// Name: 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
#include "wx/object.h"
//-----------------------------------------------------------------------------
-// PCX decoding
+// 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));
// 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)
{
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;
}
-/* 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).
- //
+
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];
+ }
+
+ unsigned char* r = new unsigned char[256];
+ unsigned char* g = new unsigned char[256];
+ unsigned char* b = new unsigned char[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));
+ delete[] r; delete[] g; delete[] b;
+ }
+
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 *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.
- //
- ncolours = image->CountColours(257);
- if (ncolours <= 256)
+ // See if we can save as 8 bit.
+
+ 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
// scanline.
- //
+
if (!image->Ok())
return wxPCX_INVFORMAT;
// 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;
stream.Write(hdr, 128);
// Encode image data line by line and write it to the stream
- //
+
src = image->GetData();
for (; height; height--)
key = (r << 16) | (g << 8) | b;
hnode = (wxHNode *) h.Get(key);
- p[i] = hnode->index;
+ p[i] = (unsigned char)hnode->index;
}
break;
}
break;
}
}
-
+
RLEencode(p, bytesperline * nplanes, stream);
}
-
+
free(p);
// For 8 bit images, build the palette and write it to the stream
- //
+
if (format == wxPCX_8BIT)
{
wxNode *node;
{
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();
{
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 !!!"));
}
}
}
projects / wxWidgets.git / blobdiff