/*
 * Mesa 3-D graphics library
 * Version:  4.1
 * 
 * Copyright (C) 1999  Brian Paul   All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * DOS/DJGPP device driver v1.6 for Mesa
 *
 *  Copyright (C) 2002 - Borca Daniel
 *  Email : dborca@users.sourceforge.net
 *  Web   : http://www.geocities.com/dborca
 */


#include <pc.h>
#include <stdlib.h>

#include "video.h"
#include "vga.h"



static vl_mode modes[] = {
       {
        /* .xres    = */ 320,
        /* .yres    = */ 200,
        /* .bpp     = */ 8,
        /* .mode    = */ 0x13 | 0x4000,
        /* .scanlen = */ 320,
        /* .sel     = */ -1,
        /* .gran    = */ 320*200
       },
       {
        /* .xres    = */ -1,
        /* .yres    = */ -1,
        /* .bpp     = */ -1,
        /* .mode    = */ 0xffff,
        /* .scanlen = */ -1,
        /* .sel     = */ -1,
        /* .gran    = */ -1
       }
};

static word16 vga_ver;
static int linear_selector;
static int oldmode = -1;

#define vga_color_precision 6



/* Desc: Attempts to detect VGA, check video modes and create selectors.
 *
 * In  : -
 * Out : mode array
 *
 * Note: -
 */
static vl_mode *vga_init (void)
{
 int rv = 0;

 if (vga_ver) {
    return modes;
 }

 __asm("\n\
		movw	$0x1a00, %%ax	\n\
		int	$0x10		\n\
		cmpb	$0x1a, %%al	\n\
		jne	0f		\n\
		cmpb	$0x07, %%bl	\n\
		jb	0f		\n\
		andl	$0xff, %%ebx	\n\
		movl	%%ebx, %0	\n\
 0:":"=g"(rv)::"%eax", "%ebx");
 if (rv == 0) {
    return NULL;
 }

 if (_create_selector(&linear_selector, 0xa0000, 0x10000)) {
    return NULL;
 }

 modes[0].sel = linear_selector;

 vga_ver = rv;
 return modes;
}



/* Desc: Frees all resources allocated by VGA init code.
 *
 * In  : -
 * Out : -
 *
 * Note: -
 */
static void vga_fini (void)
{
 if (vga_ver) {
    _remove_selector(&linear_selector);
 }
}



/* Desc: Attempts to enter specified video mode.
 *
 * In  : ptr to mode structure, refresh rate
 * Out : 0 if success
 *
 * Note: -
 */
static int vga_entermode (vl_mode *p, int refresh)
{
 if (!(p->mode & 0x4000)) {
    return -1;
 }
 VGA.blit = _can_mmx() ? vesa_l_dump_virtual_mmx : vesa_l_dump_virtual;

 if (oldmode == -1) {
    __asm("\n\
		movb	$0x0f, %%ah	\n\
		int	$0x10		\n\
		andl	$0xff, %%eax	\n\
		movl	%%eax, %0	\n\
    ":"=g"(oldmode)::"%eax", "%ebx");
 }

 __asm("int $0x10"::"a"(p->mode&0xff));

 return 0;

 (void)refresh; /* silence compiler warning */
}



/* Desc: Restores to the mode prior to first call to vga_entermode.
 *
 * In  : -
 * Out : -
 *
 * Note: -
 */
static void vga_restore (void)
{
 if (oldmode != -1) {
    __asm("int $0x10"::"a"(oldmode));
    oldmode = -1;
 }
}



/* Desc: set one palette entry
 *
 * In  : color index, R, G, B
 * Out : -
 *
 * Note: uses integer values
 */
static void vga_setCI_i (int index, int red, int green, int blue)
{
#if 0
 __asm("\n\
		movw $0x1010, %%ax	\n\
		movb %1, %%dh		\n\
		movb %2, %%ch		\n\
		int  $0x10		\n\
 "::"b"(index), "m"(red), "m"(green), "c"(blue):"%eax", "%edx");
#else
 outportb(0x03C8, index);
 outportb(0x03C9, red);
 outportb(0x03C9, green);
 outportb(0x03C9, blue);
#endif
}



/* Desc: set one palette entry
 *
 * In  : color index, R, G, B
 * Out : -
 *
 * Note: uses normalized values
 */
static void vga_setCI_f (int index, float red, float green, float blue)
{
 float max = (1 << vga_color_precision) - 1;

 vga_setCI_i(index, (int)(red * max), (int)(green * max), (int)(blue * max));
}



/* Desc: state retrieval
 *
 * In  : parameter name, ptr to storage
 * Out : 0 if request successfully processed
 *
 * Note: -
 */
static int vga_get (int pname, int *params)
{
 switch (pname) {
        case VL_GET_CI_PREC:
             params[0] = vga_color_precision;
             break;
        default:
             return -1;
 }
 return 0;
}



/*
 * the driver
 */
vl_driver VGA = {
          vga_init,
          vga_entermode,
          NULL,
          vga_setCI_f,
          vga_setCI_i,
          vga_get,
          vga_restore,
          vga_fini
};
