/***************************************************************************

  osdepend.c

  OS dependant stuff (display handling, keyboard scan...)
  This is the only file which should me modified in order to port the
  emulator to a different system.

***************************************************************************/

#include <pc.h>
#include <sys/farptr.h>
#include <stdio.h>
#include <go32.h>
#include <allegro.h>
#include "osdepend.h"
#include "TwkUser.c"


#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
#define SCREEN_MODE GFX_VESA1

#define HARDCODED_WIDTH 256
#define HARDCODED_HEIGHT 256
/*
#define HARDCODED_WIDTH 224
#define HARDCODED_HEIGHT 288
*/

int bitmap_width,bitmap_height;
int first_free_pen;
unsigned char *bitmap;



/* put here anything you need to do when the program is started. Return 0 if */
/* initialization was successful, nonzero otherwise. */
int osd_init(void)
{
	allegro_init();
	install_keyboard();		/* Allegro keyboard handler */
	first_free_pen = 0;

	return 0;
}


/* put here cleanup routines to be executed when the program is terminated. */
void osd_exit(void)
{
}



Register scr224x288[] =
{
	{ 0x3c2, 0x00, 0xa7},{ 0x3d4, 0x00, 0x71},{ 0x3d4, 0x01, 0x37},
	{ 0x3d4, 0x02, 0x64},{ 0x3d4, 0x03, 0x92},{ 0x3d4, 0x04, 0x4f},
	{ 0x3d4, 0x05, 0x98},{ 0x3d4, 0x06, 0x46},{ 0x3d4, 0x07, 0x1f},
	{ 0x3d4, 0x08, 0x00},{ 0x3d4, 0x09, 0x40},{ 0x3d4, 0x10, 0x31},
	{ 0x3d4, 0x11, 0x80},{ 0x3d4, 0x12, 0x1f},{ 0x3d4, 0x13, 0x1c},
	{ 0x3d4, 0x14, 0x40},{ 0x3d4, 0x15, 0x2f},{ 0x3d4, 0x16, 0x44},
	{ 0x3d4, 0x17, 0xe3},{ 0x3c4, 0x01, 0x01},{ 0x3c4, 0x02, 0x0f},
	{ 0x3c4, 0x04, 0x0e},{ 0x3ce, 0x05, 0x40},{ 0x3ce, 0x06, 0x05},
	{ 0x3c0, 0x10, 0x41},{ 0x3c0, 0x13, 0x00}
};

Register scr256x256[] =
{
	{ 0x3c2, 0x00, 0xe3},{ 0x3d4, 0x00, 0x5f},{ 0x3d4, 0x01, 0x3f},
	{ 0x3d4, 0x02, 0x40},{ 0x3d4, 0x03, 0x82},{ 0x3d4, 0x04, 0x4A},
	{ 0x3d4, 0x05, 0x9A},{ 0x3d4, 0x06, 0x23},{ 0x3d4, 0x07, 0xb2},
	{ 0x3d4, 0x08, 0x00},{ 0x3d4, 0x09, 0x61},{ 0x3d4, 0x10, 0x0a},
	{ 0x3d4, 0x11, 0xac},{ 0x3d4, 0x12, 0xff},{ 0x3d4, 0x13, 0x20},
	{ 0x3d4, 0x14, 0x40},{ 0x3d4, 0x15, 0x07},{ 0x3d4, 0x16, 0x1a},
	{ 0x3d4, 0x17, 0xa3},{ 0x3c4, 0x01, 0x01},{ 0x3c4, 0x04, 0x0e},
	{ 0x3ce, 0x05, 0x40},{ 0x3ce, 0x06, 0x05},{ 0x3c0, 0x10, 0x41},
	{ 0x3c0, 0x13, 0x00}
};


/* Create a display screen, or window, large enough to accomodate a bitmap */
/* of the given dimensions. I don't do any test here (224x288 will just do */
/* for now) but one could e.g. open a window of the exact dimensions */
/* provided. Return a bitmap pointer or 0 in case of error. */
unsigned char *osd_create_display(int width,int height)
{
	bitmap_width = width;
	bitmap_height = height;

#ifdef USE_VESA
	if (set_gfx_mode(SCREEN_MODE,SCREEN_WIDTH,SCREEN_HEIGHT,0,0) != 0)
		return 0;
#else
	if (width != HARDCODED_WIDTH || height != HARDCODED_HEIGHT)
		return 0;

	/* big hack: open a mode 13h screen using Allegro, then load the custom screen */
	/* definition over it. */
	if (set_gfx_mode(GFX_VGA,320,200,0,0) != 0)
		return 0;

/*	outRegArray(scr224x288,sizeof(scr224x288)/sizeof(Register));*/
	outRegArray(scr256x256,sizeof(scr256x256)/sizeof(Register));
#endif

	bitmap = malloc(width * height * sizeof(unsigned char));

	return bitmap;
}



/* shut up the display */
void osd_close_display(void)
{
	set_gfx_mode(GFX_TEXT,80,25,0,0);
	free(bitmap);
}



int osd_obtain_pen(unsigned char red, unsigned char green, unsigned char blue)
{
	RGB rgb;


	rgb.r = red >> 2;
	rgb.g = green >> 2;
	rgb.b = blue >> 2;
	set_color(first_free_pen,&rgb);

	return first_free_pen++;
}



/* Update the display. */
/* As an additional bonus, this function also saves the screen as a PCX file */
/* when the user presses F5. This is not required for porting. */
void osd_update_display(void)
{
#ifdef USE_VESA
	int y;
	int width4 = bitmap_width / 4;
	unsigned long *lb = (unsigned long *)bitmap;


	for (y = 0;y < bitmap_height;y++)
	{
		unsigned long address;


		address = bmp_write_line(screen,y + (SCREEN_HEIGHT - bitmap_height) / 2)
				+ (SCREEN_WIDTH - bitmap_width) / 2;
		_dosmemputl(lb,width4,address);
		lb += width4;
	}
#else
	/* copy the bitmap to screen memory */
	_dosmemputl(bitmap,bitmap_width * bitmap_height / 4,0xa0000);
#endif

	/* if the user pressed F12, save a snapshot of the screen. */
	if (osd_key_pressed(OSD_KEY_F12))
	{
		BITMAP *bmp;
		PALETTE pal;
		char name[13];
		FILE *f;
		static int snapno;
		int y;


		do
		{
			sprintf(name,"snap%04d.pcx",snapno);
			/* avoid overwriting of existing files */
			if ((f = fopen(name,"rb")) != 0)
			{
				fclose(f);
				snapno++;
			}
		} while (f != 0);

		get_palette(pal);
		bmp = create_bitmap(bitmap_width,bitmap_height);
		for (y = 0;y < bitmap_height;y++)
			memcpy(bmp->line[y],&bitmap[y * bitmap_width],bitmap_width);
		save_pcx(name,bmp,pal);
		destroy_bitmap(bmp);
		snapno++;

		/* wait for the user to release F12 */
		while (osd_key_pressed(OSD_KEY_F12));
	}
}



/* check if a key is pressed. The keycode is the standard PC keyboard code, as */
/* defined in osdepend.h. Return 0 if the key is not pressed, nonzero otherwise. */
int osd_key_pressed(int keycode)
{
	return key[keycode];
}