scummvm/engines/scumm/bomp.cpp
2014-02-18 02:39:38 +01:00

372 lines
8.8 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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "scumm/scumm.h"
#include "scumm/akos.h"
#include "scumm/bomp.h"
#include "scumm/util.h"
namespace Scumm {
static int32 setupBompScale(byte *scaling, int32 size, byte scale);
static void bompScaleFuncX(byte *line_buffer, byte *scaling_x_ptr, byte skip, int32 size);
static void bompApplyShadow0(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency, bool HE7Check);
static void bompApplyShadow1(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency);
static void bompApplyShadow3(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency);
static void bompApplyActorPalette(uint16 *actorPalette, byte *line_buffer, int32 size);
void decompressBomp(byte *dst, const byte *src, int w, int h) {
assert(w > 0);
assert(h > 0);
do {
bompDecodeLine(dst, src + 2, w);
src += READ_LE_UINT16(src) + 2;
dst += w;
} while (--h);
}
void bompDecodeLine(byte *dst, const byte *src, int len) {
assert(len > 0);
int num;
byte code, color;
while (len > 0) {
code = *src++;
num = (code >> 1) + 1;
if (num > len)
num = len;
len -= num;
if (code & 1) {
color = *src++;
memset(dst, color, num);
} else {
memcpy(dst, src, num);
src += num;
}
dst += num;
}
}
void bompDecodeLineReverse(byte *dst, const byte *src, int len) {
assert(len > 0);
dst += len;
int num;
byte code, color;
while (len > 0) {
code = *src++;
num = (code >> 1) + 1;
if (num > len)
num = len;
len -= num;
dst -= num;
if (code & 1) {
color = *src++;
memset(dst, color, num);
} else {
memcpy(dst, src, num);
src += num;
}
}
}
void bompApplyMask(byte *line_buffer, byte *mask, byte maskbit, int32 size, byte transparency) {
while (1) {
do {
if (size-- == 0)
return;
if (*mask & maskbit) {
*line_buffer = transparency;
}
line_buffer++;
maskbit >>= 1;
} while (maskbit);
mask++;
maskbit = 128;
}
}
void bompApplyShadow(int shadowMode, const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency, bool HE7Check) {
assert(size > 0);
switch (shadowMode) {
case 0:
bompApplyShadow0(shadowPalette, line_buffer, dst, size, transparency, HE7Check);
break;
case 1:
bompApplyShadow1(shadowPalette, line_buffer, dst, size, transparency);
break;
case 3:
bompApplyShadow3(shadowPalette, line_buffer, dst, size, transparency);
break;
default:
error("Unknown shadow mode %d", shadowMode);
}
}
void bompApplyShadow0(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency, bool HE7Check) {
while (size-- > 0) {
byte tmp = *line_buffer++;
if (tmp != transparency) {
if (HE7Check)
*dst = shadowPalette[tmp];
else
*dst = tmp;
}
dst++;
}
}
void bompApplyShadow1(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency) {
while (size-- > 0) {
byte tmp = *line_buffer++;
if (tmp != transparency) {
if (tmp == 13) {
tmp = shadowPalette[*dst];
}
*dst = tmp;
}
dst++;
}
}
void bompApplyShadow3(const byte *shadowPalette, const byte *line_buffer, byte *dst, int32 size, byte transparency) {
while (size-- > 0) {
byte tmp = *line_buffer++;
if (tmp != transparency) {
if (tmp < 8) {
tmp = shadowPalette[*dst + (tmp << 8)];
}
*dst = tmp;
}
dst++;
}
}
void bompApplyActorPalette(uint16 *actorPalette, byte *line_buffer, int32 size) {
actorPalette[255] = 255;
while (size-- > 0) {
*line_buffer = actorPalette[*line_buffer];
line_buffer++;
}
}
void bompScaleFuncX(byte *line_buffer, byte *scaling_x_ptr, byte skip, int32 size) {
byte *line_ptr1 = line_buffer;
byte *line_ptr2 = line_buffer;
byte tmp = *scaling_x_ptr++;
while (size--) {
if ((skip & tmp) == 0) {
*line_ptr1++ = *line_ptr2;
}
line_ptr2++;
skip >>= 1;
if (skip == 0) {
skip = 128;
tmp = *scaling_x_ptr++;
}
}
}
void drawBomp(const BompDrawData &bd) {
const byte *src;
byte *dst;
byte *mask = 0;
Common::Rect clip;
byte *scalingYPtr = 0;
byte skip_y_bits = 0x80;
byte skip_y_new = 0;
byte tmp;
byte bomp_scaling_x[64];
byte bomp_scaling_y[64];
if (bd.x < 0) {
clip.left = -bd.x;
} else {
clip.left = 0;
}
if (bd.y < 0) {
clip.top = -bd.y;
} else {
clip.top = 0;
}
clip.right = bd.srcwidth;
if (clip.right > bd.dst.w - bd.x) {
clip.right = bd.dst.w - bd.x;
}
clip.bottom = bd.srcheight;
if (clip.bottom > bd.dst.h - bd.y) {
clip.bottom = bd.dst.h - bd.y;
}
src = bd.src;
// FIXME: This gets passed a const destination Surface. Intuitively this
// should never get written to. But sadly it does... For now we simply
// cast the const qualifier away.
dst = (byte *)const_cast<void *>(bd.dst.getBasePtr((bd.x + clip.left), bd.y));
const byte maskbit = revBitMask((bd.x + clip.left) & 7);
// Mask against any additionally imposed mask
if (bd.maskPtr) {
mask = bd.maskPtr + (bd.y * bd.numStrips) + ((bd.x + clip.left) / 8);
}
// Setup vertical scaling
if (bd.scale_y != 255) {
int scaleBottom = setupBompScale(bomp_scaling_y, bd.srcheight, bd.scale_y);
scalingYPtr = bomp_scaling_y;
skip_y_new = *scalingYPtr++;
skip_y_bits = 0x80;
if (clip.bottom > scaleBottom) {
clip.bottom = scaleBottom;
}
}
// Setup horizontal scaling
if (bd.scale_x != 255) {
int scaleRight = setupBompScale(bomp_scaling_x, bd.srcwidth, bd.scale_x);
if (clip.right > scaleRight) {
clip.right = scaleRight;
}
}
const int width = clip.right - clip.left;
if (width <= 0)
return;
int pos_y = 0;
byte line_buffer[1024];
byte *line_ptr = line_buffer + clip.left;
// Loop over all lines
while (pos_y < clip.bottom) {
// Decode a single (bomp encoded) line, reversed if we are in mirror mode
if (bd.mirror)
bompDecodeLineReverse(line_buffer, src + 2, bd.srcwidth);
else
bompDecodeLine(line_buffer, src + 2, bd.srcwidth);
src += READ_LE_UINT16(src) + 2;
// If vertical scaling is enabled, do it
if (bd.scale_y != 255) {
// A bit set means we should skip this line...
tmp = skip_y_new & skip_y_bits;
// Advance the scale-skip bit mask, if it's 0, get the next scale-skip byte
skip_y_bits /= 2;
if (skip_y_bits == 0) {
skip_y_bits = 0x80;
skip_y_new = *scalingYPtr++;
}
// Skip the current line if the above check tells us to
if (tmp != 0)
continue;
}
// Perform horizontal scaling
if (bd.scale_x != 255) {
bompScaleFuncX(line_buffer, bomp_scaling_x, 0x80, bd.srcwidth);
}
// The first clip.top lines are to be clipped, i.e. not drawn
if (clip.top > 0) {
clip.top--;
} else {
// Replace the parts of the line which are masked with the transparency color
if (bd.maskPtr)
bompApplyMask(line_ptr, mask, maskbit, width, 255);
// Apply custom color map, if available
if (bd.actorPalette)
bompApplyActorPalette(bd.actorPalette, line_ptr, width);
// Finally, draw the decoded, scaled, masked and recolored line onto
// the target surface, using the specified shadow mode
bompApplyShadow(bd.shadowMode, bd.shadowPalette, line_ptr, dst, width, 255);
}
// Advance to the next line
pos_y++;
mask += bd.numStrips;
dst += bd.dst.pitch;
}
}
int32 setupBompScale(byte *scaling, int32 size, byte scale) {
static const int offsets[8] = { 3, 2, 1, 0, 7, 6, 5, 4 };
int32 count;
byte bitsCount = 0;
count = (256 - size / 2);
assert(0 <= count && count < 768);
const byte *scaleTable = bigCostumeScaleTable + count;
count = (size + 7) / 8;
while (count--) {
byte scaleMask = 0;
for (int i = 0; i < 8; i++) {
byte scaleTest = *(scaleTable + offsets[i]);
scaleMask <<= 1;
if (scale < scaleTest) {
scaleMask |= 1;
} else {
bitsCount++;
}
}
scaleTable += 8;
*scaling++ = scaleMask;
}
size &= 7;
if (size != 0) {
--scaling;
if ((*scaling & revBitMask(size)) == 0) {
*scaling |= revBitMask(size);
bitsCount--;
}
}
return bitsCount;
}
} // End of namespace Scumm