Exemplo n.º 1
0
        public int ScriptShape(string inChars, int charPos, int length, SCRIPT_ITEM[] items, OPENTYPE_TAG[] scriptTags, int itemsCount, IntPtr hWnd, string faceName, int fontHeight, out ushort[] logClust, out SCRIPT_CHARPROP[] charProps, out ushort[] glyphs, out SCRIPT_GLYPHPROP[] glyphProps)
        {
            if (string.IsNullOrEmpty(inChars))
            {
                throw new ArgumentException("inChars");
            }
            if (items == null || items.Length <= 0)
            {
                throw new ArgumentException("items");
            }
            if (itemsCount >= items.Length)
            {
                throw new ArgumentException("itemsCount");
            }
            if (charPos < 0)
            {
                throw new ArgumentException("charPos");
            }
            if (charPos >= inChars.Length)
            {
                throw new ArgumentException("charPos");
            }
            if (length <= 0)
            {
                throw new ArgumentException("length");
            }
            if (charPos + length > inChars.Length)
            {
                throw new ArgumentOutOfRangeException("length");
            }
            if (string.IsNullOrEmpty(faceName))
            {
                throw new ArgumentException("faceName");
            }
            if (fontHeight <= 0)
            {
                throw new ArgumentException("fontHeight");
            }
            int itemIndex;

            for (itemIndex = 0; itemIndex < itemsCount - 1; itemIndex++)
            {
                if (items[itemIndex].iCharPos <= charPos)
                {
                    if (items[itemIndex + 1].iCharPos >= charPos + length)
                    {
                        break;
                    }
                }
            }
            if (itemIndex == itemsCount - 1)
            {
                if (items[itemIndex].iCharPos > charPos)
                {
                    throw new ArgumentOutOfRangeException("length");
                }
            }
            SCRIPT_ANALYSIS psa        = items[itemIndex].a;
            string          shapeChars = inChars.Substring(charPos, length);
            OPENTYPE_TAG    tagScript  = scriptTags[itemIndex];
            OPENTYPE_TAG    tagLangSys = new OPENTYPE_TAG('\0', '\0', '\0', '\0');

            int[] rangeChars = new int[]
            {
                length
            };
            logClust   = new ushort[length];
            charProps  = new SCRIPT_CHARPROP[length];
            glyphs     = new ushort[length];
            glyphProps = new SCRIPT_GLYPHPROP[length];
            for (int index = 0; index < length; index++)
            {
                glyphProps[index] = default(SCRIPT_GLYPHPROP);
                logClust[index]   = 0;
                charProps[index]  = default(SCRIPT_CHARPROP);
                glyphs[index]     = 0;
            }
            int pcGlyphs = 0;

            OPENTYPE_FEATURE_RECORD[] arRecord   = new OPENTYPE_FEATURE_RECORD[1];
            OPENTYPE_FEATURE_RECORD   potfRecord = default(OPENTYPE_FEATURE_RECORD);

            arRecord[0]           = potfRecord;
            potfRecord.tagFeature = new OPENTYPE_TAG('v', 'e', 'r', 't');
            potfRecord.lParameter = 1u;
            TEXTRANGE_PROPERTIES[] arRangeProperty = new TEXTRANGE_PROPERTIES[1];
            TEXTRANGE_PROPERTIES   rpRangeProperty = default(TEXTRANGE_PROPERTIES);

            arRangeProperty[0]          = rpRangeProperty;
            rpRangeProperty.cotfRecords = 1;
            int    cRanges     = 1;
            IntPtr arRecordPtr = Marshal.AllocHGlobal(Marshal.SizeOf(potfRecord));

            Marshal.StructureToPtr(potfRecord, arRecordPtr, false);
            IntPtr arRangePtr = Marshal.AllocHGlobal(Marshal.SizeOf(rpRangeProperty));

            rpRangeProperty.potfRecords = arRecordPtr;
            Marshal.StructureToPtr(rpRangeProperty, arRangePtr, false);
            IntPtr hDC  = User32.GetDC(hWnd);
            IntPtr font = Gdi32.CreateFontIndirect(new LOGFONT
            {
                lfCharSet  = FontCharSet.DEFAULT_CHARSET,
                lfHeight   = fontHeight,
                lfFaceName = faceName
            });
            IntPtr oldFont = Gdi32.SelectObject(hDC, font);
            int    hresult = Usp10.ScriptShapeOpenType(hDC, ref this._psc, ref psa, tagScript, tagLangSys, rangeChars, ref arRangePtr, cRanges, shapeChars, length, length, logClust, charProps, glyphs, glyphProps, ref pcGlyphs);

            Gdi32.SelectObject(hDC, oldFont);
            Gdi32.DeleteObject(font);
            User32.ReleaseDC(hWnd, hDC);
            Marshal.FreeHGlobal(arRecordPtr);
            Marshal.FreeHGlobal(arRangePtr);
            Marshal.ThrowExceptionForHR(hresult);
            return(pcGlyphs);
        }
            // This article provides a real-world tutorial of how to actually use the API, including
            // a discussion of many gotchas not identified in the MSDN documentation.
            // http://www.catch22.net/tuts/uniscribe-mysteries
            // http://www.catch22.net/tuts/more-uniscribe-mysteries
            // http://www.catch22.net/tuts/drawing-styled-text-uniscribe
            // From the developer of Google Chrome's uniscribe client:
            // https://maxradi.us/documents/uniscribe/
            // Arabic embedded (RTL) example:
            // http://blogs.msdn.com/b/vsarabic/archive/2011/08/21/text-rendering.aspx
            // Devanagari example:
            // http://www.omniglot.com/language/articles/devanagari.htm
            // UTF16 non-zero plane exahere:
            // https://en.wikipedia.org/wiki/UTF-16#Examples
            // http://www.i18nguy.com/unicode-example-plane1.html
            // "Displaying Text with Uniscribe"
            // https://msdn.microsoft.com/en-us/library/windows/desktop/dd317792%28v=vs.85%29.aspx
            internal static TextItems AnalyzeText(
                TextServiceUniscribe service,
                IntPtr hdc,
                IntPtr hText,
                FontRunInfo[] fontRuns)
            {
                TextItems o = new TextItems(service);
                try
                {

                    o.fontRuns = fontRuns;
                    for (int i = 0; i < fontRuns.Length; i++)
                    {
                        o.count += fontRuns[i].count;
                        o.lineHeight = Math.Max(o.lineHeight, fontRuns[i].fontHeight);
                    }
                    if (o.count == 0)
                    {
                        return o;
                    }

                    int hr;

                    // Lay Out Text Using Uniscribe

                    // 1. Call ScriptRecordDigitSubstitution only when starting or when receiving a WM_SETTINGCHANGE message.

                    // 2. (Optional) Call ScriptIsComplex to determine if the paragraph requires complex processing.
                    hr = ScriptIsComplex(
                        hText,
                        o.count,
                        ScriptIsComplexFlags.SIC_ASCIIDIGIT | ScriptIsComplexFlags.SIC_COMPLEX);
                    if (hr < 0)
                    {
                        Marshal.ThrowExceptionForHR(hr);
                    }
                    // Optional: if S_FALSE (1) is returned, one can fall back to TextRenderer and simplified hit testing

                    // 3. (Optional) If using Uniscribe to handle bidirectional text and/or digit substitution, call
                    // ScriptApplyDigitSubstitution to prepare the SCRIPT_CONTROL and SCRIPT_STATE structures as inputs
                    // to ScriptItemize. If skipping this step, but still requiring digit substitution, substitute
                    // national digits for Unicode U+0030 through U+0039 (European digits). For information about digit
                    // substitution, see Digit Shapes.
                    hr = ScriptApplyDigitSubstitution(
                        IntPtr.Zero,
                        out o.sControl,
                        out o.sState);
                    if (hr < 0)
                    {
                        Marshal.ThrowExceptionForHR(hr);
                    }

                    // 4. Call ScriptItemize to divide the paragraph into items. If not using Uniscribe for digit
                    // substitution and the bidirectional order is known, for example, because of the keyboard layout
                    // used to enter the character, call ScriptItemize. In the call, provide null pointers for the
                    // SCRIPT_CONTROL and SCRIPT_STATE structures. This technique generates items by use of the shaping
                    // engine only, and the items can be reordered using the engine information.
                    // Note: Typically, applications that work only with left-to-right scripts and without any digit
                    // substitution should pass null pointers for the SCRIPT_CONTROL and SCRIPT_STATE structures.

                    {
                        int cMaxItems = 8;
                        SCRIPT_ITEM[] sItems;
                        OPENTYPE_TAG[] sTags;
                        while (true)
                        {
                            sItems = new SCRIPT_ITEM[cMaxItems + 1]; // method adds terminator;
                            sTags = new OPENTYPE_TAG[cMaxItems];
                            hr = ScriptItemizeOpenType(
                                hText,
                                o.count,
                                cMaxItems,
                                ref o.sControl,
                                ref o.sState,
                                sItems,
                                sTags,
                                out o.cItems);
                            if (hr == E_OUTOFMEMORY)
                            {
                                cMaxItems *= 2;
                                continue;
                            }
                            if (hr < 0)
                            {
                                Marshal.ThrowExceptionForHR(hr);
                            }
                            break;
                        }

                        o.sItems = sItems;
                        o.sTags = sTags;
                    }

                    // 5. Merge the item information with the run information to produce ranges.
                    {
                        int fontRunOffset = 0;
                        int f = 0;
                        int i = 0;
                        while ((f < o.fontRuns.Length) && (i < o.cItems))
                        {
                            if (fontRunOffset + o.fontRuns[f].count > o.sItems[i + 1].iCharPos)
                            {
                                // run is longer - current item remains intact; advance to next
                                i++;
                                continue;
                            }
                            else if (fontRunOffset + o.fontRuns[f].count < o.sItems[i + 1].iCharPos)
                            {
                                // item too long - split

                                Array.Resize(ref o.sItems, o.cItems + 1 + 1);
                                Array.Copy(o.sItems, i, o.sItems, i + 1, o.sItems.Length - (i + 1));
                                Array.Resize(ref o.sTags, o.cItems + 1);
                                Array.Copy(o.sTags, i, o.sTags, i + 1, o.sTags.Length - (i + 1));
                                o.cItems++;

                                o.sItems[i + 1].iCharPos = fontRunOffset + o.fontRuns[f].count;
                            }
                            Debug.Assert(fontRunOffset + o.fontRuns[f].count == o.sItems[i + 1].iCharPos);
                            fontRunOffset += o.fontRuns[f].count;
                            f++;
                            i++;
                        }
                        Debug.Assert(fontRunOffset == o.count);
                        Debug.Assert(o.sItems[o.cItems].iCharPos == o.count);
                    }

                    // 6. Call ScriptShape to identify clusters and generate glyphs.
                    o.sItemsExtra = new ItemInfo[o.cItems];
                    o.logAttrs = new SCRIPT_LOGATTR[o.count];
                    for (int i = 0; i < o.cItems; i++)
                    {
                        int start = o.sItems[i].iCharPos;
                        int length = o.sItems[i + 1].iCharPos - start;

                        Font font = null;
                        for (int f = 0, pos = 0; f < o.fontRuns.Length; pos += o.fontRuns[f].count, f++)
                        {
                            font = o.fontRuns[f].font;
                            if (pos < start + length)
                            {
                                break;
                            }
                        }

                        int cMaxGlyphs = (3 * o.count / 2) + 16; // recommended starting value
                        short[] glyphs;
                        short[] logicalClusters;
                        SCRIPT_VISATTR[] visAttrs; // superceded by glyphProps
                        SCRIPT_GLYPHPROP[] glyphProps;
                        int cGlyphs;
                        int fallbackLevel = 0;
                        Font fallbackFont = null;
                        SCRIPT_CHARPROP[] charProps = new SCRIPT_CHARPROP[length];
                        while (true)
                        {
                            glyphs = new short[cMaxGlyphs];
                            logicalClusters = new short[cMaxGlyphs];
                            visAttrs = new SCRIPT_VISATTR[cMaxGlyphs];
                            glyphProps = new SCRIPT_GLYPHPROP[cMaxGlyphs];

                            bool needFallback = false;
                            int fontCacheIndex = service.FontCacheIndex(font);

                            GDIFont gdiFont;
                            if (!service.fontToHFont.TryGetValue(font, out gdiFont))
                            {
                                gdiFont = new GDIFont(font);
                                service.fontToHFont.Add(font, gdiFont);
                            }
                            GDI.SelectObject(hdc, gdiFont);

                #if false // choose old or OpenType API
                        hr = ScriptShape(
                            hdc,
                            ref service.caches[fontCacheIndex].cache,
                            new IntPtr(hText.ToInt64() + start * 2),
                            length,
                            cMaxGlyphs,
                            ref o.sItems[i].a,
                            glyphs,
                            logicalClusters,
                            visAttrs,
                            out cGlyphs);
                #else
                            hr = ScriptShapeOpenType(
                                hdc,
                                ref service.caches[fontCacheIndex].cache,
                                ref o.sItems[i].a,
                                o.sTags[i], // tagScript
                                o.sTags[i], // tagLangSys -- right thing to pass here?
                                null, // rcRangeChars
                                null, // rpRangeProperties
                                0, // cRanges
                                new IntPtr(hText.ToInt64() + start * 2),
                                length,
                                cMaxGlyphs,
                                logicalClusters,
                                charProps,
                                glyphs,
                                glyphProps, // supercedes visAttrs
                                out cGlyphs);
                #endif
                            if (hr == E_OUTOFMEMORY)
                            {
                                cMaxGlyphs *= 2;
                                glyphs = new short[cMaxGlyphs];
                                logicalClusters = new short[cMaxGlyphs];
                                visAttrs = new SCRIPT_VISATTR[cMaxGlyphs];
                                continue;
                            }
                            if (hr == USP_E_SCRIPT_NOT_IN_FONT)
                            {
                                needFallback = true;
                                goto FontFallback;
                            }
                            if (hr < 0)
                            {
                                Marshal.ThrowExceptionForHR(hr);
                            }
                            // 7. If ScriptShape returns the code USP_E_SCRIPT_NOT_IN_FONT or S_OK with the output containing
                            // missing glyphs, select characters from a different font. Either substitute another font or disable
                            // shaping by setting the eScript member of the SCRIPT_ANALYSIS structure passed to ScriptShape to
                            // SCRIPT_UNDEFINED. For more information, see Using Font Fallback.
                            SCRIPT_FONTPROPERTIES sfp;
                            ScriptGetFontProperties(
                                hdc,
                                ref service.caches[fontCacheIndex].cache,
                                out sfp);
                            for (int j = 0; j < cGlyphs; j++)
                            {
                                if (glyphs[j] == sfp.wgDefault)
                                {
                                    needFallback = true;
                                    break;
                                }
                            }
                        FontFallback:
                            if (needFallback)
                            {
                                // What worked:
                                // https://code.google.com/p/chromium/codesearch#chromium/src/ui/gfx/font_fallback_win.cc&q=uniscribe&sq=package:chromium&l=283&dr=CSs
                                // http://stackoverflow.com/questions/16828868/how-to-automatically-choose-most-suitable-font-for-different-language
                                // What didn't work:
                                // The totally unhelpful Uniscribe font/script fallback documentation:
                                // https://msdn.microsoft.com/en-us/library/windows/desktop/dd374105%28v=vs.85%29.aspx
                                // MSDN Globalization how-to page about font fallback:
                                // https://msdn.microsoft.com/en-us/goglobal/bb688134.aspx
                                // ScriptShape page:
                                // https://msdn.microsoft.com/en-us/library/windows/desktop/dd368564(v=vs.85).aspx

                                fallbackLevel++;
                                switch (fallbackLevel)
                                {
                                    case 1:
                                        GDI.LOGFONT fallbackLF;
                                        if (GetUniscribeFallbackFont(
                                            font,
                                            new IntPtr(hText.ToInt64() + 2 * start),
                                            length,
                                            out fallbackLF))
                                        {
                                            fallbackFont = null;
                                            foreach (KeyValuePair<GDI.LOGFONT, Font> item in service.fallbackFonts)
                                            {
                                                if (String.Equals(item.Key.lfFaceName, fallbackLF.lfFaceName)
                                                    && (item.Key.lfCharSet == fallbackLF.lfCharSet)
                                                    && (item.Key.lfHeight == fallbackLF.lfHeight))
                                                {
                                                    fallbackFont = item.Value;
                                                    break;
                                                }
                                            }
                                            if (fallbackFont == null)
                                            {
                                                fallbackFont = Font.FromLogFont(fallbackLF);
                                                service.fallbackFonts.Add(new KeyValuePair<GDI.LOGFONT, Font>(fallbackLF, fallbackFont));
                                            }
                                            font = fallbackFont;
                                            continue;
                                        }
                                        continue;

                                    case 2:
                                        if (o.sItems[i].a.eScript != SCRIPT_UNDEFINED)
                                        {
                                            o.sItems[i].a.eScript = SCRIPT_UNDEFINED;
                                        }
                                        continue;

                                    default:
                                        // give up
                                        break;
                                }
                            }

                            break;
                        }

                        // 8. Call ScriptPlace to generate advance widths and x and y positions for the glyphs in each
                        // successive range. This is the first step for which text size becomes a consideration.
                        int[] iAdvances = new int[cGlyphs];
                        GOFFSET[] goffsets = new GOFFSET[cGlyphs];
                        ABC abc = new ABC();
                        {
                            int fontCacheIndex = service.FontCacheIndex(font);
                #if false // choose old or OpenType API
                        hr = ScriptPlace(
                            hdc,
                            ref service.caches[fontCacheIndex].cache,
                            glyphs,
                            cGlyphs,
                            visAttrs,
                            ref o.sItems[i].a,
                            iAdvances,
                            goffsets,
                            out abc);
                #else
                            hr = ScriptPlaceOpenType(
                                hdc,
                                ref service.caches[fontCacheIndex].cache,
                                ref o.sItems[i].a,
                                o.sTags[i], // tagScript
                                o.sTags[i], // tagLangSys -- right thing to pass here?
                                null, // rcRangeChars
                                null, // rpRangeProperties
                                0, // cRanges
                                new IntPtr(hText.ToInt64() + start * 2),
                                logicalClusters,
                                charProps,
                                length,
                                glyphs,
                                glyphProps,
                                cGlyphs,
                                iAdvances,
                                goffsets,
                                out abc);
                #endif
                            if (hr < 0)
                            {
                                Marshal.ThrowExceptionForHR(hr);
                            }
                        }

                        o.sItemsExtra[i].glyphs = glyphs;
                        o.sItemsExtra[i].logicalClusters = logicalClusters;
                        o.sItemsExtra[i].visAttrs = visAttrs;
                        o.sItemsExtra[i].cGlyphs = cGlyphs;
                        o.sItemsExtra[i].charProps = charProps;
                        o.sItemsExtra[i].glyphProps = glyphProps;

                        o.sItemsExtra[i].iAdvances = iAdvances;
                        o.sItemsExtra[i].goffsets = goffsets;
                        o.sItemsExtra[i].abc = abc;

                        o.sItemsExtra[i].fallbackFont = fallbackFont;

                        // 9. Sum the range sizes until the line overflows.

                        // 10. Break the range on a word boundary by using the fSoftBreak and fWhiteSpace members in the
                        // logical attributes. To break a single character cluster off the run, use the information returned
                        // by calling ScriptBreak.
                        // Note: Decide if the first code point of a range should be a word break point because the last
                        // character of the previous range requires it. For example, if one range ends in a comma, consider
                        // the first character of the next range to be a word break point.
                        SCRIPT_LOGATTR[] logAttrs1 = new SCRIPT_LOGATTR[o.count];
                        hr = ScriptBreak(
                            new IntPtr(hText.ToInt64() + 2 * start),
                            length,
                            ref o.sItems[i].a,
                            logAttrs1);
                        if (hr < 0)
                        {
                            Marshal.ThrowExceptionForHR(hr);
                        }
                        Array.Copy(logAttrs1, 0, o.logAttrs, o.sItems[i].iCharPos, length);

                        // 11. Repeat steps 6 through 10 for each line in the paragraph. However, if breaking the last run
                        // on the line, call ScriptShape to reshape the remaining part of the run as the first run on the
                        // next line.
                    }

                    // Display Text Using Uniscribe

                    // 1. For each run, do the following:
                    // a. If the style has changed since the last run, update the handle to the device context by releasing
                    //    and getting it again.
                    // b. Call ScriptShape to generate glyphs for the run.
                    // c. Call ScriptPlace to generate an advance width and an x,y offset for each glyph.

                    // 2. Do the following to establish the correct visual order for the runs in the line:
                    // a. Extract an array of bidirectional embedding levels, one per range. The embedding level is
                    //    given by (SCRIPT_ITEM) si.(SCRIPT_ANALYSIS) a. (SCRIPT_STATE) s.uBidiLevel.
                    // b. Pass this array to ScriptLayout to generate a map of visual positions to logical positions.
                    byte[] bidiEmbeddingLevels = new byte[o.cItems];
                    for (int i = 0; i < o.cItems; i++)
                    {
                        bidiEmbeddingLevels[i] = (byte)o.sItems[i].a.s.uBidiLevel;
                    }
                    o.iVisualToLogical = new int[o.cItems];
                    o.iLogicalToVisual = new int[o.cItems];
                    hr = ScriptLayout(
                        o.cItems,
                        bidiEmbeddingLevels,
                        o.iVisualToLogical,
                        o.iLogicalToVisual);
                    if (hr < 0)
                    {
                        Marshal.ThrowExceptionForHR(hr);
                    }

                    for (int i = 0; i < o.cItems; i++)
                    {
                        for (int j = 0; j < o.sItemsExtra[i].iAdvances.Length; j++)
                        {
                            o.sItemsExtra[i].totalWidth += o.sItemsExtra[i].iAdvances[j];
                        }
                    }
                }
                catch (Exception)
                {
                    o.Dispose();
                    throw;
                }

                return o;
            }