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2026-02-02 04:50:13 +01:00

255 lines
6.8 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/endian.h"
#include "common/util.h"
namespace Grim {
static int16 imcTable1[] = {
7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
};
static int8 imcTable2[] = {
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5,
5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
};
static int8 imcOtherTable1[] = {
-1, 4, -1, 4
};
static int8 imcOtherTable2[] = {
-1, -1, 2, 6, -1, -1, 2, 6
};
static int8 imcOtherTable3[] = {
-1, -1, -1, -1, 1, 2, 4, 6,
-1, -1, -1, -1, 1, 2, 4, 6
};
static int8 imcOtherTable4[] = {
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 2, 2, 4, 5, 6,
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 2, 2, 4, 5, 6
};
static int8 imcOtherTable5[] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 2, 2, 2,
2, 4, 4, 4, 5, 5, 6, 6,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 2, 2, 2,
2, 4, 4, 4, 5, 5, 6, 6
};
static int8 imcOtherTable6[] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 6, 6, 6, 6,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 4, 4, 4, 4, 4, 4,
5, 5, 5, 5, 6, 6, 6, 6
};
static int8 *offsets[] = {
imcOtherTable1, imcOtherTable2, imcOtherTable3,
imcOtherTable4, imcOtherTable5, imcOtherTable6
};
void vimaInit(uint16 *destTable) {
int destTableStartPos, incer;
for (destTableStartPos = 0, incer = 0; destTableStartPos < 64; destTableStartPos++, incer++) {
unsigned int destTablePos, imcTable1Pos;
for (imcTable1Pos = 0, destTablePos = destTableStartPos;
imcTable1Pos < sizeof(imcTable1) / sizeof(imcTable1[0]); imcTable1Pos++, destTablePos += 64) {
int put = 0, count, tableValue;
for (count = 32, tableValue = imcTable1[imcTable1Pos]; count != 0; count >>= 1, tableValue >>= 1) {
if (incer & count) {
put += tableValue;
}
}
destTable[destTablePos] = put;
}
}
}
void decompressVima(const byte *src, int16 *dest, int destLen, uint16 *destTable, bool isSmush) {
int numChannels = 1;
byte sBytes[2];
int16 sWords[2];
sBytes[0] = *src++;
if (sBytes[0] & 0x80) {
sBytes[0] = ~sBytes[0];
numChannels = 2;
}
sWords[0] = READ_BE_UINT16(src);
src += 2;
if (numChannels > 1) {
sBytes[1] = *src++;
sWords[1] = READ_BE_UINT16(src);
src += 2;
}
int numSamples = destLen / (numChannels * 2);
if (READ_BE_UINT32(src) == MKTAG('I', 'M', 'A', '4')) {
int outputWord = 0;
int currTablePos = 0;
static const int tableDeltas[16] = {
-1, -1, -1, -1,
2, 4, 6, 8,
-1, -1, -1, -1,
2, 4, 6, 8
};
int16 *destPos = dest;
int curai = 7;
byte inputByte = 0;
bool nibbleSwitch = false;
src += 4;
if (isSmush) {
outputWord = READ_LE_INT16(src);
currTablePos = src[2];
src += 3;
}
for (int sample = 0; sample < numSamples; sample++) {
byte nibble;
if (!nibbleSwitch) {
inputByte = *src++;
nibble = inputByte >> 4;
} else
nibble = inputByte & 0xf;
nibbleSwitch = !nibbleSwitch;
currTablePos = CLIP(currTablePos + tableDeltas[nibble & 0xf], 0, 88);
int delta = curai >> 3;
if (nibble & 4) {
delta = delta + curai;
}
if (nibble & 2) {
delta = delta + (curai >> 1);
}
if (nibble & 1) {
delta = delta + (curai >> 2);
}
if (nibble & 8) {
delta = -delta;
}
outputWord = CLIP(outputWord + delta, -0x8000, 0x7fff);
if (currTablePos > 0)
curai = imcTable1[currTablePos];
for (int channel = 0; channel < numChannels; channel++)
WRITE_LE_UINT16(destPos + channel, outputWord);
destPos += numChannels;
}
return;
}
int bits = READ_BE_UINT16(src);
int bitPtr = 0;
src += 2;
for (int channel = 0; channel < numChannels; channel++) {
int16 *destPos = dest + channel;
int currTablePos = sBytes[channel];
int outputWord = sWords[channel];
for (int sample = 0; sample < numSamples; sample++) {
int numBits = imcTable2[currTablePos];
bitPtr += numBits;
int highBit = 1 << (numBits - 1);
int lowBits = highBit - 1;
int val = (bits >> (16 - bitPtr)) & (highBit | lowBits);
if (bitPtr > 7) {
bits = ((bits & 0xff) << 8) | *src++;
bitPtr -= 8;
}
if (val & highBit)
val ^= highBit;
else
highBit = 0;
if (val == lowBits) {
outputWord = ((int16)(bits << bitPtr) & 0xffffff00);
bits = ((bits & 0xff) << 8) | *src++;
outputWord |= ((bits >> (8 - bitPtr)) & 0xff);
bits = ((bits & 0xff) << 8) | *src++;
} else {
int index = (val << (7 - numBits)) | (currTablePos << 6);
int delta = destTable[index];
if (val)
delta += (imcTable1[currTablePos] >> (numBits - 1));
if (highBit)
delta = -delta;
outputWord += delta;
if (outputWord < -0x8000)
outputWord = -0x8000;
else if (outputWord > 0x7fff)
outputWord = 0x7fff;
}
WRITE_LE_UINT16(destPos, outputWord);
destPos += numChannels;
currTablePos += offsets[numBits - 2][val];
if (currTablePos < 0)
currTablePos = 0;
else if (currTablePos > 88)
currTablePos = 88;
}
}
}
} // end of namespace Grim