static TIMER_CALLBACK( display_enable_changed_timer_cb )
{
crtc6845_state *chip = ptr;
/* call the callback function -- we know it exists */
chip->intf->display_enable_changed(is_display_enabled(chip));
update_timer(chip);
}
static TIMER_CALLBACK( de_changed_timer_cb )
{
device_t *device = (device_t *)ptr;
crtc_ega_t *crtc_ega = get_safe_token(device);
/* call the callback function -- we know it exists */
crtc_ega->intf->on_de_changed(device, is_display_enabled(crtc_ega));
update_de_changed_timer(crtc_ega);
}
static void update_timer(crtc6845_state *chip)
{
INT16 next_y;
UINT16 next_x;
attotime duration;
if (chip->has_valid_parameters && (chip->display_enable_changed_timer != 0))
{
if (is_display_enabled(chip))
{
/* we are in a display region,
get the location of the next blanking start */
/* normally, it's at end the current raster line */
next_y = video_screen_get_vpos(chip->intf->scrnum);
next_x = chip->last_max_x + 1;
/* but if visible width = horiz_total, then we need
to go to the beginning of VBLANK */
if (next_x == chip->last_horiz_total)
{
next_y = chip->last_max_y + 1;
next_x = 0;
/* abnormal case, no vertical blanking, either */
if (next_y == chip->last_vert_total)
next_y = -1;
}
}
else
{
/* we are in a blanking region,
get the location of the next display start */
next_x = 0;
next_y = (video_screen_get_vpos(chip->intf->scrnum) + 1) % chip->last_vert_total;
/* if we would now fall in the vertical blanking, we need
to go to the top of the screen */
if (next_y > chip->last_max_y)
next_y = 0;
}
if (next_y != -1)
duration = video_screen_get_time_until_pos(chip->intf->scrnum, next_y, next_x);
else
duration = attotime_never;
timer_adjust(chip->display_enable_changed_timer, duration, 0, attotime_never);
}
}
static void update_de_changed_timer(crtc_ega_t *crtc_ega)
{
if (crtc_ega->has_valid_parameters && (crtc_ega->de_changed_timer != NULL))
{
INT16 next_y;
UINT16 next_x;
attotime duration;
/* we are in a display region, get the location of the next blanking start */
if (is_display_enabled(crtc_ega))
{
/* normally, it's at end the current raster line */
next_y = crtc_ega->screen->vpos();
next_x = crtc_ega->max_visible_x + 1;
/* but if visible width = horiz_pix_total, then we need
to go to the beginning of VBLANK */
if (next_x == crtc_ega->horiz_pix_total)
{
next_y = crtc_ega->max_visible_y + 1;
next_x = 0;
/* abnormal case, no vertical blanking, either */
if (next_y == crtc_ega->vert_pix_total)
next_y = -1;
}
}
/* we are in a blanking region, get the location of the next display start */
else
{
next_x = 0;
next_y = (crtc_ega->screen->vpos() + 1) % crtc_ega->vert_pix_total;
/* if we would now fall in the vertical blanking, we need
to go to the top of the screen */
if (next_y > crtc_ega->max_visible_y)
next_y = 0;
}
if (next_y != -1)
duration = crtc_ega->screen->time_until_pos(next_y, next_x);
else
duration = attotime::never;
crtc_ega->de_changed_timer->adjust(duration);
}
}