// license:BSD-3-Clause // copyright-holders:Ernesto Corvi, Juergen Buchmueller, Alex Pasadyn, Aaron Giles, Nicola Salmoria #include "emu.h" #include "includes/polepos.h" /* modified vertical position built from three nibbles (12 bit) * of ROMs 136014-142, 136014-143, 136014-144 * The value RVP (road vertical position, lower 12 bits) is added * to this value and the upper 10 bits of the result are used to * address the playfield video memory (AB0 - AB9). */ /*************************************************************************** Convert the color PROMs. Pole Position has three 256x4 palette PROMs (one per gun) and a lot ;-) of 256x4 lookup table PROMs. The palette PROMs are connected to the RGB output this way: bit 3 -- 220 ohm resistor -- RED/GREEN/BLUE -- 470 ohm resistor -- RED/GREEN/BLUE -- 1 kohm resistor -- RED/GREEN/BLUE bit 0 -- 2.2kohm resistor -- RED/GREEN/BLUE ***************************************************************************/ void polepos_state::polepos_palette(palette_device &palette) { uint8_t const *const color_prom = memregion("proms")->base(); /******************************************************* * Color PROMs * Sheet 15B: middle, 136014-137,138,139 * Inputs: MUX0 ... MUX3, ALPHA/BACK, SPRITE/BACK, 128V, COMPBLANK * * Note that we only decode the lower 128 colors because * the upper 128 are all black and used during the * horizontal and vertical blanking periods. * The purpose of the 128V input is to use a different palette for the * background and for the road; it is irrelevant for alpha and * sprites because their palette is the same in both halves. * Anyway, we emulate that to a certain extent, using different * colortables for the two halves of the screen. We don't support the * palette change in the middle of a sprite, however. * Also, note that priority encoding is done is such a way that alpha * will use palette bank 2 or 3 depending on whether there is a sprite * below the pixel or not. That would be tricky to emulate, and it's * not needed because of course the two banks are the same. *******************************************************/ for (int i = 0; i < 128; i++) { int bit0, bit1, bit2, bit3; // Sheet 15B: 136014-0137 red component bit0 = BIT(color_prom[0x000 + i], 0); bit1 = BIT(color_prom[0x000 + i], 1); bit2 = BIT(color_prom[0x000 + i], 2); bit3 = BIT(color_prom[0x000 + i], 3); int const r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; // Sheet 15B: 136014-0138 green component bit0 = BIT(color_prom[0x100 + i], 0); bit1 = BIT(color_prom[0x100 + i], 1); bit2 = BIT(color_prom[0x100 + i], 2); bit3 = BIT(color_prom[0x100 + i], 3); int const g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; // Sheet 15B: 136014-0139 blue component bit0 = BIT(color_prom[0x200 + i], 0); bit1 = BIT(color_prom[0x200 + i], 1); bit2 = BIT(color_prom[0x200 + i], 2); bit3 = BIT(color_prom[0x200 + i], 3); int const b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; palette.set_indirect_color(i, rgb_t(r, g, b)); } /******************************************************* * Alpha colors (colors 0x000-0x1ff) * Sheet 15B: top left, 136014-140 * Inputs: SHFT0, SHFT1 and CHA8* ... CHA13* *******************************************************/ for (int i = 0; i < 64*4; i++) { int const color = color_prom[0x300 + i]; palette.set_pen_indirect(0x0000 + i, (color != 15) ? (0x020 + color) : 0x2f); palette.set_pen_indirect(0x0100 + i, (color != 15) ? (0x060 + color) : 0x2f); } /******************************************************* * Background colors (colors 0x200-0x2ff) * Sheet 13A: left, 136014-141 * Inputs: SHFT2, SHFT3 and CHA8 ... CHA13 * The background is only in the top half of the screen *******************************************************/ for (int i = 0; i < 64*4; i++) { int const color = color_prom[0x400 + i]; palette.set_pen_indirect(0x0200 + i, 0x000 + color); } /******************************************************* * Sprite colors (colors 0x300-0xaff) * Sheet 14B: right, 136014-146 * Inputs: CUSTOM0 ... CUSTOM3 and DATA0 ... DATA5 *******************************************************/ for (int i = 0; i < 64*16; i++) { int const color = color_prom[0xc00 + i]; palette.set_pen_indirect(0x0300 + i, (color != 15) ? (0x010 + color) : 0x1f); palette.set_pen_indirect(0x0700 + i, (color != 15) ? (0x050 + color) : 0x1f); } /******************************************************* * Road colors (colors 0xb00-0x0eff) * Sheet 13A: bottom left, 136014-145 * Inputs: R1 ... R6 and CHA0 ... CHA3 * The road is only in the bottom half of the screen *******************************************************/ for (int i = 0; i < 64*16; i++) { int const color = color_prom[0x800 + i]; palette.set_pen_indirect(0x0b00 + i, 0x040 + color); } /* 136014-142, 136014-143, 136014-144 Vertical position modifiers */ for (int i = 0; i < 256; i++) { int const j = color_prom[0x500 + i] + (color_prom[0x600 + i] << 4) + (color_prom[0x700 + i] << 8); m_vertical_position_modifier[i] = j; } } /*************************************************************************** Callbacks for the TileMap code ***************************************************************************/ TILE_GET_INFO_MEMBER(polepos_state::bg_get_tile_info) { uint16_t word = m_view16_memory[tile_index]; int code = (word & 0xff) | ((word & 0x4000) >> 6); int color = (word & 0x3f00) >> 8; SET_TILE_INFO_MEMBER(1, code, color, 0); } TILE_GET_INFO_MEMBER(polepos_state::tx_get_tile_info) { uint16_t word = m_alpha16_memory[tile_index]; int code = (word & 0xff) | ((word & 0x4000) >> 6); int color = (word & 0x3f00) >> 8; /* I assume the purpose of CHACL is to allow the Z80 to control the display (therefore using only the bottom 8 bits of tilemap RAM) in case the Z8002 is not working. */ if (m_chacl == 0) { code &= 0xff; color = 0; } /* 128V input to the palette PROM */ if (tile_index >= 32*16) color |= 0x40; SET_TILE_INFO_MEMBER(0, code, color, 0); tileinfo.group = color; } /*************************************************************************** Start the video hardware emulation. ***************************************************************************/ void polepos_state::video_start() { m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(polepos_state::bg_get_tile_info)), TILEMAP_SCAN_COLS, 8, 8, 64, 16); m_tx_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(polepos_state::tx_get_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32); m_tx_tilemap->configure_groups(*m_gfxdecode->gfx(0), 0x2f); save_item(NAME(m_road16_vscroll)); save_item(NAME(m_chacl)); save_item(NAME(m_scroll)); } /*************************************************************************** Sprite memory ***************************************************************************/ READ8_MEMBER(polepos_state::sprite_r) { return m_sprite16_memory[offset] & 0xff; } WRITE8_MEMBER(polepos_state::sprite_w) { m_sprite16_memory[offset] = (m_sprite16_memory[offset] & 0xff00) | data; } /*************************************************************************** Road memory ***************************************************************************/ READ8_MEMBER(polepos_state::road_r) { return m_road16_memory[offset] & 0xff; } WRITE8_MEMBER(polepos_state::road_w) { m_road16_memory[offset] = (m_road16_memory[offset] & 0xff00) | data; } WRITE16_MEMBER(polepos_state::road16_vscroll_w) { COMBINE_DATA(&m_road16_vscroll); } /*************************************************************************** View memory ***************************************************************************/ WRITE16_MEMBER(polepos_state::view16_w) { COMBINE_DATA(&m_view16_memory[offset]); if (offset < 0x400) m_bg_tilemap->mark_tile_dirty(offset); } READ8_MEMBER(polepos_state::view_r) { return m_view16_memory[offset] & 0xff; } WRITE8_MEMBER(polepos_state::view_w) { m_view16_memory[offset] = (m_view16_memory[offset] & 0xff00) | data; if (offset < 0x400) m_bg_tilemap->mark_tile_dirty(offset); } WRITE16_MEMBER(polepos_state::view16_hscroll_w) { COMBINE_DATA(&m_scroll); m_bg_tilemap->set_scrollx(0,m_scroll); } WRITE_LINE_MEMBER(polepos_state::chacl_w) { m_chacl = state; m_tx_tilemap->mark_all_dirty(); } /*************************************************************************** Alpha memory ***************************************************************************/ WRITE16_MEMBER(polepos_state::alpha16_w) { COMBINE_DATA(&m_alpha16_memory[offset]); m_tx_tilemap->mark_tile_dirty(offset); } READ8_MEMBER(polepos_state::alpha_r) { return m_alpha16_memory[offset] & 0xff; } WRITE8_MEMBER(polepos_state::alpha_w) { m_alpha16_memory[offset] = (m_alpha16_memory[offset] & 0xff00) | data; m_tx_tilemap->mark_tile_dirty(offset); } /*************************************************************************** Display refresh ***************************************************************************/ void polepos_state::draw_road(bitmap_ind16 &bitmap) { const uint8_t *road_control = memregion("gfx5")->base(); const uint8_t *road_bits1 = road_control + 0x2000; const uint8_t *road_bits2 = road_control + 0x4000; /* loop over the lower half of the screen */ for (int y = 128; y < 256; y++) { int xoffs, yoffs, xscroll, roadpal; uint16_t scanline[256 + 8]; uint16_t *dest = scanline; pen_t pen_base; /* first add the vertical position modifier and the vertical scroll */ yoffs = ((m_vertical_position_modifier[y] + m_road16_vscroll) >> 3) & 0x1ff; /* then use that as a lookup into the road memory */ roadpal = m_road16_memory[yoffs] & 15; /* this becomes the palette base for the scanline */ pen_base = 0x0b00 + (roadpal << 6); /* now fetch the horizontal scroll offset for this scanline */ xoffs = m_road16_memory[0x380 + (y & 0x7f)] & 0x3ff; /* the road is drawn in 8-pixel chunks, so round downward and adjust the base */ /* note that we assume there is at least 8 pixels of slop on the left/right */ xscroll = xoffs & 7; xoffs &= ~7; /* loop over 8-pixel chunks */ for (int x = 0; x < 256 / 8 + 1; x++, xoffs += 8) { /* if the 0x200 bit of the xoffset is set, a special pin on the custom */ /* chip is set and the /CE and /OE for the road chips is disabled */ if (xoffs & 0x200) { /* in this case, it looks like we just fill with 0 */ for (int i = 0; i < 8; i++) *dest++ = pen_base | 0; } /* otherwise, we clock in the bits and compute the road value */ else { /* the road ROM offset comes from the current scanline and the X offset */ int romoffs = ((y & 0x07f) << 6) + ((xoffs & 0x1f8) >> 3); /* fetch the current data from the road ROMs */ int control = road_control[romoffs]; int bits1 = road_bits1[romoffs]; int bits2 = road_bits2[(romoffs & 0xfff) | ((romoffs & 0x1000) >> 1)]; /* extract the road value and the carry-in bit */ int roadval = control & 0x3f; int carin = control >> 7; /* draw this 8-pixel chunk */ for (int i = 8; i > 0; i--) { int bits = BIT(bits1,i) + (BIT(bits2,i) << 1); if (!carin && bits) bits++; *dest++ = pen_base | (roadval & 0x3f); roadval += bits; } } } /* draw the scanline */ draw_scanline16(bitmap, 0, y, 256, &scanline[xscroll], nullptr); } } void polepos_state::zoom_sprite(bitmap_ind16 &bitmap,int big, uint32_t code,uint32_t color,int flipx,int sx,int sy, int sizex,int sizey) { gfx_element *gfx = m_gfxdecode->gfx(big ? 3 : 2); const uint8_t *gfxdata = gfx->get_data(code % gfx->elements()); uint8_t *scaling_rom = memregion("gfx6")->base(); uint32_t transmask = m_palette->transpen_mask(*gfx, color, 0x1f); int coloroffs = gfx->colorbase() + color * gfx->granularity(); if (flipx) flipx = big ? 0x1f : 0x0f; for (int y = 0;y <= sizey;y++) { int yy = (sy + y) & 0x1ff; /* the following should be a reasonable reproduction of how the real hardware works */ if (yy >= 0x10 && yy < 0xf0) { int dy = scaling_rom[(y << 6) + sizey] & 0x1f; int xx = sx & 0x3ff; int siz = 0; int offs = 0; const uint8_t *src; if (!big) dy >>= 1; src = gfxdata + dy * gfx->rowbytes(); for (int x = (big ? 0x40 : 0x20);x > 0;x--) { if (xx < 0x100) { int pen = src[offs/2 ^ flipx]; if (!((transmask >> pen) & 1)) bitmap.pix16(yy, xx) = pen + coloroffs; } offs++; siz = siz+1+sizex; if (siz & 0x40) { siz &= 0x3f; xx = (xx+1) & 0x3ff; } } } } } void polepos_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect ) { uint16_t *posmem = &m_sprite16_memory[0x380]; uint16_t *sizmem = &m_sprite16_memory[0x780]; for (int i = 0; i < 64; i++, posmem += 2, sizmem += 2) { int sx = (posmem[1] & 0x3ff) - 0x40 + 4; int sy = 512 - (posmem[0] & 0x1ff) + 1; // sprites are buffered and delayed by one scanline int sizex = (sizmem[1] & 0x3f00) >> 8; int sizey = (sizmem[0] & 0x3f00) >> 8; int code = sizmem[0] & 0x7f; int flipx = sizmem[0] & 0x80; int color = sizmem[1] & 0x3f; /* 128V input to the palette PROM */ if (sy >= 128) color |= 0x40; zoom_sprite(bitmap, (sizmem[0] & 0x8000) ? 1 : 0, code, color, flipx, sx, sy, sizex,sizey); } } uint32_t polepos_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) { rectangle clip = cliprect; clip.max_y = 127; m_bg_tilemap->draw(screen, bitmap, clip, 0,0); draw_road(bitmap); draw_sprites(bitmap,cliprect); m_tx_tilemap->draw(screen, bitmap, cliprect, 0,0); return 0; }