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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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mario.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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173 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
static int gfx_bank,palette_bank;
unsigned char *mario_scrolly;
/***************************************************************************
Convert the color PROMs into a more useable format.
Mario Bros. has a 512x8 palette PROM; interstingly, bytes 0-255 contain an
inverted palette, as other Nintendo games like Donkey Kong, while bytes
256-511 contain a non inverted palette. This was probably done to allow
connection to both the special Nintendo and a standard monitor.
The palette PROM is connected to the RGB output this way:
bit 7 -- 220 ohm resistor -- inverter -- RED
-- 470 ohm resistor -- inverter -- RED
-- 1 kohm resistor -- inverter -- RED
-- 220 ohm resistor -- inverter -- GREEN
-- 470 ohm resistor -- inverter -- GREEN
-- 1 kohm resistor -- inverter -- GREEN
-- 220 ohm resistor -- inverter -- BLUE
bit 0 -- 470 ohm resistor -- inverter -- BLUE
***************************************************************************/
void mario_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 >> 5) & 1;
bit1 = (*color_prom >> 6) & 1;
bit2 = (*color_prom >> 7) & 1;
*(palette++) = 255 - (0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2);
/* green component */
bit0 = (*color_prom >> 2) & 1;
bit1 = (*color_prom >> 3) & 1;
bit2 = (*color_prom >> 4) & 1;
*(palette++) = 255 - (0x21 * bit0 + 0x47 * bit1 + 0x97 * bit2);
/* blue component */
bit0 = (*color_prom >> 0) & 1;
bit1 = (*color_prom >> 1) & 1;
*(palette++) = 255 - (0x55 * bit0 + 0xaa * bit1);
color_prom++;
}
/* characters use the same palette as sprites, however characters */
/* use only colors 64-127 and 192-255. */
for (i = 0;i < 8;i++)
{
COLOR(0,4*i) = 8*i + 64;
COLOR(0,4*i+1) = 8*i+1 + 64;
COLOR(0,4*i+2) = 8*i+2 + 64;
COLOR(0,4*i+3) = 8*i+3 + 64;
}
for (i = 0;i < 8;i++)
{
COLOR(0,4*i+8*4) = 8*i + 192;
COLOR(0,4*i+8*4+1) = 8*i+1 + 192;
COLOR(0,4*i+8*4+2) = 8*i+2 + 192;
COLOR(0,4*i+8*4+3) = 8*i+3 + 192;
}
/* sprites */
for (i = 0;i < TOTAL_COLORS(1);i++)
COLOR(1,i) = i;
}
WRITE_HANDLER( mario_gfxbank_w )
{
if (gfx_bank != (data & 1))
{
memset(dirtybuffer,1,videoram_size);
gfx_bank = data & 1;
}
}
WRITE_HANDLER( mario_palettebank_w )
{
if (palette_bank != (data & 1))
{
memset(dirtybuffer,1,videoram_size);
palette_bank = data & 1;
}
}
/***************************************************************************
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 mario_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 * gfx_bank,
(videoram[offs] >> 5) + 8 * palette_bank,
0,0,
8*sx,8*sy,
0,TRANSPARENCY_NONE,0);
}
}
/* copy the temporary bitmap to the screen */
{
int scrolly;
/* I'm not positive the scroll direction is right */
scrolly = -*mario_scrolly - 17;
copyscrollbitmap(bitmap,tmpbitmap,0,0,1,&scrolly,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
}
/* Draw the sprites. */
for (offs = 0;offs < spriteram_size;offs += 4)
{
if (spriteram[offs])
{
drawgfx(bitmap,Machine->gfx[1],
spriteram[offs + 2],
(spriteram[offs + 1] & 0x0f) + 16 * palette_bank,
spriteram[offs + 1] & 0x80,spriteram[offs + 1] & 0x40,
spriteram[offs + 3] - 8,240 - spriteram[offs] + 8,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}
}