/***************************************************************************
video.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
UINT8 *firetrap_bg1videoram;
UINT8 *firetrap_bg2videoram;
UINT8 *firetrap_fgvideoram;
static tilemap *fg_tilemap, *bg1_tilemap, *bg2_tilemap;
/***************************************************************************
Convert the color PROMs into a more useable format.
Fire Trap has one 256x8 and one 256x4 palette PROMs.
I don't know for sure how the palette PROMs are connected to the RGB
output, but it's probably the usual:
bit 7 -- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 2.2kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
-- 1 kohm resistor -- RED
bit 0 -- 2.2kohm resistor -- RED
bit 3 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 1 kohm resistor -- BLUE
bit 0 -- 2.2kohm resistor -- BLUE
***************************************************************************/
PALETTE_INIT( firetrap )
{
int i;
for (i = 0;i < machine->drv->total_colors;i++)
{
int bit0,bit1,bit2,bit3,r,g,b;
bit0 = (color_prom[i] >> 0) & 0x01;
bit1 = (color_prom[i] >> 1) & 0x01;
bit2 = (color_prom[i] >> 2) & 0x01;
bit3 = (color_prom[i] >> 3) & 0x01;
r = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[i] >> 4) & 0x01;
bit1 = (color_prom[i] >> 5) & 0x01;
bit2 = (color_prom[i] >> 6) & 0x01;
bit3 = (color_prom[i] >> 7) & 0x01;
g = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[i + machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[i + machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[i + machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[i + machine->drv->total_colors] >> 3) & 0x01;
b = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
palette_set_color(machine,i,MAKE_RGB(r,g,b));
}
}
/***************************************************************************
Callbacks for the TileMap code
***************************************************************************/
static TILEMAP_MAPPER( get_fg_memory_offset )
{
return (row ^ 0x1f) + (col << 5);
}
static TILEMAP_MAPPER( get_bg_memory_offset )
{
return ((row & 0x0f) ^ 0x0f) | ((col & 0x0f) << 4) |
/* hole at bit 8 */
((row & 0x10) << 5) | ((col & 0x10) << 6);
}
static TILE_GET_INFO( get_fg_tile_info )
{
int code, color;
code = firetrap_fgvideoram[tile_index];
color = firetrap_fgvideoram[tile_index + 0x400];
SET_TILE_INFO(
0,
code | ((color & 0x01) << 8),
color >> 4,
0);
}
INLINE void get_bg_tile_info(running_machine *machine, tile_data *tileinfo, int tile_index, UINT8 *bgvideoram, int gfx_region)
{
int code, color;
code = bgvideoram[tile_index];
color = bgvideoram[tile_index + 0x100];
SET_TILE_INFO(
gfx_region,
code + ((color & 0x03) << 8),
(color & 0x30) >> 4,
TILE_FLIPXY((color & 0x0c) >> 2));
}
static TILE_GET_INFO( get_bg1_tile_info )
{
get_bg_tile_info(machine, tileinfo, tile_index, firetrap_bg1videoram, 1);
}
static TILE_GET_INFO( get_bg2_tile_info )
{
get_bg_tile_info(machine, tileinfo, tile_index, firetrap_bg2videoram, 2);
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
VIDEO_START( firetrap )
{
fg_tilemap = tilemap_create(get_fg_tile_info, get_fg_memory_offset,TILEMAP_TYPE_PEN, 8, 8,32,32);
bg1_tilemap = tilemap_create(get_bg1_tile_info,get_bg_memory_offset,TILEMAP_TYPE_PEN,16,16,32,32);
bg2_tilemap = tilemap_create(get_bg2_tile_info,get_bg_memory_offset,TILEMAP_TYPE_PEN, 16,16,32,32);
tilemap_set_transparent_pen(fg_tilemap,0);
tilemap_set_transparent_pen(bg1_tilemap,0);
}
/***************************************************************************
Memory handlers
***************************************************************************/
WRITE8_HANDLER( firetrap_fgvideoram_w )
{
firetrap_fgvideoram[offset] = data;
tilemap_mark_tile_dirty(fg_tilemap,offset & 0x3ff);
}
WRITE8_HANDLER( firetrap_bg1videoram_w )
{
firetrap_bg1videoram[offset] = data;
tilemap_mark_tile_dirty(bg1_tilemap,offset & 0x6ff);
}
WRITE8_HANDLER( firetrap_bg2videoram_w )
{
firetrap_bg2videoram[offset] = data;
tilemap_mark_tile_dirty(bg2_tilemap,offset & 0x6ff);
}
WRITE8_HANDLER( firetrap_bg1_scrollx_w )
{
static UINT8 scroll[2];
scroll[offset] = data;
tilemap_set_scrollx(bg1_tilemap,0,scroll[0] | (scroll[1] << 8));
}
WRITE8_HANDLER( firetrap_bg1_scrolly_w )
{
static UINT8 scroll[2];
scroll[offset] = data;
tilemap_set_scrolly(bg1_tilemap,0,-(scroll[0] | (scroll[1] << 8)));
}
WRITE8_HANDLER( firetrap_bg2_scrollx_w )
{
static UINT8 scroll[2];
scroll[offset] = data;
tilemap_set_scrollx(bg2_tilemap,0,scroll[0] | (scroll[1] << 8));
}
WRITE8_HANDLER( firetrap_bg2_scrolly_w )
{
static UINT8 scroll[2];
scroll[offset] = data;
tilemap_set_scrolly(bg2_tilemap,0,-(scroll[0] | (scroll[1] << 8)));
}
/***************************************************************************
Display refresh
***************************************************************************/
static void draw_sprites(running_machine *machine, mame_bitmap *bitmap, const rectangle *cliprect)
{
int offs;
for (offs = 0;offs < spriteram_size; offs += 4)
{
int sx,sy,flipx,flipy,code,color;
/* the meaning of bit 3 of [offs] is unknown */
sy = spriteram[offs];
sx = spriteram[offs + 2];
code = spriteram[offs + 3] + 4 * (spriteram[offs + 1] & 0xc0);
color = ((spriteram[offs + 1] & 0x08) >> 2) | (spriteram[offs + 1] & 0x01);
flipx = spriteram[offs + 1] & 0x04;
flipy = spriteram[offs + 1] & 0x02;
if (flip_screen)
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
if (spriteram[offs + 1] & 0x10) /* double width */
{
if (flip_screen) sy -= 16;
drawgfx(bitmap,machine->gfx[3],
code & ~1,
color,
flipx,flipy,
sx,flipy ? sy : sy + 16,
cliprect,TRANSPARENCY_PEN,0);
drawgfx(bitmap,machine->gfx[3],
code | 1,
color,
flipx,flipy,
sx,flipy ? sy + 16 : sy,
cliprect,TRANSPARENCY_PEN,0);
/* redraw with wraparound */
drawgfx(bitmap,machine->gfx[3],
code & ~1,
color,
flipx,flipy,
sx - 256,flipy ? sy : sy + 16,
cliprect,TRANSPARENCY_PEN,0);
drawgfx(bitmap,machine->gfx[3],
code | 1,
color,
flipx,flipy,
sx - 256,flipy ? sy + 16 : sy,
cliprect,TRANSPARENCY_PEN,0);
}
else
{
drawgfx(bitmap,machine->gfx[3],
code,
color,
flipx,flipy,
sx,sy,
cliprect,TRANSPARENCY_PEN,0);
/* redraw with wraparound */
drawgfx(bitmap,machine->gfx[3],
code,
color,
flipx,flipy,
sx - 256,sy,
cliprect,TRANSPARENCY_PEN,0);
}
}
}
VIDEO_UPDATE( firetrap )
{
tilemap_draw(bitmap,cliprect,bg2_tilemap,0,0);
tilemap_draw(bitmap,cliprect,bg1_tilemap,0,0);
draw_sprites(machine,bitmap,cliprect);
tilemap_draw(bitmap,cliprect,fg_tilemap,0,0);
return 0;
}