// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
Atari System 1 hardware
****************************************************************************/
#include "emu.h"
#include "includes/atarisy1.h"
/*************************************
*
* Constants
*
*************************************/
/* the color and remap PROMs are mapped as follows */
#define PROM1_BANK_4 0x80 /* active low */
#define PROM1_BANK_3 0x40 /* active low */
#define PROM1_BANK_2 0x20 /* active low */
#define PROM1_BANK_1 0x10 /* active low */
#define PROM1_OFFSET_MASK 0x0f /* postive logic */
#define PROM2_BANK_6_OR_7 0x80 /* active low */
#define PROM2_BANK_5 0x40 /* active low */
#define PROM2_PLANE_5_ENABLE 0x20 /* active high */
#define PROM2_PLANE_4_ENABLE 0x10 /* active high */
#define PROM2_PF_COLOR_MASK 0x0f /* negative logic */
#define PROM2_BANK_7 0x08 /* active low, plus PROM2_BANK_6_OR_7 low as well */
#define PROM2_MO_COLOR_MASK 0x07 /* negative logic */
/*************************************
*
* Statics
*
*************************************/
static const gfx_layout objlayout_4bpp =
{
8,8, /* 8*8 sprites */
4096, /* 4096 of them */
4, /* 4 bits per pixel */
{ 3*8*0x10000, 2*8*0x10000, 1*8*0x10000, 0*8*0x10000 },
{ 0, 1, 2, 3, 4, 5, 6, 7 },
{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
8*8 /* every sprite takes 8 consecutive bytes */
};
static const gfx_layout objlayout_5bpp =
{
8,8, /* 8*8 sprites */
4096, /* 4096 of them */
5, /* 5 bits per pixel */
{ 4*8*0x10000, 3*8*0x10000, 2*8*0x10000, 1*8*0x10000, 0*8*0x10000 },
{ 0, 1, 2, 3, 4, 5, 6, 7 },
{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
8*8 /* every sprite takes 8 consecutive bytes */
};
static const gfx_layout objlayout_6bpp =
{
8,8, /* 8*8 sprites */
4096, /* 4096 of them */
6, /* 6 bits per pixel */
{ 5*8*0x10000, 4*8*0x10000, 3*8*0x10000, 2*8*0x10000, 1*8*0x10000, 0*8*0x10000 },
{ 0, 1, 2, 3, 4, 5, 6, 7 },
{ 0*8, 1*8, 2*8, 3*8, 4*8, 5*8, 6*8, 7*8 },
8*8 /* every sprite takes 8 consecutive bytes */
};
/*************************************
*
* Tilemap callbacks
*
*************************************/
TILE_GET_INFO_MEMBER(atarisy1_state::get_alpha_tile_info)
{
uint16_t data = m_alpha_tilemap->basemem_read(tile_index);
int code = data & 0x3ff;
int color = (data >> 10) & 0x07;
int opaque = data & 0x2000;
SET_TILE_INFO_MEMBER(0, code, color, opaque ? TILE_FORCE_LAYER0 : 0);
}
TILE_GET_INFO_MEMBER(atarisy1_state::get_playfield_tile_info)
{
uint16_t data = m_playfield_tilemap->basemem_read(tile_index);
uint16_t lookup = m_playfield_lookup[((data >> 8) & 0x7f) | (m_playfield_tile_bank << 7)];
int gfxindex = (lookup >> 8) & 15;
int code = ((lookup & 0xff) << 8) | (data & 0xff);
int color = 0x20 + (((lookup >> 12) & 15) << m_bank_color_shift[gfxindex]);
SET_TILE_INFO_MEMBER(gfxindex, code, color, (data >> 15) & 1);
}
/*************************************
*
* Generic video system start
*
*************************************/
const atari_motion_objects_config atarisy1_state::s_mob_config =
{
0, /* index to which gfx system */
8, /* number of motion object banks */
1, /* are the entries linked? */
1, /* 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 */
0x38, /* maximum number of links to visit/scanline (0=all) */
0x100, /* base palette entry */
0x100, /* maximum number of colors */
0, /* transparent pen index */
{{ 0,0,0,0x003f }}, /* mask for the link */
{{ 0,0xffff,0,0 }}, /* mask for the code index */
{{ 0,0xff00,0,0 }}, /* mask for the color */
{{ 0,0,0x3fe0,0 }}, /* mask for the X position */
{{ 0x3fe0,0,0,0 }}, /* mask for the Y position */
{{ 0 }}, /* mask for the width, in tiles*/
{{ 0x000f,0,0,0 }}, /* mask for the height, in tiles */
{{ 0x8000,0,0,0 }}, /* mask for the horizontal flip */
{{ 0 }}, /* mask for the vertical flip */
{{ 0,0,0x8000,0 }}, /* mask for the priority */
{{ 0 }}, /* mask for the neighbor */
{{ 0 }}, /* mask for absolute coordinates */
{{ 0,0xffff,0,0 }}, /* mask for the special value */
0xffff /* resulting value to indicate "special" */
};
VIDEO_START_MEMBER(atarisy1_state,atarisy1)
{
/* first decode the graphics */
uint16_t motable[256];
decode_gfx(m_playfield_lookup, motable);
/* modify the motion object code lookup */
std::vector<uint32_t> &codelookup = m_mob->code_lookup();
for (unsigned int i = 0; i < codelookup.size(); i++)
codelookup[i] = (i & 0xff) | ((motable[i >> 8] & 0xff) << 8);
/* modify the motion object color and gfx lookups */
std::vector<uint8_t> &colorlookup = m_mob->color_lookup();
std::vector<uint8_t> &gfxlookup = m_mob->gfx_lookup();
for (unsigned int i = 0; i < colorlookup.size(); i++)
{
colorlookup[i] = ((motable[i] >> 12) & 15) << 1;
gfxlookup[i] = (motable[i] >> 8) & 15;
}
/* reset the statics */
m_mob->set_yscroll(256);
m_next_timer_scanline = -1;
/* save state */
save_item(NAME(m_playfield_tile_bank));
save_item(NAME(m_playfield_priority_pens));
save_item(NAME(m_next_timer_scanline));
}
/*************************************
*
* Graphics bank selection
*
*************************************/
WRITE16_MEMBER( atarisy1_state::atarisy1_bankselect_w )
{
uint16_t oldselect = *m_bankselect;
uint16_t newselect = oldselect, diff;
int scanline = m_screen->vpos();
/* update memory */
COMBINE_DATA(&newselect);
diff = oldselect ^ newselect;
/* sound CPU reset */
if (BIT(diff, 7))
{
m_outlatch->clear_w(BIT(newselect, 7));
m_audiocpu->set_input_line(INPUT_LINE_RESET, BIT(newselect, 7) ? CLEAR_LINE : ASSERT_LINE);
if (!BIT(newselect, 7)) m_soundcomm->sound_cpu_reset();
}
/* if MO or playfield banks change, force a partial update */
if (diff & 0x003c)
m_screen->update_partial(scanline);
/* motion object bank select */
m_mob->set_bank((newselect >> 3) & 7);
update_timers(scanline);
/* playfield bank select */
if (diff & 0x0004)
{
m_playfield_tile_bank = (newselect >> 2) & 1;
m_playfield_tilemap->mark_all_dirty();
}
/* stash the new value */
*m_bankselect = newselect;
}
/*************************************
*
* Playfield priority pens
*
*************************************/
WRITE16_MEMBER( atarisy1_state::atarisy1_priority_w )
{
uint16_t oldpens = m_playfield_priority_pens;
uint16_t newpens = oldpens;
/* force a partial update in case this changes mid-screen */
COMBINE_DATA(&newpens);
if (oldpens != newpens)
m_screen->update_partial(m_screen->vpos());
m_playfield_priority_pens = newpens;
}
/*************************************
*
* Playfield horizontal scroll
*
*************************************/
WRITE16_MEMBER( atarisy1_state::atarisy1_xscroll_w )
{
uint16_t oldscroll = *m_xscroll;
uint16_t newscroll = oldscroll;
/* force a partial update in case this changes mid-screen */
COMBINE_DATA(&newscroll);
if (oldscroll != newscroll)
m_screen->update_partial(m_screen->vpos());
/* set the new scroll value */
m_playfield_tilemap->set_scrollx(0, newscroll);
/* update the data */
*m_xscroll = newscroll;
}
/*************************************
*
* Playfield vertical scroll
*
*************************************/
TIMER_DEVICE_CALLBACK_MEMBER(atarisy1_state::atarisy1_reset_yscroll_callback)
{
m_playfield_tilemap->set_scrolly(0, param);
}
WRITE16_MEMBER( atarisy1_state::atarisy1_yscroll_w )
{
uint16_t oldscroll = *m_yscroll;
uint16_t newscroll = oldscroll;
int scanline = m_screen->vpos();
int adjusted_scroll;
/* force a partial update in case this changes mid-screen */
COMBINE_DATA(&newscroll);
m_screen->update_partial(scanline);
/* because this latches a new value into the scroll base,
we need to adjust for the scanline */
adjusted_scroll = newscroll;
if (scanline <= m_screen->visible_area().bottom())
adjusted_scroll -= (scanline + 1);
m_playfield_tilemap->set_scrolly(0, adjusted_scroll);
/* but since we've adjusted it, we must reset it to the normal value
once we hit scanline 0 again */
m_yscroll_reset_timer->adjust(m_screen->time_until_pos(0), newscroll);
/* update the data */
*m_yscroll = newscroll;
}
/*************************************
*
* Sprite RAM write handler
*
*************************************/
WRITE16_MEMBER( atarisy1_state::atarisy1_spriteram_w )
{
int active_bank = m_mob->bank();
uint16_t *spriteram = m_mob->spriteram();
int oldword = spriteram[offset];
int newword = oldword;
COMBINE_DATA(&newword);
/* if the data changed, and it modified the live sprite bank, do some extra work */
if (oldword != newword && (offset >> 8) == active_bank)
{
/* if modifying a timer, beware */
if (((offset & 0xc0) == 0x00 && spriteram[offset | 0x40] == 0xffff) ||
((offset & 0xc0) == 0x40 && (newword == 0xffff || oldword == 0xffff)))
{
/* if the timer is in the active bank, update the display list */
spriteram[offset] = data;
update_timers(m_screen->vpos());
}
/* if we're about to modify data in the active sprite bank, make sure the video is up-to-date */
/* Road Runner needs this to work; note the +2 kludge -- +1 would be correct since the video */
/* renders the next scanline's sprites to the line buffers, but Road Runner still glitches */
/* without the extra +1 */
else
m_screen->update_partial(m_screen->vpos() + 2);
}
/* let the MO handler do the basic work */
spriteram[offset] = data;
}
/*************************************
*
* MO interrupt handlers
*
*************************************/
TIMER_DEVICE_CALLBACK_MEMBER(atarisy1_state::atarisy1_int3off_callback)
{
/* clear the state */
scanline_int_ack_w();
}
TIMER_DEVICE_CALLBACK_MEMBER(atarisy1_state::atarisy1_int3_callback)
{
int scanline = param;
/* update the state */
scanline_int_write_line(1);
/* set a timer to turn it off */
m_int3off_timer->adjust(m_screen->scan_period());
/* determine the time of the next one */
m_next_timer_scanline = -1;
update_timers(scanline);
}
/*************************************
*
* MO interrupt state read
*
*************************************/
READ16_MEMBER( atarisy1_state::atarisy1_int3state_r )
{
return m_scanline_int_state ? 0x0080 : 0x0000;
}
/*************************************
*
* Timer updater
*
*************************************/
void atarisy1_state::update_timers(int scanline)
{
int offset = m_mob->bank() * 64 * 4;
int link = 0, best = scanline, found = 0;
uint8_t spritevisit[64];
/* track which ones we've visited */
memset(spritevisit, 0, sizeof(spritevisit));
/* walk the list until we loop */
while (!spritevisit[link])
{
/* timers are indicated by 0xffff in entry 2 */
if (m_mob->spriteram()[offset + link + 0x40] == 0xffff)
{
int data = m_mob->spriteram()[offset + link];
int vsize = (data & 15) + 1;
int ypos = (256 - (data >> 5) - vsize * 8 - 1) & 0x1ff;
/* note that we found something */
found = 1;
/* is this a better entry than the best so far? */
if (best <= scanline)
{
if ((ypos <= scanline && ypos < best) || ypos > scanline)
best = ypos;
}
else
{
if (ypos < best)
best = ypos;
}
}
/* link to the next */
spritevisit[link] = 1;
link = m_mob->spriteram()[offset + link + 0xc0] & 0x3f;
}
/* if nothing was found, use scanline -1 */
if (!found)
best = -1;
/* update the timer */
if (best != m_next_timer_scanline)
{
m_next_timer_scanline = best;
/* set a new one */
if (best != -1)
m_scanline_timer->adjust(m_screen->time_until_pos(best), best);
else
m_scanline_timer->reset();
}
}
/*************************************
*
* Main refresh
*
*************************************/
uint32_t atarisy1_state::screen_update_atarisy1(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)
{
/* high priority MO? */
if (mo[x] & atari_motion_objects_device::PRIORITY_MASK)
{
/* only gets priority if MO pen is not 1 */
if ((mo[x] & 0x0f) != 1)
pf[x] = 0x300 + ((pf[x] & 0x0f) << 4) + (mo[x] & 0x0f);
}
/* low priority */
else
{
/* priority pens for playfield color 0 */
if ((pf[x] & 0xf8) != 0 || !(m_playfield_priority_pens & (1 << (pf[x] & 0x07))))
pf[x] = mo[x];
}
}
}
/* add the alpha on top */
m_alpha_tilemap->draw(screen, bitmap, cliprect, 0, 0);
return 0;
}
/*************************************
*
* Graphics decoding
*
*************************************/
void atarisy1_state::decode_gfx(uint16_t *pflookup, uint16_t *molookup)
{
uint8_t *prom1 = &memregion("proms")->as_u8(0x000);
uint8_t *prom2 = &memregion("proms")->as_u8(0x200);
int obj, i;
/* reset the globals */
memset(&m_bank_gfx[0][0], 0, sizeof(m_bank_gfx));
/* loop for two sets of objects */
for (obj = 0; obj < 2; obj++)
{
/* loop for 256 objects in the set */
for (i = 0; i < 256; i++, prom1++, prom2++)
{
int bank, bpp, color, offset;
/* determine the bpp */
bpp = 4;
if (*prom2 & PROM2_PLANE_4_ENABLE)
{
bpp = 5;
if (*prom2 & PROM2_PLANE_5_ENABLE)
bpp = 6;
}
/* determine the offset */
offset = *prom1 & PROM1_OFFSET_MASK;
/* determine the bank */
bank = get_bank(*prom1, *prom2, bpp);
/* set the value */
if (obj == 0)
{
/* playfield case */
color = (~*prom2 & PROM2_PF_COLOR_MASK) >> (bpp - 4);
if (bank == 0)
{
bank = 1;
offset = color = 0;
}
pflookup[i] = offset | (bank << 8) | (color << 12);
}
else
{
/* motion objects (high bit ignored) */
color = (~*prom2 & PROM2_MO_COLOR_MASK) >> (bpp - 4);
molookup[i] = offset | (bank << 8) | (color << 12);
}
}
}
}
/*************************************
*
* Graphics bank mapping
*
*************************************/
int atarisy1_state::get_bank(uint8_t prom1, uint8_t prom2, int bpp)
{
const uint8_t *srcdata;
int bank_index, gfx_index;
/* determine the bank index */
if ((prom1 & PROM1_BANK_1) == 0)
bank_index = 1;
else if ((prom1 & PROM1_BANK_2) == 0)
bank_index = 2;
else if ((prom1 & PROM1_BANK_3) == 0)
bank_index = 3;
else if ((prom1 & PROM1_BANK_4) == 0)
bank_index = 4;
else if ((prom2 & PROM2_BANK_5) == 0)
bank_index = 5;
else if ((prom2 & PROM2_BANK_6_OR_7) == 0)
{
if ((prom2 & PROM2_BANK_7) == 0)
bank_index = 7;
else
bank_index = 6;
}
else
return 0;
/* find the bank */
if (m_bank_gfx[bpp - 4][bank_index])
return m_bank_gfx[bpp - 4][bank_index];
/* if the bank is out of range, call it 0 */
memory_region *tiles = memregion("tiles");
if (0x80000 * (bank_index - 1) >= tiles->bytes())
return 0;
/* don't have one? let's make it ... first find any empty slot */
for (gfx_index = 0; gfx_index < MAX_GFX_ELEMENTS; gfx_index++)
if (m_gfxdecode->gfx(gfx_index) == nullptr)
break;
assert(gfx_index != MAX_GFX_ELEMENTS);
/* decode the graphics */
srcdata = &tiles->as_u8(0x80000 * (bank_index - 1));
switch (bpp)
{
case 4:
m_gfxdecode->set_gfx(gfx_index,std::make_unique<gfx_element>(m_palette, objlayout_4bpp, srcdata, 0, 0x40, 256));
break;
case 5:
m_gfxdecode->set_gfx(gfx_index,std::make_unique<gfx_element>(m_palette, objlayout_5bpp, srcdata, 0, 0x40, 256));
break;
case 6:
m_gfxdecode->set_gfx(gfx_index,std::make_unique<gfx_element>(m_palette, objlayout_6bpp, srcdata, 0, 0x40, 256));
break;
default:
fatalerror("Unsupported bpp\n");
}
/* set the color information */
m_gfxdecode->gfx(gfx_index)->set_granularity(8);
m_bank_color_shift[gfx_index] = bpp - 3;
/* set the entry and return it */
return m_bank_gfx[bpp - 4][bank_index] = gfx_index;
}