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AmigActive 10
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AACD 10.iso
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vidhrdw
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espial.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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169 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *espial_attributeram;
unsigned char *espial_column_scroll;
/***************************************************************************
Convert the color PROMs into a more useable format.
Espial has two 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 3 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 220 ohm resistor -- GREEN
bit 0 -- 470 ohm resistor -- GREEN
bit 3 -- 1 kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
bit 0 -- 1 kohm resistor -- RED
***************************************************************************/
void espial_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;
/* red component */
bit0 = (color_prom[0] >> 0) & 0x01;
bit1 = (color_prom[0] >> 1) & 0x01;
bit2 = (color_prom[0] >> 2) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* green component */
bit0 = (color_prom[0] >> 3) & 0x01;
bit1 = (color_prom[Machine->drv->total_colors] >> 0) & 0x01;
bit2 = (color_prom[Machine->drv->total_colors] >> 1) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* blue component */
bit0 = 0;
bit1 = (color_prom[Machine->drv->total_colors] >> 2) & 0x01;
bit2 = (color_prom[Machine->drv->total_colors] >> 3) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
color_prom++;
}
}
WRITE_HANDLER( espial_attributeram_w )
{
if (espial_attributeram[offset] != data)
{
espial_attributeram[offset] = 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 espial_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs;
/* for every character in the Video RAM, check if it has been modified */
/* since last time and update it accordingly. */
for (offs = videoram_size - 1;offs >= 0;offs--)
{
if (dirtybuffer[offs])
{
int sx,sy;
dirtybuffer[offs] = 0;
sx = offs % 32;
sy = offs / 32;
drawgfx(tmpbitmap,Machine->gfx[0],
videoram[offs] + 256*(espial_attributeram[offs] & 0x03),
colorram[offs],
espial_attributeram[offs] & 0x04,espial_attributeram[offs] & 0x08,
8*sx,8*sy,
0,TRANSPARENCY_NONE,0);
}
}
/* copy the temporary bitmap to the screen */
{
int scroll[32];
for (offs = 0;offs < 32;offs++)
scroll[offs] = -espial_column_scroll[offs];
copyscrollbitmap(bitmap,tmpbitmap,0,0,32,scroll,&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 = 0;offs < spriteram_size/2;offs++)
{
int sx,sy,code,color,flipx,flipy;
sx = spriteram[offs + 16];
sy = 240 - spriteram_2[offs];
code = spriteram[offs] >> 1;
color = spriteram_2[offs + 16];
flipx = spriteram_3[offs] & 0x04;
flipy = spriteram_3[offs] & 0x08;
if (spriteram[offs] & 1) /* double height */
{
drawgfx(bitmap,Machine->gfx[1],
code,
color,
flipx,flipy,
sx,sy - 16,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
drawgfx(bitmap,Machine->gfx[1],
code + 1,
color,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
else
drawgfx(bitmap,Machine->gfx[1],
code,
color,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}