+//-----------------------------------------------------------------------------
+// RLE encoding and decoding
+//-----------------------------------------------------------------------------
+
+void RLEencode(unsigned char *p, unsigned int size, wxOutputStream& s)
+{
+ unsigned int data, last, cont;
+
+ // Write 'size' bytes. The PCX official specs say there will be
+ // a decoding break at the end of each scanline, so in order to
+ // force this decoding break use this function to write, at most,
+ // _one_ complete scanline at a time.
+
+ last = (unsigned char) *(p++);
+ cont = 1;
+ size--;
+
+ while (size-- > 0)
+ {
+ data = (unsigned char) *(p++);
+
+ // Up to 63 bytes with the same value can be stored using
+ // a single { cont, value } pair.
+ //
+ if ((data == last) && (cont < 63))
+ {
+ cont++;
+ }
+ else
+ {
+ // need to write a 'counter' byte?
+ if ((cont > 1) || ((last & 0xC0) == 0xC0))
+ s.PutC((char) (cont | 0xC0));
+
+ s.PutC((char) last);
+ last = data;
+ cont = 1;
+ }
+ }
+
+ // write the last one and return;
+ if ((cont > 1) || ((last & 0xC0) == 0xC0))
+ s.PutC((char) (cont | 0xC0));
+
+ s.PutC((char) last);
+}
+
+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++) = (unsigned char)data;
+ size--;
+ }
+ else
+ {
+ cont = data & 0x3F;
+ data = (unsigned char)s.GetC();
+ for (i = 1; i <= cont; i++)
+ *(p++) = (unsigned char)data;
+ size -= cont;
+ }
+ }
+}
+
+
+//-----------------------------------------------------------------------------
+// PCX reading and saving
+//-----------------------------------------------------------------------------
+
+// PCX header
+#define HDR_MANUFACTURER 0
+#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
+#define HDR_PALETTEINFO 68
+
+// image formats
+enum {
+ wxPCX_8BIT, // 8 bpp, 1 plane (8 bit)
+ wxPCX_24BIT // 8 bpp, 3 planes (24 bit)
+};
+
+// error codes
+enum {
+ wxPCX_OK = 0, // everything was OK
+ wxPCX_INVFORMAT = 1, // error in pcx file format
+ wxPCX_MEMERR = 2, // error allocating memory
+ 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
+// (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, 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];
+ 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 = wxPCX_24BIT;
+ else if ((nplanes == 1) && (bitsperpixel == 8))
+ format = wxPCX_8BIT;
+ else
+ 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.
+
+ // Resize the image and allocate memory for a scanline.
+
+ image->Create(width, height);
+
+ if (!image->Ok())
+ return wxPCX_MEMERR;
+
+ if ((p = (unsigned char *) malloc(bytesperline * nplanes)) == NULL)
+ return wxPCX_MEMERR;
+
+ // Now start reading the file, line by line, and store
+ // the data in the format required by wxImage.
+
+ dst = image->GetData();
+
+ for (j = height; j; j--)
+ {
+ if (encoding)
+ RLEdecode(p, bytesperline * nplanes, stream);
+ else
+ stream.Read(p, bytesperline * nplanes);
+
+ switch (format)
+ {
+ case wxPCX_8BIT:
+ {
+ for (i = 0; i < width; i++)
+ {
+ // first pass, just store the colour index
+ *dst = p[i];
+ dst += 3;
+ }
+ break;
+ }
+ case wxPCX_24BIT:
+ {
+ for (i = 0; i < width; i++)
+ {
+ *(dst++) = p[i];
+ *(dst++) = p[i + bytesperline];
+ *(dst++) = p[i + 2 * bytesperline];
+ }
+ 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). 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
+ int format = wxPCX_24BIT; // image format (8 bit, 24 bit)
+ wxImageHistogram histogram; // image histogram
+ unsigned long key; // key in the hashtable
+ unsigned int i;
+
+ // See if we can save as 8 bit.
+
+ if (image->CountColours(256) <= 256)
+ {
+ image->ComputeHistogram(histogram);
+ format = wxPCX_8BIT;
+ nplanes = 1;
+ }
+
+ // 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();
+ bytesperline = width;
+ if (bytesperline % 2)
+ bytesperline++;
+
+ if ((p = (unsigned char *) malloc(bytesperline * nplanes)) == NULL)
+ return wxPCX_MEMERR;
+
+ // 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_VERSION] = 5;
+ hdr[HDR_ENCODING] = 1;
+ hdr[HDR_NPLANES] = nplanes;
+ hdr[HDR_BITSPERPIXEL] = 8;
+ 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:
+ {
+ unsigned char r, g, b;
+
+ for (i = 0; i < width; i++)
+ {
+ r = *(src++);
+ g = *(src++);
+ b = *(src++);
+ key = (r << 16) | (g << 8) | b;
+
+ p[i] = (unsigned char)histogram[key].index;
+ }
+ break;
+ }
+ case wxPCX_24BIT:
+ {
+ for (i = 0; i < width; i++)
+ {
+ p[i] = *(src++);
+ p[i + bytesperline] = *(src++);
+ p[i + 2 * bytesperline] = *(src++);
+ }
+ 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)
+ {
+ // 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);
+ stream.Write(pal, 768);
+ }
+
+ return wxPCX_OK;
+}
+
+//-----------------------------------------------------------------------------
+// wxPCXHandler
+//-----------------------------------------------------------------------------
+
+bool wxPCXHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
projects / wxWidgets.git / blobdiff