+ // Clear hash table and send Clear to make sure the decoder does the same.
+ ClearHashTable();
+
+ return wxGIFHandler_WriteByte(stream, (wxUint8)bpp)
+ && CompressOutput(stream, m_clearCode);
+}
+
+bool wxGIFHandler::CompressLine(wxOutputStream *stream,
+ const wxUint8 *line, int lineLen)
+{
+ int i = 0, crntCode, newCode;
+ unsigned long newKey;
+ wxUint8 pixel;
+ if (m_crntCode == FIRST_CODE) // It's first time!
+ crntCode = line[i++];
+ else
+ crntCode = m_crntCode; // Get last code in compression.
+
+ while (i < lineLen)
+ {
+ // Decode lineLen items.
+ pixel = line[i++]; // Get next pixel from stream.
+ // Form a new unique key to search hash table for the code combines
+ // crntCode as Prefix string with Pixel as postfix char.
+ newKey = (((unsigned long) crntCode) << 8) + pixel;
+ if ((newCode = ExistsHashTable(newKey)) >= 0)
+ {
+ // This Key is already there, or the string is old one, so
+ // simply take new code as our crntCode:
+ crntCode = newCode;
+ }
+ else
+ {
+ // Put it in hash table, output the prefix code, and make our
+ // crntCode equal to Pixel.
+ if (!CompressOutput(stream, crntCode))
+ {
+ return false;
+ }
+
+ crntCode = pixel;
+
+ // If however the HashTable is full, we send a clear first and
+ // Clear the hash table.
+ if (m_runningCode >= LZ_MAX_CODE)
+ {
+ // Time to do some clearance:
+ if (!CompressOutput(stream, m_clearCode))
+ {
+ return false;
+ }
+
+ m_runningCode = m_EOFCode + 1;
+ m_runningBits = 8 + 1;
+ m_maxCode1 = 1 << m_runningBits;
+ ClearHashTable();
+ }
+ else
+ {
+ // Put this unique key with its relative Code in hash table:
+ InsertHashTable(newKey, m_runningCode++);
+ }
+ }
+ }
+ // Preserve the current state of the compression algorithm:
+ m_crntCode = crntCode;
+ if (m_pixelCount == 0)
+ {
+ // We are done - output last Code and flush output buffers:
+ if (!CompressOutput(stream, crntCode)
+ || !CompressOutput(stream, m_EOFCode)
+ || !CompressOutput(stream, FLUSH_OUTPUT))
+ {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+#endif // wxUSE_STREAMS
+
+bool wxGIFHandler::InitHashTable()
+{
+ if (!m_hashTable)
+ {
+ m_hashTable = new GifHashTableType();
+ }
+
+ if (!m_hashTable)
+ {
+ return false;
+ }
+
+ ClearHashTable();
+
+ return true;
+}
+
+void wxGIFHandler::ClearHashTable()
+{
+ int index = HT_SIZE;
+ wxUint32 *HTable = m_hashTable->HTable;
+
+ while (--index>=0)
+ {
+ HTable[index] = 0xfffffffful;
+ }
+}
+
+void wxGIFHandler::InsertHashTable(unsigned long key, int code)
+{
+ int hKey = wxGIFHandler_KeyItem(key);
+ wxUint32 *HTable = m_hashTable->HTable;
+
+ while (HT_GET_KEY(HTable[hKey]) != 0xFFFFFL)
+ {
+ hKey = (hKey + 1) & HT_KEY_MASK;
+ }
+ HTable[hKey] = HT_PUT_KEY(key) | HT_PUT_CODE(code);
+}
+
+
+int wxGIFHandler::ExistsHashTable(unsigned long key)
+{
+ int hKey = wxGIFHandler_KeyItem(key);
+ wxUint32 *HTable = m_hashTable->HTable, HTKey;
+
+ while ((HTKey = HT_GET_KEY(HTable[hKey])) != 0xFFFFFL)
+ {
+ if (key == HTKey)
+ {
+ return HT_GET_CODE(HTable[hKey]);
+ }
+ hKey = (hKey + 1) & HT_KEY_MASK;
+ }
+ return -1;
+}
+
+// ---------------------------------------------------------------------------
+// implementation of global private functions
+// ---------------------------------------------------------------------------
+
+int wxGIFHandler_KeyItem(unsigned long item)
+{
+ return ((item >> 12) ^ item) & HT_KEY_MASK;
+}
+
+#if wxUSE_STREAMS
+
+int wxGIFHandler_BitSize(int n)
+{
+ int i;
+ for (i = 1; i <= 8; i++)
+ {
+ if ((1 << i) >= n)
+ {
+ break;
+ }
+ }
+ return i;
+}
+
+#if wxUSE_PALETTE
+bool wxGIFHandler_GetPalette(const wxImage& image,
+ wxRGB *pal, int *pPalCount, int *pMaskIndex)
+{
+ if (!image.HasPalette())
+ {
+ return false;
+ }
+
+ const wxPalette& palette = image.GetPalette();
+ int palCount = palette.GetColoursCount();
+
+ for (int i = 0; i < palCount; ++i)
+ {
+ if (!palette.GetRGB(i, &pal[i].red, &pal[i].green, &pal[i].blue))
+ {
+ break;
+ }
+ }
+ if (image.HasMask())
+ {
+ wxRGB mask;
+
+ mask.red = image.GetMaskRed();
+ mask.green = image.GetMaskGreen();
+ mask.blue = image.GetMaskBlue();
+ *pMaskIndex = wxGIFHandler_PaletteFind(mask, pal, palCount);
+ if ( (*pMaskIndex == wxNOT_FOUND) && (palCount < 256))
+ {
+ *pMaskIndex = palCount;
+ pal[palCount++] = mask;
+ }
+ }
+ else
+ {
+ *pMaskIndex = wxNOT_FOUND;
+ }
+ *pPalCount = palCount;
+
+ return true;
+}
+#endif // wxUSE_PALETTE
+
+int wxGIFHandler_PaletteFind(const wxRGB& clr, const wxRGB *array, int count)
+{
+ for (int i = 0; i < count; i++)
+ {
+ if ( (clr.red == array[i].red)
+ && (clr.green == array[i].green)
+ && (clr.blue == array[i].blue))
+ {
+ return i;
+ }
+ }
+
+ return wxNOT_FOUND;
+}
+
+bool wxGIFHandler_Write(wxOutputStream *stream, const void *buf, size_t len)
+{
+ return (len == stream->Write(buf, len).LastWrite());
+}
+
+bool wxGIFHandler_WriteByte(wxOutputStream *stream, wxUint8 byte)
+{
+ return wxGIFHandler_Write(stream, &byte, sizeof(byte));
+}
+
+bool wxGIFHandler_WriteWord(wxOutputStream *stream, wxUint16 word)
+{
+ wxUint8 buf[2];
+
+ buf[0] = word & 0xff;
+ buf[1] = (word >> 8) & 0xff;
+ return wxGIFHandler_Write(stream, &word, sizeof(word));
+}
+
+bool wxGIFHandler_WriteHeader(wxOutputStream *stream, int width, int height,
+ bool loop, const wxRGB *pal, int palCount)
+{
+ const int bpp = wxGIFHandler_BitSize(palCount);
+ wxUint8 buf[3];
+
+ bool ok = wxGIFHandler_Write(stream, GIF89_HDR, sizeof(GIF89_HDR)-1)
+ && wxGIFHandler_WriteWord(stream, (wxUint16) width)
+ && wxGIFHandler_WriteWord(stream, (wxUint16) height);
+
+ buf[0] = 0x80;
+ buf[0] |=(bpp - 1) << 5;
+ buf[0] |=(bpp - 1);
+ buf[1] = 0; // background color == entry 0
+ buf[2] = 0; // aspect ratio 1:1
+ ok = ok && wxGIFHandler_Write(stream, buf, sizeof(buf))
+ && wxGIFHandler_WritePalette(stream, pal, palCount, bpp);
+
+ if (loop)
+ {
+ ok = ok && wxGIFHandler_WriteLoop(stream);
+ }
+
+ return ok;
+}
+
+bool wxGIFHandler_WriteRect(wxOutputStream *stream, int width, int height)
+{
+ return wxGIFHandler_WriteWord(stream, 0) // left
+ && wxGIFHandler_WriteWord(stream, 0) // top
+ && wxGIFHandler_WriteWord(stream, (wxUint16) width)
+ && wxGIFHandler_WriteWord(stream, (wxUint16) height);
+}
+
+#if wxUSE_PALETTE
+bool wxGIFHandler_WriteTerm(wxOutputStream *stream)
+{
+ return wxGIFHandler_WriteByte(stream, GIF_MARKER_ENDOFDATA);
+}
projects / wxWidgets.git / blobdiff