// Purpose: wxImage PCX handler
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
// Version: 1.00
-// Last rev: 1999/08/24
-// Copyright: (c) Guillermo Rodriguez Garcia
+// CVS-ID: $Id$
+// Copyright: (c) 1999 Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#pragma hdrstop
#endif
+#ifndef WX_PRECOMP
+# include "wx/defs.h"
+#endif
+
+#if wxUSE_STREAMS && wxUSE_PCX
+
#include "wx/image.h"
#include "wx/wfstream.h"
#include "wx/module.h"
#include "wx/log.h"
+
+//-----------------------------------------------------------------------------
+// PCX decoding
+//-----------------------------------------------------------------------------
+
+void RLEencode(unsigned char *WXUNUSED(p), unsigned int WXUNUSED(size), wxOutputStream& WXUNUSED(s))
+{
+}
+
+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)
+ {
+ 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;
+ size--;
+ }
+ else
+ {
+ cont = data & 0x3F;
+ data = (unsigned char)s.GetC();
+ for (i = 1; i <= cont; i++)
+ *(p++) = data;
+ size -= cont;
+ }
+ }
+}
+
+
+/* PCX header */
+#define HDR_VERSION 1
+#define HDR_ENCODING 2
+#define HDR_BITSPERPIXEL 3
+#define HDR_XMIN 4
+#define HDR_YMIN 6
+#define HDR_XMAX 8
+#define HDR_YMAX 10
+#define HDR_NPLANES 65
+#define HDR_BYTESPERLINE 66
+
+/* image formats */
+#define IMAGE_8BIT 0 // 8 bpp, 1 plane (8 bit)
+#define IMAGE_24BIT 1 // 8 bpp, 3 planes (24 bit)
+
+/* error codes */
+#define E_OK 0 // everything was OK
+#define E_FORMATO 1 // error in pcx file format
+#define E_MEMORIA 2 // error allocating memory
+#define E_VERSION 3 // error in pcx version number
+
+
+// ReadPCX:
+// Loads a PCX file into the wxImage object pointed by image.
+// Returns E_OK on success, or an error code otherwise (see
+// above for error codes)
+//
+int ReadPCX(wxImage *image, wxInputStream& 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 *dst; // pointer into wxImage data
+ unsigned int width, height; // size of the image
+ unsigned int bytesperline; // bytes per line (each plane)
+ int bitsperpixel; // bits per pixel (each plane)
+ 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;
+
+ // 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 E_VERSION;
+
+ // Extract all image info from the PCX header.
+ //
+ encoding = hdr[HDR_ENCODING];
+ nplanes = hdr[HDR_NPLANES];
+ bitsperpixel = hdr[HDR_BITSPERPIXEL];
+ bytesperline = hdr[HDR_BYTESPERLINE] + 256 * hdr[HDR_BYTESPERLINE + 1];
+ width = (hdr[HDR_XMAX] + 256 * hdr[HDR_XMAX + 1]) -
+ (hdr[HDR_XMIN] + 256 * hdr[HDR_XMIN + 1]) + 1;
+ height = (hdr[HDR_YMAX] + 256 * hdr[HDR_YMAX + 1]) -
+ (hdr[HDR_YMIN] + 256 * hdr[HDR_YMIN + 1]) + 1;
+
+ // 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 = IMAGE_24BIT;
+ else if ((nplanes == 1) && (bitsperpixel == 8))
+ format = IMAGE_8BIT;
+ else
+ return E_FORMATO;
+
+ // If the image is of type IMAGE_8BIT, then there is a
+ // palette at the end of the file. Read it now before
+ // proceeding.
+ //
+ if (format == IMAGE_8BIT)
+ {
+ pos = stream.TellI();
+ stream.SeekI(-769, wxFromEnd);
+
+ if (stream.GetC() != 12)
+ return E_FORMATO;
+
+ stream.Read(pal, 768);
+ stream.SeekI(pos, wxFromStart);
+ }
+
+ // Allocate memory for a scanline and resize the image.
+ //
+ image->Create(width, height);
+
+ if (!image->Ok())
+ return E_MEMORIA;
+
+ if ((p = (unsigned char *) malloc(bytesperline * nplanes)) == NULL)
+ return E_MEMORIA;
+
+ // Now start reading the file, line by line, and store
+ // the data in the format required by wxImage.
+ //
+ dst = image->GetData();
+
+ for (; height; height--)
+ {
+ if (encoding)
+ RLEdecode(p, bytesperline * nplanes, stream);
+ else
+ stream.Read(p, bytesperline * nplanes);
+
+ switch (format)
+ {
+ case IMAGE_8BIT:
+ {
+ for (i = 0; i < width; i++)
+ {
+ *(dst++) = pal[ 3 * (p[i]) ];
+ *(dst++) = pal[ 3 * (p[i]) + 1];
+ *(dst++) = pal[ 3 * (p[i]) + 2];
+ }
+ break;
+ }
+ case IMAGE_24BIT:
+ {
+ for (i = 0; i < width; i++)
+ {
+ *(dst++) = p[i];
+ *(dst++) = p[i + bytesperline];
+ *(dst++) = p[i + 2 * bytesperline];
+ }
+ break;
+ }
+ }
+ }
+
+ free(p);
+
+ return E_OK;
+}
+
+
//-----------------------------------------------------------------------------
// wxPCXHandler
//-----------------------------------------------------------------------------
IMPLEMENT_DYNAMIC_CLASS(wxPCXHandler,wxImageHandler)
#endif
-#if wxUSE_STREAMS
-
bool wxPCXHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose )
{
+ int error;
+
+ if (!CanRead(stream))
+ {
+ if (verbose)
+ wxLogError(wxT("wxPCXHandler: this is not a PCX file"));
+
+ return FALSE;
+ }
+
image->Destroy();
- if (verbose)
- wxLogDebug(_T("wxPCXHandler::LoadFile still not implemented"));
+ if ((error = ReadPCX(image, stream)) != E_OK)
+ {
+ if (verbose)
+ {
+ switch (error)
+ {
+ case E_FORMATO: wxLogError(wxT("wxPCXHandler: image format unsupported")); break;
+ case E_MEMORIA: wxLogError(wxT("wxPCXHandler: couldn't allocate memory")); break;
+ case E_VERSION: wxLogError(wxT("wxPCXHandler: version number too low")); break;
+ default: wxLogError(wxT("wxPCXHandler: unknown error !!!"));
+ }
+ }
+ image->Destroy();
+ return FALSE;
+ }
- return FALSE;
+ return TRUE;
}
-bool wxPCXHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
+bool wxPCXHandler::SaveFile( wxImage *WXUNUSED(image), wxOutputStream& WXUNUSED(stream), bool verbose )
{
if (verbose)
- wxLogDebug(_T("wxPCXHandler::SaveFile still not implemented"));
+ wxLogError(wxT("wxPCXHandler::SaveFile still not implemented"));
return FALSE;
}
-bool wxPCXHandler::CanRead( wxInputStream& stream )
+bool wxPCXHandler::DoCanRead( wxInputStream& stream )
{
- return FALSE;
-}
+ unsigned char c;
+ off_t pos;
+ pos = stream.TellI();
+ stream.SeekI(0, wxFromStart);
+ c = stream.GetC();
+ stream.SeekI(pos, wxFromStart);
-#endif // wxUSE_STREAMS
+ // not very safe, but this is all we can get from PCX header :-(
+ return (c == 10);
+}
+#endif // wxUSE_STREAMS && wxUSE_PCX
projects / wxWidgets.git / blobdiff