/*************************************************************************** video.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "includes/bankp.h" /*************************************************************************** Convert the color PROMs into a more useable format. Bank Panic has a 32x8 palette PROM (I'm not sure whether the second 16 bytes are used - they contain the same colors as the first 16 with only one different) and two 256x4 lookup table PROMs (one for charset #1, one for charset #2 - only the first 128 nibbles seem to be used). I don't know for sure how the palette PROM is connected to the RGB output, but it's probably the usual: 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 ***************************************************************************/ PALETTE_INIT( bankp ) { int i; /* allocate the colortable */ machine.colortable = colortable_alloc(machine, 32); for (i = 0; i < 32; i++) { int bit0, bit1, bit2, r, g, b; /* red component */ bit0 = (*color_prom >> 0) & 0x01; bit1 = (*color_prom >> 1) & 0x01; bit2 = (*color_prom >> 2) & 0x01; r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; /* green component */ bit0 = (*color_prom >> 3) & 0x01; bit1 = (*color_prom >> 4) & 0x01; bit2 = (*color_prom >> 5) & 0x01; g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; /* blue component */ bit0 = 0; bit1 = (*color_prom >> 6) & 0x01; bit2 = (*color_prom >> 7) & 0x01; b = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; colortable_palette_set_color(machine.colortable, i, MAKE_RGB(r,g,b)); color_prom++; } /* color_prom now points to the beginning of the lookup table */ /* charset #1 lookup table */ for (i = 0; i < machine.gfx[0]->total_colors * machine.gfx[0]->color_granularity; i++) colortable_entry_set_value(machine.colortable, machine.gfx[0]->color_base + i, *color_prom++ & 0x0f); color_prom += 128; /* skip the bottom half of the PROM - seems to be not used */ /* charset #2 lookup table */ for (i = 0; i < machine.gfx[1]->total_colors * machine.gfx[1]->color_granularity; i++) colortable_entry_set_value(machine.colortable, machine.gfx[1]->color_base + i, *color_prom++ & 0x0f); /* the bottom half of the PROM seems to be not used */ } WRITE8_HANDLER( bankp_scroll_w ) { bankp_state *state = space->machine().driver_data(); state->m_scroll_x = data; } WRITE8_HANDLER( bankp_videoram_w ) { bankp_state *state = space->machine().driver_data(); state->m_videoram[offset] = data; tilemap_mark_tile_dirty(state->m_fg_tilemap, offset); } WRITE8_HANDLER( bankp_colorram_w ) { bankp_state *state = space->machine().driver_data(); state->m_colorram[offset] = data; tilemap_mark_tile_dirty(state->m_fg_tilemap, offset); } WRITE8_HANDLER( bankp_videoram2_w ) { bankp_state *state = space->machine().driver_data(); state->m_videoram2[offset] = data; tilemap_mark_tile_dirty(state->m_bg_tilemap, offset); } WRITE8_HANDLER( bankp_colorram2_w ) { bankp_state *state = space->machine().driver_data(); state->m_colorram2[offset] = data; tilemap_mark_tile_dirty(state->m_bg_tilemap, offset); } WRITE8_HANDLER( bankp_out_w ) { bankp_state *state = space->machine().driver_data(); /* bits 0-1 are playfield priority */ /* TODO: understand how this works */ state->m_priority = data & 0x03; /* bits 2-3 unknown (2 is used) */ /* bit 4 controls NMI */ state->m_nmi_mask = (data & 0x10) >> 4; /* bit 5 controls screen flip */ flip_screen_set(space->machine(), data & 0x20); /* bits 6-7 unknown */ } static TILE_GET_INFO( get_bg_tile_info ) { bankp_state *state = machine.driver_data(); int code = state->m_videoram2[tile_index] + 256 * (state->m_colorram2[tile_index] & 0x07); int color = state->m_colorram2[tile_index] >> 4; int flags = (state->m_colorram2[tile_index] & 0x08) ? TILE_FLIPX : 0; SET_TILE_INFO(1, code, color, flags); tileinfo->group = color; } static TILE_GET_INFO( get_fg_tile_info ) { bankp_state *state = machine.driver_data(); int code = state->m_videoram[tile_index] + 256 * ((state->m_colorram[tile_index] & 3) >> 0); int color = state->m_colorram[tile_index] >> 3; int flags = (state->m_colorram[tile_index] & 0x04) ? TILE_FLIPX : 0; SET_TILE_INFO(0, code, color, flags); tileinfo->group = color; } VIDEO_START( bankp ) { bankp_state *state = machine.driver_data(); state->m_bg_tilemap = tilemap_create(machine, get_bg_tile_info, tilemap_scan_rows, 8, 8, 32, 32); state->m_fg_tilemap = tilemap_create(machine, get_fg_tile_info, tilemap_scan_rows, 8, 8, 32, 32); colortable_configure_tilemap_groups(machine.colortable, state->m_bg_tilemap, machine.gfx[1], 0); colortable_configure_tilemap_groups(machine.colortable, state->m_fg_tilemap, machine.gfx[0], 0); state->save_item(NAME(state->m_scroll_x)); state->save_item(NAME(state->m_priority)); } SCREEN_UPDATE( bankp ) { bankp_state *state = screen->machine().driver_data(); if (flip_screen_get(screen->machine())) { tilemap_set_scrollx(state->m_fg_tilemap, 0, -state->m_scroll_x); tilemap_set_scrollx(state->m_bg_tilemap, 0, 0); } else { tilemap_set_scrollx(state->m_fg_tilemap, 0, state->m_scroll_x); tilemap_set_scrollx(state->m_bg_tilemap, 0, 0); } // only one bit matters? switch (state->m_priority) { case 0: // combat hawk uses this tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, TILEMAP_DRAW_OPAQUE, 0); tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, 0, 0); break; case 1: tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, TILEMAP_DRAW_OPAQUE, 0); tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, 0, 0); break; case 2: tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, TILEMAP_DRAW_OPAQUE, 0); tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0); break; case 3: tilemap_draw(bitmap, cliprect, state->m_fg_tilemap, TILEMAP_DRAW_OPAQUE, 0); // just a guess tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0); break; } return 0; }