wgl.c

winNT技术操作系统,国外开放的原代码和LIUX一样

/* $Id: wgl.c,v 1.9 2005/07/01 15:56:14 kschultz Exp $ */

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * File name 	: wgl.c
 * WGL stuff. Added by Oleg Letsinsky, [e-mail]
 * Some things originated from the 3Dfx WGL functions
 */

/* 
 * This file contains the implementation of the wgl* functions for
 * Mesa on Windows.  Since these functions are provided by Windows in
 * GDI/OpenGL, we must supply our versions that work with Mesa here.
 */


/* We're essentially building part of GDI here, so define this so that
 * we get the right export linkage. */
#define _GDI32_
#include <windows.h>

#include "GL/wmesa.h"   /* protos for wmesa* functions */

typedef struct wmesa_context *PWMC;

/*
 * Pixel Format Descriptors
 */

/* Extend the PFD to include DB flag */
struct __pixelformat__
{
    PIXELFORMATDESCRIPTOR pfd;
    GLboolean doubleBuffered;
};

/* These are the PFD's supported by this driver. */
struct __pixelformat__	pfd[] =
{
#if 0
    /* Double Buffer, alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT|PFD_DOUBLEBUFFER|PFD_SWAP_COPY,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,	
	    8, 8,	
	    8, 16,	
	    8, 24,
	    0, 0, 0, 0, 0,	
	    16,	8,	
	    0, 0, 0,	
	    0, 0, 0 
	},
        GL_TRUE
    },
    /* Single Buffer, alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,	
	    8, 8,	
	    8, 16,	
	    8, 24,
	    0, 0, 0, 0,	0,	
	    16,	8,
	    0, 0, 0,	
	    0, 0, 0
	},
        GL_FALSE
    },
#endif
    /* Double Buffer, no alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT|PFD_DOUBLEBUFFER|PFD_SWAP_COPY,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,
	    8, 8,
	    8, 16,
	    0, 0,
	    0, 0, 0, 0,	0,
	    16,	8,
	    0, 0, 0, 
	    0, 0, 0 
	},
        GL_TRUE
    },
    /* Single Buffer, no alpha */
    {	
	{
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,
	    8, 8,
	    8, 16,
	    0, 0,
	    0, 0, 0, 0,	0,
	    16,	8,
	    0, 0, 0,
	    0, 0, 0 
	},
        GL_FALSE
    },
};

int npfd = sizeof(pfd) / sizeof(pfd[0]);


/*
 * Contexts
 */

typedef struct {
    WMesaContext ctx;
    HDC hdc;
} MesaWglCtx;

#define MESAWGL_CTX_MAX_COUNT 20

static MesaWglCtx wgl_ctx[MESAWGL_CTX_MAX_COUNT];

static unsigned ctx_count = 0;
static int ctx_current = -1;
static unsigned curPFD = 0;

WINGDIAPI HGLRC GLAPIENTRY wglCreateContext(HDC hdc)
{
    HWND hWnd;
    int i = 0;
    if(!(hWnd = WindowFromDC(hdc))) {
	SetLastError(0);
	return(NULL);
    }
    if (!ctx_count) {
	for(i=0;i<MESAWGL_CTX_MAX_COUNT;i++) {
	    wgl_ctx[i].ctx = NULL;
	    wgl_ctx[i].hdc = NULL;
	}
    }
    for( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
        if ( wgl_ctx[i].ctx == NULL ) {
            wgl_ctx[i].ctx = 
		WMesaCreateContext(hWnd, NULL, GL_TRUE,
				   pfd[curPFD-1].doubleBuffered, 
				   pfd[curPFD-1].pfd.cAlphaBits ? 
				   GL_TRUE : GL_FALSE);
            if (wgl_ctx[i].ctx == NULL)
                break;
            wgl_ctx[i].hdc = hdc;
            ctx_count++;
            return ((HGLRC)wgl_ctx[i].ctx);
        }
    }
    SetLastError(0);
    return(NULL);
}

WINGDIAPI BOOL GLAPIENTRY wglDeleteContext(HGLRC hglrc)
{
    int i;
    for ( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
    	if ( wgl_ctx[i].ctx == (PWMC) hglrc ){
            WMesaMakeCurrent((PWMC) hglrc);
            WMesaDestroyContext();
            wgl_ctx[i].ctx = NULL;
            wgl_ctx[i].hdc = NULL;
            ctx_count--;
            return(TRUE);
    	}
    }
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI HGLRC GLAPIENTRY wglGetCurrentContext(VOID)
{
    if (ctx_current < 0)
	return 0;
    else
	return (HGLRC) wgl_ctx[ctx_current].ctx;
}

WINGDIAPI HDC GLAPIENTRY wglGetCurrentDC(VOID)
{
    if (ctx_current < 0)
	return 0;
    else
	return wgl_ctx[ctx_current].hdc;
}

WINGDIAPI BOOL GLAPIENTRY wglMakeCurrent(HDC hdc,HGLRC hglrc)
{
    int i;
    
    if (!hdc || !hglrc) {
	WMesaMakeCurrent(NULL);
	ctx_current = -1;
	return TRUE;
    }
    
    for ( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
	if ( wgl_ctx[i].ctx == (PWMC) hglrc ) {
	    wgl_ctx[i].hdc = hdc;
	    WMesaMakeCurrent( (WMesaContext) hglrc );
	    ctx_current = i;
	    return TRUE;
	}
    }
    return FALSE;
}


WINGDIAPI int GLAPIENTRY wglChoosePixelFormat(HDC hdc,
					      CONST 
					      PIXELFORMATDESCRIPTOR *ppfd)
{
    int		i,best = -1,bestdelta = 0x7FFFFFFF,delta;
    (void) hdc;
    
    if(ppfd->nSize != sizeof(PIXELFORMATDESCRIPTOR) || ppfd->nVersion != 1)
	{
	    SetLastError(0);
	    return(0);
	}
    for(i = 0; i < npfd;i++)
	{
	    delta = 0;
	    if(
		(ppfd->dwFlags & PFD_DRAW_TO_WINDOW) &&
		!(pfd[i].pfd.dwFlags & PFD_DRAW_TO_WINDOW))
		continue;
	    if(
		(ppfd->dwFlags & PFD_DRAW_TO_BITMAP) &&
		!(pfd[i].pfd.dwFlags & PFD_DRAW_TO_BITMAP))
		continue;
	    if(
		(ppfd->dwFlags & PFD_SUPPORT_GDI) &&
		!(pfd[i].pfd.dwFlags & PFD_SUPPORT_GDI))
		continue;
	    if(
		(ppfd->dwFlags & PFD_SUPPORT_OPENGL) &&
		!(pfd[i].pfd.dwFlags & PFD_SUPPORT_OPENGL))
		continue;
	    if(
		!(ppfd->dwFlags & PFD_DOUBLEBUFFER_DONTCARE) &&
		((ppfd->dwFlags & PFD_DOUBLEBUFFER) != 
		 (pfd[i].pfd.dwFlags & PFD_DOUBLEBUFFER)))
		continue;
	    if(
		!(ppfd->dwFlags & PFD_STEREO_DONTCARE) &&
		((ppfd->dwFlags & PFD_STEREO) != 
		 (pfd[i].pfd.dwFlags & PFD_STEREO)))
		continue;
	    if(ppfd->iPixelType != pfd[i].pfd.iPixelType)
		delta++;
	    if(ppfd->cAlphaBits != pfd[i].pfd.cAlphaBits)
		delta++;
	    if(delta < bestdelta)
		{
		    best = i + 1;
		    bestdelta = delta;
		    if(bestdelta == 0)
			break;
		}
	}
    if(best == -1)
	{
	    SetLastError(0);
	    return(0);
	}
    return(best);
}

WINGDIAPI int GLAPIENTRY wglDescribePixelFormat(HDC hdc,
					        int iPixelFormat,
					        UINT nBytes,
					        LPPIXELFORMATDESCRIPTOR ppfd)
{
    (void) hdc;
    
    if(ppfd == NULL)
	return(npfd);
    if(iPixelFormat < 1 || iPixelFormat > npfd || 
       nBytes != sizeof(PIXELFORMATDESCRIPTOR))
	{
	    SetLastError(0);
	    return(0);
	}
    *ppfd = pfd[iPixelFormat - 1].pfd;
    return(npfd);
}

WINGDIAPI PROC GLAPIENTRY wglGetProcAddress(LPCSTR lpszProc)
{
    PROC p = (PROC) _glapi_get_proc_address((const char *) lpszProc);
    if (p)
	return p;
    
    SetLastError(0);
    return(NULL);
}

WINGDIAPI int GLAPIENTRY wglGetPixelFormat(HDC hdc)
{
    (void) hdc;
    if(curPFD == 0) {
	SetLastError(0);
	return(0);
    }
    return(curPFD);
}

WINGDIAPI BOOL GLAPIENTRY wglSetPixelFormat(HDC hdc,int iPixelFormat,
					    PIXELFORMATDESCRIPTOR *ppfd)
{
    (void) hdc;
    
    if(iPixelFormat < 1 || iPixelFormat > npfd ||