/***************************************************************************
Atari Subs hardware
***************************************************************************/
#include "driver.h"
#include "subs.h"
#include "sound/discrete.h"
WRITE8_HANDLER( subs_invert1_w )
{
if ((offset & 0x01) == 1)
{
palette_set_color(Machine, 0, MAKE_RGB(0x00, 0x00, 0x00));
palette_set_color(Machine, 1, MAKE_RGB(0xFF, 0xFF, 0xFF));
}
else
{
palette_set_color(Machine, 1, MAKE_RGB(0x00, 0x00, 0x00));
palette_set_color(Machine, 0, MAKE_RGB(0xFF, 0xFF, 0xFF));
}
}
WRITE8_HANDLER( subs_invert2_w )
{
if ((offset & 0x01) == 1)
{
palette_set_color(Machine, 2, MAKE_RGB(0x00, 0x00, 0x00));
palette_set_color(Machine, 3, MAKE_RGB(0xFF, 0xFF, 0xFF));
}
else
{
palette_set_color(Machine, 3, MAKE_RGB(0x00, 0x00, 0x00));
palette_set_color(Machine, 2, MAKE_RGB(0xFF, 0xFF, 0xFF));
}
}
VIDEO_UPDATE( subs )
{
int offs;
/* for every character in the Video RAM, check if it has been modified */
/* since last time and update it accordingly. */
for (offs = videoram_size - 1;offs >= 0;offs--)
{
int charcode;
int sx,sy;
int left_enable,right_enable;
int left_sonar_window,right_sonar_window;
left_sonar_window = 0;
right_sonar_window = 0;
charcode = videoram[offs];
/* Which monitor is this for? */
right_enable = charcode & 0x40;
left_enable = charcode & 0x80;
sx = 8 * (offs % 32);
sy = 8 * (offs / 32);
/* Special hardware logic for sonar windows */
if ((sy >= (128+64)) && (sx < 32))
left_sonar_window = 1;
else if ((sy >= (128+64)) && (sx >= (128+64+32)))
right_sonar_window = 1;
else
charcode = charcode & 0x3F;
/* Draw the left screen */
if (screen==0)
{
if ((left_enable || left_sonar_window) && (!right_sonar_window))
{
drawgfx(bitmap,machine->gfx[0],
charcode, 1,
0,0,sx,sy,
cliprect,TRANSPARENCY_NONE,0);
}
else
{
drawgfx(bitmap,machine->gfx[0],
0, 1,
0,0,sx,sy,
cliprect,TRANSPARENCY_NONE,0);
}
}
/* Draw the right screen */
if (screen==1)
{
if ((right_enable || right_sonar_window) && (!left_sonar_window))
{
drawgfx(bitmap,machine->gfx[0],
charcode, 0,
0,0,sx,sy,
cliprect,TRANSPARENCY_NONE,0);
}
else
{
drawgfx(bitmap,machine->gfx[0],
0, 0,
0,0,sx,sy,
cliprect,TRANSPARENCY_NONE,0);
}
}
}
/* draw the motion objects */
for (offs = 0; offs < 4; offs++)
{
int sx,sy;
int charcode;
int prom_set;
int sub_enable;
sx = spriteram[0x00 + (offs * 2)] - 16;
sy = spriteram[0x08 + (offs * 2)] - 16;
charcode = spriteram[0x09 + (offs * 2)];
if (offs < 2)
sub_enable = spriteram[0x01 + (offs * 2)] & 0x80;
else
sub_enable = 1;
prom_set = charcode & 0x01;
charcode = (charcode >> 3) & 0x1F;
/* Left screen - special check for drawing right screen's sub */
if (screen==0)
{
if ((offs!=0) || (sub_enable))
{
drawgfx(bitmap,machine->gfx[1],
charcode + 32 * prom_set,
0,
0,0,sx,sy,
cliprect,TRANSPARENCY_PEN,0);
}
}
/* Right screen - special check for drawing left screen's sub */
if (screen==1)
{
if ((offs!=1) || (sub_enable))
{
drawgfx(bitmap,machine->gfx[1],
charcode + 32 * prom_set,
0,
0,0,sx,sy,
cliprect,TRANSPARENCY_PEN,0);
}
}
}
/* Update sound */
discrete_sound_w(SUBS_LAUNCH_DATA, spriteram[5] & 0x0f); // Launch data
discrete_sound_w(SUBS_CRASH_DATA, spriteram[5] >> 4); // Crash/explode data
return 0;
}