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AmigActive 10
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AACD 10.iso
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vidhrdw
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sauro.c
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C/C++ Source or Header
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2000-04-04
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5KB
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208 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
extern unsigned char *sauro_videoram2;
extern unsigned char *sauro_colorram2;
static int scroll1;
static int scroll2;
static int flipscreen;
/***************************************************************************
Convert the color PROMs into a more useable format.
***************************************************************************/
void sauro_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[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++;
}
}
WRITE_HANDLER( sauro_scroll1_w )
{
scroll1 = data;
}
static int scroll2_map [8] = {2, 1, 4, 3, 6, 5, 0, 7};
static int scroll2_map_flip[8] = {0, 7, 2, 1, 4, 3, 6, 5};
WRITE_HANDLER( sauro_scroll2_w )
{
int* map = (flipscreen ? scroll2_map_flip : scroll2_map);
scroll2 = (data & 0xf8) | map[data & 7];
}
WRITE_HANDLER( sauro_flipscreen_w )
{
if (flipscreen != data)
{
flipscreen = data;
memset(dirtybuffer, 1, videoram_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 sauro_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs,code,sx,sy,color,flipx;
/* for every character in the backround RAM, check if it has been modified */
/* since last time and update it accordingly. */
for (offs = 0; offs < videoram_size; offs ++)
{
if (!dirtybuffer[offs]) continue;
dirtybuffer[offs] = 0;
code = videoram[offs] + ((colorram[offs] & 0x07) << 8);
sx = 8 * (offs / 32);
sy = 8 * (offs % 32);
color = (colorram[offs] >> 4) & 0x0f;
flipx = colorram[offs] & 0x08;
if (flipscreen)
{
flipx = !flipx;
sx = 248 - sx;
sy = 248 - sy;
}
drawgfx(tmpbitmap,Machine->gfx[1],
code,
color,
flipx,flipscreen,
sx,sy,
0,TRANSPARENCY_NONE,0);
}
if (!flipscreen)
{
int scroll = -scroll1;
copyscrollbitmap(bitmap,tmpbitmap,1,&scroll ,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
else
{
copyscrollbitmap(bitmap,tmpbitmap,1,&scroll1,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* draw the frontmost playfield. They are characters, but draw them as sprites */
for (offs = 0; offs < videoram_size; offs++)
{
code = sauro_videoram2[offs] + ((sauro_colorram2[offs] & 0x07) << 8);
/* Skip spaces */
if (code == 0x19) continue;
sx = 8 * (offs / 32);
sy = 8 * (offs % 32);
color = (sauro_colorram2[offs] >> 4) & 0x0f;
flipx = sauro_colorram2[offs] & 0x08;
sx = (sx - scroll2) & 0xff;
if (flipscreen)
{
flipx = !flipx;
sx = 248 - sx;
sy = 248 - sy;
}
drawgfx(bitmap,Machine->gfx[0],
code,
color,
flipx,flipscreen,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
};
/* Draw the sprites. The order is important for correct priorities */
/* Weird, sprites entries don't start on DWORD boundary */
for (offs = 3;offs < spriteram_size - 1;offs += 4)
{
sy = spriteram[offs];
if (sy == 0xf8) continue;
code = spriteram[offs+1] + ((spriteram[offs+3] & 0x03) << 8);
sx = spriteram[offs+2];
sy = 236 - sy;
color = (spriteram[offs+3] >> 4) & 0x0f;
/* I'm not really sure how this bit works */
if (spriteram[offs+3] & 0x08)
{
if (sx > 0xc0)
{
/* Sign extend */
sx = (signed int)(signed char)sx;
}
}
else
{
if (sx < 0x40) continue;
}
flipx = spriteram[offs+3] & 0x04;
if (flipscreen)
{
flipx = !flipx;
sx = (235 - sx) & 0xff; /* The &0xff is not 100% percent correct */
sy = 240 - sy;
}
drawgfx(bitmap, Machine->gfx[2],
code,
color,
flipx,flipscreen,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}