home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
AmigActive 10
/
AACD 10.iso
/
AACD
/
Games
/
MAME
/
src
/
vidhrdw
/
terracre.c
< prev
next >
Wrap
C/C++ Source or Header
|
2000-05-04
|
7KB
|
246 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *terrac_videoram;
size_t terrac_videoram_size;
unsigned char terrac_scrolly[2];
static struct osd_bitmap *tmpbitmap2;
static unsigned char *dirtybuffer2;
static const unsigned char *spritepalettebank;
/***************************************************************************
Convert color prom.
***************************************************************************/
void terrac_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 0-15 */
for (i = 0;i < TOTAL_COLORS(0);i++)
COLOR(0,i) = i;
/* background tiles use colors 192-255 in four banks */
/* the bottom two bits of the color code select the palette bank for */
/* pens 0-7; the top two bits for pens 8-15. */
for (i = 0;i < TOTAL_COLORS(1);i++)
{
if (i & 8) COLOR(1,i) = 192 + (i & 0x0f) + ((i & 0xc0) >> 2);
else COLOR(1,i) = 192 + (i & 0x0f) + ((i & 0x30) >> 0);
}
/* sprites use colors 128-191 in four banks */
/* The lookup table tells which colors to pick from the selected bank */
/* the bank is selected by another PROM and depends on the top 8 bits of */
/* the sprite code. The PROM selects the bank *separately* for pens 0-7 and */
/* 8-15 (like for tiles). */
for (i = 0;i < TOTAL_COLORS(2)/16;i++)
{
int j;
for (j = 0;j < 16;j++)
{
if (i & 8)
COLOR(2,i + j * (TOTAL_COLORS(2)/16)) = 128 + ((j & 0x0c) << 2) + (*color_prom & 0x0f);
else
COLOR(2,i + j * (TOTAL_COLORS(2)/16)) = 128 + ((j & 0x03) << 4) + (*color_prom & 0x0f);
}
color_prom++;
}
/* color_prom now points to the beginning of the sprite palette bank table */
spritepalettebank = color_prom; /* we'll need it at run time */
}
WRITE_HANDLER( terrac_videoram2_w )
{
int oldword = READ_WORD(&terrac_videoram[offset]);
int newword = COMBINE_WORD(oldword,data);
if (oldword != newword)
{
WRITE_WORD(&terrac_videoram[offset],newword);
dirtybuffer2[offset] = 1;
dirtybuffer2[offset+1] = 1;
}
}
READ_HANDLER( terrac_videoram2_r )
{
return READ_WORD (&terrac_videoram[offset]);
}
/***************************************************************************
Stop the video hardware emulation.
***************************************************************************/
void terrac_vh_stop(void)
{
free(dirtybuffer2);
osd_free_bitmap(tmpbitmap2);
generic_vh_stop();
}
/***************************************************************************
Start the video hardware emulation.
***************************************************************************/
int terrac_vh_start(void)
{
if (generic_vh_start() != 0)
return 1;
if ((dirtybuffer2 = malloc(terrac_videoram_size)) == 0)
{
terrac_vh_stop();
return 1;
}
memset(dirtybuffer2,1,terrac_videoram_size);
/* the background area is 4 x 1 (90 Rotated!) */
if ((tmpbitmap2 = osd_new_bitmap(4*Machine->drv->screen_width,
1*Machine->drv->screen_height,Machine->scrbitmap->depth)) == 0)
{
terrac_vh_stop();
return 1;
}
return 0;
}
/***************************************************************************
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 terracre_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs,x,y;
for (y = 0; y < 64; y++)
{
for (x = 0; x < 16; x++)
{
if ((dirtybuffer2[x*2 + y*64]) || (dirtybuffer2[x*2 + y*64+1]))
{
int code = READ_WORD(&terrac_videoram[x*2 + y*64]) & 0x01ff;
int color = (READ_WORD(&terrac_videoram[x*2 + y*64])&0x7800)>>11;
dirtybuffer2[x*2 + y*64] = dirtybuffer2[x*2 + y*64+1] = 0;
drawgfx(tmpbitmap2,Machine->gfx[1],
code,
color,
0,0,
16 * y,16 * x,
0,TRANSPARENCY_NONE,0);
}
}
}
/* copy the background graphics */
if (READ_WORD(terrac_scrolly) & 0x2000) /* background disable */
fillbitmap(bitmap,Machine->pens[0],&Machine->drv->visible_area);
else
{
int scrollx;
scrollx = -READ_WORD(terrac_scrolly);
copyscrollbitmap(bitmap,tmpbitmap2,1,&scrollx,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
for (x = 0;x <spriteram_size;x += 8)
{
int code;
int attr = READ_WORD(&spriteram[x+4]) & 0xff;
int color = (attr & 0xf0) >> 4;
int flipx = attr & 0x04;
int flipy = attr & 0x08;
int sx,sy;
sx = (READ_WORD(&spriteram[x+6]) & 0xff) - 0x80 + 256 * (attr & 1);
sy = 240 - (READ_WORD(&spriteram[x]) & 0xff);
code = (READ_WORD(&spriteram[x+2]) & 0xff) + ((attr & 0x02) << 7);
drawgfx(bitmap,Machine->gfx[2],
code,
color + 16 * (spritepalettebank[code >> 1] & 0x0f),
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
for (offs = videoram_size - 2;offs >= 0;offs -= 2)
{
int sx,sy;
sx = (offs/2) / 32;
sy = (offs/2) % 32;
drawgfx(bitmap,Machine->gfx[0],
READ_WORD(&videoram[offs]) & 0xff,
0,
0,0,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,15);
}
}