// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-/*
- We don't put pragma implement in this file because it is already present in
- src/common/image.cpp
-*/
+#ifdef __GNUG__
+#pragma implementation "imagpcx.h"
+#endif
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#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/object.h"
//-----------------------------------------------------------------------------
-// PCX decoding
+// RLE encoding and decoding
//-----------------------------------------------------------------------------
void RLEencode(unsigned char *p, unsigned int size, wxOutputStream& s)
}
}
-
// Write the last one and return;
//
if ((cont > 1) || ((last & 0xC0) == 0xC0))
}
-/* PCX header */
+//-----------------------------------------------------------------------------
+// PCX reading and saving
+//-----------------------------------------------------------------------------
+
+// PCX header
#define HDR_MANUFACTURER 0
#define HDR_VERSION 1
#define HDR_ENCODING 2
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).
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 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.
- if (stream.GetC() != 12)
- return wxPCX_INVFORMAT;
- stream.Read(pal, 768);
- stream.SeekI(pos, wxFromStart);
- }
-
- // Allocate memory for a scanline and resize the image.
+ // Resize the image and allocate memory for a scanline.
//
image->Create(width, height);
//
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];
+ }
+ }
+
return wxPCX_OK;
}
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; // number of planes
- int format; // image format (8 bit, 24 bit)
+ int nplanes = 3; // number of planes
+ int format = wxPCX_24BIT; // image format (8 bit, 24 bit)
wxHashTable h(wxKEY_INTEGER); // image histogram
- unsigned long ncolours; // num. of different colours
unsigned long key; // key in the hashtable
unsigned int i;
- // Get the histogram of the image, and decide whether to save
- // as 8 bit or 24 bit, according to the number of colours.
+ // See if we can save as 8 bit.
//
- ncolours = image->CountColours(257);
-
- if (ncolours <= 256)
+ if (image->CountColours(256) <= 256)
{
image->ComputeHistogram(h);
format = wxPCX_8BIT;
nplanes = 1;
}
- else
- {
- format = wxPCX_24BIT;
- nplanes = 3;
- }
// Get image dimensions, calculate bytesperline (must be even,
// according to PCX specs) and allocate space for one complete
break;
}
}
-
+
RLEencode(p, bytesperline * nplanes, stream);
}