/**
* Returns the next code-block in the current tile for the specified component, as a copy (see
* below). The order in which code-blocks are returned is not specified. However each code-block
* is returned only once and all code-blocks will be returned if the method is called 'N' times,
* where 'N' is the number of code-blocks in the tile. After all the code-blocks have been
* returned for the current tile calls to this method will return 'null'.
*
* <p>When changing the current tile (through 'setTile()' or 'nextTile()') this method will always
* return the first code-block, as if this method was never called before for the new current
* tile.
*
* <p>The data returned by this method is always a copy of the internal data of this object, and
* it can be modified "in place" without any problems after being returned. The 'offset' of the
* returned data is 0, and the 'scanw' is the same as the code-block width. The 'magbits' of the
* returned data is not set by this method and should be ignored. See the 'CBlkWTData' class.
*
* <p>The 'ulx' and 'uly' members of the returned 'CBlkWTData' object contain the coordinates of
* the top-left corner of the block, with respect to the tile, not the subband.
*
* @param c The component for which to return the next code-block.
* @param cblk If non-null this object will be used to return the new code-block. If null a new
* one will be allocated and returned. If the "data" array of the object is non-null it will
* be reused, if possible, to return the data.
* @return The next code-block in the current tile for component 'c', or null if all code-blocks
* for the current tile have been returned.
* @see CBlkWTData
*/
public CBlkWTData getNextCodeBlock(int c, CBlkWTData cblk) {
// We can not directly use getNextInternCodeBlock() since that returns
// a reference to the internal buffer, we have to copy that data
int j, k;
int w;
Object dst_data; // a int[] or float[] object
int[] dst_data_int;
float[] dst_data_float;
Object src_data; // a int[] or float[] object
intData = (filters.getWTDataType(tIdx, c) == DataBlk.TYPE_INT);
dst_data = null;
// Cache the data array, if any
if (cblk != null) {
dst_data = cblk.getData();
}
// Get the next code-block
cblk = getNextInternCodeBlock(c, cblk);
if (cblk == null) {
return null; // No more code-blocks in current tile for component
// c
}
// Ensure size of output buffer
if (intData) { // int data
dst_data_int = (int[]) dst_data;
if (dst_data_int == null || dst_data_int.length < cblk.w * cblk.h) {
dst_data = new int[cblk.w * cblk.h];
}
} else { // float data
dst_data_float = (float[]) dst_data;
if (dst_data_float == null || dst_data_float.length < cblk.w * cblk.h) {
dst_data = new float[cblk.w * cblk.h];
}
}
// Copy data line by line
src_data = cblk.getData();
w = cblk.w;
for (j = w * (cblk.h - 1), k = cblk.offset + (cblk.h - 1) * cblk.scanw;
j >= 0;
j -= w, k -= cblk.scanw) {
System.arraycopy(src_data, k, dst_data, j, w);
}
cblk.setData(dst_data);
cblk.offset = 0;
cblk.scanw = w;
return cblk;
}
