// license:BSD-3-Clause // copyright-holders:Zsolt Vasvari /*************************************************************************** video.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "video/resnet.h" #include "includes/sbasketb.h" /*************************************************************************** Convert the color PROMs into a more useable format. Super Basketball has three 256x4 palette PROMs (one per gun) and two 256x4 lookup table PROMs (one for characters, one for sprites). I don't know for sure how the palette PROMs are connected to the RGB output, but it's probably the usual: 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 sbasketb_state::sbasketb_palette(palette_device &palette) const { const uint8_t *color_prom = memregion("proms")->base(); static constexpr int resistances[4] = { 2000, 1000, 470, 220 }; // compute the color output resistor weights double rweights[4], gweights[4], bweights[4]; compute_resistor_weights(0, 255, -1.0, 4, resistances, rweights, 1000, 0, 4, resistances, gweights, 1000, 0, 4, resistances, bweights, 1000, 0); // create a lookup table for the palette for (int i = 0; i < 0x100; i++) { int bit0, bit1, bit2, bit3; // red component bit0 = BIT(color_prom[i | 0x000], 0); bit1 = BIT(color_prom[i | 0x000], 1); bit2 = BIT(color_prom[i | 0x000], 2); bit3 = BIT(color_prom[i | 0x000], 3); int const r = combine_weights(rweights, bit0, bit1, bit2, bit3); // green component bit0 = BIT(color_prom[i | 0x100], 0); bit1 = BIT(color_prom[i | 0x100], 1); bit2 = BIT(color_prom[i | 0x100], 2); bit3 = BIT(color_prom[i | 0x100], 3); int const g = combine_weights(gweights, bit0, bit1, bit2, bit3); // blue component bit0 = BIT(color_prom[i | 0x200], 0); bit1 = BIT(color_prom[i | 0x200], 1); bit2 = BIT(color_prom[i | 0x200], 2); bit3 = BIT(color_prom[i | 0x200], 3); int const b = combine_weights(bweights, bit0, bit1, bit2, bit3); palette.set_indirect_color(i, rgb_t(r, g, b)); } // color_prom now points to the beginning of the lookup table color_prom += 0x300; // characters use colors 0xf0-0xff for (int i = 0; i < 0x100; i++) { uint8_t const ctabentry = (color_prom[i] & 0x0f) | 0xf0; palette.set_pen_indirect(i, ctabentry); } // sprites use colors 0-256 (?) in 16 banks for (int i = 0; i < 0x100; i++) { for (int j = 0; j < 0x10; j++) { uint8_t const ctabentry = (j << 4) | (color_prom[i + 0x100] & 0x0f); palette.set_pen_indirect(0x100 + ((j << 8) | i), ctabentry); } } } WRITE8_MEMBER(sbasketb_state::sbasketb_videoram_w) { m_videoram[offset] = data; m_bg_tilemap->mark_tile_dirty(offset); } WRITE8_MEMBER(sbasketb_state::sbasketb_colorram_w) { m_colorram[offset] = data; m_bg_tilemap->mark_tile_dirty(offset); } WRITE_LINE_MEMBER(sbasketb_state::flipscreen_w) { flip_screen_set(state); machine().tilemap().mark_all_dirty(); } WRITE_LINE_MEMBER(sbasketb_state::spriteram_select_w) { m_spriteram_select = state; } TILE_GET_INFO_MEMBER(sbasketb_state::get_bg_tile_info) { int code = m_videoram[tile_index] + ((m_colorram[tile_index] & 0x20) << 3); 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 sbasketb_state::video_start() { m_bg_tilemap = &machine().tilemap().create(*m_gfxdecode, tilemap_get_info_delegate(*this, FUNC(sbasketb_state::get_bg_tile_info)), TILEMAP_SCAN_ROWS, 8, 8, 32, 32); m_bg_tilemap->set_scroll_cols(32); save_item(NAME(m_spriteram_select)); } void sbasketb_state::draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect ) { uint8_t *spriteram = m_spriteram; int offs = m_spriteram_select ? 0x100 : 0; int i; for (i = 0; i < 64; i++, offs += 4) { int sx = spriteram[offs + 2]; int sy = spriteram[offs + 3]; if (sx || sy) { int code = spriteram[offs + 0] | ((spriteram[offs + 1] & 0x20) << 3); int color = (spriteram[offs + 1] & 0x0f) + 16 * *m_palettebank; int flipx = spriteram[offs + 1] & 0x40; int flipy = spriteram[offs + 1] & 0x80; if (flip_screen()) { sx = 240 - sx; sy = 240 - sy; flipx = !flipx; flipy = !flipy; } m_gfxdecode->gfx(1)->transpen(bitmap,cliprect, code, color, flipx, flipy, sx, sy, 0); } } } uint32_t sbasketb_state::screen_update_sbasketb(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) { int col; for (col = 6; col < 32; col++) m_bg_tilemap->set_scrolly(col, *m_scroll); m_bg_tilemap->draw(screen, bitmap, cliprect, 0, 0); draw_sprites(bitmap, cliprect); return 0; }