diff options
Diffstat (limited to 'src/mame/video/gunsmoke.c')
-rw-r--r-- | src/mame/video/gunsmoke.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/mame/video/gunsmoke.c b/src/mame/video/gunsmoke.c new file mode 100644 index 00000000000..79ec0530b2a --- /dev/null +++ b/src/mame/video/gunsmoke.c @@ -0,0 +1,216 @@ +#include "driver.h" + +#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]) + +UINT8 *gunsmoke_scrollx; +UINT8 *gunsmoke_scrolly; + +static UINT8 chon, objon, bgon; +static UINT8 sprite3bank; + +static tilemap *bg_tilemap, *fg_tilemap; + +/*************************************************************************** + + Convert the color PROMs into a more useable format. + + Gunsmoke has three 256x4 palette PROMs (one per gun) and a lot ;-) of + 256x4 lookup table PROMs. + The palette PROMs are connected to the RGB output this way: + + 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 + +***************************************************************************/ +PALETTE_INIT( gunsmoke ) +{ + int i; + + for (i = 0; i < machine->drv->total_colors; i++) + { + int bit0, bit1, bit2, bit3, r, g, b; + + bit0 = (color_prom[0] >> 0) & 0x01; + bit1 = (color_prom[0] >> 1) & 0x01; + bit2 = (color_prom[0] >> 2) & 0x01; + bit3 = (color_prom[0] >> 3) & 0x01; + + r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; + + bit0 = (color_prom[machine->drv->total_colors] >> 0) & 0x01; + bit1 = (color_prom[machine->drv->total_colors] >> 1) & 0x01; + bit2 = (color_prom[machine->drv->total_colors] >> 2) & 0x01; + bit3 = (color_prom[machine->drv->total_colors] >> 3) & 0x01; + + g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; + + bit0 = (color_prom[2*machine->drv->total_colors] >> 0) & 0x01; + bit1 = (color_prom[2*machine->drv->total_colors] >> 1) & 0x01; + bit2 = (color_prom[2*machine->drv->total_colors] >> 2) & 0x01; + bit3 = (color_prom[2*machine->drv->total_colors] >> 3) & 0x01; + + b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3; + + palette_set_color(machine, i, MAKE_RGB(r, g, b)); + color_prom++; + } + + color_prom += 2 * machine->drv->total_colors; + /* color_prom now points to the beginning of the lookup table */ + + /* characters use colors 64-79 */ + for (i = 0; i < TOTAL_COLORS(0); i++) + COLOR(0, i) = *(color_prom++) + 64; + color_prom += 128; /* skip the bottom half of the PROM - not used */ + + /* background tiles use colors 0-63 */ + for (i = 0; i < TOTAL_COLORS(1); i++) + { + COLOR(1, i) = color_prom[0] + 16 * (color_prom[256] & 0x03); + color_prom++; + } + color_prom += TOTAL_COLORS(1); + + /* sprites use colors 128-255 */ + for (i = 0; i < TOTAL_COLORS(2); i++) + { + COLOR(2, i) = color_prom[0] + 16 * (color_prom[256] & 0x07) + 128; + color_prom++; + } + color_prom += TOTAL_COLORS(2); +} + +WRITE8_HANDLER( gunsmoke_videoram_w ) +{ + videoram[offset] = data; + tilemap_mark_tile_dirty(fg_tilemap, offset); +} + +WRITE8_HANDLER( gunsmoke_colorram_w ) +{ + colorram[offset] = data; + tilemap_mark_tile_dirty(fg_tilemap, offset); +} + +WRITE8_HANDLER( gunsmoke_c804_w ) +{ + /* bits 0 and 1 are for coin counters */ + coin_counter_w(1, data & 0x01); + coin_counter_w(0, data & 0x02); + + /* bits 2 and 3 select the ROM bank */ + memory_set_bank(1, (data & 0x0c) >> 2); + + /* bit 5 resets the sound CPU? - we ignore it */ + + /* bit 6 flips screen */ + flip_screen_set(data & 0x40); + + /* bit 7 enables characters? */ + chon = data & 0x80; +} + +WRITE8_HANDLER( gunsmoke_d806_w ) +{ + /* bits 0-2 select the sprite 3 bank */ + sprite3bank = data & 0x07; + + /* bit 4 enables bg 1? */ + bgon = data & 0x10; + + /* bit 5 enables sprites? */ + objon = data & 0x20; +} + +static TILE_GET_INFO( get_bg_tile_info ) +{ + UINT8 *tilerom = memory_region(REGION_GFX4); + + int offs = tile_index * 2; + int attr = tilerom[offs + 1]; + int code = tilerom[offs] + ((attr & 0x01) << 8); + int color = (attr & 0x3c) >> 2; + int flags = TILE_FLIPYX((attr & 0xc0) >> 6); + + SET_TILE_INFO(1, code, color, flags); +} + +static TILE_GET_INFO( get_fg_tile_info ) +{ + int attr = colorram[tile_index]; + int code = videoram[tile_index] + ((attr & 0xe0) << 2); + int color = attr & 0x1f; + + SET_TILE_INFO(0, code, color, 0); +} + +VIDEO_START( gunsmoke ) +{ + /* configure ROM banking */ + UINT8 *rombase = memory_region(REGION_CPU1); + memory_configure_bank(1, 0, 4, &rombase[0x10000], 0x4000); + + /* create tilemaps */ + bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_cols, + TILEMAP_TYPE_PEN, 32, 32, 2048, 8); + + fg_tilemap = tilemap_create(get_fg_tile_info, tilemap_scan_rows, + TILEMAP_TYPE_COLORTABLE, 8, 8, 32, 32); + + tilemap_set_transparent_pen(fg_tilemap, 0x4f); + + /* register for saving */ + state_save_register_global(chon); + state_save_register_global(objon); + state_save_register_global(bgon); + state_save_register_global(sprite3bank); +} + +static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect) +{ + int offs; + + for (offs = spriteram_size - 32; offs >= 0; offs -= 32) + { + int attr = spriteram[offs + 1]; + int bank = (attr & 0xc0) >> 6; + int code = spriteram[offs]; + int color = attr & 0x0f; + int flipx = 0; + int flipy = attr & 0x10; + int sx = spriteram[offs + 3] - ((attr & 0x20) << 3); + int sy = spriteram[offs + 2]; + + if (bank == 3) bank += sprite3bank; + code += 256 * bank; + + if (flip_screen) + { + sx = 240 - sx; + sy = 240 - sy; + flipx = !flipx; + flipy = !flipy; + } + + drawgfx(bitmap, machine->gfx[2], code, color, flipx, flipy, + sx, sy, cliprect, TRANSPARENCY_PEN, 0); + } +} + +VIDEO_UPDATE( gunsmoke ) +{ + tilemap_set_scrollx(bg_tilemap, 0, gunsmoke_scrollx[0] + 256 * gunsmoke_scrollx[1]); + tilemap_set_scrolly(bg_tilemap, 0, gunsmoke_scrolly[0]); + + if (bgon) + tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0); + else + fillbitmap(bitmap, get_black_pen(machine), cliprect); + + if (objon) draw_sprites(machine, bitmap, cliprect); + if (chon) tilemap_draw(bitmap, cliprect, fg_tilemap, 0, 0); + return 0; +} |