );
                if ( y + h > glw_state.desktopHeight )
                    y = ( glw_state.desktopHeight - h );
            }
        }

        g_wv.hWnd = CreateWindowEx (
             exstyle, 
             WINDOW_CLASS_NAME,
             "Quake 3: Arena",
             stylebits,
             x, y, w, h,
             NULL,
             NULL,
             g_wv.hInstance,
             NULL);

        if ( !g_wv.hWnd )
        {
            ri.Error (ERR_FATAL, "GLW_CreateWindow() - Couldn't create window");
        }
    
        ShowWindow( g_wv.hWnd, SW_SHOW );
        UpdateWindow( g_wv.hWnd );
        ri.Printf( PRINT_ALL, "...created window@%d,%d (%dx%d)\n", x, y, w, h );
    }
    else
    {
        ri.Printf( PRINT_ALL, "...window already present, CreateWindowEx skipped\n" );
    }

    if ( !GLW_InitDriver( drivername, colorbits ) )
    {
        ShowWindow( g_wv.hWnd, SW_HIDE );
        DestroyWindow( g_wv.hWnd );
        g_wv.hWnd = NULL;

        return qfalse;
    }

    SetForegroundWindow( g_wv.hWnd );
    SetFocus( g_wv.hWnd );

    return qtrue;
}

static void PrintCDSError( int value )
{
    switch ( value )
    {
    case DISP_CHANGE_RESTART:
        ri.Printf( PRINT_ALL, "restart required\n" );
        break;
    case DISP_CHANGE_BADPARAM:
        ri.Printf( PRINT_ALL, "bad param\n" );
        break;
    case DISP_CHANGE_BADFLAGS:
        ri.Printf( PRINT_ALL, "bad flags\n" );
        break;
    case DISP_CHANGE_FAILED:
        ri.Printf( PRINT_ALL, "DISP_CHANGE_FAILED\n" );
        break;
    case DISP_CHANGE_BADMODE:
        ri.Printf( PRINT_ALL, "bad mode\n" );
        break;
    case DISP_CHANGE_NOTUPDATED:
        ri.Printf( PRINT_ALL, "not updated\n" );
        break;
    default:
        ri.Printf( PRINT_ALL, "unknown error %d\n", value );
        break;
    }
}

/*
** GLW_SetMode
*/
static rserr_t GLW_SetMode( const char *drivername, 
                            int mode, 
                            int colorbits, 
                            qboolean cdsFullscreen )
{
    HDC hDC;
    const char *win_fs[] = { "W", "FS" };
    int     cdsRet;
    DEVMODE dm;
        
    //
    // print out informational messages
    //
    ri.Printf( PRINT_ALL, "...setting mode %d:", mode );
    if ( !R_GetModeInfo( &glConfig.vidWidth, &glConfig.vidHeight, &glConfig.windowAspect, mode ) )
    {
        ri.Printf( PRINT_ALL, " invalid mode\n" );
        return RSERR_INVALID_MODE;
    }
    ri.Printf( PRINT_ALL, " %d %d %s\n", glConfig.vidWidth, glConfig.vidHeight, win_fs[cdsFullscreen] );

    //
    // check our desktop attributes
    //
    hDC = GetDC( GetDesktopWindow() );
    glw_state.desktopBitsPixel = GetDeviceCaps( hDC, BITSPIXEL );
    glw_state.desktopWidth = GetDeviceCaps( hDC, HORZRES );
    glw_state.desktopHeight = GetDeviceCaps( hDC, VERTRES );
    ReleaseDC( GetDesktopWindow(), hDC );

    //
    // verify desktop bit depth
    //
    if ( glConfig.driverType != GLDRV_VOODOO )
    {
        if ( glw_state.desktopBitsPixel < 15 || glw_state.desktopBitsPixel == 24 )
        {
            if ( colorbits == 0 || ( !cdsFullscreen && colorbits >= 15 ) )
            {
                if ( MessageBox( NULL,
                            "It is highly unlikely that a correct\n"
                            "windowed display can be initialized with\n"
                            "the current desktop display depth.  Select\n"
                            "'OK' to try anyway.  Press 'Cancel' if you\n"
                            "have a 3Dfx Voodoo, Voodoo-2, or Voodoo Rush\n"
                            "3D accelerator installed, or if you otherwise\n"
                            "wish to quit.",
                            "Low Desktop Color Depth",
                            MB_OKCANCEL | MB_ICONEXCLAMATION ) != IDOK )
                {
                    return RSERR_INVALID_MODE;
                }
            }
        }
    }

    // do a CDS if needed
    if ( cdsFullscreen )
    {
        memset( &dm, 0, sizeof( dm ) );
        
        dm.dmSize = sizeof( dm );
        
        dm.dmPelsWidth  = glConfig.vidWidth;
        dm.dmPelsHeight = glConfig.vidHeight;
        dm.dmFields     = DM_PELSWIDTH | DM_PELSHEIGHT;

        if ( r_displayRefresh->integer != 0 )
        {
            dm.dmDisplayFrequency = r_displayRefresh->integer;
            dm.dmFields |= DM_DISPLAYFREQUENCY;
        }
        
        // try to change color depth if possible
        if ( colorbits != 0 )
        {
            if ( glw_state.allowdisplaydepthchange )
            {
                dm.dmBitsPerPel = colorbits;
                dm.dmFields |= DM_BITSPERPEL;
                ri.Printf( PRINT_ALL, "...using colorsbits of %d\n", colorbits );
            }
            else
            {
                ri.Printf( PRINT_ALL, "WARNING:...changing depth not supported on Win95 < pre-OSR 2.x\n" );
            }
        }
        else
        {
            ri.Printf( PRINT_ALL, "...using desktop display depth of %d\n", glw_state.desktopBitsPixel );
        }

        //
        // if we're already in fullscreen then just create the window
        //
        if ( glw_state.cdsFullscreen )
        {
            ri.Printf( PRINT_ALL, "...already fullscreen, avoiding redundant CDS\n" );

            if ( !GLW_CreateWindow ( drivername, glConfig.vidWidth, glConfig.vidHeight, colorbits, qtrue ) )
            {
                ri.Printf( PRINT_ALL, "...restoring display settings\n" );
                ChangeDisplaySettings( 0, 0 );
                return RSERR_INVALID_MODE;
            }
        }
        //
        // need to call CDS
        //
        else
        {
            ri.Printf( PRINT_ALL, "...calling CDS: " );
            
            // try setting the exact mode requested, because some drivers don't report
            // the low res modes in EnumDisplaySettings, but still work
            if ( ( cdsRet = ChangeDisplaySettings( &dm, CDS_FULLSCREEN ) ) == DISP_CHANGE_SUCCESSFUL )
            {
                ri.Printf( PRINT_ALL, "ok\n" );

                if ( !GLW_CreateWindow ( drivername, glConfig.vidWidth, glConfig.vidHeight, colorbits, qtrue) )
                {
                    ri.Printf( PRINT_ALL, "...restoring display settings\n" );
                    ChangeDisplaySettings( 0, 0 );
                    return RSERR_INVALID_MODE;
                }
                
                glw_state.cdsFullscreen = qtrue;
            }
            else
            {
                //
                // the exact mode failed, so scan EnumDisplaySettings for the next largest mode
                //
                DEVMODE     devmode;
                int         modeNum;

                ri.Printf( PRINT_ALL, "failed, " );
                
                PrintCDSError( cdsRet );
            
                ri.Printf( PRINT_ALL, "...trying next higher resolution:" );
                
                // we could do a better matching job here...
                for ( modeNum = 0 ; ; modeNum++ ) {
                    if ( !EnumDisplaySettings( NULL, modeNum, &devmode ) ) {
                        modeNum = -1;
                        break;
                    }
                    if ( devmode.dmPelsWidth >= glConfig.vidWidth
                        && devmode.dmPelsHeight >= glConfig.vidHeight
                        && devmode.dmBitsPerPel >= 15 ) {
                        break;
                    }
                }

                if ( modeNum != -1 && ( cdsRet = ChangeDisplaySettings( &devmode, CDS_FULLSCREEN ) ) == DISP_CHANGE_SUCCESSFUL )
                {
                    ri.Printf( PRINT_ALL, " ok\n" );
                    if ( !GLW_CreateWindow( drivername, glConfig.vidWidth, glConfig.vidHeight, colorbits, qtrue) )
                    {
                        ri.Printf( PRINT_ALL, "...restoring display settings\n" );
                        ChangeDisplaySettings( 0, 0 );
                        return RSERR_INVALID_MODE;
                    }
                    
                    glw_state.cdsFullscreen = qtrue;
                }
                else
                {
                    ri.Printf( PRINT_ALL, " failed, " );
                    
                    PrintCDSError( cdsRet );
                    
                    ri.Printf( PRINT_ALL, "...restoring display settings\n" );
                    ChangeDisplaySettings( 0, 0 );
                    
                    glw_state.cdsFullscreen = qfalse;
                    glConfig.isFullscreen = qfalse;
                    if ( !GLW_CreateWindow( drivername, glConfig.vidWidth, glConfig.vidHeight, colorbits, qfalse) )
                    {
                        return RSERR_INVALID_MODE;
                    }
                    return RSERR_INVALID_FULLSCREEN;
                }
            }
        }
    }
    else
    {
        if ( glw_state.cdsFullscreen )
        {
            ChangeDisplaySettings( 0, 0 );
        }

        glw_state.cdsFullscreen = qfalse;
        if ( !GLW_CreateWindow( drivername, glConfig.vidWidth, glConfig.vidHeight, colorbits, qfalse ) )
        {
            return RSERR_INVALID_MODE;
        }
    }

    //
    // success, now check display frequency, although this won't be valid on Voodoo(2)
    //
    memset( &dm, 0, sizeof( dm ) );
    dm.dmSize = sizeof( dm );
    if ( EnumDisplaySettings( NULL, ENUM_CURRENT_SETTINGS, &dm ) )
    {
        glConfig.displayFrequency = dm.dmDisplayFrequency;
    }

    // NOTE: this is overridden later on standalone 3Dfx drivers
    glConfig.isFullscreen = cdsFullscreen;

    return RSERR_OK;
}

/*
** GLW_InitExtensions
*/
static void GLW_InitExtensions( void )
{
    if ( !r_allowExtensions->integer )
    {
        ri.Printf( PRINT_ALL, "*** IGNORING OPENGL EXTENSIONS ***\n" );
        return;
    }

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

    // GL_S3_s3tc
    glConfig.textureCompression = TC_NONE;
    if ( strstr( glConfig.extensions_string, "GL_S3_s3tc" ) )
    {
        if ( r_ext_compressed_textures->integer )
        {
            glConfig.textureCompression = TC_S3TC;
            ri.Printf( PRINT_ALL, "...using GL_S3_s3tc\n" );
        }
        else
        {
            glConfig.textureCompression = TC_NONE;
            ri.Printf( PRINT_ALL, "...ignoring GL_S3_s3tc\n" );
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "...GL_S3_s3tc not found\n" );
    }

    // GL_EXT_texture_env_add
    glConfig.textureEnvAddAvailable = qfalse;
    if ( strstr( glConfig.extensions_string, "EXT_texture_env_add" ) )
    {
        if ( r_ext_texture_env_add->integer )
        {
            glConfig.textureEnvAddAvailable = qtrue;
            ri.Printf( PRINT_ALL, "...using GL_EXT_texture_env_add\n" );
        }
        else
        {
            glConfig.textureEnvAddAvailable = qfalse;
            ri.Printf( PRINT_ALL, "...ignoring GL_EXT_texture_env_add\n" );
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "...GL_EXT_texture_env_add not found\n" );
    }

    // WGL_EXT_swap_control
    qwglSwapIntervalEXT = ( BOOL (WINAPI *)(int)) qwglGetProcAddress( "wglSwapIntervalEXT" );
    if ( qwglSwapIntervalEXT )
    {
        ri.Printf( PRINT_ALL, "...using WGL_EXT_swap_control\n" );
        r_swapInterval->modified = qtrue;   // force a set next frame
    }
    else
    {
        ri.Printf( PRINT_ALL, "...WGL_EXT_swap_control not found\n" );
    }

    // GL_ARB_multitexture
    qglMultiTexCoord2fARB = NULL;
    qglActiveTextureARB = NULL;
    qglClientActiveTextureARB = NULL;
    if ( strstr( glConfig.extensions_string, "GL_ARB_multitexture" )  )
    {
        if ( r_ext_multitexture->integer )
        {
            qglMultiTexCoord2fARB = ( PFNGLMULTITEXCOORD2FARBPROC ) qwglGetProcAddress( "glMultiTexCoord2fARB" );
            qglActiveTextureARB = ( PFNGLACTIVETEXTUREARBPROC ) qwglGetProcAddress( "glActiveTextureARB" );
            qglClientActiveTextureARB = ( PFNGLCLIENTACTIVETEXTUREARBPROC ) qwglGetProcAddress( "glClientActiveTextureARB" );

            if ( qglActiveTextureARB )
            {
                qglGetIntegerv( GL_MAX_ACTIVE_TEXTURES_ARB, &glConfig.maxActiveTextures );

                if ( glConfig.maxActiveTextures > 1 )
                {
                    ri.Printf( PRINT_ALL, "...using GL_ARB_multitexture\n" );
                }
                else
                {
                    qglMultiTexCoord2fARB = NULL;
                    qglActiveTextureARB = NULL;
                    qglClientActiveTextureARB = NULL;
                    ri.Printf( PRINT_ALL, "...not using GL_ARB_multitexture, < 2 texture units\n" );
                }
            }
        }
        else
        {
            ri.Printf( PRINT_ALL, "...ignoring GL_ARB_multitexture\n" );
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "...GL_ARB_multitexture not found\n" );
    }

    // GL_EXT_compiled_vertex_array
    qglLockArraysEXT = NULL;
    qglUnlockArraysEXT = NULL;
    if ( strstr( glConfig.extensions_string, "GL_EXT_compiled_vertex_array" ) && ( glConfig.hardwareType != GLHW_RIVA128 ) )
    {
        if ( r_ext_compiled_vertex_array->integer )
        {
            ri.Printf( PRINT_ALL, "...using GL_EXT_compiled_vertex_array\n" );
            qglLockArraysEXT = ( void ( APIENTRY * )( int, int ) ) qwglGetProcAddress( "glLockArraysEXT" );
            qglUnlockArraysEXT = ( void ( APIENTRY * )( void ) ) qwglGetProcAddress( "glUnlockArraysEXT" );
            if (!qglLockArraysEXT || !qglUnlockArraysEXT) {
                ri.Error (ERR_FATAL, "bad getprocaddress");
            }
        }
        else
        {
            ri.Printf( PRINT_ALL, "...ignoring GL_EXT_compiled_vertex_array\n" );
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "...GL_EXT_compiled_vertex_array not found\n" );
    }

    // WGL_3DFX_gamma_control
    qwglGetDeviceGammaRamp3DFX = NULL;
    qwglSetDeviceGammaRamp3DFX = NULL;

    if ( strstr( glConfig.extensions_string, "WGL_3DFX_gamma_control" ) )
    {
        if ( !r_ignorehwgamma->integer && r_ext_gamma_control->integer )
        {
            qwglGetDeviceGammaRamp3DFX = ( BOOL ( WINAPI * )( HDC, LPVOID ) ) qwglGetProcAddress( "wglGetDeviceGammaRamp3DFX" );
            qwglSetDeviceGammaRamp3DFX = ( BOOL ( WINAPI * )( HDC, LPVOID ) ) qwglGetProcAddress( "wglSetDeviceGammaRamp3DFX" );

            if ( qwglGetDeviceGammaRamp3DFX && qwglSetDeviceGammaRamp3DFX )
            {
                ri.Printf( PRINT_ALL, "...using WGL_3DFX_gamma_control\n" );
            }
            else
            {
                qwglGetDeviceGammaRamp3DFX = NULL;
                qwglSetDeviceGammaRamp3DFX = NULL;
            }
        }
        else
        {
            ri.Printf( PRINT_ALL, "...ignoring WGL_3DFX_gamma_control\n" );
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "...WGL_3DFX_gamma_control not found\n" );
    }
}

/*
** GLW_CheckOSVersion
*/
static qboolean GLW_CheckOSVersion( void )
{
#define OSR2_BUILD_NUMBER 1111

    OSVERSIONINFO   vinfo;

    vinfo.dwOSVersionInfoSize = sizeof(vinfo);

    glw_state.allowdisplaydepthchange = qfalse;

    if ( GetVersionEx( &vinfo) )
    {
        if ( vinfo.dwMajorVersion > 4 )
        {
            glw_state.allowdisplaydepthchange = qtrue;
        }
        else if ( vinfo.dwMajorVersion == 4 )
        {
            if ( vinfo.dwPlatformId == VER_PLATFORM_WIN32_NT )
            {
                glw_state.allowdisplaydepthchange = qtrue;
            }
            else if ( vinfo.dwPlatformId == VER_PLATFORM_WIN32_WINDOWS )
            {
                if ( LOWORD( vinfo.dwBuildNumber ) >= OSR2_BUILD_NUMBER )
                {
                    glw_state.allowdisplaydepthchange = qtrue;
                }
            }
        }
    }
    else
    {
        ri.Printf( PRINT_ALL, "GLW_CheckOSVersion() - GetVersionEx failed\n" );
        return qfalse;
    }

    return qtrue;
}

/*
** GLW_LoadOpenGL
**
** GLimp_win.c internal function that attempts to load and use 
** a specific OpenGL DLL.
*/
static qboolean GLW_LoadOpenGL( const char *drivername )
{
    char buffer[1024];
    qboolean cdsFullscreen;

    Q_strncpyz( buffer, drivername, sizeof(buffer) );
    Q_strlwr(buffer);

    //
    // determine if we're on a standalone driver
    //
    if ( strstr( buffer, "opengl32" ) != 0 || r_maskMinidriver->integer )
    {
        glConfig.driverType = GLDRV_ICD;
    }
    else
    {
        glConfig.driverType = GLDRV_STANDALONE;

        ri.Printf( PRINT_ALL, "...assuming '%s' is a standalone driver\n", drivername );

        if ( strstr( buffer, _3DFX_DRIVER_NAME ) )
        {
            glConfig.driverType = GLDRV_VOODOO;
        }
    }

    // disable the 3Dfx splash screen
    _putenv("FX_GLIDE_NO_SPLASH=0");

    //
    // load the driver and bind our function pointers to it
    // 
    if ( QGL_Init( buffer ) ) 
    {
        cdsFullscreen = r_fullscreen->integer;

        // create the window and set up the context
        if ( !GLW_StartDriverAndSetMode( drivername, r_mode->integer, r_colorbits->integer, cdsFullscreen ) )
        {
            // if we're on a 24/32-bit desktop and we're going fullscreen on an ICD,
            // try it again but with a 16-bit desktop
            if ( glConfig.driverType == GLDRV_ICD )
            {
                if ( r_colorbits->integer != 16 ||
                     cdsFullscreen != qtrue ||
                     r_mode->integer != 3 )
                {
                    if ( !GLW_StartDriverAndSetMode( drivername, 3, 16, qtrue ) )
                    {
                        goto fail;
                    }
                }
            }
            else
            {
                goto fail;
            }
        }

        if ( glConfig.driverType == GLDRV_VOODOO )
        {
            glConfig.isFullscreen = qtrue;
        }

        return qtrue;
    }
fail:

    QGL_Shutdown();

    return qfalse;
}

/*
** GLimp_EndFrame
*/
void GLimp_EndFrame (void)
{
    //
    // swapinterval stuff
    //
    if ( r_swapInterval->modified ) {
        r_swapInterval->modified = qfalse;

        if ( !glConfig.stereoEnabled ) {    // why?
            if ( qwglSwapIntervalEXT ) {
                qwglSwapIntervalEXT( r_swapInterval->integer );
            }
        }
    }


    // don't flip if drawing to front buffer
    if ( Q_stricmp( r_drawBuffer->string, "GL_FRONT" ) != 0 )
    {
        if ( glConfig.driverType > GLDRV_ICD )
        {
            if ( !qwglSwapBuffers( glw_state.hDC ) )
            {
                ri.Error( ERR_FATAL, "GLimp_EndFrame() - SwapBuffers() failed!\n" );
            }
        }
        else
        {
            SwapBuffers( glw_state.hDC );
        }
    }

    // check logging
    QGL_EnableLogging( r_logFile->integer );
}

static void GLW_StartOpenGL( void )
{
    qboolean attemptedOpenGL32 = qfalse;
    qboolean attempted3Dfx = qfalse;

    //
    // load and initialize the specific OpenGL driver
    //
    if ( !GLW_LoadOpenGL( r_glDriver->string ) )
    {
        if ( !Q_stricmp( r_glDriver->string, OPENGL_DRIVER_NAME ) )
        {
            attemptedOpenGL32 = qtrue;
        }
        else if ( !Q_stricmp( r_glDriver->string, _3DFX_DRIVER_NAME ) )
        {
            attempted3Dfx = qtrue;
        }

        if ( !attempted3Dfx )
        {
            attempted3Dfx = qtrue;
            if ( GLW_LoadOpenGL( _3DFX_DRIVER_NAME ) )
            {
                ri.Cvar_Set( "r_glDriver", _3DFX_DRIVER_NAME );
                r_glDriver->modified = qfalse;
            }
            else
            {
                if ( !attemptedOpenGL32 )
                {
                    if ( !GLW_LoadOpenGL( OPENGL_DRIVER_NAME ) )
                    {
                        ri.Error( ERR_FATAL, "GLW_StartOpenGL() - could not load OpenGL subsystem\n" );
                    }
                    ri.Cvar_Set( "r_glDriver", OPENGL_DRIVER_NAME );
                    r_glDriver->modified = qfalse;
                }
                else
                {
                    ri.Error( ERR_FATAL, "GLW_StartOpenGL() - could not load OpenGL subsystem\n" );
                }
            }
        }
        else if ( !attemptedOpenGL32 )
        {
            attemptedOpenGL32 = qtrue;
            if ( GLW_LoadOpenGL( OPENGL_DRIVER_NAME ) )
            {
                ri.Cvar_Set( "r_glDriver", OPENGL_DRIVER_NAME );
                r_glDriver->modified = qfalse;
            }
            else
            {
                ri.Error( ERR_FATAL, "GLW_StartOpenGL() - could not load OpenGL subsystem\n" );
            }
        }
    }
}

/*
** GLimp_Init
**
** This is the platform specific OpenGL initialization function.  It
** is responsible for loading OpenGL, initializing it, setting
** extensions, creating a window of the appropriate size, doing
** fullscreen manipulations, etc.  Its overall responsibility is
** to make sure that a functional OpenGL subsystem is operating
** when it returns to the ref.
*/
void GLimp_Init( void )
{
    char    buf[1024];
    cvar_t *lastValidRenderer = ri.Cvar_Get( "r_lastValidRenderer", "(uninitialized)", CVAR_ARCHIVE );
    cvar_t  *cv;

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

    //
    // check OS version to see if we can do fullscreen display changes
    //
    if ( !GLW_CheckOSVersion() )
    {
        ri.Error( ERR_FATAL, "GLimp_Init() - incorrect operating system\n" );
    }

    // save off hInstance and wndproc
    cv = ri.Cvar_Get( "win_hinstance", "", 0 );
    sscanf( cv->string, "%i", (int *)&g_wv.hInstance );

    cv = ri.Cvar_Get( "win_wndproc", "", 0 );
    sscanf( cv->string, "%i", (int *)&glw_state.wndproc );

    r_allowSoftwareGL = ri.Cvar_Get( "r_allowSoftwareGL", "0", CVAR_LATCH );
    r_maskMinidriver = ri.Cvar_Get( "r_maskMinidriver", "0", CVAR_LATCH );

    // load appropriate DLL and initialize subsystem
    GLW_StartOpenGL();

    // get our config strings
    Q_strncpyz( glConfig.vendor_string, qglGetString (GL_VENDOR), sizeof( glConfig.vendor_string ) );
    Q_strncpyz( glConfig.renderer_string, qglGetString (GL_RENDERER), sizeof( glConfig.renderer_string ) );
    Q_strncpyz( glConfig.version_string, qglGetString (GL_VERSION), sizeof( glConfig.version_string ) );
    Q_strncpyz( glConfig.extensions_string, qglGetString (GL_EXTENSIONS), sizeof( glConfig.extensions_string ) );

    //
    // chipset specific configuration
    //
    Q_strncpyz( buf, glConfig.renderer_string, sizeof(buf) );
    Q_strlwr( buf );

    //
    // NOTE: if changing cvars, do it within this block.  This allows them
    // to be overridden when testing driver fixes, etc. but only sets
    // them to their default state when the hardware is first installed/run.
    //
    if ( Q_stricmp( lastValidRenderer->string, glConfig.renderer_string ) )
    {
        glConfig.hardwareType = GLHW_GENERIC;

        ri.Cvar_Set( "r_textureMode", "GL_LINEAR_MIPMAP_NEAREST" );

        // VOODOO GRAPHICS w/ 2MB
        if ( strstr( buf, "voodoo graphics/1 tmu/2 mb" ) )
        {
            ri.Cvar_Set( "r_picmip", "2" );
            ri.Cvar_Get( "r_picmip", "1", CVAR_ARCHIVE | CVAR_LATCH );
        }
        else
        {
            ri.Cvar_Set( "r_picmip", "1" );

            if ( strstr( buf, "rage 128" ) || strstr( buf, "rage128" ) )
            {
                ri.Cvar_Set( "r_finish", "0" );
            }
            // Savage3D and Savage4 should always have trilinear enabled
            else if ( strstr( buf, "savage3d" ) || strstr( buf, "s3 savage4" ) )
            {
                ri.Cvar_Set( "r_texturemode", "GL_LINEAR_MIPMAP_LINEAR" );
            }
        }
    }
    
    //
    // this is where hardware specific workarounds that should be
    // detected/initialized every startup should go.
    //
    if ( strstr( buf, "banshee" ) || strstr( buf, "voodoo3" ) )
    {
        glConfig.hardwareType = GLHW_3DFX_2D3D;
    }
    // VOODOO GRAPHICS w/ 2MB
    else if ( strstr( buf, "voodoo graphics/1 tmu/2 mb" ) )
    {
    }
    else if ( strstr( buf, "glzicd" ) )
    {
    }
    else if ( strstr( buf, "rage pro" ) || strstr( buf, "Rage Pro" ) || strstr( buf, "ragepro" ) )
    {
        glConfig.hardwareType = GLHW_RAGEPRO;
    }
    else if ( strstr( buf, "rage 128" ) )
    {
    }
    else if ( strstr( buf, "permedia2" ) )
    {
        glConfig.hardwareType = GLHW_PERMEDIA2;
    }
    else if ( strstr( buf, "riva 128" ) )
    {
        glConfig.hardwareType = GLHW_RIVA128;
    }
    else if ( strstr( buf, "riva tnt " ) )
    {
    }

    ri.Cvar_Set( "r_lastValidRenderer", glConfig.renderer_string );

    GLW_InitExtensions();
    WG_CheckHardwareGamma();
}

/*
** GLimp_Shutdown
**
** This routine does all OS specific shutdown procedures for the OpenGL
** subsystem.
*/
void GLimp_Shutdown( void )
{
//  const char *strings[] = { "soft", "hard" };
    const char *success[] = { "failed", "success" };
    int retVal;

    // FIXME: Brian, we need better fallbacks from partially initialized failures
    if ( !qwglMakeCurrent ) {
        return;
    }

    ri.Printf