/***************************************************************************
Atari G42 hardware
*****************************************************************************
MO data has 12 bits total: MVID0-11
MVID9-11 form the priority
MVID0-9 form the color bits
PF data has 13 bits total: PF.VID0-12
PF.VID10-12 form the priority
PF.VID0-9 form the color bits
Upper bits come from the low 5 bits of the HSCROLL value in alpha RAM
Playfield bank comes from low 2 bits of the VSCROLL value in alpha RAM
For GX2, there are 4 bits of bank
****************************************************************************/
#include "emu.h"
#include "video/atarirle.h"
#include "includes/atarig42.h"
/*************************************
*
* Tilemap callbacks
*
*************************************/
static TILE_GET_INFO( get_alpha_tile_info )
{
atarig42_state *state = machine.driver_data<atarig42_state>();
UINT16 data = state->m_alpha[tile_index];
int code = data & 0xfff;
int color = (data >> 12) & 0x0f;
int opaque = data & 0x8000;
SET_TILE_INFO(1, code, color, opaque ? TILE_FORCE_LAYER0 : 0);
}
static TILE_GET_INFO( get_playfield_tile_info )
{
atarig42_state *state = machine.driver_data<atarig42_state>();
UINT16 data = state->m_playfield[tile_index];
int code = (state->m_playfield_tile_bank << 12) | (data & 0xfff);
int color = (state->m_playfield_base >> 5) + ((state->m_playfield_color_bank << 3) & 0x18) + ((data >> 12) & 7);
SET_TILE_INFO(0, code, color, (data >> 15) & 1);
tileinfo->category = (state->m_playfield_color_bank >> 2) & 7;
}
static TILEMAP_MAPPER( atarig42_playfield_scan )
{
int bank = 1 - (col / (num_cols / 2));
return bank * (num_rows * num_cols / 2) + row * (num_cols / 2) + (col % (num_cols / 2));
}
/*************************************
*
* Video system start
*
*************************************/
VIDEO_START( atarig42 )
{
atarig42_state *state = machine.driver_data<atarig42_state>();
/* blend the playfields and free the temporary one */
atarigen_blend_gfx(machine, 0, 2, 0x0f, 0x30);
/* initialize the playfield */
state->m_playfield_tilemap = tilemap_create(machine, get_playfield_tile_info, atarig42_playfield_scan, 8,8, 128,64);
/* initialize the motion objects */
state->m_rle = machine.device("rle");
/* initialize the alphanumerics */
state->m_alpha_tilemap = tilemap_create(machine, get_alpha_tile_info, tilemap_scan_rows, 8,8, 64,32);
tilemap_set_transparent_pen(state->m_alpha_tilemap, 0);
/* save states */
state->save_item(NAME(state->m_current_control));
state->save_item(NAME(state->m_playfield_tile_bank));
state->save_item(NAME(state->m_playfield_color_bank));
state->save_item(NAME(state->m_playfield_xscroll));
state->save_item(NAME(state->m_playfield_yscroll));
}
/*************************************
*
* Periodic scanline updater
*
*************************************/
WRITE16_HANDLER( atarig42_mo_control_w )
{
atarig42_state *state = space->machine().driver_data<atarig42_state>();
logerror("MOCONT = %d (scan = %d)\n", data, space->machine().primary_screen->vpos());
/* set the control value */
COMBINE_DATA(&state->m_current_control);
}
void atarig42_scanline_update(screen_device &screen, int scanline)
{
atarig42_state *state = screen.machine().driver_data<atarig42_state>();
UINT16 *base = &state->m_alpha[(scanline / 8) * 64 + 48];
int i;
if (scanline == 0) logerror("-------\n");
/* keep in range */
if (base >= &state->m_alpha[0x800])
return;
/* update the playfield scrolls */
for (i = 0; i < 8; i++)
{
UINT16 word;
word = *base++;
if (word & 0x8000)
{
int newscroll = (word >> 5) & 0x3ff;
int newbank = word & 0x1f;
if (newscroll != state->m_playfield_xscroll)
{
if (scanline + i > 0)
screen.update_partial(scanline + i - 1);
tilemap_set_scrollx(state->m_playfield_tilemap, 0, newscroll);
state->m_playfield_xscroll = newscroll;
}
if (newbank != state->m_playfield_color_bank)
{
if (scanline + i > 0)
screen.update_partial(scanline + i - 1);
tilemap_mark_all_tiles_dirty(state->m_playfield_tilemap);
state->m_playfield_color_bank = newbank;
}
}
word = *base++;
if (word & 0x8000)
{
int newscroll = ((word >> 6) - (scanline + i)) & 0x1ff;
int newbank = word & 7;
if (newscroll != state->m_playfield_yscroll)
{
if (scanline + i > 0)
screen.update_partial(scanline + i - 1);
tilemap_set_scrolly(state->m_playfield_tilemap, 0, newscroll);
state->m_playfield_yscroll = newscroll;
}
if (newbank != state->m_playfield_tile_bank)
{
if (scanline + i > 0)
screen.update_partial(scanline + i - 1);
tilemap_mark_all_tiles_dirty(state->m_playfield_tilemap);
state->m_playfield_tile_bank = newbank;
}
}
}
}
/*************************************
*
* Main refresh
*
*************************************/
SCREEN_UPDATE( atarig42 )
{
atarig42_state *state = screen->machine().driver_data<atarig42_state>();
bitmap_t *priority_bitmap = screen->machine().priority_bitmap;
/* draw the playfield */
bitmap_fill(priority_bitmap, cliprect, 0);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 0, 0);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 1, 1);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 2, 2);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 3, 3);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 4, 4);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 5, 5);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 6, 6);
tilemap_draw(bitmap, cliprect, state->m_playfield_tilemap, 7, 7);
/* copy the motion objects on top */
{
bitmap_t *mo_bitmap = atarirle_get_vram(state->m_rle, 0);
int left = cliprect->min_x;
int top = cliprect->min_y;
int right = cliprect->max_x + 1;
int bottom = cliprect->max_y + 1;
int x, y;
/* now blend with the playfield */
for (y = top; y < bottom; y++)
{
UINT16 *pf = (UINT16 *)bitmap->base + y * bitmap->rowpixels;
UINT16 *mo = (UINT16 *)mo_bitmap->base + y * mo_bitmap->rowpixels;
UINT8 *pri = (UINT8 *)priority_bitmap->base + priority_bitmap->rowpixels * y;
for (x = left; x < right; x++)
if (mo[x])
{
int pfpri = pri[x];
int mopri = mo[x] >> ATARIRLE_PRIORITY_SHIFT;
if (mopri >= pfpri)
pf[x] = mo[x] & ATARIRLE_DATA_MASK;
}
}
}
/* add the alpha on top */
tilemap_draw(bitmap, cliprect, state->m_alpha_tilemap, 0, 0);
return 0;
}
SCREEN_EOF( atarig42 )
{
atarig42_state *state = machine.driver_data<atarig42_state>();
atarirle_eof(state->m_rle);
}