/*
	vid_svgalib.c

	Linux SVGALib video routines

	Copyright (C) 1996-1997  Id Software, Inc.
	Copyright (C) 1999-2000  Nelson Rush.
	Copyright (C) 1999-2000  Marcus Sundberg [mackan@stacken.kth.se]
	Copyright (C) 1999-2000  David Symonds [xoxus@usa.net]
	Copyright (C) 1999,2000  contributors of the QuakeForge project
	Please see the file "AUTHORS" for a list of contributors

	This program 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.

	This program 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 this program; if not, write to:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

	$Id$
*/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#if defined(HAVE_SYS_IO_H)
# include <sys/io.h>
#elif defined(HAVE_ASM_IO_H)
# include <asm/io.h>
#endif

#include <stdio.h>
#include <vga.h>

#include "cmd.h"
#include "console.h"
#include "cvar.h"
#include "d_local.h"
#include "host.h"
#include "input.h"
#include "qargs.h"
#include "qendian.h"
#include "sys.h"

void        VGA_UpdatePlanarScreen (void *srcbuffer);


unsigned short d_8to16table[256];

static int  num_modes, current_mode;
static vga_modeinfo *modes;

static byte vid_current_palette[768];

static int  svgalib_inited = 0;
static int  svgalib_backgrounded = 0;
static int  UseDisplay = 1;

static cvar_t *vid_mode;
static cvar_t *vid_redrawfull;
static cvar_t *vid_waitforrefresh;

static char *framebuffer_ptr;


static byte backingbuf[48 * 24];

int         VGA_width, VGA_height, VGA_rowbytes, VGA_bufferrowbytes, VGA_planar;
byte       *VGA_pagebase;

int         VID_options_items = 0;


void
D_BeginDirectRect (int x, int y, byte * pbitmap, int width, int height)
{
	int         i, j, k, plane, reps, repshift, offset, vidpage, off;

	if (!svgalib_inited || !vid.direct || svgalib_backgrounded
		|| !vga_oktowrite ())return;

	if (vid.aspect > 1.5) {
		reps = 2;
		repshift = 1;
	} else {
		reps = 1;
		repshift = 0;
	}

	vidpage = 0;
	vga_setpage (0);

	if (VGA_planar) {
		for (plane = 0; plane < 4; plane++) {
			/* Select the correct plane for reading and writing */
			outb (0x02, 0x3C4);
			outb (1 << plane, 0x3C5);
			outb (4, 0x3CE);
			outb (plane, 0x3CF);

			for (i = 0; i < (height << repshift); i += reps) {
				for (k = 0; k < reps; k++) {
					for (j = 0; j < (width >> 2); j++) {
						backingbuf[(i + k) * 24 + (j << 2) + plane] =
							vid.direct[(y + i + k) * VGA_rowbytes +
									   (x >> 2) + j];
						vid.direct[(y + i + k) * VGA_rowbytes + (x >> 2) + j] =
							pbitmap[(i >> repshift) * 24 + (j << 2) + plane];
					}
				}
			}
		}
	} else {
		for (i = 0; i < (height << repshift); i += reps) {
			for (j = 0; j < reps; j++) {
				offset = x + ((y << repshift) + i + j)
					* vid.rowbytes;
				off = offset % 0x10000;
				if ((offset / 0x10000) != vidpage) {
					vidpage = offset / 0x10000;
					vga_setpage (vidpage);
				}
				memcpy (&backingbuf[(i + j) * 24], vid.direct + off, width);
				memcpy (vid.direct + off,
						&pbitmap[(i >> repshift) * width], width);
			}
		}
	}
}


void
D_EndDirectRect (int x, int y, int width, int height)
{
	int         i, j, k, plane, reps, repshift, offset, vidpage, off;

	if (!svgalib_inited || !vid.direct || svgalib_backgrounded
		|| !vga_oktowrite ())return;

	if (vid.aspect > 1.5) {
		reps = 2;
		repshift = 1;
	} else {
		reps = 1;
		repshift = 0;
	}

	vidpage = 0;
	vga_setpage (0);

	if (VGA_planar) {
		for (plane = 0; plane < 4; plane++) {
			/* Select the correct plane for writing */
			outb (2, 0x3C4);
			outb (1 << plane, 0x3C5);
			outb (4, 0x3CE);
			outb (plane, 0x3CF);

			for (i = 0; i < (height << repshift); i += reps) {
				for (k = 0; k < reps; k++) {
					for (j = 0; j < (width >> 2); j++) {
						vid.direct[(y + i + k) * VGA_rowbytes + (x >> 2) + j] =
							backingbuf[(i + k) * 24 + (j << 2) + plane];
					}
				}
			}
		}
	} else {
		for (i = 0; i < (height << repshift); i += reps) {
			for (j = 0; j < reps; j++) {
				offset = x + ((y << repshift) + i + j)
					* vid.rowbytes;
				off = offset % 0x10000;
				if ((offset / 0x10000) != vidpage) {
					vidpage = offset / 0x10000;
					vga_setpage (vidpage);
				}
				memcpy (vid.direct + off, &backingbuf[(i + j) * 24], width);
			}
		}
	}
}


#if 0
static void
VID_Gamma_f (void)
{
	float       gamma, f, inf;
	unsigned char palette[768];
	int         i;

	if (Cmd_Argc () == 2) {
		gamma = atof (Cmd_Argv (1));

		for (i = 0; i < 768; i++) {
			f = pow ((host_basepal[i] + 1) / 256.0, gamma);
			inf = f * 255 + 0.5;
			if (inf < 0)
				inf = 0;
			if (inf > 255)
				inf = 255;
			palette[i] = inf;
		}

		VID_SetPalette (palette);

		/* Force a surface cache flush */
		vid.recalc_refdef = 1;
	}
}
#endif


static void
VID_DescribeMode_f (void)
{
	int         modenum;

	modenum = atoi (Cmd_Argv (1));
	if ((modenum >= num_modes) || (modenum < 0) || !modes[modenum].width) {
		Con_Printf ("Invalid video mode: %d!\n", modenum);
	}
	Con_Printf ("%d: %d x %d - ", modenum,
				modes[modenum].width, modes[modenum].height);
	if (modes[modenum].bytesperpixel == 0) {
		Con_Printf ("ModeX\n");
	} else {
		Con_Printf ("%d bpp\n", modes[modenum].bytesperpixel << 3);
	}
}


static void
VID_DescribeModes_f (void)
{
	int         i;

	for (i = 0; i < num_modes; i++) {
		if (modes[i].width) {
			Con_Printf ("%d: %d x %d - ", i, modes[i].width, modes[i].height);
			if (modes[i].bytesperpixel == 0)
				Con_Printf ("ModeX\n");
			else
				Con_Printf ("%d bpp\n", modes[i].bytesperpixel << 3);
		}
	}
}


/*
================
VID_NumModes
================
*/
static int
VID_NumModes (void)
{
	int         i, i1 = 0;

	for (i = 0; i < num_modes; i++) {
		i1 += modes[i].width ? 1 : 0;
	}
	return (i1);
}


static void
VID_NumModes_f (void)
{
	Con_Printf ("%d modes\n", VID_NumModes ());
}


static void
VID_Debug_f (void)
{
	Con_Printf ("mode: %d\n", current_mode);
	Con_Printf ("height x width: %d x %d\n", vid.height, vid.width);
	Con_Printf ("bpp: %d\n", modes[current_mode].bytesperpixel * 8);
	Con_Printf ("vid.aspect: %f\n", vid.aspect);
}


static void
VID_InitModes (void)
{
	int         i;

	/* Get complete information on all modes */
	num_modes = vga_lastmodenumber () + 1;
	modes = malloc (num_modes * sizeof (vga_modeinfo));
	for (i = 0; i < num_modes; i++) {
		if (vga_hasmode (i)) {
			memcpy (&modes[i], vga_getmodeinfo (i), sizeof (vga_modeinfo));
		} else {
			modes[i].width = 0;			// means not available
		}
	}

	/* Filter for modes we don't support */
	for (i = 0; i < num_modes; i++) {
		if (modes[i].bytesperpixel != 1 && modes[i].colors != 256) {
			modes[i].width = 0;
		}
	}
}


static int
get_mode (char *name, int width, int height, int depth)
{
	int         i, ok, match;

	match = (!!width) + (!!height) * 2 + (!!depth) * 4;

	if (name) {
		i = vga_getmodenumber (name);
		if (!modes[i].width) {
			Sys_Printf ("Mode [%s] not supported\n", name);
			i = G320x200x256;
		}
	} else {
		for (i = 0; i < num_modes; i++) {
			if (modes[i].width) {
				ok = (modes[i].width == width)
					+ (modes[i].height == height) * 2
					+ (modes[i].bytesperpixel == depth / 8) * 4;
				if ((ok & match) == ok)
					break;
			}
		}
		if (i == num_modes) {
			Sys_Printf ("Mode %dx%d (%d bits) not supported\n",
						width, height, depth);
			i = G320x200x256;
		}
	}

	return i;
}


void
VID_InitBuffers (void)
{
	int         buffersize, zbuffersize, cachesize;
	void       *vid_surfcache;

	// Calculate the sizes we want first
	buffersize = vid.rowbytes * vid.height;
	zbuffersize = vid.width * vid.height * sizeof (*d_pzbuffer);
	cachesize = D_SurfaceCacheForRes (vid.width, vid.height);

	// Free the old screen buffer
	if (vid.buffer) {
		free (vid.buffer);
		vid.conbuffer = vid.buffer = NULL;
	}
	// Free the old z-buffer
	if (d_pzbuffer) {
		free (d_pzbuffer);
		d_pzbuffer = NULL;
	}
	// Free the old surface cache
	vid_surfcache = D_SurfaceCacheAddress ();
	if (vid_surfcache) {
		D_FlushCaches ();
		free (vid_surfcache);
		vid_surfcache = NULL;
	}
	// Allocate the new screen buffer
	vid.conbuffer = vid.buffer = calloc (buffersize, 1);
	if (!vid.conbuffer) {
		Sys_Error ("Not enough memory for video mode\n");
	}
	// Allocate the new z-buffer
	d_pzbuffer = calloc (zbuffersize, 1);
	if (!d_pzbuffer) {
		free (vid.buffer);
		vid.conbuffer = vid.buffer = NULL;
		Sys_Error ("Not enough memory for video mode\n");
	}
	// Allocate the new surface cache; free the z-buffer if we fail
	vid_surfcache = calloc (cachesize, 1);
	if (!vid_surfcache) {
		free (vid.buffer);
		free (d_pzbuffer);
		vid.conbuffer = vid.buffer = NULL;
		d_pzbuffer = NULL;
		Sys_Error ("Not enough memory for video mode\n");
	}

	D_InitCaches (vid_surfcache, cachesize);
}


void
VID_Shutdown (void)
{
	Sys_Printf ("VID_Shutdown\n");

	if (!svgalib_inited)
		return;

	if (UseDisplay) {
		vga_setmode (TEXT);
	}
	svgalib_inited = 0;
}


void
VID_ShiftPalette (unsigned char *p)
{
	VID_SetPalette (p);
}


void
VID_SetPalette (byte * palette)
{
	static int  tmppal[256 * 3];
	int        *tp;
	int         i;

	if (!svgalib_inited || svgalib_backgrounded)
		return;

	memcpy (vid_current_palette, palette, sizeof (vid_current_palette));

	if (vga_getcolors () == 256) {
		tp = tmppal;
		for (i = 256 * 3; i; i--) {
			*(tp++) = *(palette++) >> 2;
		}

		if (UseDisplay && vga_oktowrite ()) {
			vga_setpalvec (0, 256, tmppal);
		}
	}
}


int
VID_SetMode (int modenum, unsigned char *palette)
{
	int         err;

	if ((modenum >= num_modes) || (modenum < 0) || !modes[modenum].width) {
		Cvar_SetValue (vid_mode, current_mode);

		Con_Printf ("No such video mode: %d\n", modenum);

		return 0;
	}

	Cvar_SetValue (vid_mode, modenum);

	current_mode = modenum;

	vid.width = modes[current_mode].width;
	vid.height = modes[current_mode].height;

	VGA_width = modes[current_mode].width;
	VGA_height = modes[current_mode].height;
	VGA_planar = modes[current_mode].bytesperpixel == 0;
	VGA_rowbytes = modes[current_mode].linewidth;
	vid.rowbytes = modes[current_mode].linewidth;
	if (VGA_planar) {
		VGA_bufferrowbytes = modes[current_mode].linewidth * 4;
		vid.rowbytes = modes[current_mode].linewidth * 4;
	}

	vid.aspect = ((float) vid.height / (float) vid.width) * (320.0 / 240.0);
	vid.colormap = (pixel_t *) host_colormap;
	vid.fullbright = 256 - LittleLong (*((int *) vid.colormap + 2048));
	vid.conrowbytes = vid.rowbytes;
	vid.conwidth = vid.width;
	vid.conheight = vid.height;
	vid.numpages = 1;

	vid.maxwarpwidth = WARP_WIDTH;
	vid.maxwarpheight = WARP_HEIGHT;

	// alloc screen buffer, z-buffer, and surface cache
	VID_InitBuffers ();

	/* get goin' */
	err = vga_setmode (current_mode);
	if (err) {
		Sys_Error ("Video mode failed: %d\n", modenum);
	}
	VID_SetPalette (palette);

	VGA_pagebase = vid.direct = framebuffer_ptr = (char *) vga_getgraphmem ();
#if 0
	if (vga_setlinearaddressing () > 0) {
		framebuffer_ptr = (char *) vga_getgraphmem ();
	}
#endif
	if (!framebuffer_ptr) {
		Sys_Error ("This mode isn't hapnin'\n");
	}

	vga_setpage (0);

	svgalib_inited = 1;

	/* Force a surface cache flush */
	vid.recalc_refdef = 1;

	return 1;
}

static void
goto_background (void)
{
	svgalib_backgrounded = 1;
}

static void
comefrom_background (void)
{
	svgalib_backgrounded = 0;
}


void
VID_Init (unsigned char *palette)
{
	int         w, h, d;
	int         err;

	// plugin_load("in_svgalib.so");

	if (svgalib_inited)
		return;

#if 0
	Cmd_AddCommand ("gamma", VID_Gamma_f);
#endif

	if (UseDisplay) {
		err = vga_init ();
		if (err)
			Sys_Error ("SVGALib failed to allocate a new VC\n");

		if (vga_runinbackground_version () == 1) {
			Con_Printf ("SVGALIB background support detected\n");
			vga_runinbackground (VGA_GOTOBACK, goto_background);
			vga_runinbackground (VGA_COMEFROMBACK, comefrom_background);
			vga_runinbackground (1);
		} else {
			vga_runinbackground (0);
		}

		VID_InitModes ();

		Cmd_AddCommand ("vid_nummodes", VID_NumModes_f);
		Cmd_AddCommand ("vid_describemode", VID_DescribeMode_f);
		Cmd_AddCommand ("vid_describemodes", VID_DescribeModes_f);
		Cmd_AddCommand ("vid_debug", VID_Debug_f);

		/* Interpret command-line params */
		w = h = d = 0;
		if (getenv ("GSVGAMODE")) {
			current_mode = get_mode (getenv ("GSVGAMODE"), w, h, d);
		} else if (COM_CheckParm ("-mode")) {
			current_mode =
				get_mode (com_argv[COM_CheckParm ("-mode") + 1], w, h, d);
		} else if (COM_CheckParm ("-w") || COM_CheckParm ("-h")
				   || COM_CheckParm ("-d")) {
			if (COM_CheckParm ("-w")) {
				w = atoi (com_argv[COM_CheckParm ("-w") + 1]);
			}
			if (COM_CheckParm ("-h")) {
				h = atoi (com_argv[COM_CheckParm ("-h") + 1]);
			}
			if (COM_CheckParm ("-d")) {
				d = atoi (com_argv[COM_CheckParm ("-d") + 1]);
			}
			current_mode = get_mode (0, w, h, d);
		} else {
			current_mode = G320x200x256;
		}

		/* Set vid parameters */
		VID_SetMode (current_mode, palette);

		VID_SetPalette (palette);
	}
}

void
VID_Init_Cvars ()
{
	vid_mode = Cvar_Get ("vid_mode", "5", CVAR_NONE, "Sets the video mode");
	vid_redrawfull = Cvar_Get ("vid_redrawfull", "0", CVAR_NONE, "Redraw entire screen each frame instead of just dirty areas");
	vid_waitforrefresh = Cvar_Get ("vid_waitforrefresh", "0",
								   CVAR_ARCHIVE, "Wait for vertical retrace before drawing next frame");
}


void
VID_Update (vrect_t *rects)
{
	if (!svgalib_inited || svgalib_backgrounded)
		return;

	if (!vga_oktowrite ()) {
		/* Can't update screen if it's not active */
		return;
	}

	if (vid_waitforrefresh->int_val) {
		vga_waitretrace ();
	}

	if (VGA_planar) {
		VGA_UpdatePlanarScreen (vid.buffer);
	} else if (vid_redrawfull->int_val) {
		int         total = vid.rowbytes * vid.height;
		int         offset;

		for (offset = 0; offset < total; offset += 0x10000) {
			vga_setpage (offset / 0x10000);
			memcpy (framebuffer_ptr, vid.buffer + offset,
					((total - offset > 0x10000) ? 0x10000 : (total - offset)));
		}
	} else {
		int         ycount;
		int         offset;
		int         vidpage = 0;

		vga_setpage (0);

		while (rects) {
			ycount = rects->height;
			offset = rects->y * vid.rowbytes + rects->x;
			while (ycount--) {
				register int i = offset % 0x10000;

				if ((offset / 0x10000) != vidpage) {
					vidpage = offset / 0x10000;
					vga_setpage (vidpage);
				}
				if (rects->width + i > 0x10000) {
					memcpy (framebuffer_ptr + i,
							vid.buffer + offset, 0x10000 - i);
					vga_setpage (++vidpage);
					memcpy (framebuffer_ptr,
							vid.buffer + offset + 0x10000 - i,
							rects->width - 0x10000 + i);
				} else {
					memcpy (framebuffer_ptr + i,
							vid.buffer + offset, rects->width);
				}
				offset += vid.rowbytes;
			}
			rects = rects->pnext;
		}
	}

	if (vid_mode->int_val != current_mode) {
		VID_SetMode (vid_mode->int_val, vid_current_palette);
	}
}


static int  dither = 0;

void
VID_DitherOn (void)
{
	if (dither == 0) {
#if 0
		R_ViewChanged (&vrect, sb_lines, vid.aspect);
#endif
		dither = 1;
	}
}


void
VID_DitherOff (void)
{
	if (dither) {
#if 0
		R_ViewChanged (&vrect, sb_lines, vid.aspect);
#endif
		dither = 0;
	}
}


/*
================
VID_ModeInfo
================
*/
char       *
VID_ModeInfo (int modenum)
{
	static char *badmodestr = "Bad mode number";
	static char modestr[40];

	if (modenum == 0) {
		snprintf (modestr, sizeof (modestr), "%d x %d, %d bpp",
				  vid.width, vid.height, modes[current_mode].bytesperpixel * 8);
		return (modestr);
	} else {
		return (badmodestr);
	}
}


void
VID_ExtraOptionDraw (unsigned int options_draw_cursor)
{
	/* No extra option menu items yet */
}


void
VID_ExtraOptionCmd (int option_cursor)
{
#if 0
	switch (option_cursor) {
		case 1:						// Always start with 1
			break;
	}
#endif
}

void
VID_LockBuffer (void)
{
}

void
VID_UnlockBuffer (void)
{
}

void
VID_SetCaption (char *text)
{
}