worldspawn/plugins/image/bmp.cpp

/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   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 "bmp.h"

#include "ifilesystem.h"

typedef unsigned char byte;

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


typedef unsigned char PaletteEntry[4];
typedef struct {
    char id[2];
    unsigned long fileSize;
    unsigned long reserved0;
    unsigned long bitmapDataOffset;
    unsigned long bitmapHeaderSize;
    unsigned long width;
    unsigned long height;
    unsigned short planes;
    unsigned short bitsPerPixel;
    unsigned long compression;
    unsigned long bitmapDataSize;
    unsigned long hRes;
    unsigned long vRes;
    unsigned long colors;
    unsigned long importantColors;
    PaletteEntry palette[256];
} BMPHeader_t;

class ReadPixel8 {
    PaletteEntry *m_palette;
public:
    ReadPixel8(PaletteEntry *palette) : m_palette(palette)
    {
    }

    void operator()(PointerInputStream &inputStream, byte *&pixbuf) const
    {
        byte palIndex;
        inputStream.read(&palIndex, 1);
        *pixbuf++ = m_palette[palIndex][2];
        *pixbuf++ = m_palette[palIndex][1];
        *pixbuf++ = m_palette[palIndex][0];
        *pixbuf++ = 0xff;
    }
};

class ReadPixel16 {
public:
    void operator()(PointerInputStream &inputStream, byte *&pixbuf) const
    {
        unsigned short shortPixel;
        inputStream.read(reinterpret_cast<byte *>( &shortPixel ), sizeof(unsigned short)); //!\todo Is this endian safe?
        *pixbuf++ = static_cast<byte>( shortPixel & (31 << 10)) >> 7;
        *pixbuf++ = static_cast<byte>( shortPixel & (31 << 5)) >> 2;
        *pixbuf++ = static_cast<byte>( shortPixel & (31)) << 3;
        *pixbuf++ = 0xff;
    }
};

class ReadPixel24 {
public:
    void operator()(PointerInputStream &inputStream, byte *&pixbuf) const
    {
        byte bgr[3];
        inputStream.read(bgr, 3);
        *pixbuf++ = bgr[2];
        *pixbuf++ = bgr[1];
        *pixbuf++ = bgr[0];
        *pixbuf++ = 255;
    }
};

class ReadPixel32 {
public:
    void operator()(PointerInputStream &inputStream, byte *&pixbuf) const
    {
        byte bgra[4];
        inputStream.read(bgra, 4);
        *pixbuf++ = bgra[2];
        *pixbuf++ = bgra[1];
        *pixbuf++ = bgra[0];
        *pixbuf++ = bgra[3];
    }
};

template<typename ReadPixel>
void ReadBMP(PointerInputStream &inputStream, byte *bmpRGBA, int rows, int columns, ReadPixel readPixel)
{
    for (int row = rows - 1; row >= 0; row--) {
        byte *pixbuf = bmpRGBA + row * columns * 4;

        for (int column = 0; column < columns; column++) {
            readPixel(inputStream, pixbuf);
        }
    }
}

Image *LoadBMPBuff(PointerInputStream &inputStream, std::size_t length)
{
    BMPHeader_t bmpHeader;
    inputStream.read(reinterpret_cast<byte *>( bmpHeader.id ), 2);
    bmpHeader.fileSize = istream_read_uint32_le(inputStream);
    bmpHeader.reserved0 = istream_read_uint32_le(inputStream);
    bmpHeader.bitmapDataOffset = istream_read_uint32_le(inputStream);
    bmpHeader.bitmapHeaderSize = istream_read_uint32_le(inputStream);
    bmpHeader.width = istream_read_uint32_le(inputStream);
    bmpHeader.height = istream_read_uint32_le(inputStream);
    bmpHeader.planes = istream_read_uint16_le(inputStream);
    bmpHeader.bitsPerPixel = istream_read_uint16_le(inputStream);
    bmpHeader.compression = istream_read_uint32_le(inputStream);
    bmpHeader.bitmapDataSize = istream_read_uint32_le(inputStream);
    bmpHeader.hRes = istream_read_uint32_le(inputStream);
    bmpHeader.vRes = istream_read_uint32_le(inputStream);
    bmpHeader.colors = istream_read_uint32_le(inputStream);
    bmpHeader.importantColors = istream_read_uint32_le(inputStream);

    if (bmpHeader.bitsPerPixel == 8) {
        int paletteSize = bmpHeader.colors * 4;
        inputStream.read(reinterpret_cast<byte *>( bmpHeader.palette ), paletteSize);
    }

    if (bmpHeader.id[0] != 'B' && bmpHeader.id[1] != 'M') {
        globalErrorStream() << "LoadBMP: only Windows-style BMP files supported\n";
        return 0;
    }
    if (bmpHeader.fileSize != length) {
        globalErrorStream() << "LoadBMP: header size does not match file size (" << Unsigned(bmpHeader.fileSize)
                            << " vs. " << Unsigned(length) << ")\n";
        return 0;
    }
    if (bmpHeader.compression != 0) {
        globalErrorStream() << "LoadBMP: only uncompressed BMP files supported\n";
        return 0;
    }
    if (bmpHeader.bitsPerPixel < 8) {
        globalErrorStream() << "LoadBMP: monochrome and 4-bit BMP files not supported\n";
        return 0;
    }

    int columns = bmpHeader.width;
    int rows = bmpHeader.height;
    if (rows < 0) {
        rows = -rows;
    }

    RGBAImage *image = new RGBAImage(columns, rows);

    switch (bmpHeader.bitsPerPixel) {
        case 8:
            ReadBMP(inputStream, image->getRGBAPixels(), rows, columns, ReadPixel8(bmpHeader.palette));
            break;
        case 16:
            ReadBMP(inputStream, image->getRGBAPixels(), rows, columns, ReadPixel16());
            break;
        case 24:
            ReadBMP(inputStream, image->getRGBAPixels(), rows, columns, ReadPixel24());
            break;
        case 32:
            ReadBMP(inputStream, image->getRGBAPixels(), rows, columns, ReadPixel32());
            break;
        default:
            globalErrorStream() << "LoadBMP: illegal pixel_size '" << bmpHeader.bitsPerPixel << "'\n";
            image->release();
            return 0;
    }
    return image;
}

Image *LoadBMP(ArchiveFile &file)
{
    ScopedArchiveBuffer buffer(file);
    PointerInputStream inputStream(buffer.buffer);
    return LoadBMPBuff(inputStream, buffer.length);
}