/***************************************************************************
Atari Orbit video emulation
***************************************************************************/
#include "emu.h"
#include "includes/orbit.h"
WRITE8_HANDLER( orbit_playfield_w )
{
orbit_state *state = space->machine().driver_data<orbit_state>();
state->m_playfield_ram[offset] = data;
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset);
}
static TILE_GET_INFO( get_tile_info )
{
orbit_state *state = machine.driver_data<orbit_state>();
UINT8 code = state->m_playfield_ram[tile_index];
int flags = 0;
if (BIT(code, 6))
flags |= TILE_FLIPX;
if (state->m_flip_screen)
flags |= TILE_FLIPY;
SET_TILE_INFO(3, code & 0x3f, 0, flags);
}
VIDEO_START( orbit )
{
orbit_state *state = machine.driver_data<orbit_state>();
state->m_bg_tilemap = tilemap_create(machine, get_tile_info, tilemap_scan_rows, 16, 16, 32, 30);
}
static void draw_sprites( running_machine &machine, bitmap_t* bitmap, const rectangle* cliprect )
{
orbit_state *state = machine.driver_data<orbit_state>();
const UINT8* p = state->m_sprite_ram;
int i;
for (i = 0; i < 16; i++)
{
int code = *p++;
int vpos = *p++;
int hpos = *p++;
int flag = *p++;
int layout =
((flag & 0xc0) == 0x80) ? 1 :
((flag & 0xc0) == 0xc0) ? 2 : 0;
int flip_x = BIT(code, 6);
int flip_y = BIT(code, 7);
int zoom_x = 0x10000;
int zoom_y = 0x10000;
code &= 0x3f;
if (flag & 1)
code |= 0x40;
if (flag & 2)
zoom_x *= 2;
vpos = 240 - vpos;
hpos <<= 1;
vpos <<= 1;
drawgfxzoom_transpen(bitmap, cliprect, machine.gfx[layout], code, 0, flip_x, flip_y,
hpos, vpos, zoom_x, zoom_y, 0);
}
}
SCREEN_UPDATE( orbit )
{
orbit_state *state = screen->machine().driver_data<orbit_state>();
state->m_flip_screen = input_port_read(screen->machine(), "DSW2") & 8;
tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
draw_sprites(screen->machine(), bitmap, cliprect);
return 0;
}