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AmigActive 10
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AACD 10.iso
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vidhrdw
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seicross.c
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C/C++ Source or Header
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2000-04-04
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173 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
unsigned char *seicross_row_scroll;
/***************************************************************************
Convert the color PROMs into a more useable format.
Seicross has two 32x8 palette PROMs, connected to the RGB output this way:
bit 7 -- 220 ohm resistor -- BLUE
-- 470 ohm resistor -- BLUE
-- 220 ohm resistor -- GREEN
-- 470 ohm resistor -- GREEN
-- 1 kohm resistor -- GREEN
-- 220 ohm resistor -- RED
-- 470 ohm resistor -- RED
bit 0 -- 1 kohm resistor -- RED
***************************************************************************/
void seicross_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) & 0x01;
bit1 = (*color_prom >> 1) & 0x01;
bit2 = (*color_prom >> 2) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* green component */
bit0 = (*color_prom >> 3) & 0x01;
bit1 = (*color_prom >> 4) & 0x01;
bit2 = (*color_prom >> 5) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
/* blue component */
bit0 = 0;
bit1 = (*color_prom >> 6) & 0x01;
bit2 = (*color_prom >> 7) & 0x01;
*(palette++) = 0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2;
color_prom++;
}
}
WRITE_HANDLER( seicross_colorram_w )
{
if (colorram[offset] != data)
{
/* bit 5 of the address is not used for color memory. There is just */
/* 512k of memory; every two consecutive rows share the same memory */
/* region. */
offset &= 0xffdf;
dirtybuffer[offset] = 1;
dirtybuffer[offset + 0x20] = 1;
colorram[offset] = data;
colorram[offset + 0x20] = data;
}
}
/***************************************************************************
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 seicross_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs,x;
/* 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] + ((colorram[offs] & 0x10) << 4),
colorram[offs] & 0x0f,
colorram[offs] & 0x40,colorram[offs] & 0x80,
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] = -seicross_row_scroll[offs];
copyscrollbitmap(bitmap,tmpbitmap,0,0,32,scroll,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* draw sprites */
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
x=spriteram[offs + 3];
drawgfx(bitmap,Machine->gfx[1],
(spriteram[offs] & 0x3f) + ((spriteram[offs + 1] & 0x10) << 2) + 128,
spriteram[offs + 1] & 0x0f,
spriteram[offs] & 0x40,spriteram[offs] & 0x80,
x,240-spriteram[offs + 2],
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
if(x>0xf0)
drawgfx(bitmap,Machine->gfx[1],
(spriteram[offs] & 0x3f) + ((spriteram[offs + 1] & 0x10) << 2) + 128,
spriteram[offs + 1] & 0x0f,
spriteram[offs] & 0x40,spriteram[offs] & 0x80,
x-256,240-spriteram[offs + 2],
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
for (offs = spriteram_2_size - 4;offs >= 0;offs -= 4)
{
x=spriteram_2[offs + 3];
drawgfx(bitmap,Machine->gfx[1],
(spriteram_2[offs] & 0x3f) + ((spriteram_2[offs + 1] & 0x10) << 2),
spriteram_2[offs + 1] & 0x0f,
spriteram_2[offs] & 0x40,spriteram_2[offs] & 0x80,
x,240-spriteram_2[offs + 2],
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
if(x>0xf0)
drawgfx(bitmap,Machine->gfx[1],
(spriteram_2[offs] & 0x3f) + ((spriteram_2[offs + 1] & 0x10) << 2),
spriteram_2[offs + 1] & 0x0f,
spriteram_2[offs] & 0x40,spriteram_2[offs] & 0x80,
x-256,240-spriteram_2[offs + 2],
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}