diff options
Diffstat (limited to 'src/mame/video/mikie.c')
-rw-r--r-- | src/mame/video/mikie.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/src/mame/video/mikie.c b/src/mame/video/mikie.c new file mode 100644 index 00000000000..2f924410526 --- /dev/null +++ b/src/mame/video/mikie.c @@ -0,0 +1,171 @@ +/*************************************************************************** + + video.c + + Functions to emulate the video hardware of the machine. + +***************************************************************************/ + +#include "driver.h" + +static int palettebank; + +static tilemap *bg_tilemap; + +/*************************************************************************** + + Convert the color PROMs into a more useable format. + + Mikie has three 256x4 palette PROMs (one per gun) and two 256x4 lookup + table PROMs (one for characters, one for sprites). + I don't know for sure how the palette PROMs are connected to the RGB + output, but it's probably the usual: + + 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( mikie ) +{ + 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]) + + + 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 character lookup table */ + + + /* there are eight 32 colors palette banks; sprites use colors 0-15 and */ + /* characters 16-31 of each bank. */ + for (i = 0;i < TOTAL_COLORS(0)/8;i++) + { + int j; + + + for (j = 0;j < 8;j++) + COLOR(0,i + j * TOTAL_COLORS(0)/8) = (*color_prom & 0x0f) + 32 * j + 16; + + color_prom++; + } + + for (i = 0;i < TOTAL_COLORS(1)/8;i++) + { + int j; + + + for (j = 0;j < 8;j++) + COLOR(1,i + j * TOTAL_COLORS(1)/8) = (*color_prom & 0x0f) + 32 * j; + + color_prom++; + } +} + +WRITE8_HANDLER( mikie_videoram_w ) +{ + videoram[offset] = data; + tilemap_mark_tile_dirty(bg_tilemap, offset); +} + +WRITE8_HANDLER( mikie_colorram_w ) +{ + colorram[offset] = data; + tilemap_mark_tile_dirty(bg_tilemap, offset); +} + +WRITE8_HANDLER( mikie_palettebank_w ) +{ + if (palettebank != (data & 0x07)) + { + palettebank = data & 0x07; + tilemap_mark_all_tiles_dirty(ALL_TILEMAPS); + } +} + +WRITE8_HANDLER( mikie_flipscreen_w ) +{ + if (flip_screen != (data & 0x01)) + { + flip_screen_set(data & 0x01); + tilemap_mark_all_tiles_dirty(ALL_TILEMAPS); + } +} + +static TILE_GET_INFO( get_bg_tile_info ) +{ + int code = videoram[tile_index] + ((colorram[tile_index] & 0x20) << 3); + int color = (colorram[tile_index] & 0x0f) + 16 * palettebank; + int flags = ((colorram[tile_index] & 0x40) ? TILE_FLIPX : 0) | ((colorram[tile_index] & 0x80) ? TILE_FLIPY : 0); + + SET_TILE_INFO(0, code, color, flags); +} + +VIDEO_START( mikie ) +{ + bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows, + TILEMAP_TYPE_PEN, 8, 8, 32, 32); +} + +static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect) +{ + int offs; + + for (offs = 0;offs < spriteram_size;offs += 4) + { + int gfxbank = (spriteram[offs+2] & 0x40) ? 2 : 1; + int code = (spriteram[offs + 2] & 0x3f) + ((spriteram[offs + 2] & 0x80) >> 1) + ((spriteram[offs] & 0x40) << 1); + int color = (spriteram[offs] & 0x0f) + 16 * palettebank; + int sx = spriteram[offs + 3]; + int sy = 244 - spriteram[offs + 1]; + int flipx = ~spriteram[offs] & 0x10; + int flipy = spriteram[offs] & 0x20; + + if (flip_screen) + { + sy = 242 - sy; + flipy = !flipy; + } + + drawgfx(bitmap, machine->gfx[gfxbank], + code, color, + flipx,flipy, + sx,sy, + cliprect, + TRANSPARENCY_PEN, 0); + } +} + +VIDEO_UPDATE( mikie ) +{ + tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0); + draw_sprites(machine, bitmap, cliprect); + return 0; +} |