/*
 * The Python Imaging Library.
 * $Id$
 *
 * decoder for uncompressed PCD image data.
 *
 * history:
 * 96-05-10 fl Created
 * 96-05-18 fl New tables
 * 97-01-25 fl Use PhotoYCC unpacker
 *
 * notes:
 * This driver supports uncompressed PCD modes only
 * (resolutions up to 768x512).
 *
 * Copyright (c) Fredrik Lundh 1996-97.
 * Copyright (c) Secret Labs AB 1997.
 *
 * See the README file for information on usage and redistribution.
 */


#include "Imaging.h"


int
ImagingPcdDecode(Imaging im, ImagingCodecState state, UINT8* buf, Py_ssize_t bytes)
{
    int x;
    int chunk;
    UINT8* out;
    UINT8* ptr;

    ptr = buf;

    chunk = 3 * state->xsize;

    for (;;) {

        /* We need data for two full lines before we can do anything */
        if (bytes < chunk) {
            return ptr - buf;
        }

        /* Unpack first line */
        out = state->buffer;
        for (x = 0; x < state->xsize; x++) {
            out[0] = ptr[x];
            out[1] = ptr[(x+4*state->xsize)/2];
            out[2] = ptr[(x+5*state->xsize)/2];
            out += 3;
        }

        state->shuffle((UINT8*) im->image[state->y],
                   state->buffer, state->xsize);

        if (++state->y >= state->ysize) {
            return -1; /* This can hardly happen */
        }

        /* Unpack second line */
        out = state->buffer;
        for (x = 0; x < state->xsize; x++) {
            out[0] = ptr[x+state->xsize];
            out[1] = ptr[(x+4*state->xsize)/2];
            out[2] = ptr[(x+5*state->xsize)/2];
            out += 3;
        }

        state->shuffle((UINT8*) im->image[state->y],
                   state->buffer, state->xsize);

        if (++state->y >= state->ysize) {
            return -1;
        }

        ptr += chunk;
        bytes -= chunk;

    }
}
