diff --git a/src/common/imagpcx.cpp b/src/common/imagpcx.cpp index c8420edf10..d28a456f6a 100644 --- a/src/common/imagpcx.cpp +++ b/src/common/imagpcx.cpp @@ -168,8 +168,7 @@ int ReadPCX(wxImage *image, wxInputStream& stream) 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). @@ -199,23 +198,19 @@ int ReadPCX(wxImage *image, wxInputStream& stream) 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); @@ -230,7 +225,7 @@ int ReadPCX(wxImage *image, wxInputStream& stream) // dst = image->GetData(); - for (; height; height--) + for (j = height; j; j--) { if (encoding) RLEdecode(p, bytesperline * nplanes, stream); @@ -243,9 +238,9 @@ int ReadPCX(wxImage *image, wxInputStream& 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; } @@ -264,6 +259,28 @@ int ReadPCX(wxImage *image, wxInputStream& stream) 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; }