diff options
Diffstat (limited to 'src/mame/video/bankp.c')
-rw-r--r-- | src/mame/video/bankp.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/src/mame/video/bankp.c b/src/mame/video/bankp.c new file mode 100644 index 00000000000..ba2ce02cc51 --- /dev/null +++ b/src/mame/video/bankp.c @@ -0,0 +1,205 @@ +/*************************************************************************** + + video.c + + Functions to emulate the video hardware of the machine. + +***************************************************************************/ + +#include "driver.h" + +UINT8 *bankp_videoram2; +UINT8 *bankp_colorram2; + +static int scroll_x; +static int priority; + +static tilemap *bg_tilemap, *fg_tilemap; +static colortable *bankp_colortable; + + +/*************************************************************************** + + 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; + #define TOTAL_COLORS(gfxn) (machine->gfx[gfxn]->total_colors * machine->gfx[gfxn]->color_granularity) + #define COLOR(gfxn,offs) (colortable[machine->drv->gfxdecodeinfo[gfxn].color_codes_start + offs]) + + /* allocate the colortable */ + bankp_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(bankp_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(bankp_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(bankp_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 ) +{ + scroll_x = data; +} + +WRITE8_HANDLER( bankp_videoram_w ) +{ + videoram[offset] = data; + tilemap_mark_tile_dirty(fg_tilemap, offset); +} + +WRITE8_HANDLER( bankp_colorram_w ) +{ + colorram[offset] = data; + tilemap_mark_tile_dirty(fg_tilemap, offset); +} + +WRITE8_HANDLER( bankp_videoram2_w ) +{ + bankp_videoram2[offset] = data; + tilemap_mark_tile_dirty(bg_tilemap, offset); +} + +WRITE8_HANDLER( bankp_colorram2_w ) +{ + bankp_colorram2[offset] = data; + tilemap_mark_tile_dirty(bg_tilemap, offset); +} + +WRITE8_HANDLER( bankp_out_w ) +{ + /* bits 0-1 are playfield priority */ + /* TODO: understand how this works */ + priority = data & 0x03; + + /* bits 2-3 unknown (2 is used) */ + + /* bit 4 controls NMI */ + interrupt_enable_w(0,(data & 0x10)>>4); + + /* bit 5 controls screen flip */ + flip_screen_set(data & 0x20); + + /* bits 6-7 unknown */ +} + +static TILE_GET_INFO( get_bg_tile_info ) +{ + int code = bankp_videoram2[tile_index] + 256 * (bankp_colorram2[tile_index] & 0x07); + int color = bankp_colorram2[tile_index] >> 4; + int flags = (bankp_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 ) +{ + int code = videoram[tile_index] + 256 * ((colorram[tile_index] & 3) >> 0); + int color = colorram[tile_index] >> 3; + int flags = (colorram[tile_index] & 0x04) ? TILE_FLIPX : 0; + + SET_TILE_INFO(0, code, color, flags); + tileinfo->group = color; +} + +VIDEO_START( bankp ) +{ + bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows, + TILEMAP_TYPE_PEN, 8, 8, 32, 32); + + fg_tilemap = tilemap_create(get_fg_tile_info, tilemap_scan_rows, + TILEMAP_TYPE_PEN, 8, 8, 32, 32); + + colortable_configure_tilemap_groups(bankp_colortable, bg_tilemap, machine->gfx[1], 0); + colortable_configure_tilemap_groups(bankp_colortable, fg_tilemap, machine->gfx[0], 0); +} + +VIDEO_UPDATE( bankp ) +{ + if (flip_screen) + { + tilemap_set_scrollx(fg_tilemap, 0, -scroll_x); + tilemap_set_scrollx(bg_tilemap, 0, 0); + } + else + { + tilemap_set_scrollx(fg_tilemap, 0, scroll_x); + tilemap_set_scrollx(bg_tilemap, 0, 0); + } + + + // only one bit matters? + switch (priority) + { + case 0: // combat hawk uses this + tilemap_draw(bitmap, cliprect, bg_tilemap, TILEMAP_DRAW_OPAQUE, 0); + tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0); + break; + case 1: + tilemap_draw(bitmap, cliprect, bg_tilemap, TILEMAP_DRAW_OPAQUE, 0); + tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0); + break; + case 2: + tilemap_draw(bitmap, cliprect, fg_tilemap, TILEMAP_DRAW_OPAQUE, 0); + tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0); + break; + case 3: + tilemap_draw(bitmap, cliprect, fg_tilemap, TILEMAP_DRAW_OPAQUE, 0); // just a guess + tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0); + break; + } + return 0; +} |