// license:BSD-3-Clause // copyright-holders:Lee Taylor // thanks-to:John Clegg,Tomasz Slanina /*************************************************************************** video.c Traverse USA L Taylor J Clegg Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "includes/travrusa.h" /*************************************************************************** Convert the color PROMs into a more useable format. Traverse USA has one 256x8 character palette PROM (some versions have two 256x4), one 32x8 sprite palette PROM, and one 256x4 sprite color lookup table PROM. I don't know for sure how the palette PROMs are connected to the RGB output, but it's probably something like this; note that RED and BLUE are swapped wrt the usual configuration. bit 7 -- 220 ohm resistor -- RED -- 470 ohm resistor -- RED -- 220 ohm resistor -- GREEN -- 470 ohm resistor -- GREEN -- 1 kohm resistor -- GREEN -- 220 ohm resistor -- BLUE -- 470 ohm resistor -- BLUE bit 0 -- 1 kohm resistor -- BLUE ***************************************************************************/ void travrusa_state::travrusa_palette(palette_device &palette) const { const uint8_t *color_prom = memregion("proms")->base(); // create a lookup table for the palette for (int i = 0; i < 0x80; i++) { int bit0, bit1, bit2; // red component bit0 = 0; bit1 = BIT(color_prom[i], 6); bit2 = BIT(color_prom[i], 7); int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // green component bit0 = BIT(color_prom[i], 3); bit1 = BIT(color_prom[i], 4); bit2 = BIT(color_prom[i], 5); int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // blue component bit0 = BIT(color_prom[i], 0); bit1 = BIT(color_prom[i], 1); bit2 = BIT(color_prom[i], 2); int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; palette.set_indirect_color(i, rgb_t(r, g, b)); } for (int i = 0x80; i < 0x90; i++) { int bit0, bit1, bit2; // red component bit0 = 0; bit1 = BIT(color_prom[(i - 0x80) + 0x200], 6); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 7); int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // green component bit0 = BIT(color_prom[(i - 0x80) + 0x200], 3); bit1 = BIT(color_prom[(i - 0x80) + 0x200], 4); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 5); int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // blue component bit0 = BIT(color_prom[(i - 0x80) + 0x200], 0); bit1 = BIT(color_prom[(i - 0x80) + 0x200], 1); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 2); int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; palette.set_indirect_color(i, rgb_t(r, g, b)); } // color_prom now points to the beginning of the lookup table color_prom += 0x220; // characters for (int i = 0; i < 0x80; i++) palette.set_pen_indirect(i, i); // sprites for (int i = 0x80; i < 0x100; i++) { uint8_t const ctabentry = (color_prom[i - 0x80] & 0x0f) | 0x80; palette.set_pen_indirect(i, ctabentry); } } void travrusa_state::shtrider_palette(palette_device &palette) const { const uint8_t *color_prom = memregion("proms")->base(); // create a lookup table for the palette for (int i = 0; i < 0x80; i++) { int bit0, bit1, bit2; // red component bit0 = 0; bit1 = BIT(color_prom[i + 0x000], 2); bit2 = BIT(color_prom[i + 0x000], 3); int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // green component bit0 = BIT(color_prom[i + 0x100], 3); bit1 = BIT(color_prom[i + 0x000], 0); bit2 = BIT(color_prom[i + 0x000], 1); int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // blue component bit0 = BIT(color_prom[i + 0x100], 0); bit1 = BIT(color_prom[i + 0x100], 1); bit2 = BIT(color_prom[i + 0x100], 2); int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; palette.set_indirect_color(i, rgb_t(r, g, b)); } for (int i = 0x80; i < 0x90; i++) { int bit0, bit1, bit2; // red component bit0 = 0; bit1 = BIT(color_prom[(i - 0x80) + 0x200], 6); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 7); int const r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // green component bit0 = BIT(color_prom[(i - 0x80) + 0x200], 3); bit1 = BIT(color_prom[(i - 0x80) + 0x200], 4); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 5); int const g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; // blue component bit0 = BIT(color_prom[(i - 0x80) + 0x200], 0); bit1 = BIT(color_prom[(i - 0x80) + 0x200], 1); bit2 = BIT(color_prom[(i - 0x80) + 0x200], 2); int const b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; palette.set_indirect_color(i, rgb_t(r, g, b)); } // color_prom now points to the beginning of the lookup table color_prom += 0x220; // characters for (int i = 0; i < 0x80; i++) palette.set_pen_indirect(i, i); // sprites for (int i = 0x80; i < 0x100; i++) { uint8_t const ctabentry = (color_prom[i - 0x80] & 0x0f) | 0x80; palette.set_pen_indirect(i, ctabentry); } } /*************************************************************************** Callbacks for the TileMap code ***************************************************************************/ TILE_GET_INFO_MEMBER(travrusa_state::get_tile_info) { uint8_t attr = m_videoram[2 * tile_index + 1]; int flags = TILE_FLIPXY((attr & 0x30) >> 4); tileinfo.group = ((attr & 0x0f) == 0x0f) ? 1 : 0; /* tunnels */ SET_TILE_INFO_MEMBER(0, m_videoram[2 * tile_index] + ((attr & 0xc0) << 2), attr & 0x0f, flags); } /*************************************************************************** Start the video hardware emulation. ***************************************************************************/ void travrusa_state::video_start() { save_item(NAME(m_scrollx)); m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(travrusa_state::get_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 64, 32); m_bg_tilemap->set_transmask(0, 0xff, 0x00); /* split type 0 is totally transparent in front half */ m_bg_tilemap->set_transmask(1, 0x3f, 0xc0); /* split type 1 has pens 6 and 7 opaque - tunnels */ m_bg_tilemap->set_scroll_rows(4); } /*************************************************************************** Memory handlers ***************************************************************************/ WRITE8_MEMBER(travrusa_state::travrusa_videoram_w) { m_videoram[offset] = data; m_bg_tilemap->mark_tile_dirty(offset / 2); } void travrusa_state::set_scroll( ) { int i; for (i = 0; i <= 2; i++) m_bg_tilemap->set_scrollx(i, m_scrollx[0] + 256 * m_scrollx[1]); m_bg_tilemap->set_scrollx(3, 0); } WRITE8_MEMBER(travrusa_state::travrusa_scroll_x_low_w) { m_scrollx[0] = data; set_scroll(); } WRITE8_MEMBER(travrusa_state::travrusa_scroll_x_high_w) { m_scrollx[1] = data; set_scroll(); } WRITE8_MEMBER(travrusa_state::travrusa_flipscreen_w) { /* screen flip is handled both by software and hardware */ data ^= ~ioport("DSW2")->read() & 1; flip_screen_set(data & 1); machine().bookkeeping().coin_counter_w(0, data & 0x02); machine().bookkeeping().coin_counter_w(1, data & 0x20); } /*************************************************************************** Display refresh ***************************************************************************/ void travrusa_state::draw_sprites(bitmap_ind16 &bitmap,const rectangle &cliprect) { int offs; const rectangle spritevisiblearea(1*8, 31*8-1, 0*8, 24*8-1); const rectangle spritevisibleareaflip(1*8, 31*8-1, 8*8, 32*8-1); rectangle clip = cliprect; if (flip_screen()) clip &= spritevisibleareaflip; else clip &= spritevisiblearea; for (offs = m_spriteram.bytes() - 4; offs >= 0; offs -= 4) { int sx = ((m_spriteram[offs + 3] + 8) & 0xff) - 8; int sy = 240 - m_spriteram[offs]; int code = m_spriteram[offs + 2]; int attr = m_spriteram[offs + 1]; int flipx = attr & 0x40; int flipy = attr & 0x80; if (flip_screen()) { sx = 240 - sx; sy = 240 - sy; flipx = !flipx; flipy = !flipy; } m_gfxdecode->gfx(1)->transpen(bitmap,clip, code, attr & 0x0f, flipx, flipy, sx, sy, 0); } } uint32_t travrusa_state::screen_update_travrusa(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) { m_bg_tilemap->draw(screen, bitmap, cliprect, TILEMAP_DRAW_LAYER1, 0); draw_sprites(bitmap,cliprect); m_bg_tilemap->draw(screen, bitmap, cliprect, TILEMAP_DRAW_LAYER0, 0); return 0; }