#include "emu.h"
#include "includes/ohmygod.h"
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static TILE_GET_INFO( get_tile_info )
{
ohmygod_state *state = machine.driver_data<ohmygod_state>();
UINT16 code = state->m_videoram[2 * tile_index + 1];
UINT16 attr = state->m_videoram[2 * tile_index];
SET_TILE_INFO(
0,
code,
(attr & 0x0f00) >> 8,
0);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
VIDEO_START( ohmygod )
{
ohmygod_state *state = machine.driver_data<ohmygod_state>();
state->m_bg_tilemap = tilemap_create(machine, get_tile_info, tilemap_scan_rows, 8, 8, 64, 64);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE16_HANDLER( ohmygod_videoram_w )
{
ohmygod_state *state = space->machine().driver_data<ohmygod_state>();
COMBINE_DATA(&state->m_videoram[offset]);
tilemap_mark_tile_dirty(state->m_bg_tilemap, offset / 2);
}
WRITE16_HANDLER( ohmygod_spritebank_w )
{
ohmygod_state *state = space->machine().driver_data<ohmygod_state>();
if (ACCESSING_BITS_8_15)
state->m_spritebank = data & 0x8000;
}
WRITE16_HANDLER( ohmygod_scrollx_w )
{
ohmygod_state *state = space->machine().driver_data<ohmygod_state>();
COMBINE_DATA(&state->m_scrollx);
tilemap_set_scrollx(state->m_bg_tilemap, 0, state->m_scrollx - 0x81ec);
}
WRITE16_HANDLER( ohmygod_scrolly_w )
{
ohmygod_state *state = space->machine().driver_data<ohmygod_state>();
COMBINE_DATA(&state->m_scrolly);
tilemap_set_scrolly(state->m_bg_tilemap, 0, state->m_scrolly - 0x81ef);
}
/***************************************************************************
Display refresh
***************************************************************************/
static void draw_sprites( running_machine &machine, bitmap_t *bitmap, const rectangle *cliprect )
{
ohmygod_state *state = machine.driver_data<ohmygod_state>();
UINT16 *spriteram = state->m_spriteram;
int offs;
for (offs = 0; offs < state->m_spriteram_size / 4; offs += 4)
{
int sx, sy, code, color, flipx;
UINT16 *sr;
sr = state->m_spritebank ? (spriteram + state->m_spriteram_size / 4) : spriteram;
code = sr[offs + 3] & 0x0fff;
color = sr[offs + 2] & 0x000f;
sx = sr[offs + 0] - 29;
sy = sr[offs + 1];
if (sy >= 32768)
sy -= 65536;
flipx = sr[offs + 3] & 0x8000;
drawgfx_transpen(bitmap,cliprect,machine.gfx[1],
code,
color,
flipx,0,
sx,sy,0);
}
}
SCREEN_UPDATE( ohmygod )
{
ohmygod_state *state = screen->machine().driver_data<ohmygod_state>();
tilemap_draw(bitmap, cliprect, state->m_bg_tilemap, 0, 0);
draw_sprites(screen->machine(), bitmap, cliprect);
return 0;
}