/*************************************************************************** video.c Functions to emulate the video hardware of the machine. ***************************************************************************/ #include "emu.h" #include "includes/bublbobl.h" SCREEN_UPDATE( bublbobl ) { bublbobl_state *state = screen->machine().driver_data(); int offs; int sx, sy, xc, yc; int gfx_num, gfx_attr, gfx_offs; const UINT8 *prom; const UINT8 *prom_line; /* Bubble Bobble doesn't have a real video RAM. All graphics (characters */ /* and sprites) are stored in the same memory region, and information on */ /* the background character columns is stored in the area dd00-dd3f */ /* This clears & redraws the entire screen each pass */ bitmap_fill(bitmap, cliprect, 255); if (!state->m_video_enable) return 0; sx = 0; prom = screen->machine().region("proms")->base(); for (offs = 0; offs < state->m_objectram_size; offs += 4) { /* skip empty sprites */ /* this is dword aligned so the UINT32 * cast shouldn't give problems */ /* on any architecture */ if (*(UINT32 *)(&state->m_objectram[offs]) == 0) continue; gfx_num = state->m_objectram[offs + 1]; gfx_attr = state->m_objectram[offs + 3]; prom_line = prom + 0x80 + ((gfx_num & 0xe0) >> 1); gfx_offs = ((gfx_num & 0x1f) * 0x80); if ((gfx_num & 0xa0) == 0xa0) gfx_offs |= 0x1000; sy = -state->m_objectram[offs + 0]; for (yc = 0; yc < 32; yc++) { if (prom_line[yc / 2] & 0x08) continue; /* NEXT */ if (!(prom_line[yc / 2] & 0x04)) /* next column */ { sx = state->m_objectram[offs + 2]; if (gfx_attr & 0x40) sx -= 256; } for (xc = 0; xc < 2; xc++) { int goffs, code, color, flipx, flipy, x, y; goffs = gfx_offs + xc * 0x40 + (yc & 7) * 0x02 + (prom_line[yc/2] & 0x03) * 0x10; code = state->m_videoram[goffs] + 256 * (state->m_videoram[goffs + 1] & 0x03) + 1024 * (gfx_attr & 0x0f); color = (state->m_videoram[goffs + 1] & 0x3c) >> 2; flipx = state->m_videoram[goffs + 1] & 0x40; flipy = state->m_videoram[goffs + 1] & 0x80; x = sx + xc * 8; y = (sy + yc * 8) & 0xff; if (flip_screen_get(screen->machine())) { x = 248 - x; y = 248 - y; flipx = !flipx; flipy = !flipy; } drawgfx_transpen(bitmap,cliprect,screen->machine().gfx[0], code, color, flipx,flipy, x,y,15); } } sx += 16; } return 0; }