/**
* Decodes a single frame of animation. Does not colour the frame with the palette afterwards.
*
* @param framenum The number of the frame to decode.
* @param lastbytes Frame data of the last frame decoded.
* @return Raw decoded frame data.
*/
private ByteBuffer decodeFrame(int framenum, ByteBuffer lastbytes) {
int offset = wsaoffsets[framenum];
int sourcelength = wsaoffsets[framenum + 1] - offset;
// Source frame data (is at frame offset + palette size)
ByteBuffer sourcebytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(
sourcelength);
try {
inputchannel.read(sourcebytes);
} catch (IOException e) {
throw new RuntimeException(e);
}
sourcebytes.rewind();
// Intermediate and final frame data
int framesize = width() * height();
ByteBuffer intbytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(framesize);
ByteBuffer framebytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(framesize);
// First decompress from Format80, then decode as Format40
CodecUtility.decodeFormat80(sourcebytes, intbytes);
CodecUtility.decodeFormat40(intbytes, framebytes, lastbytes);
return framebytes;
}
/**
* Constructor, creates a new shp file with the given name and file data.
*
* @param name The name of this file.
* @param bytechannel Data of the file.
*/
public ShpFileCNC(String name, ReadableByteChannel bytechannel) {
super(name);
try {
// Construct file header
ByteBuffer headerbytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(
ShpFileHeaderCNC.HEADER_SIZE);
try {
bytechannel.read(headerbytes);
} catch (IOException e) {
throw new RuntimeException(e);
}
headerbytes.rewind();
shpfileheader = new ShpFileHeaderCNC(headerbytes);
// numImages() + 2 for the 0 offset and EOF pointer
ShpImageOffsetCNC[] offsets = new ShpImageOffsetCNC[numImages() + 2];
for (int i = 0; i < offsets.length; i++) {
ByteBuffer offsetbytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(
ShpImageOffsetCNC.OFFSET_SIZE);
try {
bytechannel.read(offsetbytes);
} catch (IOException e) {
throw new RuntimeException(e);
}
offsets[i] = new ShpImageOffsetCNC((ByteBuffer) offsetbytes.rewind());
}
// Decompresses the raw SHP data into palette-index data
shpimages = new ByteBuffer[numImages()];
// Decompress every frame
for (int i = 0; i < numImages(); i++) {
ShpImageOffsetCNC imageoffset = offsets[i];
// Format conversion buffers
ByteBuffer sourcebytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(
offsets[i + 1].offset - imageoffset.offset);
try {
bytechannel.read(sourcebytes);
} catch (IOException e) {
throw new RuntimeException(e);
}
sourcebytes.rewind();
ByteBuffer destbytes =
com.mikeduvall.redhorizon.util.ByteBufferFactory.createLittleEndianByteBuffer(
width() * height());
switch (imageoffset.offsetformat) {
// Format80 image
case FORMAT80:
CodecUtility.decodeFormat80(sourcebytes, destbytes);
break;
// Format40 image
case FORMAT40:
int refoffset = imageoffset.refoff;
int j;
for (j = 0; j < numImages(); j++) {
if (refoffset == offsets[j].offset) {
break;
}
}
CodecUtility.decodeFormat40(sourcebytes, destbytes, shpimages[j]);
break;
// Format20 image
case FORMAT20:
CodecUtility.decodeFormat20(sourcebytes, shpimages[i - 1], destbytes);
break;
}
// Add the decompressed image to the image array
shpimages[i] = destbytes;
}
} finally {
try {
bytechannel.close();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
