diff options
Diffstat (limited to 'src/mame/video/xybots.c')
-rw-r--r-- | src/mame/video/xybots.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/mame/video/xybots.c b/src/mame/video/xybots.c new file mode 100644 index 00000000000..f965f06a03c --- /dev/null +++ b/src/mame/video/xybots.c @@ -0,0 +1,166 @@ +/*************************************************************************** + + Atari Xybots hardware + +****************************************************************************/ + +#include "driver.h" +#include "machine/atarigen.h" +#include "includes/xybots.h" + + + +/************************************* + * + * Tilemap callbacks + * + *************************************/ + +static TILE_GET_INFO( get_alpha_tile_info ) +{ + UINT16 data = atarigen_alpha[tile_index]; + int code = data & 0x3ff; + int color = (data >> 12) & 7; + int opaque = data & 0x8000; + SET_TILE_INFO(2, code, color, opaque ? TILE_FORCE_LAYER0 : 0); +} + + +static TILE_GET_INFO( get_playfield_tile_info ) +{ + UINT16 data = atarigen_playfield[tile_index]; + int code = data & 0x1fff; + int color = (data >> 11) & 0x0f; + SET_TILE_INFO(0, code, color, (data >> 15) & 1); +} + + + +/************************************* + * + * Video system start + * + *************************************/ + +VIDEO_START( xybots ) +{ + static const struct atarimo_desc modesc = + { + 1, /* index to which gfx system */ + 1, /* number of motion object banks */ + 0, /* are the entries linked? */ + 0, /* are the entries split? */ + 0, /* render in reverse order? */ + 0, /* render in swapped X/Y order? */ + 0, /* does the neighbor bit affect the next object? */ + 0, /* pixels per SLIP entry (0 for no-slip) */ + 0, /* pixel offset for SLIPs */ + 0, /* maximum number of links to visit/scanline (0=all) */ + + 0x100, /* base palette entry */ + 0x300, /* maximum number of colors */ + 0, /* transparent pen index */ + + {{ 0x3f }}, /* mask for the link (dummy) */ + {{ 0 }}, /* mask for the graphics bank */ + {{ 0x3fff,0,0,0 }}, /* mask for the code index */ + {{ 0 }}, /* mask for the upper code index */ + {{ 0,0,0,0x000f }}, /* mask for the color */ + {{ 0,0,0,0xff80 }}, /* mask for the X position */ + {{ 0,0,0xff80,0 }}, /* mask for the Y position */ + {{ 0 }}, /* mask for the width, in tiles*/ + {{ 0,0,0x0007,0 }}, /* mask for the height, in tiles */ + {{ 0x8000,0,0,0 }}, /* mask for the horizontal flip */ + {{ 0 }}, /* mask for the vertical flip */ + {{ 0,0x000f,0,0 }}, /* mask for the priority */ + {{ 0 }}, /* mask for the neighbor */ + {{ 0 }}, /* mask for absolute coordinates */ + + {{ 0 }}, /* mask for the special value */ + 0, /* resulting value to indicate "special" */ + NULL /* callback routine for special entries */ + }; + + /* initialize the playfield */ + atarigen_playfield_tilemap = tilemap_create(get_playfield_tile_info, tilemap_scan_rows, TILEMAP_TYPE_PEN, 8,8, 64,32); + + /* initialize the motion objects */ + atarimo_init(machine, 0, &modesc); + + /* initialize the alphanumerics */ + atarigen_alpha_tilemap = tilemap_create(get_alpha_tile_info, tilemap_scan_rows, TILEMAP_TYPE_PEN, 8,8, 64,32); + tilemap_set_transparent_pen(atarigen_alpha_tilemap, 0); +} + + + +/************************************* + * + * Main refresh + * + *************************************/ + +VIDEO_UPDATE( xybots ) +{ + struct atarimo_rect_list rectlist; + mame_bitmap *mobitmap; + int x, y, r; + + /* draw the playfield */ + tilemap_draw(bitmap, cliprect, atarigen_playfield_tilemap, 0, 0); + + /* draw and merge the MO */ + mobitmap = atarimo_render(machine, 0, cliprect, &rectlist); + for (r = 0; r < rectlist.numrects; r++, rectlist.rect++) + for (y = rectlist.rect->min_y; y <= rectlist.rect->max_y; y++) + { + UINT16 *mo = (UINT16 *)mobitmap->base + mobitmap->rowpixels * y; + UINT16 *pf = (UINT16 *)bitmap->base + bitmap->rowpixels * y; + for (x = rectlist.rect->min_x; x <= rectlist.rect->max_x; x++) + if (mo[x]) + { + /* verified via schematics: + + PRIEN = ~(~MOPIX3 & ~MOPIX2 & ~MOPIX1) = (MOPIX3-0 > 1) + + if (PRIEN) + PF/MO = (~MOPRI3-0 > PFCOL3-0) + else + PF/MO = (~MOPRI3-0 >= PFCOL3-0) + + if (PF/MO | ~(PRIEN & MOCOL3)) + GPC(P3-0) = PFPIX3-0 + else + GPC(P3-0) = ~MOCOL3-0 + */ + int mopriority = (mo[x] >> ATARIMO_PRIORITY_SHIFT) ^ 15; + int pfcolor = (pf[x] >> 4) & 0x0f; + int prien = ((mo[x] & 0x0f) > 1); + + if (prien) + { + if (mopriority <= pfcolor) + { + /* this first case doesn't make sense from the schematics, but it has */ + /* the correct effect */ + if (mo[x] & 0x80) + pf[x] = (mo[x] ^ 0x2f0) & ATARIMO_DATA_MASK; + else + pf[x] = mo[x] & ATARIMO_DATA_MASK; + } + } + else + { + if (mopriority < pfcolor) + pf[x] = mo[x] & ATARIMO_DATA_MASK; + } + + /* erase behind ourselves */ + mo[x] = 0; + } + } + + /* add the alpha on top */ + tilemap_draw(bitmap, cliprect, atarigen_alpha_tilemap, 0, 0); + return 0; +} |