imagbmp.cpp

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/////////////////////////////////////////////////////////////////////////////
// Name:        imagbmp.cpp
// Purpose:     wxImage BMP,ICO and CUR handlers
// Author:      Robert Roebling, Chris Elliott
// RCS-ID:      $Id: imagbmp.cpp,v 1.58 2005/09/13 16:06:41 ABX Exp $
// Copyright:   (c) Robert Roebling, Chris Elliott
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma implementation "imagbmp.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include "wx/defs.h"

#if wxUSE_IMAGE

#include "wx/imagbmp.h"
#include "wx/bitmap.h"
#include "wx/debug.h"
#include "wx/log.h"
#include "wx/app.h"
#include "wx/filefn.h"
#include "wx/wfstream.h"
#include "wx/intl.h"
#include "wx/module.h"
#include "wx/quantize.h"

// For memcpy
#include <string.h>

#ifdef __SALFORDC__
#ifdef FAR
#undef FAR
#endif
#endif

#ifdef __WXMSW__
#include "wx/msw/wrapwin.h"
#endif

//-----------------------------------------------------------------------------
// wxBMPHandler
//-----------------------------------------------------------------------------

IMPLEMENT_DYNAMIC_CLASS(wxBMPHandler,wxImageHandler)

#if wxUSE_STREAMS

#ifndef BI_RGB
    #define BI_RGB       0
#endif

#ifndef BI_RLE8
#define BI_RLE8      1
#endif

#ifndef BI_RLE4
#define BI_RLE4      2
#endif

#ifndef BI_BITFIELDS
#define BI_BITFIELDS 3
#endif

#define poffset (line * width * 3 + column * 3)

bool wxBMPHandler::SaveFile(wxImage *image,
                            wxOutputStream& stream,
                            bool verbose)
{
    return SaveDib(image, stream, verbose, true/*IsBmp*/, false/*IsMask*/);
}

bool wxBMPHandler::SaveDib(wxImage *image,
                           wxOutputStream& stream,
                           bool verbose,
                           bool IsBmp,
                           bool IsMask)

{
    wxCHECK_MSG( image, false, _T("invalid pointer in wxBMPHandler::SaveFile") );

    if ( !image->Ok() )
    {
        if ( verbose )
            wxLogError(_("BMP: Couldn't save invalid image."));
        return false;
    }

    // get the format of the BMP file to save, else use 24bpp
    unsigned format = wxBMP_24BPP;
    if ( image->HasOption(wxIMAGE_OPTION_BMP_FORMAT) )
        format = image->GetOptionInt(wxIMAGE_OPTION_BMP_FORMAT);

    wxUint16 bpp;     // # of bits per pixel
    int palette_size; // # of color map entries, ie. 2^bpp colors

    // set the bpp and appropriate palette_size, and do additional checks
    if ( (format == wxBMP_1BPP) || (format == wxBMP_1BPP_BW) )
    {
        bpp = 1;
        palette_size = 2;
    }
    else if ( format == wxBMP_4BPP )
    {
        bpp = 4;
        palette_size = 16;
    }
    else if ( (format == wxBMP_8BPP) || (format == wxBMP_8BPP_GREY) ||
              (format == wxBMP_8BPP_RED) || (format == wxBMP_8BPP_PALETTE) )
    {
        // need to set a wxPalette to use this, HOW TO CHECK IF VALID, SIZE?
        if ((format == wxBMP_8BPP_PALETTE)
#if wxUSE_PALETTE
                && !image->HasPalette()
#endif // wxUSE_PALETTE
            )
        {
            if ( verbose )
                wxLogError(_("BMP: wxImage doesn't have own wxPalette."));
            return false;
        }
        bpp = 8;
        palette_size = 256;
    }
    else  // you get 24bpp
    {
        format = wxBMP_24BPP;
        bpp = 24;
        palette_size = 0;
    }

    unsigned width = image->GetWidth();
    unsigned row_padding = (4 - int(width*bpp/8.0) % 4) % 4; // # bytes to pad to dword
    unsigned row_width = int(width * bpp/8.0) + row_padding; // # of bytes per row

    struct
    {
        // BitmapHeader:
        wxUint16  magic;          // format magic, always 'BM'
        wxUint32  filesize;       // total file size, inc. headers
        wxUint32  reserved;       // for future use
        wxUint32  data_offset;    // image data offset in the file

        // BitmapInfoHeader:
        wxUint32  bih_size;       // 2nd part's size
        wxUint32  width, height;  // bitmap's dimensions
        wxUint16  planes;         // num of planes
        wxUint16  bpp;            // bits per pixel
        wxUint32  compression;    // compression method
        wxUint32  size_of_bmp;    // size of the bitmap
        wxUint32  h_res, v_res;   // image resolution in dpi
        wxUint32  num_clrs;       // number of colors used
        wxUint32  num_signif_clrs;// number of significant colors
    } hdr;

    wxUint32 hdr_size = 14/*BitmapHeader*/ + 40/*BitmapInfoHeader*/;

    hdr.magic = wxUINT16_SWAP_ON_BE(0x4D42/*'BM'*/);
    hdr.filesize = wxUINT32_SWAP_ON_BE( hdr_size + palette_size*4 +
                                        row_width * image->GetHeight() );
    hdr.reserved = 0;
    hdr.data_offset = wxUINT32_SWAP_ON_BE(hdr_size + palette_size*4);

    hdr.bih_size = wxUINT32_SWAP_ON_BE(hdr_size - 14);
    hdr.width = wxUINT32_SWAP_ON_BE(image->GetWidth());
    if ( IsBmp )
    {
        hdr.height = wxUINT32_SWAP_ON_BE(image->GetHeight());
    }
    else
    {
        hdr.height = wxUINT32_SWAP_ON_BE(2 * image->GetHeight());
    }
    hdr.planes = wxUINT16_SWAP_ON_BE(1); // always 1 plane
    hdr.bpp = wxUINT16_SWAP_ON_BE(bpp);
    hdr.compression = 0; // RGB uncompressed
    hdr.size_of_bmp = wxUINT32_SWAP_ON_BE(row_width * image->GetHeight());
    hdr.h_res = hdr.v_res = wxUINT32_SWAP_ON_BE(72);  // 72dpi is standard
    hdr.num_clrs = wxUINT32_SWAP_ON_BE(palette_size); // # colors in colormap
    hdr.num_signif_clrs = 0;     // all colors are significant

    if ( IsBmp )
    {
        if (// VS: looks ugly but compilers tend to do ugly things with structs,
            //     like aligning hdr.filesize's ofset to dword :(
            // VZ: we should add padding then...
            !stream.Write(&hdr.magic, 2) ||
            !stream.Write(&hdr.filesize, 4) ||
            !stream.Write(&hdr.reserved, 4) ||
            !stream.Write(&hdr.data_offset, 4)
           )
        {
            if (verbose)
                wxLogError(_("BMP: Couldn't write the file (Bitmap) header."));
            return false;
        }
    }
    if ( !IsMask )
    {
        if (
            !stream.Write(&hdr.bih_size, 4) ||
            !stream.Write(&hdr.width, 4) ||
            !stream.Write(&hdr.height, 4) ||
            !stream.Write(&hdr.planes, 2) ||
            !stream.Write(&hdr.bpp, 2) ||
            !stream.Write(&hdr.compression, 4) ||
            !stream.Write(&hdr.size_of_bmp, 4) ||
            !stream.Write(&hdr.h_res, 4) ||
            !stream.Write(&hdr.v_res, 4) ||
            !stream.Write(&hdr.num_clrs, 4) ||
            !stream.Write(&hdr.num_signif_clrs, 4)
           )
        {
            if (verbose)
                wxLogError(_("BMP: Couldn't write the file (BitmapInfo) header."));
            return false;
        }
    }

    wxPalette *palette = NULL; // entries for quantized images
    wxUint8 *rgbquad = NULL;   // for the RGBQUAD bytes for the colormap
    wxImage *q_image = NULL;   // destination for quantized image

    // if <24bpp use quantization to reduce colors for *some* of the formats
    if ( (format == wxBMP_1BPP) || (format == wxBMP_4BPP) ||
         (format == wxBMP_8BPP) || (format == wxBMP_8BPP_PALETTE) )
    {
        // make a new palette and quantize the image
        if (format != wxBMP_8BPP_PALETTE)
        {
            q_image = new wxImage();

            // I get a delete error using Quantize when desired colors > 236
            int quantize = ((palette_size > 236) ? 236 : palette_size);
            // fill the destination too, it gives much nicer 4bpp images
            wxQuantize::Quantize( *image, *q_image, &palette, quantize, 0,
                                  wxQUANTIZE_FILL_DESTINATION_IMAGE );
        }
        else
        {
#if wxUSE_PALETTE
            palette = new wxPalette(image->GetPalette());
#endif // wxUSE_PALETTE
        }

        int i;
        unsigned char r, g, b;
        rgbquad = new wxUint8 [palette_size*4];

        for (i = 0; i < palette_size; i++)
        {
#if wxUSE_PALETTE
            if ( !palette->GetRGB(i, &r, &g, &b) )
#endif // wxUSE_PALETTE
                r = g = b = 0;

            rgbquad[i*4] = b;
            rgbquad[i*4+1] = g;
            rgbquad[i*4+2] = r;
            rgbquad[i*4+3] = 0;
        }
    }
    // make a 256 entry greyscale colormap or 2 entry black & white
    else if ( (format == wxBMP_8BPP_GREY) || (format == wxBMP_8BPP_RED) ||
              (format == wxBMP_1BPP_BW) )
    {
        rgbquad = new wxUint8 [palette_size*4];

        for ( int i = 0; i < palette_size; i++ )
        {
            // if 1BPP_BW then the value should be either 0 or 255
            wxUint8 c = (wxUint8)((i > 0) && (format == wxBMP_1BPP_BW) ? 255 : i);

            rgbquad[i*4] =
            rgbquad[i*4+1] =
            rgbquad[i*4+2] = c;
            rgbquad[i*4+3] = 0;
        }
    }

    // if the colormap was made, then it needs to be written
    if (rgbquad)
    {
        if ( !IsMask )
        {
            if ( !stream.Write(rgbquad, palette_size*4) )
            {
                if (verbose)
                    wxLogError(_("BMP: Couldn't write RGB color map."));
                delete[] rgbquad;
#if wxUSE_PALETTE
                delete palette;
#endif // wxUSE_PALETTE
                delete q_image;
                return false;
            }
            }
        delete []rgbquad;
    }

    // pointer to the image data, use quantized if available
    wxUint8 *data = (wxUint8*) image->GetData();
    if (q_image) if (q_image->Ok()) data = (wxUint8*) q_image->GetData();

    wxUint8 *buffer = new wxUint8[row_width];
    memset(buffer, 0, row_width);
    int y; unsigned x;
    long int pixel;

    for (y = image->GetHeight() -1; y >= 0; y--)
    {
        if ( format == wxBMP_24BPP ) // 3 bytes per pixel red,green,blue
        {
            for ( x = 0; x < width; x++ )
            {
                pixel = 3*(y*width + x);

                buffer[3*x    ] = data[pixel+2];
                buffer[3*x + 1] = data[pixel+1];
                buffer[3*x + 2] = data[pixel];
            }
        }
        else if ((format == wxBMP_8BPP) ||       // 1 byte per pixel in color
                 (format == wxBMP_8BPP_PALETTE))
        {
            for (x = 0; x < width; x++)
            {
                pixel = 3*(y*width + x);
#if wxUSE_PALETTE
                buffer[x] = (wxUint8)palette->GetPixel( data[pixel],
                                                        data[pixel+1],
                                                        data[pixel+2] );
#else
                // FIXME: what should this be? use some std palette maybe?
                buffer[x] = 0;
#endif // wxUSE_PALETTE
            }
        }
        else if ( format == wxBMP_8BPP_GREY ) // 1 byte per pix, rgb ave to grey
        {
            for (x = 0; x < width; x++)
            {
                pixel = 3*(y*width + x);
                buffer[x] = (wxUint8)(.299*data[pixel] +
                                      .587*data[pixel+1] +
                                      .114*data[pixel+2]);
            }
        }
        else if ( format == wxBMP_8BPP_RED ) // 1 byte per pixel, red as greys
        {
            for (x = 0; x < width; x++)
            {
                buffer[x] = (wxUint8)data[3*(y*width + x)];
            }
        }
        else if ( format == wxBMP_4BPP ) // 4 bpp in color
        {
            for (x = 0; x < width; x+=2)
            {
                pixel = 3*(y*width + x);

                // fill buffer, ignore if > width
#if wxUSE_PALETTE
                buffer[x/2] = (wxUint8)(