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/* 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.
*
* $URL$
* $Id$
*
*/
// Based off ffmpeg's RPZA decoder
#include "mohawk/video/rpza.h"
#include "common/system.h"
#include "graphics/colormasks.h"
namespace Mohawk {
RPZADecoder::RPZADecoder(uint16 width, uint16 height) : Graphics::Codec() {
_pixelFormat = g_system->getScreenFormat();
// We need to increase the surface size to a multiple of 4
uint16 wMod = width % 4;
if(wMod != 0)
width += 4 - wMod;
debug(2, "RPZA corrected width: %d", width);
_surface = new Graphics::Surface();
_surface->create(width, height, _pixelFormat.bytesPerPixel);
}
#define ADVANCE_BLOCK() \
pixelPtr += 4; \
if (pixelPtr >= _surface->w) { \
pixelPtr = 0; \
rowPtr += _surface->w * 4; \
} \
totalBlocks--; \
if (totalBlocks < 0) \
error("block counter just went negative (this should not happen)") \
// Convert from RGB555 to the format specified by the screen
#define PUT_PIXEL(color) \
if ((int32)blockPtr < _surface->w * _surface->h) { \
byte r = 0, g = 0, b = 0; \
Graphics::colorToRGB<Graphics::ColorMasks<555> >(color, r, g, b); \
if (_pixelFormat.bytesPerPixel == 2) \
*((uint16 *)_surface->pixels + blockPtr) = _pixelFormat.RGBToColor(r, g, b); \
else \
*((uint32 *)_surface->pixels + blockPtr) = _pixelFormat.RGBToColor(r, g, b); \
} \
blockPtr++
Graphics::Surface *RPZADecoder::decodeImage(Common::SeekableReadStream *stream) {
uint16 colorA = 0, colorB = 0;
uint16 color4[4];
uint32 rowPtr = 0;
uint32 pixelPtr = 0;
uint32 blockPtr = 0;
uint32 rowInc = _surface->w - 4;
uint16 ta;
uint16 tb;
// First byte is always 0xe1. Warn if it's different
byte firstByte = stream->readByte();
if (firstByte != 0xe1)
warning("First RPZA chunk byte is 0x%02x instead of 0xe1", firstByte);
// Get chunk size, ingnoring first byte
uint32 chunkSize = stream->readUint16BE() << 8;
chunkSize += stream->readByte();
// If length mismatch use size from MOV file and try to decode anyway
if (chunkSize != (uint32)stream->size()) {
warning("MOV chunk size != encoded chunk size; using MOV chunk size");
chunkSize = stream->size();
}
// Number of 4x4 blocks in frame
int32 totalBlocks = ((_surface->w + 3) / 4) * ((_surface->h + 3) / 4);
// Process chunk data
while ((uint32)stream->pos() < chunkSize) {
byte opcode = stream->readByte(); // Get opcode
byte numBlocks = (opcode & 0x1f) + 1; // Extract block counter from opcode
// If opcode MSbit is 0, we need more data to decide what to do
if ((opcode & 0x80) == 0) {
colorA = (opcode << 8) | stream->readByte();
opcode = 0;
if (stream->readByte() & 0x80) {
// Must behave as opcode 110xxxxx, using colorA computed
// above. Use fake opcode 0x20 to enter switch block at
// the right place
opcode = 0x20;
numBlocks = 1;
}
stream->seek(-1, SEEK_CUR);
}
switch (opcode & 0xe0) {
case 0x80: // Skip blocks
while (numBlocks--) {
ADVANCE_BLOCK();
}
break;
case 0xa0: // Fill blocks with one color
colorA = stream->readUint16BE();
while (numBlocks--) {
blockPtr = rowPtr + pixelPtr;
for (byte pixel_y = 0; pixel_y < 4; pixel_y++) {
for (byte pixel_x = 0; pixel_x < 4; pixel_x++) {
PUT_PIXEL(colorA);
}
blockPtr += rowInc;
}
ADVANCE_BLOCK();
}
break;
// Fill blocks with 4 colors
case 0xc0:
colorA = stream->readUint16BE();
case 0x20:
colorB = stream->readUint16BE();
// Sort out the colors
color4[0] = colorB;
color4[1] = 0;
color4[2] = 0;
color4[3] = colorA;
// Red components
ta = (colorA >> 10) & 0x1F;
tb = (colorB >> 10) & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
// Green components
ta = (colorA >> 5) & 0x1F;
tb = (colorB >> 5) & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
// Blue components
ta = colorA & 0x1F;
tb = colorB & 0x1F;
color4[1] |= ((11 * ta + 21 * tb) >> 5);
color4[2] |= ((21 * ta + 11 * tb) >> 5);
while (numBlocks--) {
blockPtr = rowPtr + pixelPtr;
for (byte pixel_y = 0; pixel_y < 4; pixel_y++) {
byte index = stream->readByte();
for (byte pixel_x = 0; pixel_x < 4; pixel_x++){
byte idx = (index >> (2 * (3 - pixel_x))) & 0x03;
PUT_PIXEL(color4[idx]);
}
blockPtr += rowInc;
}
ADVANCE_BLOCK();
}
break;
// Fill block with 16 colors
case 0x00:
blockPtr = rowPtr + pixelPtr;
for (byte pixel_y = 0; pixel_y < 4; pixel_y++) {
for (byte pixel_x = 0; pixel_x < 4; pixel_x++){
// We already have color of upper left pixel
if (pixel_y != 0 || pixel_x != 0)
colorA = stream->readUint16BE();
PUT_PIXEL(colorA);
}
blockPtr += rowInc;
}
ADVANCE_BLOCK();
break;
// Unknown opcode
default:
error("Unknown opcode %02x in rpza chunk", opcode);
}
}
return _surface;
}
} // End of namespace Mohawk
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