fontservices/textshaperplugin/IcuSource/layout/LayoutEngine.cpp
changeset 0 1fb32624e06b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/fontservices/textshaperplugin/IcuSource/layout/LayoutEngine.cpp	Tue Feb 02 02:02:46 2010 +0200
@@ -0,0 +1,612 @@
+
+/*
+ *
+ * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
+ *
+ */
+
+#include "LETypes.h"
+#include "LEScripts.h"
+#include "LELanguages.h"
+
+#include "LayoutEngine.h"
+#include "ArabicLayoutEngine.h"
+#include "CanonShaping.h"
+#include "HanLayoutEngine.h"
+#include "IndicLayoutEngine.h"
+#include "KhmerLayoutEngine.h"
+#include "ThaiLayoutEngine.h"
+#include "GXLayoutEngine.h"
+#include "ScriptAndLanguageTags.h"
+#include "CharSubstitutionFilter.h"
+
+#include "LEGlyphStorage.h"
+
+#include "OpenTypeUtilities.h"
+#include "GlyphSubstitutionTables.h"
+#include "MorphTables.h"
+
+#include "DefaultCharMapper.h"
+
+#include "KernTable.h"
+
+U_NAMESPACE_BEGIN
+
+#define ARRAY_SIZE(array) (sizeof array  / sizeof array[0])
+
+const LEUnicode32 DefaultCharMapper::controlChars[] = {
+    0x0009, 0x000A, 0x000D,
+    /*0x200C, 0x200D,*/ 0x200E, 0x200F,
+    0x2028, 0x2029, 0x202A, 0x202B, 0x202C, 0x202D, 0x202E,
+    0x206A, 0x206B, 0x206C, 0x206D, 0x206E, 0x206F
+};
+
+const le_int32 DefaultCharMapper::controlCharsCount = ARRAY_SIZE(controlChars);
+
+const LEUnicode32 DefaultCharMapper::mirroredChars[] = {
+    0x0028, 0x0029, // ascii paired punctuation
+    0x003c, 0x003e,
+    0x005b, 0x005d,
+    0x007b, 0x007d,
+    0x2045, 0x2046, // math symbols (not complete)
+    0x207d, 0x207e,
+    0x208d, 0x208e,
+    0x2264, 0x2265,
+    0x3008, 0x3009, // chinese paired punctuation
+    0x300a, 0x300b,
+    0x300c, 0x300d,
+    0x300e, 0x300f,
+    0x3010, 0x3011,
+    0x3014, 0x3015,
+    0x3016, 0x3017,
+    0x3018, 0x3019,
+    0x301a, 0x301b
+};
+
+const le_int32 DefaultCharMapper::mirroredCharsCount = ARRAY_SIZE(mirroredChars);
+
+LEUnicode32 DefaultCharMapper::mapChar(LEUnicode32 ch) const
+{
+    if (fFilterControls) {
+        le_int32 index = OpenTypeUtilities::search((le_uint32)ch, (le_uint32 *)controlChars, controlCharsCount);
+
+        if (controlChars[index] == ch) {
+            return 0xFFFF;
+        }
+    }
+
+    if (fMirror) {
+        le_int32 index = OpenTypeUtilities::search((le_uint32) ch, (le_uint32 *)mirroredChars, mirroredCharsCount);
+
+        if (mirroredChars[index] == ch) {
+            le_int32 mirrorOffset = ((index & 1) == 0) ? 1 : -1;
+
+            return mirroredChars[index + mirrorOffset];
+        }
+    }
+
+    return ch;
+}
+
+// This is here to get it out of LEGlyphFilter.h.
+// No particular reason to put it here, other than
+// this is a good central location...
+LEGlyphFilter::~LEGlyphFilter()
+{
+    // nothing to do
+}
+
+CharSubstitutionFilter::CharSubstitutionFilter(const LEFontInstance *fontInstance)
+  : fFontInstance(fontInstance)
+{
+    // nothing to do
+}
+
+CharSubstitutionFilter::~CharSubstitutionFilter()
+{
+    // nothing to do
+}
+
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LayoutEngine)
+
+static const LETag emptyTag = 0x00000000;
+
+static const LETag ccmpFeatureTag = LE_CCMP_FEATURE_TAG;
+
+static const LETag canonFeatures[] = {ccmpFeatureTag, emptyTag};
+
+LayoutEngine::LayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags)
+  : fGlyphStorage(NULL), fFontInstance(fontInstance), fScriptCode(scriptCode), fLanguageCode(languageCode),
+    fTypoFlags(typoFlags), fGidOfRA(0)
+{
+    fGlyphStorage = new LEGlyphStorage();
+}
+
+le_bool LayoutEngine::isBogus()
+{
+    return fGlyphStorage? FALSE : TRUE;
+}
+
+le_int32 LayoutEngine::getGlyphCount() const
+{
+    return fGlyphStorage->getGlyphCount();
+}
+
+void LayoutEngine::getCharIndices(le_int32 charIndices[], le_int32 indexBase, LEErrorCode &success) const
+{
+    fGlyphStorage->getCharIndices(charIndices, indexBase, success);
+}
+
+void LayoutEngine::getCharIndices(le_int32 charIndices[], LEErrorCode &success) const
+{
+    fGlyphStorage->getCharIndices(charIndices, success);
+}
+
+// Copy the glyphs into caller's (32-bit) glyph array, OR in extraBits
+void LayoutEngine::getGlyphs(le_uint32 glyphs[], le_uint32 extraBits, LEErrorCode &success) const
+{
+    fGlyphStorage->getGlyphs(glyphs, extraBits, success);
+}
+
+void LayoutEngine::getGlyphs(LEGlyphID glyphs[], LEErrorCode &success) const
+{
+    fGlyphStorage->getGlyphs(glyphs, success);
+}
+
+
+void LayoutEngine::getGlyphPositions(float positions[], LEErrorCode &success) const
+{
+    fGlyphStorage->getGlyphPositions(positions, success);
+}
+
+void LayoutEngine::getGlyphPosition(le_int32 glyphIndex, float &x, float &y, LEErrorCode &success) const
+{
+    fGlyphStorage->getGlyphPosition(glyphIndex, x, y, success);
+}
+
+le_int32 LayoutEngine::characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
+                LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return 0;
+    }
+
+    if (offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    const GlyphSubstitutionTableHeader *canonGSUBTable = (GlyphSubstitutionTableHeader *) CanonShaping::glyphSubstitutionTable;
+    LETag scriptTag  = OpenTypeLayoutEngine::getScriptTag(fScriptCode);
+    LETag langSysTag = OpenTypeLayoutEngine::getLangSysTag(fLanguageCode);
+    le_int32 i, dir = 1, out = 0, outCharCount = count;
+
+    if (canonGSUBTable->coversScript(scriptTag)) {
+        CharSubstitutionFilter *substitutionFilter = new CharSubstitutionFilter(fFontInstance);
+        if (!substitutionFilter) {
+            success = LE_MEMORY_ALLOCATION_ERROR;
+            return 0;
+        }
+
+		const LEUnicode *inChars = &chars[offset];
+		LEUnicode *reordered = NULL;
+
+		// This is the cheapest way to get mark reordering only for Hebrew.
+		// We could just do the mark reordering for all scripts, but most
+		// of them probably don't need it...
+		if (fScriptCode == hebrScriptCode) {
+			reordered = LE_NEW_ARRAY(LEUnicode, count);
+
+			if (reordered == NULL) {
+				success = LE_MEMORY_ALLOCATION_ERROR;
+				delete substitutionFilter;
+				return 0;
+			}
+
+			CanonShaping::reorderMarks(&chars[offset], count, rightToLeft, reordered, glyphStorage);
+			inChars = reordered;
+		}
+
+        glyphStorage.allocateGlyphArray(count, rightToLeft, success);
+        glyphStorage.allocateAuxData(success);
+
+        if (LE_FAILURE(success)) {
+            delete substitutionFilter;
+            return 0;
+        }
+
+        if (rightToLeft) {
+            out = count - 1;
+            dir = -1;
+        }
+
+        for (i = 0; i < count; i += 1, out += dir) {
+            glyphStorage[out] = (LEGlyphID) inChars[i];
+            glyphStorage.setAuxData(out, (void *) canonFeatures, success);
+        }
+
+		if (reordered != NULL) {
+			LE_DELETE_ARRAY(reordered);
+		}
+
+        outCharCount = canonGSUBTable->process(glyphStorage, rightToLeft,
+            scriptTag, langSysTag, NULL, success, substitutionFilter, NULL);
+
+        if (LE_FAILURE(success)) {
+            delete substitutionFilter;
+            return 0;
+        }
+
+        out = (rightToLeft? count - 1 : 0);
+
+        outChars = LE_NEW_ARRAY(LEUnicode, outCharCount);
+        if (!outChars) {
+            delete substitutionFilter;
+            success = LE_MEMORY_ALLOCATION_ERROR;
+            return 0;
+        }
+        for (i = 0; i < outCharCount; i += 1, out += dir) {
+            outChars[out] = (LEUnicode) LE_GET_GLYPH(glyphStorage[i]);
+        }
+
+        delete substitutionFilter;
+    }
+
+    return outCharCount;
+}
+
+le_int32 LayoutEngine::computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
+                                            LEGlyphStorage &glyphStorage, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return 0;
+    }
+
+    if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    LEUnicode *outChars = NULL;
+    le_int32 outCharCount = characterProcessing(chars, offset, count, max, rightToLeft, outChars, glyphStorage, success);
+
+    if (outChars != NULL) {
+        mapCharsToGlyphs(outChars, 0, outCharCount, rightToLeft, rightToLeft, glyphStorage, success);
+        LE_DELETE_ARRAY(outChars); // FIXME: a subclass may have allocated this, in which case this delete might not work...
+    } else {
+        mapCharsToGlyphs(chars, offset, count, rightToLeft, rightToLeft, glyphStorage, success);
+    }
+
+    return glyphStorage.getGlyphCount();
+}
+
+// Input: glyphs
+// Output: positions
+void LayoutEngine::positionGlyphs(LEGlyphStorage &glyphStorage, float x, float y, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    glyphStorage.allocatePositions(success);
+
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    le_int32 i, glyphCount = glyphStorage.getGlyphCount();
+
+    for (i = 0; i < glyphCount; i += 1) {
+        LEPoint advance;
+
+        glyphStorage.setPosition(i, x, y, success);
+
+        fFontInstance->getGlyphAdvance(glyphStorage[i], advance);
+        x += advance.fX;
+        y += advance.fY;
+    }
+
+    glyphStorage.setPosition(glyphCount, x, y, success);
+}
+
+void LayoutEngine::adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool /*reverse*/,
+                                        LEGlyphStorage &glyphStorage, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    if (chars == NULL || offset < 0 || count < 0) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return;
+    }
+
+    if (fTypoFlags & 0x1) { /* kerning enabled */
+      static const le_uint32 kernTableTag = LE_KERN_TABLE_TAG;
+
+      KernTable kt(fFontInstance, getFontTable(kernTableTag));
+      kt.process(glyphStorage);
+    }
+
+    // default is no adjustments
+    return;
+}
+
+void LayoutEngine::adjustMarkGlyphs(LEGlyphStorage &glyphStorage, LEGlyphFilter *markFilter, LEErrorCode &success)
+{
+    float xAdjust = 0;
+    le_int32 p, glyphCount = glyphStorage.getGlyphCount();
+
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    if (markFilter == NULL) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return;
+    }
+
+    float ignore, prev;
+
+    glyphStorage.getGlyphPosition(0, prev, ignore, success);
+
+    for (p = 0; p < glyphCount; p += 1) {
+        float next, xAdvance;
+        
+        glyphStorage.getGlyphPosition(p + 1, next, ignore, success);
+
+        xAdvance = next - prev;
+        glyphStorage.adjustPosition(p, xAdjust, 0, success);
+
+        if (markFilter->accept(glyphStorage[p])) {
+            xAdjust -= xAdvance;
+        }
+
+        prev = next;
+    }
+
+    glyphStorage.adjustPosition(glyphCount, xAdjust, 0, success);
+}
+
+void LayoutEngine::adjustMarkGlyphs(const LEUnicode chars[], le_int32 charCount, le_bool reverse, LEGlyphStorage &glyphStorage, LEGlyphFilter *markFilter, LEErrorCode &success)
+{
+    float xAdjust = 0;
+    le_int32 c = 0, direction = 1, p;
+    le_int32 glyphCount = glyphStorage.getGlyphCount();
+
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    if (markFilter == NULL) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return;
+    }
+
+    if (reverse) {
+        c = glyphCount - 1;
+        direction = -1;
+    }
+
+    float ignore, prev;
+
+    glyphStorage.getGlyphPosition(0, prev, ignore, success);
+
+    for (p = 0; p < charCount; p += 1, c += direction) {
+        float next, xAdvance;
+        
+        glyphStorage.getGlyphPosition(p + 1, next, ignore, success);
+
+        xAdvance = next - prev;
+        glyphStorage.adjustPosition(p, xAdjust, 0, success);
+
+        if (markFilter->accept(chars[c])) {
+            xAdjust -= xAdvance;
+        }
+
+        prev = next;
+    }
+
+    glyphStorage.adjustPosition(glyphCount, xAdjust, 0, success);
+}
+
+const void *LayoutEngine::getFontTable(LETag tableTag) const
+{
+    return fFontInstance->getFontTable(tableTag);
+}
+
+void LayoutEngine::mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror,
+                                    LEGlyphStorage &glyphStorage, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return;
+    }
+
+    glyphStorage.allocateGlyphArray(count, reverse, success);
+
+    DefaultCharMapper charMapper(TRUE, mirror);
+
+    fFontInstance->mapCharsToGlyphs(chars, offset, count, reverse, &charMapper, glyphStorage);
+}
+
+// Input: characters, font?
+// Output: glyphs, positions, char indices
+// Returns: number of glyphs
+le_int32 LayoutEngine::layoutChars(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
+                              float x, float y, LEErrorCode &success)
+{
+    if (LE_FAILURE(success)) {
+        return 0;
+    }
+
+    if (chars == NULL || offset < 0 || count < 0 || max < 0 || offset >= max || offset + count > max) {
+        success = LE_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    // 1922 mlyl: get the glyph ID of RAKAR -->
+    const LEUnicode RAKAR[] = {0xFFFF, 0xD15, 0xD4D, 0xD30, 0xFFFF};
+    if (fGidOfRA == 0 && mlymScriptCode == fScriptCode) {
+    	fGidOfRA = -1;  // 0xFFFFFFFF
+    	TInt noOfGlyphs = layoutChars(
+    			RAKAR, 		// chars - the input character context
+    			1,			// the offset of the first character to process	
+    			3,			// count - the number of characters to process	// offset
+    			5, 			// max - the number of characters in the input context	// size of text
+    			FALSE, 		// rightToLeft - TRUE if the characters are in a right to left directional run
+    			0, 			// start X
+    			0, 			// start Y
+    			success);	// result code
+    	
+    	if (!LE_FAILURE(success)) {
+    		fGidOfRA = (*fGlyphStorage)[1];
+    		(*fGlyphStorage).reset();
+    	}
+    }
+    // <-- 1922 mlyl
+    
+    le_int32 glyphCount;
+    
+    glyphCount = computeGlyphs(chars, offset, count, max, rightToLeft, *fGlyphStorage, success);
+    
+    // 1922 mlyl: put RAKAR left of the preceding glyph -->
+    if (fGidOfRA != 0 && fGidOfRA != -1 && mlymScriptCode == fScriptCode) {
+    	fGlyphStorage->forMlylRakar(fGidOfRA);
+    }
+    // <-- 1922 mlyl
+    
+    positionGlyphs(*fGlyphStorage, x, y, success);
+    adjustGlyphPositions(chars, offset, count, rightToLeft, *fGlyphStorage, success);
+
+    return glyphCount;
+}
+
+void LayoutEngine::reset()
+{
+    fGlyphStorage->reset();
+}
+    
+LayoutEngine *LayoutEngine::layoutEngineFactory(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, LEErrorCode &success)
+{
+  // 3 -> kerning and ligatures
+  return LayoutEngine::layoutEngineFactory(fontInstance, scriptCode, languageCode, 3, success);
+}
+    
+LayoutEngine *LayoutEngine::layoutEngineFactory(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success)
+{
+    static const le_uint32 gsubTableTag = LE_GSUB_TABLE_TAG;
+    static const le_uint32 mortTableTag = LE_MORT_TABLE_TAG;
+
+    if (LE_FAILURE(success)) {
+        return NULL;
+    }
+
+    const GlyphSubstitutionTableHeader *gsubTable = (const GlyphSubstitutionTableHeader *) fontInstance->getFontTable(gsubTableTag);
+    LayoutEngine *result = NULL;
+    LETag scriptTag   = 0x00000000;
+    LETag languageTag = 0x00000000;
+
+    if (gsubTable != NULL && gsubTable->coversScript(scriptTag = OpenTypeLayoutEngine::getScriptTag(scriptCode))) {
+        switch (scriptCode) {
+        case bengScriptCode:
+        case devaScriptCode:
+        case gujrScriptCode:
+        case kndaScriptCode:
+        case mlymScriptCode:
+        case oryaScriptCode:
+        case guruScriptCode:
+        case tamlScriptCode:
+        case teluScriptCode:
+            result = new IndicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+            break;
+
+        case arabScriptCode:
+            result = new ArabicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+            break;
+
+        case haniScriptCode:
+            languageTag = OpenTypeLayoutEngine::getLangSysTag(languageCode);
+
+            switch (languageCode) {
+            case korLanguageCode:
+            case janLanguageCode:
+            case zhtLanguageCode:
+            case zhsLanguageCode:
+                if (gsubTable->coversScriptAndLanguage(scriptTag, languageTag, TRUE)) {
+                    result = new HanOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+                    break;
+                }
+
+                // note: falling through to default case.
+            default:
+                result = new OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+                break;
+            }
+
+            break;
+
+        case khmrScriptCode:
+            result = new KhmerOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+            break;
+
+        default:
+            result = new OpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags, gsubTable);
+            break;
+        }
+    } else {
+        const MorphTableHeader *morphTable = (MorphTableHeader *) fontInstance->getFontTable(mortTableTag);
+
+        if (morphTable != NULL) {
+            result = new GXLayoutEngine(fontInstance, scriptCode, languageCode, morphTable);
+        } else {
+            switch (scriptCode) {
+            case bengScriptCode:
+            case devaScriptCode:
+            case gujrScriptCode:
+            case kndaScriptCode:
+            case mlymScriptCode:
+            case oryaScriptCode:
+            case guruScriptCode:
+            case tamlScriptCode:
+            case teluScriptCode:
+            {
+                result = new IndicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags);
+                break;
+            }
+
+            case arabScriptCode:
+            //case hebrScriptCode:
+                result = new UnicodeArabicOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags);
+                break;
+
+            //case hebrScriptCode:
+            //    return new HebrewOpenTypeLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags);
+
+            case thaiScriptCode:
+                result = new ThaiLayoutEngine(fontInstance, scriptCode, languageCode, typoFlags);
+                break;
+
+            default:
+                result = new LayoutEngine(fontInstance, scriptCode, languageCode, typoFlags);
+                break;
+            }
+        }
+    }
+
+    if (result && result->isBogus()) {
+        delete result;
+        result = NULL;
+    }
+    if (result == NULL) {
+        success = LE_MEMORY_ALLOCATION_ERROR;
+    }
+
+    return result;
+}
+
+LayoutEngine::~LayoutEngine() {
+    delete fGlyphStorage;
+}
+
+U_NAMESPACE_END