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snes9x/dsp2.cpp

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/*****************************************************************************\
Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
This file is licensed under the Snes9x License.
For further information, consult the LICENSE file in the root directory.
\*****************************************************************************/
#include "snes9x.h"
#include "memmap.h"
static void DSP2_Op01 (void);
static void DSP2_Op03 (void);
static void DSP2_Op05 (void);
static void DSP2_Op06 (void);
static void DSP2_Op09 (void);
static void DSP2_Op0D (void);
// convert bitmap to bitplane tile
static void DSP2_Op01 (void)
{
// Op01 size is always 32 bytes input and output
// The hardware does strange things if you vary the size
uint8 c0, c1, c2, c3;
uint8 *p1 = DSP2.parameters;
uint8 *p2a = DSP2.output;
uint8 *p2b = DSP2.output + 16; // halfway
// Process 8 blocks of 4 bytes each
for (int j = 0; j < 8; j++)
{
c0 = *p1++;
c1 = *p1++;
c2 = *p1++;
c3 = *p1++;
*p2a++ = (c0 & 0x10) << 3 |
(c0 & 0x01) << 6 |
(c1 & 0x10) << 1 |
(c1 & 0x01) << 4 |
(c2 & 0x10) >> 1 |
(c2 & 0x01) << 2 |
(c3 & 0x10) >> 3 |
(c3 & 0x01);
*p2a++ = (c0 & 0x20) << 2 |
(c0 & 0x02) << 5 |
(c1 & 0x20) |
(c1 & 0x02) << 3 |
(c2 & 0x20) >> 2 |
(c2 & 0x02) << 1 |
(c3 & 0x20) >> 4 |
(c3 & 0x02) >> 1;
*p2b++ = (c0 & 0x40) << 1 |
(c0 & 0x04) << 4 |
(c1 & 0x40) >> 1 |
(c1 & 0x04) << 2 |
(c2 & 0x40) >> 3 |
(c2 & 0x04) |
(c3 & 0x40) >> 5 |
(c3 & 0x04) >> 2;
*p2b++ = (c0 & 0x80) |
(c0 & 0x08) << 3 |
(c1 & 0x80) >> 2 |
(c1 & 0x08) << 1 |
(c2 & 0x80) >> 4 |
(c2 & 0x08) >> 1 |
(c3 & 0x80) >> 6 |
(c3 & 0x08) >> 3;
}
}
// set transparent color
static void DSP2_Op03 (void)
{
DSP2.Op05Transparent = DSP2.parameters[0];
}
// replace bitmap using transparent color
static void DSP2_Op05 (void)
{
// Overlay bitmap with transparency.
// Input:
//
// Bitmap 1: i[0] <=> i[size-1]
// Bitmap 2: i[size] <=> i[2*size-1]
//
// Output:
//
// Bitmap 3: o[0] <=> o[size-1]
//
// Processing:
//
// Process all 4-bit pixels (nibbles) in the bitmap
//
// if ( BM2_pixel == transparent_color )
// pixelout = BM1_pixel
// else
// pixelout = BM2_pixel
// The max size bitmap is limited to 255 because the size parameter is a byte
// I think size=0 is an error. The behavior of the chip on size=0 is to
// return the last value written to DR if you read DR on Op05 with
// size = 0. I don't think it's worth implementing this quirk unless it's
// proven necessary.
uint8 color;
uint8 c1, c2;
uint8 *p1 = DSP2.parameters;
uint8 *p2 = DSP2.parameters + DSP2.Op05Len;
uint8 *p3 = DSP2.output;
color = DSP2.Op05Transparent & 0x0f;
for (int32 n = 0; n < DSP2.Op05Len; n++)
{
c1 = *p1++;
c2 = *p2++;
*p3++ = (((c2 >> 4) == color) ? c1 & 0xf0: c2 & 0xf0) | (((c2 & 0x0f) == color) ? c1 & 0x0f: c2 & 0x0f);
}
}
// reverse bitmap
static void DSP2_Op06 (void)
{
// Input:
// size
// bitmap
for (int32 i = 0, j = DSP2.Op06Len - 1; i < DSP2.Op06Len; i++, j--)
DSP2.output[j] = (DSP2.parameters[i] << 4) | (DSP2.parameters[i] >> 4);
}
// multiply
static void DSP2_Op09 (void)
{
DSP2.Op09Word1 = DSP2.parameters[0] | (DSP2.parameters[1] << 8);
DSP2.Op09Word2 = DSP2.parameters[2] | (DSP2.parameters[3] << 8);
uint32 temp = DSP2.Op09Word1 * DSP2.Op09Word2;
DSP2.output[0] = temp & 0xFF;
DSP2.output[1] = (temp >> 8) & 0xFF;
DSP2.output[2] = (temp >> 16) & 0xFF;
DSP2.output[3] = (temp >> 24) & 0xFF;
}
// scale bitmap
static void DSP2_Op0D (void)
{
// Bit accurate hardware algorithm - uses fixed point math
// This should match the DSP2 Op0D output exactly
// I wouldn't recommend using this unless you're doing hardware debug.
// In some situations it has small visual artifacts that
// are not readily apparent on a TV screen but show up clearly
// on a monitor. Use Overload's scaling instead.
// This is for hardware verification testing.
//
// One note: the HW can do odd byte scaling but since we divide
// by two to get the count of bytes this won't work well for
// odd byte scaling (in any of the current algorithm implementations).
// So far I haven't seen Dungeon Master use it.
// If it does we can adjust the parameters and code to work with it
uint32 multiplier; // Any size int >= 32-bits
uint32 pixloc; // match size of multiplier
uint8 pixelarray[512];
if (DSP2.Op0DInLen <= DSP2.Op0DOutLen)
multiplier = 0x10000; // In our self defined fixed point 0x10000 == 1
else
multiplier = (DSP2.Op0DInLen << 17) / ((DSP2.Op0DOutLen << 1) + 1);
pixloc = 0;
for (int32 i = 0; i < DSP2.Op0DOutLen * 2; i++)
{
int32 j = pixloc >> 16;
if (j & 1)
pixelarray[i] = DSP2.parameters[j >> 1] & 0x0f;
else
pixelarray[i] = (DSP2.parameters[j >> 1] & 0xf0) >> 4;
pixloc += multiplier;
}
for (int32 i = 0; i < DSP2.Op0DOutLen; i++)
DSP2.output[i] = (pixelarray[i << 1] << 4) | pixelarray[(i << 1) + 1];
}
/*
static void DSP2_Op0D (void)
{
// Overload's algorithm - use this unless doing hardware testing
// One note: the HW can do odd byte scaling but since we divide
// by two to get the count of bytes this won't work well for
// odd byte scaling (in any of the current algorithm implementations).
// So far I haven't seen Dungeon Master use it.
// If it does we can adjust the parameters and code to work with it
int32 pixel_offset;
uint8 pixelarray[512];
for (int32 i = 0; i < DSP2.Op0DOutLen * 2; i++)
{
pixel_offset = (i * DSP2.Op0DInLen) / DSP2.Op0DOutLen;
if ((pixel_offset & 1) == 0)
pixelarray[i] = DSP2.parameters[pixel_offset >> 1] >> 4;
else
pixelarray[i] = DSP2.parameters[pixel_offset >> 1] & 0x0f;
}
for (int32 i = 0; i < DSP2.Op0DOutLen; i++)
DSP2.output[i] = (pixelarray[i << 1] << 4) | pixelarray[(i << 1) + 1];
}
*/
void DSP2SetByte (uint8 byte, uint16 address)
{
if ((address & 0xf000) == 0x6000 || (address >= 0x8000 && address < 0xc000))
{
if (DSP2.waiting4command)
{
DSP2.command = byte;
DSP2.in_index = 0;
DSP2.waiting4command = FALSE;
switch (byte)
{
case 0x01: DSP2.in_count = 32; break;
case 0x03: DSP2.in_count = 1; break;
case 0x05: DSP2.in_count = 1; break;
case 0x06: DSP2.in_count = 1; break;
case 0x09: DSP2.in_count = 4; break;
case 0x0D: DSP2.in_count = 2; break;
default:
#ifdef DEBUGGER
//printf("Op%02X\n", byte);
#endif
case 0x0f: DSP2.in_count = 0; break;
}
}
else
{
DSP2.parameters[DSP2.in_index] = byte;
DSP2.in_index++;
}
if (DSP2.in_count == DSP2.in_index)
{
DSP2.waiting4command = TRUE;
DSP2.out_index = 0;
switch (DSP2.command)
{
case 0x01:
DSP2.out_count = 32;
DSP2_Op01();
break;
case 0x03:
DSP2_Op03();
break;
case 0x05:
if (DSP2.Op05HasLen)
{
DSP2.Op05HasLen = FALSE;
DSP2.out_count = DSP2.Op05Len;
DSP2_Op05();
}
else
{
DSP2.Op05Len = DSP2.parameters[0];
DSP2.in_index = 0;
DSP2.in_count = 2 * DSP2.Op05Len;
DSP2.Op05HasLen = TRUE;
if (byte)
DSP2.waiting4command = FALSE;
}
break;
case 0x06:
if (DSP2.Op06HasLen)
{
DSP2.Op06HasLen = FALSE;
DSP2.out_count = DSP2.Op06Len;
DSP2_Op06();
}
else
{
DSP2.Op06Len = DSP2.parameters[0];
DSP2.in_index = 0;
DSP2.in_count = DSP2.Op06Len;
DSP2.Op06HasLen = TRUE;
if (byte)
DSP2.waiting4command = FALSE;
}
break;
case 0x09:
DSP2.out_count = 4;
DSP2_Op09();
break;
case 0x0D:
if (DSP2.Op0DHasLen)
{
DSP2.Op0DHasLen = FALSE;
DSP2.out_count = DSP2.Op0DOutLen;
DSP2_Op0D();
}
else
{
DSP2.Op0DInLen = DSP2.parameters[0];
DSP2.Op0DOutLen = DSP2.parameters[1];
DSP2.in_index = 0;
DSP2.in_count = (DSP2.Op0DInLen + 1) >> 1;
DSP2.Op0DHasLen = TRUE;
if (byte)
DSP2.waiting4command = FALSE;
}
break;
case 0x0f:
default:
break;
}
}
}
}
uint8 DSP2GetByte (uint16 address)
{
uint8 t;
if ((address & 0xf000) == 0x6000 || (address >= 0x8000 && address < 0xc000))
{
if (DSP2.out_count)
{
t = (uint8) DSP2.output[DSP2.out_index];
DSP2.out_index++;
if (DSP2.out_count == DSP2.out_index)
DSP2.out_count = 0;
}
else
t = 0xff;
}
else
t = 0x80;
return (t);
}
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