home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
AmigActive 10
/
AACD 10.iso
/
AACD
/
Games
/
MAME
/
src
/
vidhrdw
/
gunsmoke.c
< prev
next >
Wrap
C/C++ Source or Header
|
2000-04-04
|
7KB
|
290 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *gunsmoke_bg_scrolly;
unsigned char *gunsmoke_bg_scrollx;
static int chon,objon,bgon;
static int sprite3bank;
static int flipscreen;
static struct osd_bitmap * bgbitmap;
static unsigned char bgmap[9][9][2];
/***************************************************************************
Convert the color PROMs into a more useable format.
Gunsmoke has three 256x4 palette PROMs (one per gun) and a lot ;-) of
256x4 lookup table PROMs.
The palette PROMs are connected to the RGB output this way:
bit 3 -- 220 ohm resistor -- RED/GREEN/BLUE
-- 470 ohm resistor -- RED/GREEN/BLUE
-- 1 kohm resistor -- RED/GREEN/BLUE
bit 0 -- 2.2kohm resistor -- RED/GREEN/BLUE
***************************************************************************/
void gunsmoke_vh_convert_color_prom(unsigned char *palette, unsigned short *colortable,const unsigned char *color_prom)
{
int i;
#define TOTAL_COLORS(gfxn) (Machine->gfx[gfxn]->total_colors * Machine->gfx[gfxn]->color_granularity)
#define COLOR(gfxn,offs) (colortable[Machine->drv->gfxdecodeinfo[gfxn].color_codes_start + offs])
for (i = 0;i < Machine->drv->total_colors;i++)
{
int bit0,bit1,bit2,bit3;
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
bit3 = (color_prom[0] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[Machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[Machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[Machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[Machine->drv->total_colors] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[2*Machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[2*Machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[2*Machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[2*Machine->drv->total_colors] >> 3) & 0x01;
*(palette++) = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
color_prom++;
}
color_prom += 2*Machine->drv->total_colors;
/* color_prom now points to the beginning of the lookup table */
/* characters use colors 64-79 */
for (i = 0;i < TOTAL_COLORS(0);i++)
COLOR(0,i) = *(color_prom++) + 64;
color_prom += 128; /* skip the bottom half of the PROM - not used */
/* background tiles use colors 0-63 */
for (i = 0;i < TOTAL_COLORS(1);i++)
{
COLOR(1,i) = color_prom[0] + 16 * (color_prom[256] & 0x03);
color_prom++;
}
color_prom += TOTAL_COLORS(1);
/* sprites use colors 128-255 */
for (i = 0;i < TOTAL_COLORS(2);i++)
{
COLOR(2,i) = color_prom[0] + 16 * (color_prom[256] & 0x07) + 128;
color_prom++;
}
color_prom += TOTAL_COLORS(2);
}
int gunsmoke_vh_start(void)
{
if ((bgbitmap = osd_create_bitmap(9*32,9*32)) == 0)
return 1;
if (generic_vh_start() == 1)
{
osd_free_bitmap(bgbitmap);
return 1;
}
memset (bgmap, 0xff, sizeof (bgmap));
return 0;
}
void gunsmoke_vh_stop(void)
{
osd_free_bitmap(bgbitmap);
}
WRITE_HANDLER( gunsmoke_c804_w )
{
int bankaddress;
unsigned char *RAM = memory_region(REGION_CPU1);
/* bits 0 and 1 are for coin counters? - we ignore them */
/* bits 2 and 3 select the ROM bank */
bankaddress = 0x10000 + (data & 0x0c) * 0x1000;
cpu_setbank(1,&RAM[bankaddress]);
/* bit 5 resets the sound CPU? - we ignore it */
/* bit 6 flips screen */
if (flipscreen != (data & 0x40))
{
flipscreen = data & 0x40;
// memset(dirtybuffer,1,c1942_backgroundram_size);
}
/* bit 7 enables characters? */
chon = data & 0x80;
}
WRITE_HANDLER( gunsmoke_d806_w )
{
/* bits 0-2 select the sprite 3 bank */
sprite3bank = data & 0x07;
/* bit 4 enables bg 1? */
bgon = data & 0x10;
/* bit 5 enables sprites? */
objon = data & 0x20;
}
/***************************************************************************
Draw the game screen in the given osd_bitmap.
Do NOT call osd_update_display() from this function, it will be called by
the main emulation engine.
***************************************************************************/
void gunsmoke_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs,sx,sy;
int bg_scrolly, bg_scrollx;
unsigned char *p=memory_region(REGION_GFX4);
int top,left,xscroll,yscroll;
/* TODO: support flipscreen */
if (bgon)
{
bg_scrolly = gunsmoke_bg_scrolly[0] + 256 * gunsmoke_bg_scrolly[1];
bg_scrollx = gunsmoke_bg_scrollx[0];
offs = 16 * ((bg_scrolly>>5)+8)+2*(bg_scrollx>>5) ;
if (bg_scrollx & 0x80) offs -= 0x10;
top = 8 - (bg_scrolly>>5) % 9;
left = (bg_scrollx>>5) % 9;
bg_scrolly&=0x1f;
bg_scrollx&=0x1f;
for (sy = 0;sy <9;sy++)
{
int ty = (sy + top) % 9;
offs &= 0x7fff; /* Enforce limits (for top of scroll) */
for (sx = 0;sx < 9;sx++)
{
int tile, attr, offset;
int tx = (sx + left) % 9;
unsigned char *map = &bgmap[ty][tx][0];
offset=offs+(sx*2);
tile=p[offset];
attr=p[offset+1];
if (tile != map[0] || attr != map[1])
{
map[0] = tile;
map[1] = attr;
tile+=256*(attr&0x01);
drawgfx(bgbitmap,Machine->gfx[1],
tile,
(attr & 0x3c) >> 2,
attr & 0x40,attr & 0x80,
(8-ty)*32, tx*32,
0,
TRANSPARENCY_NONE,0);
}
map += 2;
}
offs-=0x10;
}
xscroll = (top*32-bg_scrolly);
yscroll = -(left*32+bg_scrollx);
copyscrollbitmap(bitmap,bgbitmap,
1,&xscroll,
1,&yscroll,
&Machine->drv->visible_area,
TRANSPARENCY_NONE,0);
}
else fillbitmap(bitmap,Machine->pens[0],&Machine->drv->visible_area);
if (objon)
{
/* Draw the sprites. */
for (offs = spriteram_size - 32;offs >= 0;offs -= 32)
{
int bank,flipx,flipy;
bank = (spriteram[offs + 1] & 0xc0) >> 6;
if (bank == 3) bank += sprite3bank;
sx = spriteram[offs + 3] - ((spriteram[offs + 1] & 0x20) << 3);
sy = spriteram[offs + 2];
flipx = 0;
flipy = spriteram[offs + 1] & 0x10;
if (flipscreen)
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(bitmap,Machine->gfx[2],
spriteram[offs] + 256 * bank,
spriteram[offs + 1] & 0x0f,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}
if (chon)
{
/* draw the frontmost playfield. They are characters, but draw them as sprites */
for (offs = videoram_size - 1;offs >= 0;offs--)
{
sx = offs % 32;
sy = offs / 32;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
}
drawgfx(bitmap,Machine->gfx[0],
videoram[offs] + ((colorram[offs] & 0xc0) << 2),
colorram[offs] & 0x1f,
!flipscreen,!flipscreen,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_COLOR,79);
}
}
}