home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
AmigActive 10
/
AACD 10.iso
/
AACD
/
Games
/
MAME
/
src
/
vidhrdw
/
srumbler.c
< prev
next >
Wrap
C/C++ Source or Header
|
2000-05-04
|
5KB
|
185 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
extern unsigned char *spriteram;
extern size_t spriteram_size;
unsigned char *srumbler_backgroundram,*srumbler_foregroundram;
static struct tilemap *bg_tilemap,*fg_tilemap;
static int flipscreen;
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static void get_fg_tile_info(int tile_index)
{
unsigned char attr = srumbler_foregroundram[2*tile_index];
SET_TILE_INFO(0,srumbler_foregroundram[2*tile_index + 1] + ((attr & 0x03) << 8),(attr & 0x3c) >> 2)
tile_info.flags = (attr & 0x40) ? TILE_IGNORE_TRANSPARENCY : 0;
}
static void get_bg_tile_info(int tile_index)
{
unsigned char attr = srumbler_backgroundram[2*tile_index];
SET_TILE_INFO(1,srumbler_backgroundram[2*tile_index + 1] + ((attr & 0x07) << 8),(attr & 0xe0) >> 5)
tile_info.flags = TILE_SPLIT((attr & 0x10) >> 4);
if (attr & 0x08) tile_info.flags |= TILE_FLIPY;
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int srumbler_vh_start(void)
{
fg_tilemap = tilemap_create(get_fg_tile_info,tilemap_scan_cols,TILEMAP_TRANSPARENT,8,8,64,32);
bg_tilemap = tilemap_create(get_bg_tile_info,tilemap_scan_cols,TILEMAP_SPLIT, 16,16,64,64);
if (!fg_tilemap || !bg_tilemap)
return 1;
fg_tilemap->transparent_pen = 3;
bg_tilemap->transmask[0] = 0xffff; /* split type 0 is totally transparent in front half */
bg_tilemap->transmask[1] = 0x07ff; /* split type 1 has pens 0-10 transparent in front half */
return 0;
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE_HANDLER( srumbler_foreground_w )
{
if (srumbler_foregroundram[offset] != data)
{
srumbler_foregroundram[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap,offset/2);
}
}
WRITE_HANDLER( srumbler_background_w )
{
if (srumbler_backgroundram[offset] != data)
{
srumbler_backgroundram[offset] = data;
tilemap_mark_tile_dirty(bg_tilemap,offset/2);
}
}
WRITE_HANDLER( srumbler_4009_w )
{
/* bit 0 flips screen */
flipscreen = data & 1;
tilemap_set_flip(ALL_TILEMAPS,flipscreen ? (TILEMAP_FLIPY | TILEMAP_FLIPX) : 0);
/* bits 4-5 used during attract mode, unknown */
/* bits 6-7 coin counters */
coin_counter_w(0,data & 0x40);
coin_counter_w(1,data & 0x80);
}
WRITE_HANDLER( srumbler_scroll_w )
{
static int scroll[4];
scroll[offset] = data;
tilemap_set_scrollx(bg_tilemap,0,scroll[0] | (scroll[1] << 8));
tilemap_set_scrolly(bg_tilemap,0,scroll[2] | (scroll[3] << 8));
}
/***************************************************************************
Display refresh
***************************************************************************/
static void draw_sprites(struct osd_bitmap *bitmap)
{
int offs;
/* Draw the sprites. */
for (offs = spriteram_size-4; offs>=0;offs -= 4)
{
/* SPRITES
=====
Attribute
0x80 Code MSB
0x40 Code MSB
0x20 Code MSB
0x10 Colour
0x08 Colour
0x04 Colour
0x02 y Flip
0x01 X MSB
*/
int code,colour,sx,sy,flipy;
int attr=spriteram[offs+1];
code = spriteram[offs];
code += ( (attr&0xe0) << 3 );
colour = (attr & 0x1c)>>2;
sy = spriteram[offs + 2];
sx = spriteram[offs + 3] + 0x100 * ( attr & 0x01);
flipy = attr & 0x02;
if (flipscreen)
{
sx = 496 - sx;
sy = 240 - sy;
flipy = !flipy;
}
drawgfx(bitmap,Machine->gfx[2],
code,
colour,
flipscreen,flipy,
sx, sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,15);
}
}
void srumbler_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
tilemap_update(ALL_TILEMAPS);
if (palette_recalc())
tilemap_mark_all_pixels_dirty(ALL_TILEMAPS);
tilemap_render(ALL_TILEMAPS);
tilemap_draw(bitmap,bg_tilemap,TILEMAP_BACK);
draw_sprites(bitmap);
tilemap_draw(bitmap,bg_tilemap,TILEMAP_FRONT);
tilemap_draw(bitmap,fg_tilemap,0);
}