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

    Atari Rampart hardware

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

#include "driver.h"
#include "machine/atarigen.h"
#include "rampart.h"



/*************************************
 *
 *  Globals we own
 *
 *************************************/

UINT16 *rampart_bitmap;



/*************************************
 *
 *  Video system start
 *
 *************************************/

VIDEO_START( rampart )
{
	static const atarimo_desc modesc =
	{
		0,					/* index to which gfx system */
		1,					/* number of motion object banks */
		1,					/* are the entries linked? */
		0,					/* are the entries split? */
		0,					/* render in reverse order? */
		0,					/* render in swapped X/Y order? */
		0,					/* does the neighbor bit affect the next object? */
		8,					/* pixels per SLIP entry (0 for no-slip) */
		0,					/* pixel offset for SLIPs */
		0,					/* maximum number of links to visit/scanline (0=all) */

		0x100,				/* base palette entry */
		0x100,				/* maximum number of colors */
		0,					/* transparent pen index */

		{{ 0x00ff,0,0,0 }},	/* mask for the link */
		{{ 0 }},			/* mask for the graphics bank */
		{{ 0,0x7fff,0,0 }},	/* mask for the code index */
		{{ 0 }},			/* mask for the upper code index */
		{{ 0,0,0x000f,0 }},	/* mask for the color */
		{{ 0,0,0xff80,0 }},	/* mask for the X position */
		{{ 0,0,0,0xff80 }},	/* mask for the Y position */
		{{ 0,0,0,0x0070 }},	/* mask for the width, in tiles*/
		{{ 0,0,0,0x0007 }},	/* mask for the height, in tiles */
		{{ 0,0x8000,0,0 }},	/* mask for the horizontal flip */
		{{ 0 }},			/* mask for the vertical flip */
		{{ 0 }},			/* mask for the priority */
		{{ 0 }},			/* mask for the neighbor */
		{{ 0 }},			/* mask for absolute coordinates */

		{{ 0 }},			/* mask for the special value */
		0,					/* resulting value to indicate "special" */
		0,					/* callback routine for special entries */
	};

	/* initialize the motion objects */
	atarimo_init(machine, 0, &modesc);

	/* set the intial scroll offset */
	atarimo_set_xscroll(0, -12);
}



/*************************************
 *
 *  Main refresh
 *
 *************************************/

VIDEO_UPDATE( rampart )
{
	atarimo_rect_list rectlist;
	bitmap_t *mobitmap;
	int x, y, r;

	/* draw the playfield */
	rampart_bitmap_render(screen->machine, bitmap, cliprect);

	/* draw and merge the MO */
	mobitmap = atarimo_render(0, cliprect, &rectlist);
	for (r = 0; r < rectlist.numrects; r++, rectlist.rect++)
		for (y = rectlist.rect->min_y; y <= rectlist.rect->max_y; y++)
		{
			UINT16 *mo = (UINT16 *)mobitmap->base + mobitmap->rowpixels * y;
			UINT16 *pf = (UINT16 *)bitmap->base + bitmap->rowpixels * y;
			for (x = rectlist.rect->min_x; x <= rectlist.rect->max_x; x++)
				if (mo[x])
				{
					/* the PCB supports more complex priorities, but the PAL is not stuffed, so we get the default */
					pf[x] = mo[x];

					/* erase behind ourselves */
					mo[x] = 0;
				}
		}
	return 0;
}



/*************************************
 *
 *  Bitmap rendering
 *
 *************************************/

void rampart_bitmap_render(running_machine *machine, bitmap_t *bitmap, const rectangle *cliprect)
{
	int x, y;

	/* update any dirty scanlines */
	for (y = cliprect->min_y; y <= cliprect->max_y; y++)
	{
		const UINT16 *src = &rampart_bitmap[256 * y];
		UINT16 *dst = BITMAP_ADDR16(bitmap, y, 0);

		/* regenerate the line */
		for (x = cliprect->min_x & ~1; x <= cliprect->max_x; x += 2)
		{
			int bits = src[(x - 8) / 2];
			dst[x + 0] = bits >> 8;
			dst[x + 1] = bits & 0xff;
		}
	}
}
