void bt459_device::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect, u8 *pixel_data)
{
// initialise the blink timer
if (m_blink_start > screen.frame_number())
m_blink_start = screen.frame_number();
// compute the blink state according to the programmed duty cycle
const bool blink_state = ((screen.frame_number() - m_blink_start) & (
(m_command_0 & CR0302) == CR0302_1616 ? 0x10 :
(m_command_0 & CR0302) == CR0302_3232 ? 0x20 :
(m_command_0 & CR0302) == CR0302_6464 ? 0x40 : 0x30)) == 0;
// compute the pixel mask from the pixel read mask and blink mask/state
const u8 pixel_mask = m_pixel_read_mask & (blink_state ? 0xffU : ~m_pixel_blink_mask);
// draw visible pixel data
switch (m_command_0 & CR0100)
{
case CR0100_1BPP:
for (int y = screen.visible_area().min_y; y <= screen.visible_area().max_y; y++)
for (int x = screen.visible_area().min_x; x <= screen.visible_area().max_x; x += 8)
{
u8 data = *pixel_data++;
bitmap.pix(y, x + 7) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 6) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 5) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 4) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 3) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 2) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 1) = get_rgb(data & 0x1, pixel_mask); data >>= 1;
bitmap.pix(y, x + 0) = get_rgb(data & 0x1, pixel_mask);
}
break;
case CR0100_2BPP:
for (int y = screen.visible_area().min_y; y <= screen.visible_area().max_y; y++)
for (int x = screen.visible_area().min_x; x <= screen.visible_area().max_x; x += 4)
{
u8 data = *pixel_data++;
bitmap.pix(y, x + 3) = get_rgb(data & 0x3, pixel_mask); data >>= 2;
bitmap.pix(y, x + 2) = get_rgb(data & 0x3, pixel_mask); data >>= 2;
bitmap.pix(y, x + 1) = get_rgb(data & 0x3, pixel_mask); data >>= 2;
bitmap.pix(y, x + 0) = get_rgb(data & 0x3, pixel_mask);
}
break;
case CR0100_4BPP:
for (int y = screen.visible_area().min_y; y <= screen.visible_area().max_y; y++)
for (int x = screen.visible_area().min_x; x <= screen.visible_area().max_x; x += 2)
{
u8 data = *pixel_data++;
bitmap.pix(y, x + 1) = get_rgb(data & 0x7, pixel_mask); data >>= 4;
bitmap.pix(y, x + 0) = get_rgb(data & 0x7, pixel_mask);
}
break;
case CR0100_8BPP:
for (int y = screen.visible_area().min_y; y <= screen.visible_area().max_y; y++)
for (int x = screen.visible_area().min_x; x <= screen.visible_area().max_x; x++)
bitmap.pix(y, x) = get_rgb(*pixel_data++, pixel_mask);
break;
}
// draw cursors when visible and not blinked off
if ((m_cursor_command & (CR47 | CR46 | CR45 | CR44)) && ((m_cursor_command & CR40) == 0 || blink_state))
{
// get 64x64 bitmap and cross hair cursor plane enable
const u8 bm_cursor_enable = (m_cursor_command & (CR47 | CR46)) >> 6;
const u8 ch_cursor_enable = (m_cursor_command & (CR45 | CR44)) >> 4;
// get cross hair cursor half thickness
const int ch_thickness = (m_cursor_command & CR4241) >> 1;
/*
* The cursor (x) value to be written is calculated as follows:
*
* Cx = desired display screen (x) position + H - P
*
* where
*
* P = 37 if 1:1 input multiplexing, 52 if 4:1 input multiplexing,
* 57 if 5:1 input multiplexing
* H = number of pixels between the first rising edge of LD*
* following the falling edge of HSYNC* to active video
*
* The cursor (y) value to be written is calculated as follows:
*
* Cy = desired display screen (y) position + V - 32
*
* where
*
* V = number of scan lines from the second sync pulse during
* vertical blanking to active video
*
* Values from $0FC0 (-64) to $0FBF (+4031) may be loaded into the
* cursor (y) register. The negative values ($0FC0 to $0FFF) are used
* in situations where V < 32, and the cursor must be moved off the
* top of the screen.
*/
const int cursor_x = m_cursor_x + (
(m_command_0 & CR0706) == CR0706_11MPX ? 37 :
(m_command_0 & CR0706) == CR0706_41MPX ? 52 :
(m_command_0 & CR0706) == CR0706_51MPX ? 57 : 0);
const int cursor_y = (m_cursor_y < 0xfc0 ? m_cursor_y : m_cursor_y - 0x1000) + 32;
// 64x64 bitmap cursor
if (bm_cursor_enable)
{
// compute target 64x64 rectangle
rectangle cursor(cursor_x - 31, cursor_x + 32, cursor_y - 31, cursor_y + 32);
// intersect with screen bitmap
cursor &= bitmap.cliprect();
// draw if any portion is visible
if (!cursor.empty())
{
for (int y = 0; y < 64; y++)
{
// get screen y pixel coordinate
const int ypos = cursor_y - 31 + y;
for (int x = 0; x < 64; x++)
{
// get screen x pixel coordinate
const int xpos = cursor_x - 31 + x;
// check if pixel is visible
if (cursor.contains(xpos, ypos))
{
// retrieve 2 bits of 64x64 bitmap cursor data
u8 data = (m_cursor_ram[y * 16 + (x >> 2)] >> ((3 - (x & 3)) << 1)) & bm_cursor_enable;
// check for dual-cursor mode and combine with cross-hair data
if (ch_cursor_enable)
if (((x >= 31 - ch_thickness) && (x <= 31 + ch_thickness)) || ((y >= 31 - ch_thickness) && (y <= 31 + ch_thickness)))
data = (m_cursor_command & CR43) ? data | ch_cursor_enable : data ^ ch_cursor_enable;
// write cursor data to screen (normal or X Window mode)
if (data && !((m_command_2 & CR21) && data == 1))
bitmap.pix(ypos, xpos) = m_cursor_color[data - 1];
}
}
}
}
}
// cross hair cursor
if (ch_cursor_enable)
{
// get the cross hair cursor color
const rgb_t ch_color = m_cursor_color[ch_cursor_enable - 1];
/*
* The window (x) value to be written is calculated as follows:
*
* Wx = desired display screen (x) position + H - P
*
* where
*
* P = 5 if 1:1 input multiplexing, 20 if 4:1 input multiplexing,
* 25 if 5:1 input multiplexing
* H = number of pixels between the first rising edge of LD*
* following the falling edge of HSYNC* to active video
*
* The window (y) value to be written is calculated as follows:
*
* Wy = desired display screen (y) position + V
*
* where
*
* V = number of scan lines from the second sync pulse during
* vertical blanking to active video
*
* Values from $0000 to $0FFF may be written to the window (x) and
* (y) registers. A full-screen cross hair is implemented by
* loading the window (x,y) registers with $0000, and the window
* width and height registers with $0FFF.
*/
const bool full_screen = (m_window_x == 0 && m_window_y == 0 && m_window_w == 0x0fff && m_window_h == 0x0fff);
const int window_x = full_screen ? screen.visible_area().min_x : m_window_x + (
(m_command_0 & CR0706) == CR0706_11MPX ? 5 :
(m_command_0 & CR0706) == CR0706_41MPX ? 20 :
(m_command_0 & CR0706) == CR0706_51MPX ? 25 : 0);
const int window_y = full_screen ? screen.visible_area().min_y : m_window_y;
/*
* The actual window width is 2, 8 or 10 pixels more than the
* value specified by the window width register, depending on
* whether 1:1, 4:1 or 5:1 input multiplexing is specified. The
* actual window height is 2 pixels more than the value specified
* by the window height register. Therefore, the minimum window
* width is 2, 8 or 10 pixels for 1:1, 4:1 and 5:1 multiplexing,
* respectively. The minimum window height is 2 pixels.
*
* Values from $0000 to $0FFF may be written to the window width
* and height registers.
*
* Note: testing indicates the cross-hair cursor should be drawn
* strictly inside the window, although this is not 100% clear from
* the documentation.
*/
const int window_w = full_screen ? screen.visible_area().width() : m_window_w + (
(m_command_0 & CR0706) == CR0706_11MPX ? 2 :
(m_command_0 & CR0706) == CR0706_41MPX ? 8 :
(m_command_0 & CR0706) == CR0706_51MPX ? 10 : 0);
const int window_h = full_screen ? screen.visible_area().height() : m_window_h + 2;
// check for dual-cursor mode
if (bm_cursor_enable)
{
// draw the cross hair cursor as vertical and horizontal filled rectangles broken by the 64x64 cursor area
rectangle v1(cursor_x - ch_thickness, cursor_x + ch_thickness, window_y + 1, cursor_y - 32);
rectangle v2(cursor_x - ch_thickness, cursor_x + ch_thickness, cursor_y + 33, window_y + window_h);
rectangle h1(window_x + 1, cursor_x - 32, cursor_y - ch_thickness, cursor_y + ch_thickness);
rectangle h2(cursor_x + 33, window_x + window_w, cursor_y - ch_thickness, cursor_y + ch_thickness);
v1 &= bitmap.cliprect();
v2 &= bitmap.cliprect();
h1 &= bitmap.cliprect();
h2 &= bitmap.cliprect();
if (!v1.empty())
bitmap.fill(ch_color, v1);
if (!v2.empty())
bitmap.fill(ch_color, v2);
if (!h1.empty())
bitmap.fill(ch_color, h1);
if (!h2.empty())
bitmap.fill(ch_color, h2);
}
else
{
// draw the cross hair cursor as unbroken vertical and horizontal filled rectangles
rectangle v(cursor_x - ch_thickness, cursor_x + ch_thickness, window_y + 1, window_y + window_h);
rectangle h(window_x + 1, window_x + window_w, cursor_y - ch_thickness, cursor_y + ch_thickness);
v &= bitmap.cliprect();
h &= bitmap.cliprect();
if (!v.empty())
bitmap.fill(ch_color, v);
if (!h.empty())
bitmap.fill(ch_color, h);
}
}
}
