// license:BSD-3-Clause // copyright-holders:Aaron Giles /*************************************************************************** Sega System 16B hardware ***************************************************************************/ #include "emu.h" #include "includes/segas16b.h" //------------------------------------------------- // video_start - initialize the video system //------------------------------------------------- void segas16b_state::video_start() { // initialize the tile/text layers m_segaic16vid->tilemap_init( 0, m_tilemap_type, 0x000, 0, 2); } //------------------------------------------------- // screen_update - render all graphics //------------------------------------------------- uint32_t segas16b_state::screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect) { // if no drawing is happening, fill with black and get out if (!m_segaic16vid->m_display_enable) { bitmap.fill(m_palette->black_pen(), cliprect); return 0; } // start the sprites drawing if (m_sprites.found()) m_sprites->draw_async(cliprect); // reset priorities screen.priority().fill(0, cliprect); // draw background opaquely first, not setting any priorities m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_BACKGROUND, 0 | TILEMAP_DRAW_OPAQUE, 0x00); m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_BACKGROUND, 1 | TILEMAP_DRAW_OPAQUE, 0x00); // draw background again, just to set the priorities on non-transparent pixels m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_BACKGROUND, 0, 0x01); m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_BACKGROUND, 1, 0x02); // draw foreground m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_FOREGROUND, 0, 0x02); m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_FOREGROUND, 1, 0x04); // text layer m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_TEXT, 0, 0x04); m_segaic16vid->tilemap_draw( screen, bitmap, cliprect, 0, segaic16_video_device::TILEMAP_TEXT, 1, 0x08); // mix in sprites if (!m_sprites.found()) return 0; bitmap_ind16 &sprites = m_sprites->bitmap(); for (const sparse_dirty_rect *rect = m_sprites->first_dirty_rect(cliprect); rect != nullptr; rect = rect->next()) for (int y = rect->min_y; y <= rect->max_y; y++) { uint16_t *dest = &bitmap.pix(y); uint16_t *src = &sprites.pix(y); uint8_t *pri = &screen.priority().pix(y); for (int x = rect->min_x; x <= rect->max_x; x++) { // only process written pixels uint16_t pix = src[x]; if (pix != 0xffff) { // compare sprite priority against tilemap priority int priority = (pix >> 10) & 3; if ((1 << priority) > pri[x]) { // if the color is set to maximum, shadow pixels underneath us if ((pix & 0x03f0) == 0x03f0) dest[x] += m_palette_entries; // otherwise, just add in sprite palette base else dest[x] = m_spritepalbase | (pix & 0x3ff); } } } } return 0; }