/***************************************************************************
Atari Xybots hardware
****************************************************************************/
#include "driver.h"
#include "machine/atarigen.h"
#include "includes/xybots.h"
/*************************************
*
* Tilemap callbacks
*
*************************************/
static TILE_GET_INFO( get_alpha_tile_info )
{
UINT16 data = atarigen_alpha[tile_index];
int code = data & 0x3ff;
int color = (data >> 12) & 7;
int opaque = data & 0x8000;
SET_TILE_INFO(2, code, color, opaque ? TILE_FORCE_LAYER0 : 0);
}
static TILE_GET_INFO( get_playfield_tile_info )
{
UINT16 data = atarigen_playfield[tile_index];
int code = data & 0x1fff;
int color = (data >> 11) & 0x0f;
SET_TILE_INFO(0, code, color, (data >> 15) & 1);
}
/*************************************
*
* Video system start
*
*************************************/
VIDEO_START( xybots )
{
static const struct atarimo_desc modesc =
{
1, /* index to which gfx system */
1, /* number of motion object banks */
0, /* 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? */
0, /* 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 */
0x300, /* maximum number of colors */
0, /* transparent pen index */
{{ 0x3f }}, /* mask for the link (dummy) */
{{ 0 }}, /* mask for the graphics bank */
{{ 0x3fff,0,0,0 }}, /* mask for the code index */
{{ 0 }}, /* mask for the upper code index */
{{ 0,0,0,0x000f }}, /* mask for the color */
{{ 0,0,0,0xff80 }}, /* mask for the X position */
{{ 0,0,0xff80,0 }}, /* mask for the Y position */
{{ 0 }}, /* mask for the width, in tiles*/
{{ 0,0,0x0007,0 }}, /* mask for the height, in tiles */
{{ 0x8000,0,0,0 }}, /* mask for the horizontal flip */
{{ 0 }}, /* mask for the vertical flip */
{{ 0,0x000f,0,0 }}, /* 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" */
NULL /* callback routine for special entries */
};
/* initialize the playfield */
atarigen_playfield_tilemap = tilemap_create(get_playfield_tile_info, tilemap_scan_rows, TILEMAP_TYPE_PEN, 8,8, 64,32);
/* initialize the motion objects */
atarimo_init(machine, 0, &modesc);
/* initialize the alphanumerics */
atarigen_alpha_tilemap = tilemap_create(get_alpha_tile_info, tilemap_scan_rows, TILEMAP_TYPE_PEN, 8,8, 64,32);
tilemap_set_transparent_pen(atarigen_alpha_tilemap, 0);
}
/*************************************
*
* Main refresh
*
*************************************/
VIDEO_UPDATE( xybots )
{
struct atarimo_rect_list rectlist;
mame_bitmap *mobitmap;
int x, y, r;
/* draw the playfield */
tilemap_draw(bitmap, cliprect, atarigen_playfield_tilemap, 0, 0);
/* draw and merge the MO */
mobitmap = atarimo_render(machine, 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])
{
/* verified via schematics:
PRIEN = ~(~MOPIX3 & ~MOPIX2 & ~MOPIX1) = (MOPIX3-0 > 1)
if (PRIEN)
PF/MO = (~MOPRI3-0 > PFCOL3-0)
else
PF/MO = (~MOPRI3-0 >= PFCOL3-0)
if (PF/MO | ~(PRIEN & MOCOL3))
GPC(P3-0) = PFPIX3-0
else
GPC(P3-0) = ~MOCOL3-0
*/
int mopriority = (mo[x] >> ATARIMO_PRIORITY_SHIFT) ^ 15;
int pfcolor = (pf[x] >> 4) & 0x0f;
int prien = ((mo[x] & 0x0f) > 1);
if (prien)
{
if (mopriority <= pfcolor)
{
/* this first case doesn't make sense from the schematics, but it has */
/* the correct effect */
if (mo[x] & 0x80)
pf[x] = (mo[x] ^ 0x2f0) & ATARIMO_DATA_MASK;
else
pf[x] = mo[x] & ATARIMO_DATA_MASK;
}
}
else
{
if (mopriority < pfcolor)
pf[x] = mo[x] & ATARIMO_DATA_MASK;
}
/* erase behind ourselves */
mo[x] = 0;
}
}
/* add the alpha on top */
tilemap_draw(bitmap, cliprect, atarigen_alpha_tilemap, 0, 0);
return 0;
}