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AmigActive 10
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AACD 10.iso
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AACD
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MAME
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src
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vidhrdw
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bombjack.c
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C/C++ Source or Header
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2000-04-04
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4KB
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191 lines
/***************************************************************************
vidhrdw.c
Functions to emulate the video hardware of the machine.
***************************************************************************/
#include "driver.h"
#include "vidhrdw/generic.h"
static int background_image;
static int flipscreen;
WRITE_HANDLER( bombjack_background_w )
{
if (background_image != data)
{
memset(dirtybuffer,1,videoram_size);
background_image = data;
}
}
WRITE_HANDLER( bombjack_flipscreen_w )
{
if (flipscreen != (data & 1))
{
flipscreen = data & 1;
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 bombjack_vh_screenrefresh(struct osd_bitmap *bitmap,int full_refresh)
{
int offs,base;
if (palette_recalc())
memset(dirtybuffer,1,videoram_size);
base = 0x200 * (background_image & 0x07);
/* 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--)
{
int sx,sy;
int tilecode,tileattribute;
sx = offs % 32;
sy = offs / 32;
if (background_image & 0x10)
{
int bgoffs;
bgoffs = base+16*(sy/2)+sx/2;
tilecode = memory_region(REGION_GFX4)[bgoffs],
tileattribute = memory_region(REGION_GFX4)[bgoffs + 0x100];
}
else
{
tilecode = 0xff;
tileattribute = 0; /* avoid compiler warning */
}
if (dirtybuffer[offs])
{
if (flipscreen)
{
sx = 31 - sx;
sy = 31 - sy;
}
/* draw the background (this can be handled better) */
if (tilecode != 0xff)
{
struct rectangle clip;
int flipy;
clip.min_x = 8*sx;
clip.max_x = 8*sx+7;
clip.min_y = 8*sy;
clip.max_y = 8*sy+7;
flipy = tileattribute & 0x80;
if (flipscreen) flipy = !flipy;
drawgfx(tmpbitmap,Machine->gfx[1],
tilecode,
tileattribute & 0x0f,
flipscreen,flipy,
16*(sx/2),16*(sy/2),
&clip,TRANSPARENCY_NONE,0);
drawgfx(tmpbitmap,Machine->gfx[0],
videoram[offs] + 16 * (colorram[offs] & 0x10),
colorram[offs] & 0x0f,
flipscreen,flipscreen,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
else
drawgfx(tmpbitmap,Machine->gfx[0],
videoram[offs] + 16 * (colorram[offs] & 0x10),
colorram[offs] & 0x0f,
flipscreen,flipscreen,
8*sx,8*sy,
&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
dirtybuffer[offs] = 0;
}
}
/* copy the character mapped graphics */
copybitmap(bitmap,tmpbitmap,0,0,0,0,&Machine->drv->visible_area,TRANSPARENCY_NONE,0);
/* Draw the sprites. */
for (offs = spriteram_size - 4;offs >= 0;offs -= 4)
{
/*
abbbbbbb cdefgggg hhhhhhhh iiiiiiii
a use big sprites (32x32 instead of 16x16)
bbbbbbb sprite code
c x flip
d y flip (used only in death sequence?)
e ? (set when big sprites are selected)
f ? (set only when the bonus (B) materializes?)
gggg color
hhhhhhhh x position
iiiiiiii y position
*/
int sx,sy,flipx,flipy;
sx = spriteram[offs+3];
if (spriteram[offs] & 0x80)
sy = 225-spriteram[offs+2];
else
sy = 241-spriteram[offs+2];
flipx = spriteram[offs+1] & 0x40;
flipy = spriteram[offs+1] & 0x80;
if (flipscreen)
{
if (spriteram[offs+1] & 0x20)
{
sx = 224 - sx;
sy = 224 - sy;
}
else
{
sx = 240 - sx;
sy = 240 - sy;
}
flipx = !flipx;
flipy = !flipy;
}
drawgfx(bitmap,Machine->gfx[(spriteram[offs] & 0x80) ? 3 : 2],
spriteram[offs] & 0x7f,
spriteram[offs+1] & 0x0f,
flipx,flipy,
sx,sy,
&Machine->drv->visible_area,TRANSPARENCY_PEN,0);
}
}