BizHawk/waterbox/picodrive/pico/cd/gfx_dma.c

80 lines
1.6 KiB
C

/*
* PicoDrive
* (C) notaz, 2007
*
* This work is licensed under the terms of MAME license.
* See COPYING file in the top-level directory.
*/
#include "../pico_int.h"
#include "cell_map.c"
#ifndef UTYPES_DEFINED
typedef unsigned short u16;
#endif
// check: Heart of the alien, jaguar xj 220
PICO_INTERNAL void DmaSlowCell(unsigned int source, unsigned int a, int len, unsigned char inc)
{
unsigned char *base;
unsigned int asrc, a2;
u16 *r;
base = Pico_mcd->word_ram1M[Pico_mcd->s68k_regs[3]&1];
switch (Pico.video.type)
{
case 1: // vram
r = Pico.vram;
for(; len; len--)
{
asrc = cell_map(source >> 2) << 2;
asrc |= source & 2;
// if(a&1) d=(d<<8)|(d>>8); // ??
r[a>>1] = *(u16 *)(base + asrc);
source += 2;
// AutoIncrement
a=(u16)(a+inc);
}
rendstatus |= PDRAW_SPRITES_MOVED;
break;
case 3: // cram
Pico.m.dirtyPal = 1;
r = Pico.cram;
for(a2=a&0x7f; len; len--)
{
asrc = cell_map(source >> 2) << 2;
asrc |= source & 2;
r[a2>>1] = *(u16 *)(base + asrc);
source += 2;
// AutoIncrement
a2+=inc;
// good dest?
if(a2 >= 0x80) break;
}
a=(a&0xff00)|a2;
break;
case 5: // vsram[a&0x003f]=d;
r = Pico.vsram;
for(a2=a&0x7f; len; len--)
{
asrc = cell_map(source >> 2) << 2;
asrc |= source & 2;
r[a2>>1] = *(u16 *)(base + asrc);
source += 2;
// AutoIncrement
a2+=inc;
// good dest?
if(a2 >= 0x80) break;
}
a=(a&0xff00)|a2;
break;
}
// remember addr
Pico.video.addr=(u16)a;
}