// license:BSD-3-Clause
// copyright-holders:Chris Moore, Nicola Salmoria
/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "emu.h"
#include "includes/bublbobl.h"
uint32_t bublbobl_state::screen_update_bublbobl(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
int offs;
int sx, sy, xc, yc;
int gfx_num, gfx_attr, gfx_offs;
const uint8_t *prom;
const uint8_t *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(255, cliprect);
if (!m_video_enable)
return 0;
sx = 0;
prom = memregion("proms")->base();
for (offs = 0; offs < m_objectram.bytes(); offs += 4)
{
/* skip empty sprites */
/* this is dword aligned so the uint32_t * cast shouldn't give problems */
/* on any architecture */
if (*(uint32_t *)(&m_objectram[offs]) == 0)
continue;
gfx_num = m_objectram[offs + 1];
gfx_attr = 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 = -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 = 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 = m_videoram[goffs] + 256 * (m_videoram[goffs + 1] & 0x03) + 1024 * (gfx_attr & 0x0f);
color = (m_videoram[goffs + 1] & 0x3c) >> 2;
flipx = m_videoram[goffs + 1] & 0x40;
flipy = m_videoram[goffs + 1] & 0x80;
x = sx + xc * 8;
y = (sy + yc * 8) & 0xff;
if (flip_screen())
{
x = 248 - x;
y = 248 - y;
flipx = !flipx;
flipy = !flipy;
}
m_gfxdecode->gfx(0)->transpen(bitmap,cliprect,
code,
color,
flipx,flipy,
x,y,15);
}
}
sx += 16;
}
return 0;
}