/*************************************
*
* Main refresh
*
*************************************/
uint32_t screen_update_atarisy2(screen_device screen, bitmap_ind16 bitmap, rectangle cliprect)
{
// start drawing
m_mob.op0.draw_async(cliprect);
// reset priorities
bitmap_ind8 priority_bitmap = screen.priority();
priority_bitmap.fill(0, cliprect);
// draw the playfield
m_playfield_tilemap.op0.tilemap.draw(screen, bitmap, cliprect, 0, 0);
m_playfield_tilemap.op0.tilemap.draw(screen, bitmap, cliprect, 1, 1);
m_playfield_tilemap.op0.tilemap.draw(screen, bitmap, cliprect, 2, 2);
m_playfield_tilemap.op0.tilemap.draw(screen, bitmap, cliprect, 3, 3);
// draw and merge the MO
bitmap_ind16 mobitmap = m_mob.op0.bitmap();
for (sparse_dirty_rect rect = m_mob.op0.first_dirty_rect(cliprect); rect != null; rect = rect.next())
{
for (int y = rect.m_rect.top(); y <= rect.m_rect.bottom(); y++)
{
PointerU16 mo = mobitmap.pix(y); //uint16_t const *const mo = &mobitmap.pix(y);
PointerU16 pf = bitmap.pix(y); //uint16_t *const pf = &bitmap.pix(y);
PointerU8 pri = priority_bitmap.pix(y); //uint8_t const *const pri = &priority_bitmap.pix(y);
for (int x = rect.m_rect.left(); x <= rect.m_rect.right(); x++)
{
if (mo[x] != 0xffff)
{
int mopriority = mo[x] >> atari_motion_objects_device.PRIORITY_SHIFT;
// high priority PF?
if (((mopriority + pri[x]) & 2) != 0)
{
// only gets priority if PF pen is less than 8
if ((pf[x] & 0x08) == 0)
{
pf[x] = (uint16_t)(mo[x] & atari_motion_objects_device.DATA_MASK);
}
}
// low priority
else
{
pf[x] = (uint16_t)(mo[x] & atari_motion_objects_device.DATA_MASK);
}
}
}
}
}
// add the alpha on top
m_alpha_tilemap.op0.tilemap.draw(screen, bitmap, cliprect, 0, 0);
return(0);
}
public void draw_starfield(bitmap_ind16 bitmap, rectangle cliprect, int flip)
{
if (m_enable == 0)
{
return;
}
uint16_t pre_vis_cycle_count = m_pre_vis_cycle_count;
uint16_t post_vis_cycle_count = m_post_vis_cycle_count;
// Advance the LFSR during the pre-visible portion of the frame
do
{
m_lfsr = get_next_lfsr_state(m_lfsr);
} while ((--pre_vis_cycle_count) != 0);
// Now we are in visible portion of the frame - Output all LFSR hits here
for (int y = m_offset_y; y < VISIBLE_LINES + m_offset_y; y++)
{
for (int x = m_offset_x; x < STARFIELD_PIXEL_WIDTH + m_offset_x; x++)
{
// Check lfsr for hit
if ((m_lfsr & LFSR_HIT_MASK) == LFSR_HIT_VALUE)
{
uint8_t star_set = (uint8_t)bitswap(m_lfsr, 10, 8);
if ((m_set_a == star_set) || (m_set_b == star_set))
{
// don't draw the stars that are beyond the X limit
if (x < m_limit_x)
{
int dx = x;
if (flip != 0)
{
dx += 64;
}
if (cliprect.contains(dx, y))
{
uint8_t color;
color = (uint8_t)((m_lfsr >> 5) & 0x7);
color |= (uint8_t)((m_lfsr << 3) & 0x18);
color |= (uint8_t)((m_lfsr << 2) & 0x20);
color = (uint8_t)((~color) & 0x3F);
bitmap.pix(y, dx)[0] = (uint16_t)(STARS_COLOR_BASE + color);
}
}
}
}
// Advance LFSR
m_lfsr = get_next_lfsr_state(m_lfsr);
}
}
// Advance the LFSR during the post-visible portion of the frame
do
{
m_lfsr = get_next_lfsr_state(m_lfsr);
} while ((--post_vis_cycle_count) != 0);
}