view src/video/gem/SDL_gemvideo.c @ 1554:0ca607a5d173

Fixed bug #84 Date: Sun, 23 Oct 2005 16:39:03 +0200 From: "A. Schmid" <sahib@phreaker.net> Subject: [SDL] no software surfaces with svgalib driver? Hi, I noticed that the SDL (1.2.9) svgalib driver only makes use of linear addressable (framebuffer) video modes. On older systems (like one of mine), linear addressable modes are often not available. Especially for cards with VESA VBE < 2.0 the svgalib vesa driver is unusable, since VESA only supports framebuffering for VBE 2.0 and later. The changes necessary to add support for software surfaces seem to be relatively small. I only had to hack src/video/svga/SDL_svgavideo.c (see attached patch). The code worked fine for me, but it is no more than a proof of concept and should be reviewed (probably has a memory leak when switching modes). It also uses the vgagl library (included in the svgalib package) and needs to be linked against it. -Alex
author Sam Lantinga <slouken@libsdl.org>
date Sun, 19 Mar 2006 12:04:40 +0000
parents 8d9bb0cf2c2a
children e49147870aac 417f2af2bd52
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/*
	GEM video driver

	Patrice Mandin
	and work from
	Olivier Landemarre, Johan Klockars, Xavier Joubert, Claude Attard
*/

/* Mint includes */
#include <gem.h>
#include <gemx.h>
#include <mint/osbind.h>
#include <mint/cookie.h>

#include "SDL_endian.h"
#include "SDL_video.h"
#include "SDL_mouse.h"
#include "../SDL_sysvideo.h"
#include "../SDL_pixels_c.h"
#include "../../events/SDL_events_c.h"
#include "../SDL_cursor_c.h"

#include "../ataricommon/SDL_ataric2p_s.h"
#include "../ataricommon/SDL_atarieddi_s.h"
#include "../ataricommon/SDL_atarimxalloc_c.h"
#include "../ataricommon/SDL_atarigl_c.h"

#include "SDL_gemvideo.h"
#include "SDL_gemevents_c.h"
#include "SDL_gemmouse_c.h"
#include "SDL_gemwm_c.h"
#include "../ataricommon/SDL_xbiosevents_c.h"
#include "../ataricommon/SDL_ataridevmouse_c.h"

/* Defines */

/*#define DEBUG_VIDEO_GEM	1*/

#define GEM_VID_DRIVER_NAME "gem"

#undef MIN
#define MIN(a,b) (((a)<(b)) ? (a) : (b))
#undef MAX
#define MAX(a,b) (((a)>(b)) ? (a) : (b))

/* Variables */

static unsigned char vdi_index[256] = {
	0,  2,  3,  6,  4,  7,  5,   8,
	9, 10, 11, 14, 12, 15, 13, 255
};

static const unsigned char empty_name[]="";

/* Initialization/Query functions */
static int GEM_VideoInit(_THIS, SDL_PixelFormat *vformat);
static SDL_Rect **GEM_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags);
static SDL_Surface *GEM_SetVideoMode(_THIS, SDL_Surface *current, int width, int height, int bpp, Uint32 flags);
static int GEM_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors);
static void GEM_VideoQuit(_THIS);

/* Hardware surface functions */
static int GEM_AllocHWSurface(_THIS, SDL_Surface *surface);
static int GEM_LockHWSurface(_THIS, SDL_Surface *surface);
static int GEM_FlipHWSurface(_THIS, SDL_Surface *surface);
static void GEM_UnlockHWSurface(_THIS, SDL_Surface *surface);
static void GEM_FreeHWSurface(_THIS, SDL_Surface *surface);
static void GEM_UpdateRects(_THIS, int numrects, SDL_Rect *rects);
#if 0
static int GEM_ToggleFullScreen(_THIS, int on);
#endif

/* Internal functions */
static void GEM_FreeBuffers(_THIS);
static void GEM_ClearScreen(_THIS);
static void GEM_ClearRect(_THIS, short *rect);
static void GEM_SetNewPalette(_THIS, Uint16 newpal[256][3]);
static void GEM_LockScreen(_THIS);
static void GEM_UnlockScreen(_THIS);
static void refresh_window(_THIS, int winhandle, short *rect);

#if SDL_VIDEO_OPENGL
/* OpenGL functions */
static void GEM_GL_SwapBuffers(_THIS);
#endif

/* GEM driver bootstrap functions */

static int GEM_Available(void)
{
	/* Test if AES available */
	if (appl_init() == -1)
		return 0;

	appl_exit();
	return 1;
}

static void GEM_DeleteDevice(SDL_VideoDevice *device)
{
	SDL_free(device->hidden);
	SDL_free(device);
}

static SDL_VideoDevice *GEM_CreateDevice(int devindex)
{
	SDL_VideoDevice *device;
	int vectors_mask;
	unsigned long dummy;

	/* Initialize all variables that we clean on shutdown */
	device = (SDL_VideoDevice *)SDL_malloc(sizeof(SDL_VideoDevice));
	if ( device ) {
		SDL_memset(device, 0, (sizeof *device));
		device->hidden = (struct SDL_PrivateVideoData *)
				SDL_malloc((sizeof *device->hidden));
		device->gl_data = (struct SDL_PrivateGLData *)
				SDL_malloc((sizeof *device->gl_data));
	}
	if ( (device == NULL) || (device->hidden == NULL) ) {
		SDL_OutOfMemory();
		if ( device ) {
			SDL_free(device);
		}
		return(0);
	}
	SDL_memset(device->hidden, 0, (sizeof *device->hidden));
	SDL_memset(device->gl_data, 0, sizeof(*device->gl_data));

	/* Set the function pointers */
	device->VideoInit = GEM_VideoInit;
	device->ListModes = GEM_ListModes;
	device->SetVideoMode = GEM_SetVideoMode;
	device->SetColors = GEM_SetColors;
	device->UpdateRects = NULL /*GEM_UpdateRects*/;
	device->VideoQuit = GEM_VideoQuit;
	device->AllocHWSurface = GEM_AllocHWSurface;
	device->LockHWSurface = GEM_LockHWSurface;
	device->UnlockHWSurface = GEM_UnlockHWSurface;
	device->FlipHWSurface = GEM_FlipHWSurface;
	device->FreeHWSurface = GEM_FreeHWSurface;
	device->ToggleFullScreen = NULL /*GEM_ToggleFullScreen*/;

	/* Window manager */
	device->SetCaption = GEM_SetCaption;
	device->SetIcon = GEM_SetIcon;
	device->IconifyWindow = GEM_IconifyWindow;
	device->GrabInput = GEM_GrabInput;

	/* Events */
	device->InitOSKeymap = GEM_InitOSKeymap;
	device->PumpEvents = GEM_PumpEvents;

	/* Mouse */
	device->FreeWMCursor = GEM_FreeWMCursor;
	device->CreateWMCursor = GEM_CreateWMCursor;
	device->ShowWMCursor = GEM_ShowWMCursor;
	device->WarpWMCursor = NULL /*GEM_WarpWMCursor*/;
	device->CheckMouseMode = GEM_CheckMouseMode;

#if SDL_VIDEO_OPENGL
	/* OpenGL functions */
	device->GL_LoadLibrary = SDL_AtariGL_LoadLibrary;
	device->GL_GetProcAddress = SDL_AtariGL_GetProcAddress;
	device->GL_GetAttribute = SDL_AtariGL_GetAttribute;
	device->GL_MakeCurrent = SDL_AtariGL_MakeCurrent;
	device->GL_SwapBuffers = GEM_GL_SwapBuffers;
#endif

	device->hidden->use_dev_mouse =
		(SDL_AtariDevMouse_Open()!=0) ? SDL_TRUE : SDL_FALSE;

	vectors_mask = ATARI_XBIOS_JOYSTICKEVENTS;	/* XBIOS joystick events */
	if (!(device->hidden->use_dev_mouse)) {
		vectors_mask |= ATARI_XBIOS_MOUSEEVENTS;	/* XBIOS mouse events */
	}
	if (Getcookie(C_MiNT, &dummy)==C_FOUND) {
		vectors_mask = 0;
	}

	SDL_AtariXbios_InstallVectors(vectors_mask);

	device->free = GEM_DeleteDevice;

	return device;
}

VideoBootStrap GEM_bootstrap = {
	GEM_VID_DRIVER_NAME, "Atari GEM video driver",
	GEM_Available, GEM_CreateDevice
};

static void VDI_ReadExtInfo(_THIS, short *work_out)
{
	unsigned long EdDI_version;
	unsigned long cookie_EdDI;
	Uint32 num_colours;
	Uint16 clut_type, num_bits;

	/* Read EdDI informations */
	if  (Getcookie(C_EdDI, &cookie_EdDI) == C_NOTFOUND) {
		return;
	}
	
	EdDI_version = Atari_get_EdDI_version( (void *)cookie_EdDI);

	vq_scrninfo(VDI_handle, work_out);

	VDI_format = work_out[0];
	clut_type = work_out[1];
	num_bits = work_out[2];
	num_colours = *((Uint32 *) &work_out[3]);

	/* With EdDI>=1.1, we can have screen pitch, address and format
	 * so we can directly write to screen without using vro_cpyfm
	 */
	if (EdDI_version >= EDDI_11) {
		VDI_pitch = work_out[5];
		VDI_screen = (void *) *((unsigned long *) &work_out[6]);
	}

	switch(clut_type) {
		case VDI_CLUT_HARDWARE:
			{
				int i;
				Uint16 *tmp_p;

				tmp_p = (Uint16 *)&work_out[16];

				for (i=0;i<256;i++) {
					vdi_index[*tmp_p++] = i;
				}
			}
			break;
		case VDI_CLUT_SOFTWARE:
			{
				int component; /* red, green, blue, alpha, overlay */
				int num_bit;
				unsigned short *tmp_p;

				/* We can build masks with info here */
				tmp_p = (unsigned short *) &work_out[16];
				for (component=0;component<5;component++) {
					for (num_bit=0;num_bit<16;num_bit++) {
						unsigned short valeur;

						valeur = *tmp_p++;

						if (valeur == 0xffff) {
							continue;
						}

						switch(component) {
							case 0:
								VDI_redmask |= 1<< valeur;
								break;
							case 1:
								VDI_greenmask |= 1<< valeur;
								break;
							case 2:
								VDI_bluemask |= 1<< valeur;
								break;
							case 3:
								VDI_alphamask |= 1<< valeur;
								break;
						}
					}
				}
			}

			/* Remove lower green bits for Intel endian screen */
			if ((VDI_greenmask == ((7<<13)|3)) || (VDI_greenmask == ((7<<13)|7))) {
				VDI_greenmask &= ~(7<<13);
			}
			break;
		case VDI_CLUT_NONE:
			break;
	}
}

int GEM_VideoInit(_THIS, SDL_PixelFormat *vformat)
{
	int i, menubar_size;
	short work_in[12], work_out[272], dummy;

	/* Open AES (Application Environment Services) */
	if (appl_init() == -1) {
		fprintf(stderr,"Can not open AES\n");
		return 1;
	}

	/* Read version and features */
	GEM_version = aes_global[0];
	if (GEM_version >= 0x0410) {
		short ap_gout[4], errorcode;
		
		GEM_wfeatures=0;
		errorcode=appl_getinfo(AES_WINDOW, &ap_gout[0], &ap_gout[1], &ap_gout[2], &ap_gout[3]);

		if (errorcode==0) {
			GEM_wfeatures=ap_gout[0];			
		}
	}	

	/* Ask VDI physical workstation handle opened by AES */
	VDI_handle = graf_handle(&dummy, &dummy, &dummy, &dummy);
	if (VDI_handle<1) {
		fprintf(stderr,"Wrong VDI handle %d returned by AES\n",VDI_handle);
		return 1;
	}

	/* Open virtual VDI workstation */
	work_in[0]=Getrez()+2;
	for(i = 1; i < 10; i++)
		work_in[i] = 1;
	work_in[10] = 2;

	v_opnvwk(work_in, &VDI_handle, work_out);
	if (VDI_handle == 0) {
		fprintf(stderr,"Can not open VDI virtual workstation\n");
		return 1;
	}

	/* Read fullscreen size */
	VDI_w = work_out[0] + 1;
	VDI_h = work_out[1] + 1;

	/* Read desktop size and position */
	if (!wind_get(DESKTOP_HANDLE, WF_WORKXYWH, &GEM_desk_x, &GEM_desk_y, &GEM_desk_w, &GEM_desk_h)) {
		fprintf(stderr,"Can not read desktop properties\n");
		return 1;
	}

	/* Read bit depth */
	vq_extnd(VDI_handle, 1, work_out);
	VDI_bpp = work_out[4];
	VDI_oldnumcolors=0;

	switch(VDI_bpp) {
		case 8:
			VDI_pixelsize=1;
			break;
		case 15:
		case 16:
			VDI_pixelsize=2;
			break;
		case 24:
			VDI_pixelsize=3;
			break;
		case 32:
			VDI_pixelsize=4;
			break;
		default:
			fprintf(stderr,"%d bits colour depth not supported\n",VDI_bpp);
			return 1;
	}

	/* Setup hardware -> VDI palette mapping */
	for(i = 16; i < 255; i++) {
		vdi_index[i] = i;
	}
	vdi_index[255] = 1;

	/* Save current palette */
	if (VDI_bpp>8) {
		VDI_oldnumcolors=1<<8;
	} else {
		VDI_oldnumcolors=1<<VDI_bpp;
	}
	
	for(i = 0; i < VDI_oldnumcolors; i++) {
		short rgb[3];

		vq_color(VDI_handle, i, 0, rgb);

		VDI_oldpalette[i][0] = rgb[0];
		VDI_oldpalette[i][1] = rgb[1];
		VDI_oldpalette[i][2] = rgb[2];
	}
	VDI_setpalette = GEM_SetNewPalette;
	SDL_memcpy(VDI_curpalette,VDI_oldpalette,sizeof(VDI_curpalette));

	/* Setup screen info */
	GEM_title_name = empty_name;
	GEM_icon_name = empty_name;

	GEM_handle = -1;
	GEM_locked = SDL_FALSE;
	GEM_win_fulled = SDL_FALSE;
	GEM_fullscreen = SDL_FALSE;
	GEM_lock_redraw = SDL_TRUE;	/* Prevent redraw till buffers are setup */

	VDI_screen = NULL;
	VDI_pitch = VDI_w * VDI_pixelsize;
	VDI_format = ( (VDI_bpp <= 8) ? VDI_FORMAT_INTER : VDI_FORMAT_PACK);
	VDI_redmask = VDI_greenmask = VDI_bluemask = VDI_alphamask = 0;
	VDI_ReadExtInfo(this, work_out);

#ifdef DEBUG_VIDEO_GEM
	printf("sdl:video:gem: screen: address=0x%08x, pitch=%d\n", VDI_screen, VDI_pitch);
	printf("sdl:video:gem: format=%d\n", VDI_format);
	printf("sdl:video:gem: masks: 0x%08x, 0x%08x, 0x%08x, 0x%08x\n",
		VDI_alphamask, VDI_redmask, VDI_greenmask, VDI_bluemask
	);
#endif

	/* Setup destination mfdb */
	VDI_dst_mfdb.fd_addr = NULL;

	/* Determine the current screen size */
	this->info.current_w = VDI_w;
	this->info.current_h = VDI_h;

	/* Determine the screen depth */
	/* we change this during the SDL_SetVideoMode implementation... */
	vformat->BitsPerPixel = VDI_bpp;

	/* Set mouse cursor to arrow */
	graf_mouse(ARROW, NULL);

	/* Init chunky to planar routine */
	SDL_Atari_C2pConvert = SDL_Atari_C2pConvert8;

	/* Setup VDI fill functions */
	vsf_color(VDI_handle,0);
	vsf_interior(VDI_handle,1);
	vsf_perimeter(VDI_handle,0);

	/* Menu bar save buffer */
	menubar_size = GEM_desk_w * GEM_desk_y * VDI_pixelsize;
	GEM_menubar=Atari_SysMalloc(menubar_size,MX_PREFTTRAM);

	/* Fill video modes list */
	SDL_modelist[0] = SDL_malloc(sizeof(SDL_Rect));
	SDL_modelist[0]->x = 0;
	SDL_modelist[0]->y = 0;
	SDL_modelist[0]->w = VDI_w;
	SDL_modelist[0]->h = VDI_h;

	SDL_modelist[1] = NULL;

#if SDL_VIDEO_OPENGL
	SDL_AtariGL_InitPointers(this);
#endif

	/* We're done! */
	return(0);
}

SDL_Rect **GEM_ListModes(_THIS, SDL_PixelFormat *format, Uint32 flags)
{
	if (format->BitsPerPixel != VDI_bpp) {
		return ((SDL_Rect **)NULL);
	}

	if (flags & SDL_FULLSCREEN) {
		return (SDL_modelist);
	}

	return((SDL_Rect **)-1);
}

static void GEM_FreeBuffers(_THIS)
{
	/* Release buffer */
	if ( GEM_buffer2 ) {
		Mfree( GEM_buffer2 );
		GEM_buffer2=NULL;
	}

	if ( GEM_buffer1 ) {
		Mfree( GEM_buffer1 );
		GEM_buffer1=NULL;
	}
}

static void GEM_ClearRect(_THIS, short *rect)
{
	short oldrgb[3], rgb[3]={0,0,0};

	vq_color(VDI_handle, vdi_index[0], 0, oldrgb);
	vs_color(VDI_handle, vdi_index[0], rgb);

	vsf_color(VDI_handle,0);
	vsf_interior(VDI_handle,1);
	vsf_perimeter(VDI_handle,0);
	v_bar(VDI_handle, rect);

	vs_color(VDI_handle, vdi_index[0], oldrgb);
}

static void GEM_ClearScreen(_THIS)
{
	short pxy[4];

	v_hide_c(VDI_handle);

	pxy[0] = pxy[1] = 0;
	pxy[2] = VDI_w - 1;
	pxy[3] = VDI_h - 1;
	GEM_ClearRect(this, pxy);

	v_show_c(VDI_handle, 1);
}

static void GEM_SetNewPalette(_THIS, Uint16 newpal[256][3])
{
	int i;
	short rgb[3];

	if (VDI_oldnumcolors==0)
		return;

	for(i = 0; i < VDI_oldnumcolors; i++) {
		rgb[0] = newpal[i][0];
		rgb[1] = newpal[i][1];
		rgb[2] = newpal[i][2];

		vs_color(VDI_handle, i, rgb);
	}
}

static void GEM_LockScreen(_THIS)
{
	if (!GEM_locked) {
		/* Lock AES */
		wind_update(BEG_UPDATE);
		wind_update(BEG_MCTRL);
		/* Reserve memory space, used to be sure of compatibility */
		form_dial( FMD_START, 0,0,0,0, 0,0,VDI_w,VDI_h);

		/* Save menu bar */
		if (GEM_menubar) {
			MFDB mfdb_src;
			short blitcoords[8];

			mfdb_src.fd_addr=GEM_menubar;
			mfdb_src.fd_w=GEM_desk_w;
			mfdb_src.fd_h=GEM_desk_y;
			mfdb_src.fd_wdwidth=GEM_desk_w>>4;
			mfdb_src.fd_nplanes=VDI_bpp;
			mfdb_src.fd_stand=
				mfdb_src.fd_r1=
				mfdb_src.fd_r2=
				mfdb_src.fd_r3= 0;

			blitcoords[0] = blitcoords[4] = 0;
			blitcoords[1] = blitcoords[5] = 0;
			blitcoords[2] = blitcoords[6] = GEM_desk_w-1;
			blitcoords[3] = blitcoords[7] = GEM_desk_y-1;

			vro_cpyfm(VDI_handle, S_ONLY, blitcoords, &VDI_dst_mfdb, &mfdb_src);
		}

		GEM_locked=SDL_TRUE;
	}
}

static void GEM_UnlockScreen(_THIS)
{
	if (GEM_locked) {
		/* Restore menu bar */
		if (GEM_menubar) {
			MFDB mfdb_src;
			short blitcoords[8];

			mfdb_src.fd_addr=GEM_menubar;
			mfdb_src.fd_w=GEM_desk_w;
			mfdb_src.fd_h=GEM_desk_y;
			mfdb_src.fd_wdwidth=GEM_desk_w>>4;
			mfdb_src.fd_nplanes=VDI_bpp;
			mfdb_src.fd_stand=
				mfdb_src.fd_r1=
				mfdb_src.fd_r2=
				mfdb_src.fd_r3= 0;

			blitcoords[0] = blitcoords[4] = 0;
			blitcoords[1] = blitcoords[5] = 0;
			blitcoords[2] = blitcoords[6] = GEM_desk_w-1;
			blitcoords[3] = blitcoords[7] = GEM_desk_y-1;

			vro_cpyfm(VDI_handle, S_ONLY, blitcoords, &mfdb_src, &VDI_dst_mfdb);
		}

		/* Restore screen memory, and send REDRAW to all apps */
		form_dial( FMD_FINISH, 0,0,0,0, 0,0,VDI_w,VDI_h);
		/* Unlock AES */
		wind_update(END_MCTRL);
		wind_update(END_UPDATE);

		GEM_locked=SDL_FALSE;
	}
}

SDL_Surface *GEM_SetVideoMode(_THIS, SDL_Surface *current,
				int width, int height, int bpp, Uint32 flags)
{
	int maxwidth, maxheight;
	Uint32 modeflags, screensize;
	SDL_bool use_shadow1, use_shadow2;

	/*--- Verify if asked mode can be used ---*/
	if (flags & SDL_FULLSCREEN) {
		maxwidth=VDI_w;
		maxheight=VDI_h;
	} else {
		/* Windowed mode */
		maxwidth=GEM_desk_w;
		maxheight=GEM_desk_h;
	}

	/* width must be multiple of 16, for vro_cpyfm() and c2p_convert() */
	if ((width & 15) != 0) {
		width = (width | 15) +1;
	}

	if ((maxwidth < width) || (maxheight < height) || (VDI_bpp != bpp)) {
		SDL_SetError("Couldn't find requested mode in list");
		return(NULL);
	}

	/*--- Allocate the new pixel format for the screen ---*/
	if ( ! SDL_ReallocFormat(current, VDI_bpp, VDI_redmask, VDI_greenmask, VDI_bluemask, VDI_alphamask) ) {
		SDL_SetError("Couldn't allocate new pixel format for requested mode");
		return(NULL);
	}

	screensize = width * height * VDI_pixelsize;

#ifdef DEBUG_VIDEO_GEM
	printf("sdl:video:gem: setvideomode(): %dx%dx%d = %d\n", width, height, bpp, screensize);
#endif

	/*--- Allocate shadow buffers if needed, and conversion operations ---*/
	GEM_FreeBuffers(this);

	GEM_bufops=0;
	use_shadow1=use_shadow2=SDL_FALSE;
	if (VDI_screen && (flags & SDL_FULLSCREEN)) {
		if (VDI_format==VDI_FORMAT_INTER) {
			use_shadow1=SDL_TRUE;
			GEM_bufops = B2S_C2P_1TOS;
		}
	} else {
		use_shadow1=SDL_TRUE;
		if (VDI_format==VDI_FORMAT_PACK) {
			GEM_bufops = B2S_VROCPYFM_1TOS;
		} else {
			use_shadow2=SDL_TRUE;
			GEM_bufops = B2S_C2P_1TO2|B2S_VROCPYFM_2TOS;
		}
	}

	if (use_shadow1) {
		GEM_buffer1 = Atari_SysMalloc(screensize, MX_PREFTTRAM);
		if (GEM_buffer1==NULL) {
			SDL_SetError("Can not allocate %d KB for frame buffer", screensize>>10);
			return NULL;
		}
		SDL_memset(GEM_buffer1, 0, screensize);
#ifdef DEBUG_VIDEO_GEM
		printf("sdl:video:gem: setvideomode(): allocated buffer 1\n");
#endif
	}

	if (use_shadow2) {
		GEM_buffer2 = Atari_SysMalloc(screensize, MX_PREFTTRAM);
		if (GEM_buffer2==NULL) {
			SDL_SetError("Can not allocate %d KB for shadow buffer", screensize>>10);
			return NULL;
		}
		SDL_memset(GEM_buffer2, 0, screensize);
#ifdef DEBUG_VIDEO_GEM
		printf("sdl:video:gem: setvideomode(): allocated buffer 2\n");
#endif
	}

	/*--- Initialize screen ---*/
	modeflags = SDL_PREALLOC;
	if (VDI_bpp == 8) {
		modeflags |= SDL_HWPALETTE;
	}

	if (flags & SDL_FULLSCREEN) {
		GEM_LockScreen(this);

		GEM_ClearScreen(this);

		modeflags |= SDL_FULLSCREEN;
		if (VDI_screen && (VDI_format==VDI_FORMAT_PACK) && !use_shadow1) {
			modeflags |= SDL_HWSURFACE;
		} else {
			modeflags |= SDL_SWSURFACE;
		}

		GEM_fullscreen = SDL_TRUE;
	} else {
		int old_win_type;
		short x2,y2,w2,h2;

		GEM_UnlockScreen(this);

		/* Set window gadgets */
		old_win_type = GEM_win_type;
		if (!(flags & SDL_NOFRAME)) {
			GEM_win_type=NAME|MOVER|CLOSER|SMALLER;
			if (flags & SDL_RESIZABLE) {
				GEM_win_type |= FULLER|SIZER;
				modeflags |= SDL_RESIZABLE;
			}
		} else {
			GEM_win_type=0;
			modeflags |= SDL_NOFRAME;
		}
		modeflags |= SDL_SWSURFACE;

		/* Recreate window ? only for different widget or non-created window */
		if ((old_win_type != GEM_win_type) || (GEM_handle < 0)) {
			/* Calculate window size */
			if (!wind_calc(WC_BORDER, GEM_win_type, 0,0,width,height, &x2,&y2,&w2,&h2)) {
				GEM_FreeBuffers(this);
				SDL_SetError("Can not calculate window attributes");
				return NULL;
			}

			/* Center window */
			x2 = GEM_desk_x+((GEM_desk_w-w2)>>1);
			y2 = GEM_desk_y+((GEM_desk_h-h2)>>1);

			/* Destroy existing window */
			if (GEM_handle >= 0) {
				wind_close(GEM_handle);
				wind_delete(GEM_handle);
			}

			/* Create window */
			GEM_handle=wind_create(GEM_win_type, x2,y2,w2,h2);
			if (GEM_handle<0) {
				GEM_FreeBuffers(this);
				SDL_SetError("Can not create window");
				return NULL;
			}

#ifdef DEBUG_VIDEO_GEM
			printf("sdl:video:gem: handle=%d\n", GEM_handle);
#endif

			/* Setup window name */
			wind_set(GEM_handle,WF_NAME,(short)(((unsigned long)GEM_title_name)>>16),(short)(((unsigned long)GEM_title_name) & 0xffff),0,0);
			GEM_refresh_name = SDL_FALSE;

			/* Open the window */
			wind_open(GEM_handle,x2,y2,w2,h2);
		} else {
			/* Resize window if needed, to fit asked video mode */
			if (modeflags & SDL_RESIZABLE) {
				wind_get (GEM_handle, WF_WORKXYWH, &x2,&y2,&w2,&h2);
				if ((w2&15)!=0) {
					w2=(w2|15)+1;
				}
				if ((w2!=width) || (h2!=height)) {
					if (wind_calc(WC_BORDER, GEM_win_type, x2,y2,width,height, &x2,&y2,&w2,&h2)) {
						wind_set (GEM_handle, WF_CURRXYWH, x2,y2,w2,h2);
					}
				}
			}
		}

		GEM_fullscreen = SDL_FALSE;
	}

	/* Set up the new mode framebuffer */
	current->w = width;
	current->h = height;
	if (use_shadow1) {
		current->pixels = GEM_buffer1;
		current->pitch = width * VDI_pixelsize;
	} else {
		current->pixels = VDI_screen;
		current->pitch = VDI_pitch;
	}

#if SDL_VIDEO_OPENGL
	if (flags & SDL_OPENGL) {
		if (!SDL_AtariGL_Init(this, current)) {
			GEM_FreeBuffers(this);
			SDL_SetError("Can not create OpenGL context");
			return NULL;
		}

		modeflags |= SDL_OPENGL;
	}
#endif

	current->flags = modeflags;

#ifdef DEBUG_VIDEO_GEM
	printf("sdl:video:gem: surface: %dx%d\n", current->w, current->h);
#endif

	this->UpdateRects = GEM_UpdateRects;
	GEM_lock_redraw = SDL_FALSE;	/* Enable redraw */

	/* We're done */
	return(current);
}

static int GEM_AllocHWSurface(_THIS, SDL_Surface *surface)
{
	return -1;
}

static void GEM_FreeHWSurface(_THIS, SDL_Surface *surface)
{
	return;
}

static int GEM_LockHWSurface(_THIS, SDL_Surface *surface)
{
	return(0);
}

static void GEM_UnlockHWSurface(_THIS, SDL_Surface *surface)
{
	return;
}

static void GEM_UpdateRectsFullscreen(_THIS, int numrects, SDL_Rect *rects)
{
	SDL_Surface *surface;
	int i, surf_width;

	surface = this->screen;
	/* Need to be a multiple of 16 pixels */
	surf_width=surface->w;
	if ((surf_width & 15) != 0) {
		surf_width = (surf_width | 15) + 1;
	}

	if (GEM_bufops & (B2S_C2P_1TO2|B2S_C2P_1TOS)) {
		void *destscr;
		int destpitch;

		if (GEM_bufops & B2S_C2P_1TOS) {
			destscr = VDI_screen;
			destpitch = VDI_pitch;
		} else {
			destscr = GEM_buffer2;
			destpitch = surface->pitch;
		}

		for (i=0;i<numrects;i++) {
			void *source,*destination;
			int x1,x2;

			x1 = rects[i].x & ~15;
			x2 = rects[i].x+rects[i].w;
			if (x2 & 15) {
				x2 = (x2 | 15) +1;
			}

			source = surface->pixels;
			source += surface->pitch * rects[i].y;
			source += x1;

			destination = destscr;
			destination += destpitch * rects[i].y;
			destination += x1;

			SDL_Atari_C2pConvert(
				source, destination,
				x2-x1, rects[i].h,
				SDL_FALSE,
				surface->pitch, destpitch
			);
		}
	}

	if (GEM_bufops & (B2S_VROCPYFM_1TOS|B2S_VROCPYFM_2TOS)) {
		MFDB mfdb_src;
		short blitcoords[8];

		mfdb_src.fd_addr=surface->pixels;
		mfdb_src.fd_w=surf_width;
		mfdb_src.fd_h=surface->h;
		mfdb_src.fd_wdwidth= (surface->pitch/VDI_pixelsize) >> 4;
		mfdb_src.fd_nplanes=surface->format->BitsPerPixel;
		mfdb_src.fd_stand=
			mfdb_src.fd_r1=
			mfdb_src.fd_r2=
			mfdb_src.fd_r3= 0;
		if (GEM_bufops & B2S_VROCPYFM_2TOS) {
			mfdb_src.fd_addr=GEM_buffer2;
		}

		for ( i=0; i<numrects; ++i ) {
			blitcoords[0] = blitcoords[4] = rects[i].x;
			blitcoords[1] = blitcoords[5] = rects[i].y;
			blitcoords[2] = blitcoords[6] = rects[i].x + rects[i].w - 1;
			blitcoords[3] = blitcoords[7] = rects[i].y + rects[i].h - 1;

			vro_cpyfm(VDI_handle, S_ONLY, blitcoords, &mfdb_src, &VDI_dst_mfdb);
		}
	}
}

static void GEM_UpdateRectsWindowed(_THIS, int numrects, SDL_Rect *rects)
{
	short pxy[4], wind_pxy[4];
	int i;

	if (wind_get(GEM_handle, WF_WORKXYWH, &wind_pxy[0], &wind_pxy[1], &wind_pxy[2], &wind_pxy[3])==0) {
		return;
	}

	for ( i=0; i<numrects; ++i ) {
		pxy[0] = wind_pxy[0] + rects[i].x;
		pxy[1] = wind_pxy[1] + rects[i].y;
		pxy[2] = rects[i].w;
		pxy[3] = rects[i].h;

		GEM_wind_redraw(this, GEM_handle, pxy);
	}
}

static void GEM_UpdateRects(_THIS, int numrects, SDL_Rect *rects)
{
	SDL_Surface *surface;

	if (GEM_lock_redraw) {
		return;
	}

	surface = this->screen;

	if (surface->flags & SDL_FULLSCREEN) {
		GEM_UpdateRectsFullscreen(this, numrects, rects);
	} else {
		GEM_UpdateRectsWindowed(this, numrects, rects);
	}
}

static int GEM_FlipHWSurfaceFullscreen(_THIS, SDL_Surface *surface)
{
	int surf_width;

	/* Need to be a multiple of 16 pixels */
	surf_width=surface->w;
	if ((surf_width & 15) != 0) {
		surf_width = (surf_width | 15) + 1;
	}

	if (GEM_bufops & (B2S_C2P_1TO2|B2S_C2P_1TOS)) {
		void *destscr;
		int destpitch;

		if (GEM_bufops & B2S_C2P_1TOS) {
			destscr = VDI_screen;
			destpitch = VDI_pitch;
		} else {
			destscr = GEM_buffer2;
			destpitch = surface->pitch;
		}

		SDL_Atari_C2pConvert(
			surface->pixels, destscr,
			surf_width, surface->h,
			SDL_FALSE,
			surface->pitch, destpitch
		);
	}

	if (GEM_bufops & (B2S_VROCPYFM_1TOS|B2S_VROCPYFM_2TOS)) {
		MFDB mfdb_src;
		short blitcoords[8];

		mfdb_src.fd_w=surf_width;
		mfdb_src.fd_h=surface->h;
		mfdb_src.fd_wdwidth=mfdb_src.fd_w >> 4;
		mfdb_src.fd_nplanes=surface->format->BitsPerPixel;
		mfdb_src.fd_stand=
			mfdb_src.fd_r1=
			mfdb_src.fd_r2=
			mfdb_src.fd_r3= 0;
		if (GEM_bufops & B2S_VROCPYFM_1TOS) {
			mfdb_src.fd_addr=surface->pixels;
		} else {
			mfdb_src.fd_addr=GEM_buffer2;
		}

		blitcoords[0] = blitcoords[4] = 0;
		blitcoords[1] = blitcoords[5] = 0;
		blitcoords[2] = blitcoords[6] = surface->w - 1;
		blitcoords[3] = blitcoords[7] = surface->h - 1;

		vro_cpyfm(VDI_handle, S_ONLY, blitcoords, &mfdb_src, &VDI_dst_mfdb);
	}

	return(0);
}

static int GEM_FlipHWSurfaceWindowed(_THIS, SDL_Surface *surface)
{
	short	pxy[8];

	/* Update the whole window */
	wind_get(GEM_handle, WF_WORKXYWH, &pxy[0], &pxy[1], &pxy[2], &pxy[3]);

	GEM_wind_redraw(this, GEM_handle, pxy);

	return(0);
}

static int GEM_FlipHWSurface(_THIS, SDL_Surface *surface)
{
	if (GEM_lock_redraw) {
		return(0);
	}

	if (surface->flags & SDL_FULLSCREEN) {
		return GEM_FlipHWSurfaceFullscreen(this, surface);
	} else {
		return GEM_FlipHWSurfaceWindowed(this, surface);
	}
}

static int GEM_SetColors(_THIS, int firstcolor, int ncolors, SDL_Color *colors)
{
	int i;
	SDL_Surface *surface;

#ifdef DEBUG_VIDEO_GEM
	printf("sdl:video:gem: setcolors()\n");
#endif

	/* Do not change palette in True Colour */
	surface = this->screen;
	if (surface->format->BitsPerPixel > 8) {
		return 1;
	}

	for(i = 0; i < ncolors; i++)
	{
		int		r, g, b;
		short	rgb[3];

		r = colors[i].r;
		g = colors[i].g;
		b = colors[i].b;

		rgb[0] = VDI_curpalette[i][0] = (1000 * r) / 255;
		rgb[1] = VDI_curpalette[i][1] =(1000 * g) / 255;
		rgb[2] = VDI_curpalette[i][2] =(1000 * b) / 255;

		vs_color(VDI_handle, vdi_index[firstcolor+i], rgb);
	}

	return(1);
}

#if 0
static int GEM_ToggleFullScreen(_THIS, int on)
{
	if (on) {
		GEM_LockScreen(this);
	} else {
		GEM_UnlockScreen(this);
	}

	return(1);
}
#endif

/* Note:  If we are terminated, this could be called in the middle of
   another SDL video routine -- notably UpdateRects.
*/
void GEM_VideoQuit(_THIS)
{
	SDL_AtariXbios_RestoreVectors();
	if (GEM_usedevmouse) {
		SDL_AtariDevMouse_Close();
	}

	GEM_FreeBuffers(this);

#if SDL_VIDEO_OPENGL
	if (gl_active) {
		SDL_AtariGL_Quit(this, SDL_TRUE);
	}
#endif

	/* Destroy window */
	if (GEM_handle>=0) {
		wind_close(GEM_handle);
		wind_delete(GEM_handle);
		GEM_handle=-1;
	}

	GEM_UnlockScreen(this);
	if (GEM_menubar) {
		Mfree(GEM_menubar);
		GEM_menubar=NULL;
	}

	appl_exit();

	GEM_SetNewPalette(this, VDI_oldpalette);

	/* Close VDI workstation */
	if (VDI_handle) {
		v_clsvwk(VDI_handle);
	}

	/* Free mode list */
	if (SDL_modelist[0]) {
		SDL_free(SDL_modelist[0]);
		SDL_modelist[0]=NULL;
	}

	this->screen->pixels = NULL;	
}

void GEM_wind_redraw(_THIS, int winhandle, short *inside)
{
	short todo[4];

	/* Tell AES we are going to update */
	wind_update(BEG_UPDATE);

	v_hide_c(VDI_handle);

	/* Browse the rectangle list to redraw */
	if (wind_get(winhandle, WF_FIRSTXYWH, &todo[0], &todo[1], &todo[2], &todo[3])!=0) {

		while (todo[2] && todo[3]) {

			if (rc_intersect((GRECT *)inside,(GRECT *)todo)) {
				todo[2] += todo[0]-1;
				todo[3] += todo[1]-1;
				refresh_window(this, winhandle, todo);
			}

			if (wind_get(winhandle, WF_NEXTXYWH, &todo[0], &todo[1], &todo[2], &todo[3])==0) {
				break;
			}
		}

	}

	/* Update finished */
	wind_update(END_UPDATE);

	v_show_c(VDI_handle,1);
}

static void refresh_window(_THIS, int winhandle, short *rect)
{
	MFDB mfdb_src;
	short pxy[8],wind_pxy[8];
	SDL_Surface *surface;
	int iconified;

	/* Is window iconified ? */
	iconified = 0;
/*	if (GEM_wfeatures & (1<<WF_ICONIFY))*/ {
		if (wind_get(winhandle, WF_ICONIFY, &wind_pxy[0], &wind_pxy[1], &wind_pxy[2], &wind_pxy[3])!=0) {
			iconified = wind_pxy[0];
		}
	}

	if (wind_get(winhandle, WF_WORKXYWH, &wind_pxy[0], &wind_pxy[1], &wind_pxy[2], &wind_pxy[3])==0) {
		return;
	}

	if (iconified && GEM_icon) {
		short icon_rect[4], dst_rect[4];
		short iconx,icony;
		
		surface = GEM_icon;

		GEM_ClearRect(this, rect);

		/* Calculate centered icon(x,y,w,h) relative to window */
		iconx = (wind_pxy[2]-surface->w)>>1;
		icony = (wind_pxy[3]-surface->h)>>1;

		icon_rect[0] = iconx;
		icon_rect[1] = icony;
		icon_rect[2] = surface->w;
		icon_rect[3] = surface->h;

		/* Calculate redraw rectangle(x,y,w,h) relative to window */
		dst_rect[0] = rect[0]-wind_pxy[0];
		dst_rect[1] = rect[1]-wind_pxy[1];
		dst_rect[2] = rect[2]-rect[0]+1;
		dst_rect[3] = rect[3]-rect[1]+1;

		/* Does the icon rectangle must be redrawn ? */
		if (!rc_intersect((GRECT *)icon_rect, (GRECT *)dst_rect)) {
			return;
		}

#if DEBUG_VIDEO_GEM
		printf("sdl:video:gem:  clip(0,0,%d,%d) to (%d,%d,%d,%d)\n",
			surface->w-1,surface->h-1, dst_rect[0],dst_rect[1],dst_rect[2],dst_rect[3]);
		printf("sdl:video:gem:  icon(%d,%d,%d,%d)\n",
			icon_rect[0], icon_rect[1], icon_rect[2], icon_rect[3]);
		printf("sdl:video:gem: refresh_window(): draw icon\n");
#endif

		/* Calculate icon(x1,y1,x2,y2) relative to screen */
		icon_rect[0] += wind_pxy[0];
		icon_rect[1] += wind_pxy[1];
		icon_rect[2] += icon_rect[0]-1;
		icon_rect[3] += icon_rect[1]-1;

		/* Calculate intersection rectangle to redraw */
		pxy[4]=pxy[0]=MAX(icon_rect[0],rect[0]);
		pxy[5]=pxy[1]=MAX(icon_rect[1],rect[1]);
 		pxy[6]=pxy[2]=MIN(icon_rect[2],rect[2]);
	 	pxy[7]=pxy[3]=MIN(icon_rect[3],rect[3]);

		/* Calculate icon source image pos relative to window */
		pxy[0] -= wind_pxy[0]+iconx;
		pxy[1] -= wind_pxy[1]+icony;
		pxy[2] -= wind_pxy[0]+iconx;
		pxy[3] -= wind_pxy[1]+icony;

	} else {
		surface = this->screen;

#if DEBUG_VIDEO_GEM
		printf("sdl:video:gem: refresh_window(): draw frame buffer\n");
#endif

		/* Redraw all window content */
		pxy[0] = rect[0]-wind_pxy[0];
		pxy[1] = rect[1]-wind_pxy[1];
	 	pxy[2] = rect[2]-wind_pxy[0];   
	 	pxy[3] = rect[3]-wind_pxy[1];  

		pxy[4] = rect[0];
		pxy[5] = rect[1];
		pxy[6] = rect[2];  
		pxy[7] = rect[3];
	}

	if (GEM_bufops & B2S_C2P_1TO2) {
		void *src, *dest;
		int x1,x2;

		x1 = (rect[0]-wind_pxy[0]) & ~15;
		x2 = rect[2]-wind_pxy[0];
		if (x2 & 15) {
			x2 = (x2 | 15) +1;
		}

		src = surface->pixels;
		src += surface->pitch * (rect[1]-wind_pxy[1]);
		src += x1;

		dest = GEM_buffer2;
		dest += surface->pitch * (rect[1]-wind_pxy[1]);
		dest += x1;

		SDL_Atari_C2pConvert(
			src, dest,
			x2-x1, rect[3]-rect[1]+1,
			SDL_FALSE,
			surface->pitch, surface->pitch
		);
	}

	mfdb_src.fd_addr=surface->pixels;
	{
		int width;

		/* Need to be a multiple of 16 pixels */
		width=surface->w;
		if ((width & 15) != 0) {
			width = (width | 15) + 1;
		}
		mfdb_src.fd_w=width;
	}
	mfdb_src.fd_h=surface->h;
  	mfdb_src.fd_nplanes=surface->format->BitsPerPixel;
	mfdb_src.fd_wdwidth=mfdb_src.fd_w>>4;
	mfdb_src.fd_stand=
		mfdb_src.fd_r1=
  		mfdb_src.fd_r2=
	  	mfdb_src.fd_r3= 0;

	if (GEM_bufops & B2S_VROCPYFM_2TOS) {
		mfdb_src.fd_addr=GEM_buffer2;
	}

#if DEBUG_VIDEO_GEM
	printf("sdl:video:gem: redraw %dx%d: (%d,%d,%d,%d) to (%d,%d,%d,%d)\n",
		surface->w, surface->h,
		pxy[0],pxy[1],pxy[2],pxy[3],
		pxy[4],pxy[5],pxy[6],pxy[7]
	);
#endif

	vro_cpyfm( VDI_handle, S_ONLY, pxy, &mfdb_src, &VDI_dst_mfdb);
}

#if SDL_VIDEO_OPENGL

static void GEM_GL_SwapBuffers(_THIS)
{
	SDL_AtariGL_SwapBuffers(this);
	GEM_FlipHWSurface(this, this->screen);
}

#endif