// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
Atari Xybots hardware
****************************************************************************/
#include "emu.h"
#include "machine/atarigen.h"
#include "video/atarimo.h"
#include "includes/xybots.h"
/*************************************
*
* Tilemap callbacks
*
*************************************/
TILE_GET_INFO_MEMBER(xybots_state::get_alpha_tile_info)
{
uint16_t data = m_alpha_tilemap->basemem_read(tile_index);
int code = data & 0x3ff;
int color = (data >> 12) & 7;
int opaque = data & 0x8000;
SET_TILE_INFO_MEMBER(2, code, color, opaque ? TILE_FORCE_LAYER0 : 0);
}
TILE_GET_INFO_MEMBER(xybots_state::get_playfield_tile_info)
{
uint16_t data = m_playfield_tilemap->basemem_read(tile_index);
int code = data & 0x1fff;
int color = (data >> 11) & 0x0f;
SET_TILE_INFO_MEMBER(0, code, color, (data >> 15) & 1);
}
/*************************************
*
* Video system start
*
*************************************/
const atari_motion_objects_config xybots_state::s_mob_config =
{
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) */
{{ 0x3fff,0,0,0 }}, /* mask for the 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" */
};
/*************************************
*
* Main refresh
*
*************************************/
uint32_t xybots_state::screen_update_xybots(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
// start drawing
m_mob->draw_async(cliprect);
/* draw the playfield */
m_playfield_tilemap->draw(screen, bitmap, cliprect, 0, 0);
// draw and merge the MO
bitmap_ind16 &mobitmap = m_mob->bitmap();
for (const sparse_dirty_rect *rect = m_mob->first_dirty_rect(cliprect); rect != nullptr; rect = rect->next())
for (int y = rect->top(); y <= rect->bottom(); y++)
{
uint16_t *mo = &mobitmap.pix16(y);
uint16_t *pf = &bitmap.pix16(y);
for (int x = rect->left(); x <= rect->right(); x++)
if (mo[x] != 0xffff)
{
/* 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] >> atari_motion_objects_device::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) & atari_motion_objects_device::DATA_MASK;
else
pf[x] = mo[x] & atari_motion_objects_device::DATA_MASK;
}
}
else
{
if (mopriority < pfcolor)
pf[x] = mo[x] & atari_motion_objects_device::DATA_MASK;
}
}
}
/* add the alpha on top */
m_alpha_tilemap->draw(screen, bitmap, cliprect, 0, 0);
return 0;
}