/////////////////////////////////////////////////////////////////////////////
-// Name: imagpcx.cpp
+// Name: src/common/imagpcx.cpp
// Purpose: wxImage PCX handler
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
-// Version: 1.00
+// Version: 1.1
// CVS-ID: $Id$
// Copyright: (c) 1999 Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-/*
- We don't put pragma implement in this file because it is already present in
- src/common/image.cpp
-*/
-
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
-#pragma hdrstop
+ #pragma hdrstop
#endif
+#if wxUSE_IMAGE && wxUSE_PCX
+
#ifndef WX_PRECOMP
-# include "wx/defs.h"
+ #include "wx/object.h"
+ #include "wx/list.h"
+ #include "wx/log.h"
+ #include "wx/intl.h"
+ #include "wx/palette.h"
+ #include "wx/hash.h"
+ #include "wx/module.h"
#endif
-#if wxUSE_STREAMS && wxUSE_PCX
-
-#include "wx/image.h"
+#include "wx/imagpcx.h"
#include "wx/wfstream.h"
-#include "wx/module.h"
-#include "wx/log.h"
-#include "wx/intl.h"
//-----------------------------------------------------------------------------
-// PCX decoding
+// wxPCXHandler
+//-----------------------------------------------------------------------------
+
+IMPLEMENT_DYNAMIC_CLASS(wxPCXHandler,wxImageHandler)
+
+#if wxUSE_STREAMS
+
+//-----------------------------------------------------------------------------
+// RLE encoding and decoding
//-----------------------------------------------------------------------------
void RLEencode(unsigned char *p, unsigned int size, wxOutputStream& s)
{
data = (unsigned char) *(p++);
- // Up to 63 bytes with the same value can be stored using a
- // single { cont, value } pair.
+ // Up to 63 bytes with the same value can be stored using
+ // a single { cont, value } pair.
//
if ((data == last) && (cont < 63))
{
}
else
{
- // Need to write a 'counter' byte?
- //
+ // need to write a 'counter' byte?
if ((cont > 1) || ((last & 0xC0) == 0xC0))
s.PutC((char) (cont | 0xC0));
}
}
-
- // Write the last one and return;
- //
+ // write the last one and return;
if ((cont > 1) || ((last & 0xC0) == 0xC0))
s.PutC((char) (cont | 0xC0));
void RLEdecode(unsigned char *p, unsigned int size, wxInputStream& s)
{
- unsigned int i, data, cont;
-
// Read 'size' bytes. The PCX official specs say there will be
// a decoding break at the end of each scanline (but not at the
// end of each plane inside a scanline). Only use this function
// to read one or more _complete_ scanlines. Else, more than
// 'size' bytes might be read and the buffer might overflow.
- //
- while (size > 0)
+
+ while (size != 0)
{
- data = (unsigned char)s.GetC();
+ unsigned int data = (unsigned char)s.GetC();
// If ((data & 0xC0) != 0xC0), then the value read is a data
// byte. Else, it is a counter (cont = val & 0x3F) and the
// next byte is the data byte.
- //
+
if ((data & 0xC0) != 0xC0)
{
- *(p++) = data;
+ *(p++) = (unsigned char)data;
size--;
}
else
{
- cont = data & 0x3F;
+ unsigned int cont = data & 0x3F;
+ if (cont > size) // can happen only if the file is malformed
+ break;
data = (unsigned char)s.GetC();
- for (i = 1; i <= cont; i++)
- *(p++) = data;
+ for (unsigned int i = 1; i <= cont; i++)
+ *(p++) = (unsigned char)data;
size -= cont;
}
}
}
-/* PCX header */
+//-----------------------------------------------------------------------------
+// PCX reading and saving
+//-----------------------------------------------------------------------------
+
+// PCX header
#define HDR_MANUFACTURER 0
#define HDR_VERSION 1
#define HDR_ENCODING 2
wxPCX_VERERR = 3 // error in pcx version number
};
+
// ReadPCX:
// Loads a PCX file into the wxImage object pointed by image.
// Returns wxPCX_OK on success, or an error code otherwise
int nplanes; // number of planes
int encoding; // is the image RLE encoded?
int format; // image format (8 bit, 24 bit)
- unsigned int i;
- off_t pos;
+ unsigned int i, j;
// Read PCX header and check the version number (it must
// be at least 5 or higher for 8 bit and 24 bit images).
- //
+
stream.Read(hdr, 128);
if (hdr[HDR_VERSION] < 5) return wxPCX_VERERR;
// Extract all image info from the PCX header.
- //
+
encoding = hdr[HDR_ENCODING];
nplanes = hdr[HDR_NPLANES];
bitsperpixel = hdr[HDR_BITSPERPIXEL];
// Check image format. Currently supported formats are
// 8 bits (8 bpp, 1 plane) and 24 bits (8 bpp, 3 planes).
- //
+
if ((nplanes == 3) && (bitsperpixel == 8))
format = wxPCX_24BIT;
else if ((nplanes == 1) && (bitsperpixel == 8))
else
return wxPCX_INVFORMAT;
- // If the image is of type wxPCX_8BIT, then there is a
- // palette at the end of the file. Read it now before
- // proceeding.
- //
- if (format == wxPCX_8BIT)
- {
- pos = stream.TellI();
- stream.SeekI(-769, wxFromEnd);
-
- if (stream.GetC() != 12)
- return wxPCX_INVFORMAT;
+ // If the image is of type wxPCX_8BIT, then there is
+ // a palette at the end of the image data. If we were
+ // working with a file, we could seek at the end to the
+ // end (SeekI(-769, wxFromEnd) and read the palette
+ // before proceeding. Unfortunately, this would prevent
+ // loading several PCXs in a single stream, so we can't
+ // do it. Thus, 8-bit images will have to be decoded in
+ // two passes: one to read and decode the image data,
+ // and another to replace 'colour indexes' with RGB
+ // values.
- stream.Read(pal, 768);
- stream.SeekI(pos, wxFromStart);
- }
+ // Resize the image and allocate memory for a scanline.
- // Allocate memory for a scanline and resize the image.
- //
image->Create(width, height);
if (!image->Ok())
// Now start reading the file, line by line, and store
// the data in the format required by wxImage.
- //
+
dst = image->GetData();
- for (; height; height--)
+ for (j = height; j; j--)
{
if (encoding)
RLEdecode(p, bytesperline * nplanes, stream);
{
for (i = 0; i < width; i++)
{
- *(dst++) = pal[ 3 * (p[i]) ];
- *(dst++) = pal[ 3 * (p[i]) + 1];
- *(dst++) = pal[ 3 * (p[i]) + 2];
+ // first pass, just store the colour index
+ *dst = p[i];
+ dst += 3;
}
break;
}
free(p);
+ // For 8 bit images, we read the palette, and then do a second
+ // pass replacing indexes with their RGB values;
+
+ if (format == wxPCX_8BIT)
+ {
+ unsigned char index;
+
+ if (stream.GetC() != 12)
+ return wxPCX_INVFORMAT;
+
+ stream.Read(pal, 768);
+
+ p = image->GetData();
+ for (unsigned long k = height * width; k; k--)
+ {
+ index = *p;
+ *(p++) = pal[3 * index];
+ *(p++) = pal[3 * index + 1];
+ *(p++) = pal[3 * index + 2];
+ }
+
+#if wxUSE_PALETTE
+ unsigned char r[256];
+ unsigned char g[256];
+ unsigned char b[256];
+ for (i = 0; i < 256; i++)
+ {
+ r[i] = pal[3*i + 0];
+ g[i] = pal[3*i + 1];
+ b[i] = pal[3*i + 2];
+ }
+ image->SetPalette(wxPalette(256, r, g, b));
+#endif // wxUSE_PALETTE
+ }
+
return wxPCX_OK;
}
// SavePCX:
// Saves a PCX file into the wxImage object pointed by image.
// Returns wxPCX_OK on success, or an error code otherwise
-// (see above for error codes). Currently, always saves images
-// in 24 bit format. XXX
+// (see above for error codes). Will try to save as 8-bit
+// PCX if possible, and then fall back to 24-bit if there
+// are more than 256 different colours.
//
int SavePCX(wxImage *image, wxOutputStream& stream)
{
unsigned char hdr[128]; // PCX header
+ unsigned char pal[768]; // palette for 8 bit images
unsigned char *p; // space to store one scanline
unsigned char *src; // pointer into wxImage data
unsigned int width, height; // size of the image
unsigned int bytesperline; // bytes per line (each plane)
- int nplanes = 3; // number of planes
+ unsigned char nplanes = 3; // number of planes
int format = wxPCX_24BIT; // image format (8 bit, 24 bit)
+ wxImageHistogram histogram; // image histogram
+ unsigned long key; // key in the hashtable
unsigned int i;
-
- /* XXX
- build_palette();
- if (num_of_colors <= 256)
+
+ // See if we can save as 8 bit.
+
+ if (image->CountColours(256) <= 256)
{
+ image->ComputeHistogram(histogram);
format = wxPCX_8BIT;
nplanes = 1;
}
- else
- free_palette();
- */
// Get image dimensions, calculate bytesperline (must be even,
// according to PCX specs) and allocate space for one complete
// scanline.
- //
+
if (!image->Ok())
return wxPCX_INVFORMAT;
width = image->GetWidth();
height = image->GetHeight();
- nplanes = 3; /* 1 for wxPCX_8BIT */
bytesperline = width;
if (bytesperline % 2)
bytesperline++;
// Build header data and write it to the stream. Initially,
// set all bytes to zero (most values default to zero).
- //
+
memset(hdr, 0, sizeof(hdr));
hdr[HDR_MANUFACTURER] = 10;
hdr[HDR_ENCODING] = 1;
hdr[HDR_NPLANES] = nplanes;
hdr[HDR_BITSPERPIXEL] = 8;
- hdr[HDR_BYTESPERLINE] = bytesperline % 256;
- hdr[HDR_BYTESPERLINE + 1] = bytesperline / 256;
- hdr[HDR_XMAX] = (width - 1) % 256;
- hdr[HDR_XMAX + 1] = (width - 1) / 256;
- hdr[HDR_YMAX] = (height - 1) % 256;
- hdr[HDR_YMAX + 1] = (height - 1) / 256;
+ hdr[HDR_BYTESPERLINE] = (unsigned char)(bytesperline % 256);
+ hdr[HDR_BYTESPERLINE + 1] = (unsigned char)(bytesperline / 256);
+ hdr[HDR_XMAX] = (unsigned char)((width - 1) % 256);
+ hdr[HDR_XMAX + 1] = (unsigned char)((width - 1) / 256);
+ hdr[HDR_YMAX] = (unsigned char)((height - 1) % 256);
+ hdr[HDR_YMAX + 1] = (unsigned char)((height - 1) / 256);
hdr[HDR_PALETTEINFO] = 1;
stream.Write(hdr, 128);
// Encode image data line by line and write it to the stream
- //
+
src = image->GetData();
for (; height; height--)
switch (format)
{
case wxPCX_8BIT:
- /* XXX
{
+ unsigned char r, g, b;
+
for (i = 0; i < width; i++)
{
- hash = *(src++) << 24 +
- *(src++) << 16 +
- *(src++) << 8;
+ r = *(src++);
+ g = *(src++);
+ b = *(src++);
+ key = (r << 16) | (g << 8) | b;
- p[i] = palette_lookup(hash);
+ p[i] = (unsigned char)histogram[key].index;
}
break;
}
- */
case wxPCX_24BIT:
{
for (i = 0; i < width; i++)
break;
}
}
-
+
RLEencode(p, bytesperline * nplanes, stream);
}
-
+
free(p);
- /* XXX
+ // For 8 bit images, build the palette and write it to the stream:
if (format == wxPCX_8BIT)
{
+ // zero unused colours
+ memset(pal, 0, sizeof(pal));
+
+ unsigned long index;
+
+ for (wxImageHistogram::iterator entry = histogram.begin();
+ entry != histogram.end(); ++entry )
+ {
+ key = entry->first;
+ index = entry->second.index;
+ pal[3 * index] = (unsigned char)(key >> 16);
+ pal[3 * index + 1] = (unsigned char)(key >> 8);
+ pal[3 * index + 2] = (unsigned char)(key);
+ }
+
stream.PutC(12);
- dump_palette();
+ stream.Write(pal, 768);
}
- */
return wxPCX_OK;
}
-
//-----------------------------------------------------------------------------
// wxPCXHandler
//-----------------------------------------------------------------------------
-#if !USE_SHARED_LIBRARIES
-IMPLEMENT_DYNAMIC_CLASS(wxPCXHandler,wxImageHandler)
-#endif
-
bool wxPCXHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
{
int error;
if (!CanRead(stream))
{
if (verbose)
+ {
wxLogError(_("PCX: this is not a PCX file."));
+ }
- return FALSE;
+ return false;
}
image->Destroy();
{
switch (error)
{
- case wxPCX_INVFORMAT: wxLogError(_("wxPCXHandler: image format unsupported")); break;
- case wxPCX_MEMERR: wxLogError(_("wxPCXHandler: couldn't allocate memory")); break;
- case wxPCX_VERERR: wxLogError(_("wxPCXHandler: version number too low")); break;
- default: wxLogError(_("wxPCXHandler: unknown error !!!"));
+ case wxPCX_INVFORMAT: wxLogError(_("PCX: image format unsupported")); break;
+ case wxPCX_MEMERR: wxLogError(_("PCX: couldn't allocate memory")); break;
+ case wxPCX_VERERR: wxLogError(_("PCX: version number too low")); break;
+ default: wxLogError(_("PCX: unknown error !!!"));
}
}
image->Destroy();
- return FALSE;
+ return false;
}
- return TRUE;
+ return true;
}
bool wxPCXHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
{
switch (error)
{
- case wxPCX_INVFORMAT: wxLogError(_("wxPCXHandler: invalid image")); break;
- case wxPCX_MEMERR: wxLogError(_("wxPCXHandler: couldn't allocate memory")); break;
- default: wxLogError(_("wxPCXHandler: unknown error !!!"));
+ case wxPCX_INVFORMAT: wxLogError(_("PCX: invalid image")); break;
+ case wxPCX_MEMERR: wxLogError(_("PCX: couldn't allocate memory")); break;
+ default: wxLogError(_("PCX: unknown error !!!"));
}
}
}
bool wxPCXHandler::DoCanRead( wxInputStream& stream )
{
- unsigned char c;
-
- c = stream.GetC();
- stream.SeekI(-1, wxFromCurrent);
+ unsigned char c = stream.GetC(); // it's ok to modify the stream position here
+ if ( !stream )
+ return false;
// not very safe, but this is all we can get from PCX header :-(
- return (c == 10);
+ return c == 10;
}
-#endif // wxUSE_STREAMS && wxUSE_PCX
+#endif // wxUSE_STREAMS
+#endif // wxUSE_IMAGE && wxUSE_PCX
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