/*************************************************************************** video.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "includes/citycon.h" /*************************************************************************** Callbacks for the TileMap code ***************************************************************************/ static TILEMAP_MAPPER( citycon_scan ) { /* logical (col,row) -> memory offset */ return (col & 0x1f) + ((row & 0x1f) << 5) + ((col & 0x60) << 5); } static TILE_GET_INFO( get_fg_tile_info ) { citycon_state *state = machine.driver_data(); SET_TILE_INFO( 0, state->m_videoram[tile_index], (tile_index & 0x03e0) >> 5, /* color depends on scanline only */ 0); } static TILE_GET_INFO( get_bg_tile_info ) { citycon_state *state = machine.driver_data(); UINT8 *rom = machine.region("gfx4")->base(); int code = rom[0x1000 * state->m_bg_image + tile_index]; SET_TILE_INFO( 3 + state->m_bg_image, code, rom[0xc000 + 0x100 * state->m_bg_image + code], 0); } /*************************************************************************** Start the video hardware emulation. ***************************************************************************/ VIDEO_START( citycon ) { citycon_state *state = machine.driver_data(); state->m_fg_tilemap = tilemap_create(machine, get_fg_tile_info, citycon_scan, 8, 8, 128, 32); state->m_bg_tilemap = tilemap_create(machine, get_bg_tile_info, citycon_scan, 8, 8, 128, 32); tilemap_set_transparent_pen(state->m_fg_tilemap, 0); tilemap_set_scroll_rows(state->m_fg_tilemap, 32); } /*************************************************************************** Memory handlers ***************************************************************************/ WRITE8_HANDLER( citycon_videoram_w ) { citycon_state *state = space->machine().driver_data(); state->m_videoram[offset] = data; tilemap_mark_tile_dirty(state->m_fg_tilemap, offset); } WRITE8_HANDLER( citycon_linecolor_w ) { citycon_state *state = space->machine().driver_data(); state->m_linecolor[offset] = data; } WRITE8_HANDLER( citycon_background_w ) { citycon_state *state = space->machine().driver_data(); /* bits 4-7 control the background image */ if (state->m_bg_image != (data >> 4)) { state->m_bg_image = (data >> 4); tilemap_mark_all_tiles_dirty(state->m_bg_tilemap); } /* bit 0 flips screen */ /* it is also used to multiplex player 1 and player 2 controls */ flip_screen_set(space->machine(), data & 0x01); /* bits 1-3 are unknown */ // if ((data & 0x0e) != 0) logerror("background register = %02x\n", data); } static void draw_sprites( running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect ) { citycon_state *state = machine.driver_data(); int offs; for (offs = state->m_spriteram_size - 4; offs >= 0; offs -= 4) { int sx, sy, flipx; sx = state->m_spriteram[offs + 3]; sy = 239 - state->m_spriteram[offs]; flipx = ~state->m_spriteram[offs + 2] & 0x10; if (flip_screen_get(machine)) { sx = 240 - sx; sy = 238 - sy; flipx = !flipx; } drawgfx_transpen(bitmap, cliprect, machine.gfx[state->m_spriteram[offs + 1] & 0x80 ? 2 : 1], state->m_spriteram[offs + 1] & 0x7f, state->m_spriteram[offs + 2] & 0x0f, flipx,flip_screen_get(machine), sx, sy, 0); } } INLINE void changecolor_RRRRGGGGBBBBxxxx( running_machine &machine, int color, int indx ) { int data = machine.generic.paletteram.u8[2 * indx | 1] | (machine.generic.paletteram.u8[2 * indx] << 8); palette_set_color_rgb(machine, color, pal4bit(data >> 12), pal4bit(data >> 8), pal4bit(data >> 4)); } SCREEN_UPDATE( citycon ) { citycon_state *state = screen->machine().driver_data(); int offs, scroll; /* Update the virtual palette to support text color code changing on every scanline. */ for (offs = 0; offs < 256; offs++) { int indx = state->m_linecolor[offs]; int i; for (i = 0; i < 4; i++) changecolor_RRRRGGGGBBBBxxxx(screen->machine(), 640 + 4 * offs + i, 512 + 4 * indx + i); } scroll = state->m_scroll[0] * 256 + state->m_scroll[1]; tilemap_set_scrollx(state->m_bg_tilemap, 0, scroll >> 1); for (offs = 6; offs < 32; offs++) tilemap_set_scrollx(state->m_fg_tilemap, offs, scroll); tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0); tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, 0, 0); draw_sprites(screen->machine(), bitmap, cliprect); return 0; }