// license:BSD-3-Clause // copyright-holders:Nicola Salmoria /*************************************************************************** video.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "includes/seicross.h" /*************************************************************************** Convert the color PROMs into a more useable format. Seicross has two 32x8 palette PROMs, connected to the RGB output this way: bit 7 -- 220 ohm resistor -- BLUE -- 470 ohm resistor -- BLUE -- 220 ohm resistor -- GREEN -- 470 ohm resistor -- GREEN -- 1 kohm resistor -- GREEN -- 220 ohm resistor -- RED -- 470 ohm resistor -- RED bit 0 -- 1 kohm resistor -- RED ***************************************************************************/ void seicross_state::seicross_palette(palette_device &palette) const { uint8_t const *const color_prom = memregion("proms")->base(); for (int i = 0; i < palette.entries(); i++) { int bit0, bit1, bit2; // red component bit0 = BIT(color_prom[i], 0); bit1 = BIT(color_prom[i], 1); bit2 = BIT(color_prom[i], 2); 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], 6); bit1 = BIT(color_prom[i], 7); int const b = 0x4f * bit0 + 0xa8 * bit1; palette.set_pen_color(i, rgb_t(r, g, b)); } } WRITE8_MEMBER(seicross_state::videoram_w) { m_videoram[offset] = data; m_bg_tilemap->mark_tile_dirty(offset); } WRITE8_MEMBER(seicross_state::colorram_w) { /* bit 5 of the address is not used for color memory. There is just */ /* 512k of memory; every two consecutive rows share the same memory */ /* region. */ offset &= 0xffdf; m_colorram[offset] = data; m_colorram[offset + 0x20] = data; m_bg_tilemap->mark_tile_dirty(offset); m_bg_tilemap->mark_tile_dirty(offset + 0x20); } TILE_GET_INFO_MEMBER(seicross_state::get_bg_tile_info) { int code = m_videoram[tile_index] + ((m_colorram[tile_index] & 0x10) << 4); int color = m_colorram[tile_index] & 0x0f; int flags = ((m_colorram[tile_index] & 0x40) ? TILE_FLIPX : 0) | ((m_colorram[tile_index] & 0x80) ? TILE_FLIPY : 0); SET_TILE_INFO_MEMBER(0, code, color, flags); } void seicross_state::video_start() { m_bg_tilemap = &machine().tilemap().create( *m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(seicross_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32); m_bg_tilemap->set_scroll_cols(32); } void seicross_state::draw_sprites(bitmap_ind16 &bitmap, const rectangle &cliprect ) { int offs; for (offs = m_spriteram.bytes() - 4; offs >= 0; offs -= 4) { int x = m_spriteram[offs + 3]; m_gfxdecode->gfx(1)->transpen(bitmap,cliprect, (m_spriteram[offs] & 0x3f) + ((m_spriteram[offs + 1] & 0x10) << 2) + 128, m_spriteram[offs + 1] & 0x0f, m_spriteram[offs] & 0x40,m_spriteram[offs] & 0x80, x,240-m_spriteram[offs + 2],0); if(x>0xf0) m_gfxdecode->gfx(1)->transpen(bitmap,cliprect, (m_spriteram[offs] & 0x3f) + ((m_spriteram[offs + 1] & 0x10) << 2) + 128, m_spriteram[offs + 1] & 0x0f, m_spriteram[offs] & 0x40,m_spriteram[offs] & 0x80, x-256,240-m_spriteram[offs + 2],0); } for (offs = m_spriteram2.bytes() - 4; offs >= 0; offs -= 4) { int x = m_spriteram2[offs + 3]; m_gfxdecode->gfx(1)->transpen(bitmap,cliprect, (m_spriteram2[offs] & 0x3f) + ((m_spriteram2[offs + 1] & 0x10) << 2), m_spriteram2[offs + 1] & 0x0f, m_spriteram2[offs] & 0x40,m_spriteram2[offs] & 0x80, x,240-m_spriteram2[offs + 2],0); if(x>0xf0) m_gfxdecode->gfx(1)->transpen(bitmap,cliprect, (m_spriteram2[offs] & 0x3f) + ((m_spriteram2[offs + 1] & 0x10) << 2), m_spriteram2[offs + 1] & 0x0f, m_spriteram2[offs] & 0x40,m_spriteram2[offs] & 0x80, x-256,240-m_spriteram2[offs + 2],0); } } uint32_t seicross_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) { int col; for (col = 0; col < 32; col++) m_bg_tilemap->set_scrolly(col, m_row_scroll[col]); m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0); draw_sprites(bitmap, cliprect); return 0; }