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

  vidhrdw/jack.c

  Functions to emulate the video hardware of the machine.

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

#include "driver.h"
#include "vidhrdw/generic.h"


WRITE_HANDLER( jack_paletteram_w )
{
	/* RGB output is inverted */
	paletteram_BBGGGRRR_w(offset,~data);
}


READ_HANDLER( jack_flipscreen_r )
{
	flip_screen_set(offset);
	return 0;
}

WRITE_HANDLER( jack_flipscreen_w )
{
	flip_screen_set(offset);
}


VIDEO_UPDATE( jack )
{
	int offs;


	if (get_vh_global_attribute_changed())
		memset(dirtybuffer,1,videoram_size);

	/* for every character in the Video RAM, check if it has been modified */
	/* since last time and update it accordingly. */
	for (offs = videoram_size - 1;offs >= 0;offs--)
	{
		if (dirtybuffer[offs])
		{
			int sx,sy;


			dirtybuffer[offs] = 0;

			sx = offs / 32;
			sy = 31 - offs % 32;

			if (flip_screen)
			{
				sx = 31 - sx;
				sy = 31 - sy;
			}

			drawgfx(tmpbitmap,Machine->gfx[0],
					videoram[offs] + ((colorram[offs] & 0x18) << 5),
					colorram[offs] & 0x07,
					flip_screen,flip_screen,
					8*sx,8*sy,
					&Machine->visible_area,TRANSPARENCY_NONE,0);
		}
	}


	/* copy the temporary bitmap to the screen */
	copybitmap(bitmap,tmpbitmap,0,0,0,0,&Machine->visible_area,TRANSPARENCY_NONE,0);

	/* draw sprites */
	for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
	{
		int sx,sy,num, color,flipx,flipy;

		sx    = spriteram[offs + 1];
		sy    = spriteram[offs];
		num   = spriteram[offs + 2] + ((spriteram[offs + 3] & 0x08) << 5);
		color = spriteram[offs + 3] & 0x07;
		flipx = (spriteram[offs + 3] & 0x80);
		flipy = (spriteram[offs + 3] & 0x40);

		if (flip_screen)
		{
			sx = 248 - sx;
			sy = 248 - sy;
			flipx = !flipx;
			flipy = !flipy;
		}

		drawgfx(bitmap,Machine->gfx[0],
				num,
				color,
				flipx,flipy,
				sx,sy,
				&Machine->visible_area,TRANSPARENCY_PEN,0);
	}
}
