/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "pcx.h"

#include "ifilesystem.h"

typedef unsigned char byte;

#include <stdlib.h>

#include "imagelib.h"
#include "bytestreamutils.h"

/*
   =================================================================

   PCX LOADING

   =================================================================
 */

typedef struct {
    unsigned char manufacturer;
    unsigned char version;
    unsigned char encoding;
    unsigned char bits_per_pixel;
    unsigned short xmin, ymin, xmax, ymax;
    unsigned short hres, vres;
    unsigned char palette[48];
    unsigned char reserved;
    unsigned char color_planes;
    unsigned short bytes_per_line;
    unsigned short palette_type;
    unsigned char filler[58];
    unsigned char data;     // unbounded
} pcx_t;

/*
   ==============
   LoadPCX
   ==============
 */

struct PCXRLEPacket {
    byte data;
    int length;
};

inline void ByteStream_readPCXRLEPacket(PointerInputStream &inputStream, PCXRLEPacket &packet)
{
    byte d;
    inputStream.read(&d, 1);
    if ((d & 0xC0) == 0xC0) {
        packet.length = d & 0x3F;
        inputStream.read(&packet.data, 1);
    } else {
        packet.length = 1;
        packet.data = d;
    }
}

void LoadPCXBuff(byte *buffer, std::size_t len, byte **pic, byte **palette, int *width, int *height)
{
    *pic = 0;

    pcx_t pcx;
    int x, y, lsize;
    byte *out, *pix;

    /* parse the PCX file */

    PointerInputStream inputStream(buffer);

    pcx.manufacturer = istream_read_byte(inputStream);
    pcx.version = istream_read_byte(inputStream);
    pcx.encoding = istream_read_byte(inputStream);
    pcx.bits_per_pixel = istream_read_byte(inputStream);
    pcx.xmin = istream_read_int16_le(inputStream);
    pcx.ymin = istream_read_int16_le(inputStream);
    pcx.xmax = istream_read_int16_le(inputStream);
    pcx.ymax = istream_read_int16_le(inputStream);
    pcx.hres = istream_read_int16_le(inputStream);
    pcx.vres = istream_read_int16_le(inputStream);
    inputStream.read(pcx.palette, 48);
    pcx.reserved = istream_read_byte(inputStream);
    pcx.color_planes = istream_read_byte(inputStream);
    pcx.bytes_per_line = istream_read_int16_le(inputStream);
    pcx.palette_type = istream_read_int16_le(inputStream);
    inputStream.read(pcx.filler, 58);


    if (pcx.manufacturer != 0x0a
        || pcx.version != 5
        || pcx.encoding != 1
        || pcx.bits_per_pixel != 8) {
        return;
    }

    if (width) {
        *width = pcx.xmax + 1;
    }
    if (height) {
        *height = pcx.ymax + 1;
    }

    if (!pic) {
        return;
    }

    out = (byte *) malloc((pcx.ymax + 1) * (pcx.xmax + 1));

    *pic = out;
    pix = out;

    /* RR2DO2: pcx fix  */
    lsize = pcx.color_planes * pcx.bytes_per_line;

    /* go scanline by scanline */
    for (y = 0; y <= pcx.ymax; y++, pix += pcx.xmax + 1) {
        /* do a scanline */
        for (x = 0; x <= pcx.xmax;) {
            /* RR2DO2 */
            PCXRLEPacket packet;
            ByteStream_readPCXRLEPacket(inputStream, packet);

            while (packet.length-- > 0) {
                pix[x++] = packet.data;
            }
        }

        /* RR2DO2: discard any other data */
        PCXRLEPacket packet;
        while (x < lsize) {
            ByteStream_readPCXRLEPacket(inputStream, packet);
            x++;
        }
        while (packet.length-- > 0) {
            x++;
        }
    }

    /* validity check */
    if (std::size_t(inputStream.get() - buffer) > len) {
        *pic = 0;
    }

    if (palette) {
        *palette = (byte *) malloc(768);
        memcpy(*palette, buffer + len - 768, 768);
    }
}

/*
   ==============
   LoadPCX32
   ==============
 */
Image *LoadPCX32Buff(byte *buffer, std::size_t length)
{
    byte *palette;
    byte *pic8;
    int i, c, p, width, height;
    byte *pic32;

    LoadPCXBuff(buffer, length, &pic8, &palette, &width, &height);
    if (!pic8) {
        return 0;
    }

    RGBAImage *image = new RGBAImage(width, height);
    c = (width) * (height);
    pic32 = image->getRGBAPixels();
    for (i = 0; i < c; i++) {
        p = pic8[i];
        pic32[0] = palette[p * 3];
        pic32[1] = palette[p * 3 + 1];
        pic32[2] = palette[p * 3 + 2];
        pic32[3] = 255;
        pic32 += 4;
    }

    free(pic8);
    free(palette);

    return image;
}

Image *LoadPCX32(ArchiveFile &file)
{
    ScopedArchiveBuffer buffer(file);
    return LoadPCX32Buff(buffer.buffer, buffer.length);
}