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AmigActive 10
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AACD 10.iso
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MAME
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vidhrdw
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commando.c
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C/C++ Source or Header
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2000-05-04
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8KB
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290 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *commando_bgvideoram,*commando_bgcolorram;
size_t commando_bgvideoram_size;
unsigned char *commando_scrollx,*commando_scrolly;
static unsigned char *dirtybuffer2;
static struct osd_bitmap *tmpbitmap2;
static int flipscreen;
/***************************************************************************
Convert the color PROMs into a more useable format.
Commando has three 256x4 palette PROMs (one per gun), 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 commando_vh_convert_color_prom(unsigned char *palette, unsigned short *colortable,const unsigned char *color_prom)
{
int i;
for (i = 0;i < Machine->drv->total_colors;i++)
{
int bit0,bit1,bit2,bit3;
bit0 = (color_prom[i] >> 0) & 0x01;
bit1 = (color_prom[i] >> 1) & 0x01;
bit2 = (color_prom[i] >> 2) & 0x01;
bit3 = (color_prom[i] >> 3) & 0x01;
palette[3*i] = 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;
palette[3*i + 1] = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
bit0 = (color_prom[i+2*Machine->drv->total_colors] >> 0) & 0x01;
bit1 = (color_prom[i+2*Machine->drv->total_colors] >> 1) & 0x01;
bit2 = (color_prom[i+2*Machine->drv->total_colors] >> 2) & 0x01;
bit3 = (color_prom[i+2*Machine->drv->total_colors] >> 3) & 0x01;
palette[3*i + 2] = 0x0e * bit0 + 0x1f * bit1 + 0x43 * bit2 + 0x8f * bit3;
}
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int commando_vh_start(void)
{
if (generic_vh_start() != 0)
return 1;
if ((dirtybuffer2 = malloc(commando_bgvideoram_size)) == 0)
{
generic_vh_stop();
return 1;
}
memset(dirtybuffer2,1,commando_bgvideoram_size);
if (generic_vh_start() != 0)
return 1;
/* the background area is twice as tall and twice as large as the screen */
if ((tmpbitmap2 = osd_create_bitmap(2*Machine->drv->screen_width,2*Machine->drv->screen_height)) == 0)
{
free(dirtybuffer2);
generic_vh_stop();
return 1;
}
return 0;
}
/***************************************************************************
Stop the video hardware emulation.
***************************************************************************/
void commando_vh_stop(void)
{
osd_free_bitmap(tmpbitmap2);
free(dirtybuffer2);
generic_vh_stop();
}
WRITE_HANDLER( commando_bgvideoram_w )
{
if (commando_bgvideoram[offset] != data)
{
dirtybuffer2[offset] = 1;
commando_bgvideoram[offset] = data;
}
}
WRITE_HANDLER( commando_bgcolorram_w )
{
if (commando_bgcolorram[offset] != data)
{
dirtybuffer2[offset] = 1;
commando_bgcolorram[offset] = data;
}
}
WRITE_HANDLER( commando_spriteram_w )
{
if (data != spriteram[offset] && offset % 4 == 2)
logerror("%04x: sprite %d X offset (old = %d new = %d) scanline %d\n",
cpu_get_pc(),offset/4,spriteram[offset],data,255 - (cpu_getfcount() * 256 / cpu_getfperiod()));
if (data != spriteram[offset] && offset % 4 == 3)
logerror("%04x: sprite %d Y offset (old = %d new = %d) scanline %d\n",
cpu_get_pc(),offset/4,spriteram[offset],data,255 - (cpu_getfcount() * 256 / cpu_getfperiod()));
if (data != spriteram[offset] && offset % 4 == 0)
logerror("%04x: sprite %d code (old = %d new = %d) scanline %d\n",
cpu_get_pc(),offset/4,spriteram[offset],data,255 - (cpu_getfcount() * 256 / cpu_getfperiod()));
spriteram[offset] = data;
}
WRITE_HANDLER( commando_c804_w )
{
/* bits 0 and 1 are for coin counters - we ignore them */
/* bit 4 resets the sound CPU - we ignore it */
/* bit 7 flips screen */
if (flipscreen != (~data & 0x80))
{
flipscreen = ~data & 0x80;
memset(dirtybuffer2,1,commando_bgvideoram_size);
}
}
/***************************************************************************
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 commando_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs;
for (offs = commando_bgvideoram_size - 1;offs >= 0;offs--)
{
if (dirtybuffer2[offs])
{
int sx,sy,flipx,flipy;
dirtybuffer2[offs] = 0;
sx = offs / 32;
sy = offs % 32;
flipx = commando_bgcolorram[offs] & 0x10;
flipy = commando_bgcolorram[offs] & 0x20;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(tmpbitmap2,Machine->gfx[1],
commando_bgvideoram[offs] + 4*(commando_bgcolorram[offs] & 0xc0),
commando_bgcolorram[offs] & 0x0f,
flipx,flipy,
16 * sx,16 * sy,
0,TRANSPARENCY_NONE,0);
}
}
/* copy the background graphics */
{
int scrollx,scrolly;
scrollx = -(commando_scrolly[0] + 256 * commando_scrolly[1]);
scrolly = -(commando_scrollx[0] + 256 * commando_scrollx[1]);
if (flipscreen)
{
scrollx = 256 - scrollx;
scrolly = 256 - scrolly;
}
copyscrollbitmap(bitmap,tmpbitmap2,1,&scrollx,1,&scrolly,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* Draw the sprites. Note that it is important to draw them exactly in this */
/* order, to have the correct priorities. */
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
int sx,sy,flipx,flipy,bank;
/* bit 1 of [offs+1] is not used */
sx = spriteram[offs + 3] - 0x100 * (spriteram[offs + 1] & 0x01);
sy = spriteram[offs + 2];
flipx = spriteram[offs + 1] & 0x04;
flipy = spriteram[offs + 1] & 0x08;
bank = (spriteram[offs + 1] & 0xc0) >> 6;
if (flipscreen)
{
sx = 240 - sx;
sy = 240 - sy;
flipx = !flipx;
flipy = !flipy;
}
if (bank < 3)
drawgfx(bitmap,Machine->gfx[2],
spriteram[offs] + 256 * bank,
(spriteram[offs + 1] & 0x30) >> 4,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,15);
}
/* draw the frontmost playfield. They are characters, but draw them as sprites */
for (offs = videoram_size - 1;offs >= 0;offs--)
{
int sx,sy,flipx,flipy;
sx = offs % 32;
sy = offs / 32;
flipx = colorram[offs] & 0x10;
flipy = colorram[offs] & 0x20;
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
flipx = !flipx;
flipy = !flipy;
}
drawgfx(bitmap,Machine->gfx[0],
videoram[offs] + 4 * (colorram[offs] & 0xc0),
colorram[offs] & 0x0f,
flipx,flipy,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,3);
}
}