diff options
Diffstat (limited to 'src/mame/video/seicross.c')
-rw-r--r-- | src/mame/video/seicross.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/mame/video/seicross.c b/src/mame/video/seicross.c new file mode 100644 index 00000000000..b13db973d8b --- /dev/null +++ b/src/mame/video/seicross.c @@ -0,0 +1,149 @@ +/*************************************************************************** + + video.c + + Functions to emulate the video hardware of the machine. + +***************************************************************************/ + +#include "driver.h" + +UINT8 *seicross_row_scroll; + +static tilemap *bg_tilemap; + +/*************************************************************************** + + Convert the color PROMs into a more useable format. + + Seicross has two 32x8 palette PROMs, connected to the RGB output this way: + + 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( seicross ) +{ + int i; + + + for (i = 0;i < machine->drv->total_colors;i++) + { + int bit0,bit1,bit2,r,g,b; + + /* red component */ + bit0 = (color_prom[i] >> 0) & 0x01; + bit1 = (color_prom[i] >> 1) & 0x01; + bit2 = (color_prom[i] >> 2) & 0x01; + r = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; + /* green component */ + bit0 = (color_prom[i] >> 3) & 0x01; + bit1 = (color_prom[i] >> 4) & 0x01; + bit2 = (color_prom[i] >> 5) & 0x01; + g = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2; + /* blue component */ + bit0 = (color_prom[i] >> 6) & 0x01; + bit1 = (color_prom[i] >> 7) & 0x01; + b = 0x4f * bit0 + 0xa8 * bit1; + + palette_set_color(machine,i,MAKE_RGB(r,g,b)); + } +} + +WRITE8_HANDLER( seicross_videoram_w ) +{ + videoram[offset] = data; + tilemap_mark_tile_dirty(bg_tilemap, offset); +} + +WRITE8_HANDLER( seicross_colorram_w ) +{ + /* bit 5 of the address is not used for color memory. There is just */ + /* 512k of memory; every two consecutive rows share the same memory */ + /* region. */ + offset &= 0xffdf; + + colorram[offset] = data; + colorram[offset + 0x20] = data; + + tilemap_mark_tile_dirty(bg_tilemap, offset); + tilemap_mark_tile_dirty(bg_tilemap, offset + 0x20); +} + +static TILE_GET_INFO( get_bg_tile_info ) +{ + int code = videoram[tile_index] + ((colorram[tile_index] & 0x10) << 4); + int color = colorram[tile_index] & 0x0f; + 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( seicross ) +{ + bg_tilemap = tilemap_create(get_bg_tile_info, tilemap_scan_rows, + TILEMAP_TYPE_PEN, 8, 8, 32, 32); + + tilemap_set_scroll_cols(bg_tilemap, 32); +} + +static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect ) +{ + int offs; + + for (offs = spriteram_size - 4;offs >= 0;offs -= 4) + { + int x = spriteram[offs + 3]; + drawgfx(bitmap,machine->gfx[1], + (spriteram[offs] & 0x3f) + ((spriteram[offs + 1] & 0x10) << 2) + 128, + spriteram[offs + 1] & 0x0f, + spriteram[offs] & 0x40,spriteram[offs] & 0x80, + x,240-spriteram[offs + 2], + cliprect,TRANSPARENCY_PEN,0); + if(x>0xf0) + drawgfx(bitmap,machine->gfx[1], + (spriteram[offs] & 0x3f) + ((spriteram[offs + 1] & 0x10) << 2) + 128, + spriteram[offs + 1] & 0x0f, + spriteram[offs] & 0x40,spriteram[offs] & 0x80, + x-256,240-spriteram[offs + 2], + cliprect,TRANSPARENCY_PEN,0); + } + + for (offs = spriteram_2_size - 4;offs >= 0;offs -= 4) + { + int x = spriteram_2[offs + 3]; + drawgfx(bitmap,machine->gfx[1], + (spriteram_2[offs] & 0x3f) + ((spriteram_2[offs + 1] & 0x10) << 2), + spriteram_2[offs + 1] & 0x0f, + spriteram_2[offs] & 0x40,spriteram_2[offs] & 0x80, + x,240-spriteram_2[offs + 2], + cliprect,TRANSPARENCY_PEN,0); + if(x>0xf0) + drawgfx(bitmap,machine->gfx[1], + (spriteram_2[offs] & 0x3f) + ((spriteram_2[offs + 1] & 0x10) << 2), + spriteram_2[offs + 1] & 0x0f, + spriteram_2[offs] & 0x40,spriteram_2[offs] & 0x80, + x-256,240-spriteram_2[offs + 2], + cliprect,TRANSPARENCY_PEN,0); + } +} + +VIDEO_UPDATE( seicross ) +{ + int col; + + for (col = 0; col < 32; col++) + { + tilemap_set_scrolly(bg_tilemap, col, seicross_row_scroll[col]); + } + + tilemap_draw(bitmap, cliprect, bg_tilemap, 0, 0); + draw_sprites(machine, bitmap, cliprect); + return 0; +} |