view src/video/ipod/SDL_ipodvideo.c @ 4179:d7294b7c732d SDL-1.2

Date: Fri, 24 Apr 2009 17:47:07 +0200 From: Stefan Klug Subject: Re: [SDL] SVN doesn't compile for wince the patch applied for Revision 4483 was seemingly not checked for side effects. It broke the WinCE build. The attached patch should fix these problems. I'm not using SDL 1.2 on CE anymore, and therefore haven't tested the patch... but at least it compiles ;-) Regards Stefan
author Sam Lantinga <slouken@libsdl.org>
date Thu, 07 May 2009 12:40:16 +0000
parents a1b03ba2fcd0
children
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 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"

#include <sys/types.h>
#include <sys/ioctl.h>

#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <termios.h>
#include <ctype.h>

#include <linux/vt.h>
#include <linux/kd.h>
#include <linux/keyboard.h>
#include <linux/fb.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_sysevents.h"
#include "SDL_ipodvideo.h"

#define _THIS SDL_VideoDevice *this

static int iPod_VideoInit (_THIS, SDL_PixelFormat *vformat);
static SDL_Rect **iPod_ListModes (_THIS, SDL_PixelFormat *format, Uint32 flags);
static SDL_Surface *iPod_SetVideoMode (_THIS, SDL_Surface *current, int width, int height, int bpp, Uint32 flags);
static int iPod_SetColors (_THIS, int firstcolor, int ncolors, SDL_Color *colors);
static void iPod_UpdateRects (_THIS, int nrects, SDL_Rect *rects);
static void iPod_VideoQuit (_THIS);
static void iPod_PumpEvents (_THIS);

static long iPod_GetGeneration();

static int initd = 0;
static int kbfd = -1;
static int fbfd = -1;
static int oldvt = -1;
static int curvt = -1;
static int old_kbmode = -1;
static long generation = 0;
static struct termios old_termios, cur_termios;

FILE *dbgout;

#define LCD_DATA          0x10
#define LCD_CMD           0x08
#define IPOD_OLD_LCD_BASE 0xc0001000
#define IPOD_OLD_LCD_RTC  0xcf001110
#define IPOD_NEW_LCD_BASE 0x70003000
#define IPOD_NEW_LCD_RTC  0x60005010

static unsigned long lcd_base, lcd_rtc, lcd_width, lcd_height;

static long iPod_GetGeneration() 
{
    int i;
    char cpuinfo[256];
    char *ptr;
    FILE *file;
    
    if ((file = fopen("/proc/cpuinfo", "r")) != NULL) {
	while (fgets(cpuinfo, sizeof(cpuinfo), file) != NULL)
	    if (SDL_strncmp(cpuinfo, "Revision", 8) == 0)
		break;
	fclose(file);
    }
    for (i = 0; !isspace(cpuinfo[i]); i++);
    for (; isspace(cpuinfo[i]); i++);
    ptr = cpuinfo + i + 2;
    
    return SDL_strtol(ptr, NULL, 10);
}

static int iPod_Available() 
{
    return 1;
}

static void iPod_DeleteDevice (SDL_VideoDevice *device)
{
    free (device->hidden);
    free (device);
}

void iPod_InitOSKeymap (_THIS) {}

static SDL_VideoDevice *iPod_CreateDevice (int devindex)
{
    SDL_VideoDevice *this;
    
    this = (SDL_VideoDevice *)SDL_malloc (sizeof(SDL_VideoDevice));
    if (this) {
	memset (this, 0, sizeof *this);
	this->hidden = (struct SDL_PrivateVideoData *) SDL_malloc (sizeof(struct SDL_PrivateVideoData));
    }
    if (!this || !this->hidden) {
	SDL_OutOfMemory();
	if (this)
	    SDL_free (this);
	return 0;
    }
    memset (this->hidden, 0, sizeof(struct SDL_PrivateVideoData));
    
    generation = iPod_GetGeneration();

    this->VideoInit = iPod_VideoInit;
    this->ListModes = iPod_ListModes;
    this->SetVideoMode = iPod_SetVideoMode;
    this->SetColors = iPod_SetColors;
    this->UpdateRects = iPod_UpdateRects;
    this->VideoQuit = iPod_VideoQuit;
    this->AllocHWSurface = 0;
    this->CheckHWBlit = 0;
    this->FillHWRect = 0;
    this->SetHWColorKey = 0;
    this->SetHWAlpha = 0;
    this->LockHWSurface = 0;
    this->UnlockHWSurface = 0;
    this->FlipHWSurface = 0;
    this->FreeHWSurface = 0;
    this->SetCaption = 0;
    this->SetIcon = 0;
    this->IconifyWindow = 0;
    this->GrabInput = 0;
    this->GetWMInfo = 0;
    this->InitOSKeymap = iPod_InitOSKeymap;
    this->PumpEvents = iPod_PumpEvents;
    this->free = iPod_DeleteDevice;

    return this;
}

VideoBootStrap iPod_bootstrap = {
    "ipod", "iPod Framebuffer Driver",
    iPod_Available, iPod_CreateDevice
};

//--//

static int iPod_VideoInit (_THIS, SDL_PixelFormat *vformat)
{
    if (!initd) {
	/*** Code adapted/copied from SDL fbcon driver. ***/

	static const char * const tty0[] = { "/dev/tty0", "/dev/vc/0", 0 };
	static const char * const vcs[] = { "/dev/vc/%d", "/dev/tty%d", 0 };
	int i, tty0_fd;

	dbgout = fdopen (open ("/etc/sdlpod.log", O_WRONLY | O_SYNC | O_APPEND), "a");
	if (dbgout) {
	    setbuf (dbgout, 0);
	    fprintf (dbgout, "--> Started SDL <--\n");
	}

	// Try to query for a free VT
	tty0_fd = -1;
	for ( i=0; tty0[i] && (tty0_fd < 0); ++i ) {
	    tty0_fd = open(tty0[i], O_WRONLY, 0);
	}
	if ( tty0_fd < 0 ) {
	    tty0_fd = dup(0); /* Maybe stdin is a VT? */
	}
	ioctl(tty0_fd, VT_OPENQRY, &curvt);
	close(tty0_fd);

	tty0_fd = open("/dev/tty", O_RDWR, 0);
	if ( tty0_fd >= 0 ) {
	    ioctl(tty0_fd, TIOCNOTTY, 0);
	    close(tty0_fd);
	}

	if ( (geteuid() == 0) && (curvt > 0) ) {
	    for ( i=0; vcs[i] && (kbfd < 0); ++i ) {
		char vtpath[12];
		
		SDL_snprintf(vtpath, SDL_arraysize(vtpath), vcs[i], curvt);
		kbfd = open(vtpath, O_RDWR);
	    }
	}
	if ( kbfd < 0 ) {
	    if (dbgout) fprintf (dbgout, "Couldn't open any VC\n");
	    return -1;
	}
	if (dbgout) fprintf (stderr, "Current VT: %d\n", curvt);

	if (kbfd >= 0) {
	    /* Switch to the correct virtual terminal */
	    if ( curvt > 0 ) {
		struct vt_stat vtstate;
		
		if ( ioctl(kbfd, VT_GETSTATE, &vtstate) == 0 ) {
		    oldvt = vtstate.v_active;
		}
		if ( ioctl(kbfd, VT_ACTIVATE, curvt) == 0 ) {
		    if (dbgout) fprintf (dbgout, "Waiting for switch to this VT... ");
		    ioctl(kbfd, VT_WAITACTIVE, curvt);
		    if (dbgout) fprintf (dbgout, "done!\n");
		}
	    }

	    // Set terminal input mode
	    if (tcgetattr (kbfd, &old_termios) < 0) {
		if (dbgout) fprintf (dbgout, "Can't get termios\n");
		return -1;
	    }
	    cur_termios = old_termios;
	    //	    cur_termios.c_iflag &= ~(ICRNL | INPCK | ISTRIP | IXON);
	    //	    cur_termios.c_iflag |= (BRKINT);
	    //	    cur_termios.c_lflag &= ~(ICANON | ECHO | ISIG | IEXTEN);
	    //	    cur_termios.c_oflag &= ~(OPOST);
	    //	    cur_termios.c_oflag |= (ONOCR | ONLRET);
	    cur_termios.c_lflag &= ~(ICANON | ECHO | ISIG);
	    cur_termios.c_iflag &= ~(ISTRIP | IGNCR | ICRNL | INLCR | IXOFF | IXON);
	    cur_termios.c_cc[VMIN] = 0;
	    cur_termios.c_cc[VTIME] = 0;
	    
	    if (tcsetattr (kbfd, TCSAFLUSH, &cur_termios) < 0) {
		if (dbgout) fprintf (dbgout, "Can't set termios\n");
		return -1;
	    }
	    if (ioctl (kbfd, KDSKBMODE, K_MEDIUMRAW) < 0) {
		if (dbgout) fprintf (dbgout, "Can't set medium-raw mode\n");
		return -1;
	    }
	    if (ioctl (kbfd, KDSETMODE, KD_GRAPHICS) < 0) {
		if (dbgout) fprintf (dbgout, "Can't set graphics\n");
		return -1;
	    }
	}

	// Open the framebuffer
	if ((fbfd = open ("/dev/fb0", O_RDWR)) < 0) {
	    if (dbgout) fprintf (dbgout, "Can't open framebuffer\n");
	    return -1;
	} else {
	    struct fb_var_screeninfo vinfo;

	    if (dbgout) fprintf (dbgout, "Generation: %ld\n", generation);

	    if (generation >= 40000) {
		lcd_base = IPOD_NEW_LCD_BASE;
	    } else {
		lcd_base = IPOD_OLD_LCD_BASE;
	    }
	    
	    ioctl (fbfd, FBIOGET_VSCREENINFO, &vinfo);
	    close (fbfd);

	    if (lcd_base == IPOD_OLD_LCD_BASE)
		lcd_rtc = IPOD_OLD_LCD_RTC;
	    else if (lcd_base == IPOD_NEW_LCD_BASE)
		lcd_rtc = IPOD_NEW_LCD_RTC;
	    else {
		SDL_SetError ("Unknown iPod version");
		return -1;
	    }

	    lcd_width = vinfo.xres;
	    lcd_height = vinfo.yres;

	    if (dbgout) fprintf (dbgout, "LCD is %dx%d\n", lcd_width, lcd_height);
	}

	fcntl (kbfd, F_SETFL, O_RDWR | O_NONBLOCK);

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

	if ((generation >= 60000) && (generation < 70000)) {
	    vformat->BitsPerPixel = 16;
	    vformat->Rmask = 0xF800;
	    vformat->Gmask = 0x07E0;
	    vformat->Bmask = 0x001F;
	} else {
	    vformat->BitsPerPixel = 8;
	    vformat->Rmask = vformat->Gmask = vformat->Bmask = 0;
	}

	initd = 1;
	if (dbgout) fprintf (dbgout, "Initialized.\n\n");
    }
    return 0;
}

static SDL_Rect **iPod_ListModes (_THIS, SDL_PixelFormat *format, Uint32 flags)
{
    int width, height, fd;
    static SDL_Rect r;
    static SDL_Rect *rs[2] = { &r, 0 };

    if ((fd = open ("/dev/fb0", O_RDWR)) < 0) {
	return 0;
    } else {
	struct fb_var_screeninfo vinfo;
	
	ioctl (fbfd, FBIOGET_VSCREENINFO, &vinfo);
	close (fbfd);
	
	width = vinfo.xres;
	height = vinfo.yres;
    }
    r.x = r.y = 0;
    r.w = width;
    r.h = height;
    return rs;
}


static SDL_Surface *iPod_SetVideoMode (_THIS, SDL_Surface *current, int width, int height, int bpp,
				       Uint32 flags)
{
    Uint32 Rmask, Gmask, Bmask;
    if (bpp > 8) {
	Rmask = 0xF800;
	Gmask = 0x07E0;
	Bmask = 0x001F;	
    } else {
	Rmask = Gmask = Bmask = 0;
    }

    if (this->hidden->buffer) SDL_free (this->hidden->buffer);
    this->hidden->buffer = SDL_malloc (width * height * (bpp / 8));
    if (!this->hidden->buffer) {
	SDL_SetError ("Couldn't allocate buffer for requested mode");
	return 0;
    }

    memset (this->hidden->buffer, 0, width * height * (bpp / 8));

    if (!SDL_ReallocFormat (current, bpp, Rmask, Gmask, Bmask, 0)) {
	SDL_SetError ("Couldn't allocate new pixel format");
	SDL_free (this->hidden->buffer);
	this->hidden->buffer = 0;
	return 0;
    }

    if (bpp <= 8) {
	int i, j;
	for (i = 0; i < 256; i += 4) {
	    for (j = 0; j < 4; j++) {
		current->format->palette->colors[i+j].r = 85 * j;
		current->format->palette->colors[i+j].g = 85 * j;
		current->format->palette->colors[i+j].b = 85 * j;
	    }
	}
    }

    current->flags = flags & SDL_FULLSCREEN;
    this->hidden->w = current->w = width;
    this->hidden->h = current->h = height;
    current->pitch = current->w * (bpp / 8);
    current->pixels = this->hidden->buffer;

    return current;
}

static int iPod_SetColors (_THIS, int firstcolor, int ncolors, SDL_Color *colors)
{
    if (SDL_VideoSurface && SDL_VideoSurface->format && SDL_VideoSurface->format->palette) {
	int i, j;
	for (i = 0; i < 256; i += 4) {
	    for (j = 0; j < 4; j++) {
		SDL_VideoSurface->format->palette->colors[i+j].r = 85 * j;
		SDL_VideoSurface->format->palette->colors[i+j].g = 85 * j;
		SDL_VideoSurface->format->palette->colors[i+j].b = 85 * j;
	    }
	}
    }
    return 0;
}

static void iPod_VideoQuit (_THIS)
{
    ioctl (kbfd, KDSETMODE, KD_TEXT);
    tcsetattr (kbfd, TCSAFLUSH, &old_termios);
    old_kbmode = -1;

    if (oldvt > 0)
	ioctl (kbfd, VT_ACTIVATE, oldvt);
    
    if (kbfd > 0)
	close (kbfd);

    if (dbgout) {
	fprintf (dbgout, "<-- Ended SDL -->\n");
	fclose (dbgout);
    }
    
    kbfd = -1;
}

static char iPod_SC_keymap[] = {
    0,				/* 0 - no key */
    '[' - 0x40,			/* ESC (Ctrl+[) */
    '1', '2', '3', '4', '5', '6', '7', '8', '9',
    '-', '=',
    '\b', '\t',			/* Backspace, Tab (Ctrl+H,Ctrl+I) */
    'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']',
    '\n', 0,			/* Enter, Left CTRL */
    'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`',
    0, '\\',			/* left shift, backslash */
    'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/',
    0, '*', 0, ' ', 0,		/* right shift, KP mul, left alt, space, capslock */
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* F1-10 */
    0, 0,			/* numlock, scrollock */
    '7', '8', '9', '-', '4', '5', '6', '+', '1', '2', '3', '0', '.', /* numeric keypad */
    0, 0,			/* padding */
    0, 0, 0,			/* "less" (?), F11, F12 */
    0, 0, 0, 0, 0, 0, 0,	/* padding */
    '\n', 0, '/', 0, 0,	/* KP enter, Rctrl, Ctrl, KP div, PrtSc, RAlt */
    0, 0, 0, 0, 0, 0, 0, 0, 0,	/* Break, Home, Up, PgUp, Left, Right, End, Down, PgDn */
    0, 0,			/* Ins, Del */
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* padding */
    0, 0,			/* RWin, LWin */
    0				/* no key */
};
    

static void iPod_keyboard() 
{
    unsigned char keybuf[128];
    int i, nread;
    SDL_keysym keysym;
    SDL_Event ev;

    keysym.mod = 0;
    keysym.scancode = 0xff;
    memset (&ev, 0, sizeof(SDL_Event));

    nread = read (kbfd, keybuf, 128);
    for (i = 0; i < nread; i++) {
	char ascii = iPod_SC_keymap[keybuf[i] & 0x7f];

	if (dbgout) fprintf (dbgout, "Key! %02x is %c %s", keybuf[i], ascii, (keybuf[i] & 0x80)? "up" : "down");

	keysym.sym = keysym.unicode = ascii;
	ev.type = (keybuf[i] & 0x80)? SDL_KEYUP : SDL_KEYDOWN;
	ev.key.state = 0;
	ev.key.keysym = keysym;
	SDL_PushEvent (&ev);
    }
}

static void iPod_PumpEvents (_THIS) 
{
    fd_set fdset;
    int max_fd = 0;
    static struct timeval zero;
    int posted;

    do {
	posted = 0;

	FD_ZERO (&fdset);
	if (kbfd >= 0) {
	    FD_SET (kbfd, &fdset);
	    max_fd = kbfd;
	}
	if (dbgout) fprintf (dbgout, "Selecting");
	if (select (max_fd + 1, &fdset, 0, 0, &zero) > 0) {
	    if (dbgout) fprintf (dbgout, " -> match!\n");
	    iPod_keyboard();
	    posted++;
	}
	if (dbgout) fprintf (dbgout, "\n");
    } while (posted);
}

// enough space for 160x128x2
static char ipod_scr[160 * (128/4)];

#define outl(datum,addr) (*(volatile unsigned long *)(addr) = (datum))
#define inl(addr) (*(volatile unsigned long *)(addr))

/*** The following LCD code is taken from Linux kernel uclinux-2.4.24-uc0-ipod2,
     file arch/armnommu/mach-ipod/fb.c. A few modifications have been made. ***/

/* get current usec counter */
static int M_timer_get_current(void)
{
	return inl(lcd_rtc);
}

/* check if number of useconds has past */
static int M_timer_check(int clock_start, int usecs)
{
	unsigned long clock;
	clock = inl(lcd_rtc);
	
	if ( (clock - clock_start) >= usecs ) {
		return 1;
	} else {
		return 0;
	}
}

/* wait for LCD with timeout */
static void M_lcd_wait_write(void)
{
	if ( (inl(lcd_base) & 0x8000) != 0 ) {
		int start = M_timer_get_current();
			
		do {
			if ( (inl(lcd_base) & (unsigned int)0x8000) == 0 ) 
				break;
		} while ( M_timer_check(start, 1000) == 0 );
	}
}


/* send LCD data */
static void M_lcd_send_data(int data_lo, int data_hi)
{
	M_lcd_wait_write();
	
	outl(data_lo, lcd_base + LCD_DATA);
		
	M_lcd_wait_write();
	
	outl(data_hi, lcd_base + LCD_DATA);

}

/* send LCD command */
static void
M_lcd_prepare_cmd(int cmd)
{
	M_lcd_wait_write();

	outl(0x0, lcd_base + LCD_CMD);

	M_lcd_wait_write();
	
	outl(cmd, lcd_base + LCD_CMD);
	
}

/* send LCD command and data */
static void M_lcd_cmd_and_data(int cmd, int data_lo, int data_hi)
{
	M_lcd_prepare_cmd(cmd);

	M_lcd_send_data(data_lo, data_hi);
}

// Copied from uW
static void M_update_display(int sx, int sy, int mx, int my)
{
	int y;
	unsigned short cursor_pos;

	sx >>= 3;
	mx >>= 3;

	cursor_pos = sx + (sy << 5);

	for ( y = sy; y <= my; y++ ) {
		unsigned char *img_data;
		int x;

		/* move the cursor */
		M_lcd_cmd_and_data(0x11, cursor_pos >> 8, cursor_pos & 0xff);

		/* setup for printing */
		M_lcd_prepare_cmd(0x12);

		img_data = ipod_scr + (sx << 1) + (y * (lcd_width/4));

		/* loops up to 160 times */
		for ( x = sx; x <= mx; x++ ) {
		        /* display eight pixels */
			M_lcd_send_data(*(img_data + 1), *img_data);

			img_data += 2;
		}

		/* update cursor pos counter */
		cursor_pos += 0x20;
	}
}

/* get current usec counter */
static int C_timer_get_current(void)
{
	return inl(0x60005010);
}

/* check if number of useconds has past */
static int C_timer_check(int clock_start, int usecs)
{
	unsigned long clock;
	clock = inl(0x60005010);
	
	if ( (clock - clock_start) >= usecs ) {
		return 1;
	} else {
		return 0;
	}
}

/* wait for LCD with timeout */
static void C_lcd_wait_write(void)
{
	if ((inl(0x70008A0C) & 0x80000000) != 0) {
		int start = C_timer_get_current();
			
		do {
			if ((inl(0x70008A0C) & 0x80000000) == 0) 
				break;
		} while (C_timer_check(start, 1000) == 0);
	}
}
static void C_lcd_cmd_data(int cmd, int data)
{
	C_lcd_wait_write();
	outl(cmd | 0x80000000, 0x70008A0C);

	C_lcd_wait_write();
	outl(data | 0x80000000, 0x70008A0C);
}

static void C_update_display(int sx, int sy, int mx, int my)
{
	int height = (my - sy) + 1;
	int width = (mx - sx) + 1;

	char *addr = SDL_VideoSurface->pixels;

	if (width & 1) width++;

	/* start X and Y */
	C_lcd_cmd_data(0x12, (sy & 0xff));
	C_lcd_cmd_data(0x13, (((SDL_VideoSurface->w - 1) - sx) & 0xff));

	/* max X and Y */
	C_lcd_cmd_data(0x15, (((sy + height) - 1) & 0xff));
	C_lcd_cmd_data(0x16, (((((SDL_VideoSurface->w - 1) - sx) - width) + 1) & 0xff));

	addr += sx + sy * SDL_VideoSurface->pitch;

	while (height > 0) {
		int h, x, y, pixels_to_write;

		pixels_to_write = (width * height) * 2;

		/* calculate how much we can do in one go */
		h = height;
		if (pixels_to_write > 64000) {
			h = (64000/2) / width;
			pixels_to_write = (width * h) * 2;
		}

		outl(0x10000080, 0x70008A20);
		outl((pixels_to_write - 1) | 0xC0010000, 0x70008A24);
		outl(0x34000000, 0x70008A20);

		/* for each row */
		for (x = 0; x < h; x++)
		{
			/* for each column */
			for (y = 0; y < width; y += 2) {
				unsigned two_pixels;

				two_pixels = addr[0] | (addr[1] << 16);
				addr += 2;

				while ((inl(0x70008A20) & 0x1000000) == 0);

				/* output 2 pixels */
				outl(two_pixels, 0x70008B00);
			}

			addr += SDL_VideoSurface->w - width;
		}

		while ((inl(0x70008A20) & 0x4000000) == 0);

		outl(0x0, 0x70008A24);

		height = height - h;
	}
}

// Should work with photo. However, I don't have one, so I'm not sure.
static void iPod_UpdateRects (_THIS, int nrects, SDL_Rect *rects) 
{
    if (SDL_VideoSurface->format->BitsPerPixel == 16) {
	C_update_display (0, 0, lcd_width, lcd_height);
    } else {
	int i, y, x;
	for (i = 0; i < nrects; i++) {
	    SDL_Rect *r = rects + i;
	    if (!r) {
		continue;
	    }
	    
	    for (y = r->y; (y < r->y + r->h) && y < lcd_height; y++) {
		for (x = r->x; (x < r->x + r->w) && x < lcd_width; x++) {
		    ipod_scr[y*(lcd_width/4) + x/4] &= ~(3 << (2 * (x%4)));
		    ipod_scr[y*(lcd_width/4) + x/4] |=
			(((Uint8*)(SDL_VideoSurface->pixels))[ y*SDL_VideoSurface->pitch + x ] & 3) << (2 * (x%4));
		}
	    }
	}
	
	M_update_display (0, 0, lcd_width, lcd_height);
    }
}