public static void InitCache(
IOpenTypeFont font,
OpenTypeTags tableTag,
GlyphInfoList glyphInfo,
OpenTypeLayoutWorkspace workspace
)
{
Debug.Assert(tableTag == OpenTypeTags.GSUB || tableTag == OpenTypeTags.GPOS);
byte[] cacheArray = font.GetTableCache(tableTag);
unsafe
{
if (cacheArray == null)
{
workspace.TableCacheData = null;
}
else
{
workspace.TableCacheData = cacheArray;
workspace.AllocateCachePointers(glyphInfo.Length);
RenewPointers(glyphInfo, workspace, 0, glyphInfo.Length);
}
}
}
private static unsafe void RenewPointers(
GlyphInfoList glyphInfo,
OpenTypeLayoutWorkspace workspace,
int firstGlyph,
int afterLastGlyph
)
{
fixed(byte *pCache = &workspace.TableCacheData[0])
{
// If there is no chache, just exit
if (pCache == null)
{
return;
}
ushort[] cachePointers = workspace.CachePointers;
for (int i = firstGlyph; i < afterLastGlyph; i++)
{
ushort glyph = glyphInfo.Glyphs[i];
// If glyph is not there, we will point to the constant 0xFFFF in the cache
int listOffset = 2;
//Find glyph entry in the cache
int glyphCount = *((ushort *)pCache + 3);
ushort *pGlyphs = (ushort *)pCache + 4;
int low = 0, high = glyphCount;
while (low < high)
{
int mid = (low + high) >> 1;
ushort midGlyph = pGlyphs[mid * 2];
if (glyph < midGlyph)
{
high = mid;
continue;
}
if (glyph > midGlyph)
{
low = mid + 1;
continue;
}
// Found it!
listOffset = pGlyphs[mid * 2 + 1];
break;
}
// Whether we found glyph in the cache or not,
// Pointer will be set to the list, but it may be empty.
cachePointers[i] = *((ushort *)(pCache + listOffset));
}
}
}
/// <summary>
/// ShaperBuffers - constructor
/// </summary>
/// <SecurityNote>
/// Critical: This code accepts checked pointers and extracts
/// unsafe pointers.
/// </SecurityNote>
public ShaperBuffers(ushort charCount, ushort glyphCount)
{
// the charCount is used to provide an initial size for the
// various buffers used by the shaper(s). These may
// grow over the shaper's life
_glyphInfoList = new GlyphInfoList((glyphCount > charCount ? glyphCount : charCount), 16, false);
_charMap = new UshortList(charCount, 16);
_layoutWorkspace = new OpenTypeLayoutWorkspace();
_charMap.SetRange(0, charCount);
if (glyphCount > 0)
{
_glyphInfoList.SetRange(0, glyphCount);
}
}
private static unsafe ushort GetCacheLookupCount(OpenTypeLayoutWorkspace workspace)
{
// If there is no chache, just exit
if (workspace.TableCacheData == null)
{
return(0);
}
fixed(byte *pCacheByte = &workspace.TableCacheData[0])
{
ushort *pCache = (ushort *)pCacheByte;
return(pCache[2]);
}
}
public static unsafe void FindNextLookup(
OpenTypeLayoutWorkspace workspace,
GlyphInfoList glyphInfo,
ushort firstLookupIndex,
out ushort lookupIndex,
out int firstGlyph
)
{
if (firstLookupIndex >= GetCacheLookupCount(workspace))
{
// For lookups that did not fit into cache, just say we should always try it
lookupIndex = firstLookupIndex;
firstGlyph = 0;
return;
}
ushort[] cachePointers = workspace.CachePointers;
int glyphCount = glyphInfo.Length;
lookupIndex = 0xffff;
firstGlyph = 0;
for (int i = 0; i < glyphCount; i++)
{
// Sync up inside the list up to the minimal lookup requested
// No additional boundary checks are necessary, because every list terminates with 0xffff
while (cachePointers[i] < firstLookupIndex)
{
cachePointers[i]++;
}
//Now we know that our index is higher or equal than firstLookup index
if (cachePointers[i] < lookupIndex)
{
// We now have new minimum
lookupIndex = cachePointers[i];
firstGlyph = i;
}
}
if (lookupIndex == 0xffff)
{
// We can't just say we are done, there may be lookups that did not fit into cache
lookupIndex = GetCacheLookupCount(workspace);
firstGlyph = 0;
}
}
/// <summary>
/// ShaperBuffers - constructor
/// </summary>
/// <SecurityNote>
/// Critical: This code accepts checked pointers and extracts
/// unsafe pointers.
/// </SecurityNote>
public ShaperBuffers(ushort charCount, ushort glyphCount)
{
// the charCount is used to provide an initial size for the
// various buffers used by the shaper(s). These may
// grow over the shaper's life
_glyphInfoList = new GlyphInfoList((glyphCount > charCount ? glyphCount : charCount), 16, false);
_charMap = new UshortList(charCount, 16);
_layoutWorkspace = new OpenTypeLayoutWorkspace();
_charMap.SetRange(0,charCount);
if (glyphCount > 0)
{
_glyphInfoList.SetRange(0,glyphCount);
}
}
public static void OnGlyphsChanged(
OpenTypeLayoutWorkspace workspace,
GlyphInfoList glyphInfo,
int oldLength,
int firstGlyphChanged,
int afterLastGlyphChanged
)
{
unsafe
{
if (workspace.TableCacheData == null)
{
return;
}
}
workspace.UpdateCachePointers(oldLength, glyphInfo.Length, firstGlyphChanged, afterLastGlyphChanged);
RenewPointers(glyphInfo, workspace, firstGlyphChanged, afterLastGlyphChanged);
}
public static unsafe bool FindNextGlyphInLookup(
OpenTypeLayoutWorkspace workspace,
ushort lookupIndex,
bool isLookupReversal,
ref int firstGlyph,
ref int afterLastGlyph
)
{
if (lookupIndex >= GetCacheLookupCount(workspace))
{
return(true);
}
ushort[] cachePointers = workspace.CachePointers;
if (!isLookupReversal)
{
for (int i = firstGlyph; i < afterLastGlyph; i++)
{
if (cachePointers[i] == lookupIndex)
{
firstGlyph = i;
return(true);
}
}
return(false);
}
else
{
for (int i = afterLastGlyph - 1; i >= firstGlyph; i--)
{
if (cachePointers[i] == lookupIndex)
{
afterLastGlyph = i + 1;
return(true);
}
}
return(false);
}
}
/// <summary>
/// Position glyphs according to features defined in the font.
/// </summary>
/// <param name="Font">In: Font access interface</param>
/// <param name="workspace">In: Workspace for layout engine</param>
/// <param name="ScriptTag">In: Script tag</param>
/// <param name="LangSysTag">In: LangSys tag</param>
/// <param name="Metrics">In: LayoutMetrics</param>
/// <param name="FeatureSet">In: List of features to apply</param>
/// <param name="featureCount">In: Actual number of features in <paramref name="FeatureSet"/></param>
/// <param name="featureSetOffset">In: offset of input characters inside FeatureSet</param>
/// <param name="CharCount">In: Characters count (i.e. <paramref name="Charmap"/>.Length);</param>
/// <param name="Charmap">In: Char to glyph mapping</param>
/// <param name="Glyphs">In/out: List of GlyphInfo structs</param>
/// <param name="Advances">In/out: Glyphs adv.widths</param>
/// <param name="Offsets">In/out: Glyph offsets</param>
/// <returns>Substitution result</returns>
internal static OpenTypeLayoutResult PositionGlyphs(
IOpenTypeFont Font,
OpenTypeLayoutWorkspace workspace,
uint ScriptTag,
uint LangSysTag,
LayoutMetrics Metrics,
Feature[] FeatureSet,
int featureCount,
int featureSetOffset,
int CharCount,
UshortList Charmap,
GlyphInfoList Glyphs,
int *Advances,
LayoutOffset *Offsets
)
{
try
{
FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
if (!GposTable.IsPresent)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
GPOSHeader GposHeader = new GPOSHeader(0);
ScriptList ScriptList = GposHeader.GetScriptList(GposTable);
ScriptTable Script = ScriptList.FindScript(GposTable, ScriptTag);
if (Script.IsNull)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
LangSysTable LangSys = Script.FindLangSys(GposTable, LangSysTag);
if (LangSys.IsNull)
{
return(OpenTypeLayoutResult.LangSysNotFound);
}
FeatureList FeatureList = GposHeader.GetFeatureList(GposTable);
LookupList LookupList = GposHeader.GetLookupList(GposTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GPOS,
GposTable,
Metrics,
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
Advances,
Offsets
);
}
catch (FileFormatException)
{
return(OpenTypeLayoutResult.BadFontTable);
}
return(OpenTypeLayoutResult.Success);
}
/* This is unused code, but will be used later so it is just commented out for now.
*
* /// <summary>
* /// Enumerates scripts in a font
* /// </summary>
* internal static OpenTypeLayoutResult GetScriptList (
* IOpenTypeFont Font, // In: Font access interface
* out TagInfo[] Scripts // Out: Array of scripts supported
* )
* {
* ushort i;
* ushort GposNewTags;
*
* Scripts=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ushort GsubScriptCount;
* ushort GposScriptCount;
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* Scripts = Array.Empty<TagInfo>();
* return OpenTypeLayoutResult.Success;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScriptCount = GsubScriptList.GetScriptCount(GsubTable);
* }
* else
* {
* GsubScriptList = new ScriptList(FontTable.InvalidOffset);
* GsubScriptCount = 0;
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScriptCount = GposScriptList.GetScriptCount(GposTable);
* }
* else
* {
* GposScriptList = new ScriptList(FontTable.InvalidOffset);
* GposScriptCount = 0;
* }
*
* //This is true in most cases that there is no new tags in GPOS.
* //So, we allocate this array then check GPOS for new tags
* Scripts = new TagInfo[GsubScriptCount];
*
* for(i=0; i<GsubScriptCount; i++)
* {
* Scripts[i].Tag = GsubScriptList.GetScriptTag(GsubTable,i);
* Scripts[i].TagFlags = TagInfoFlags.Substitution;
* }
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
*
* for(i=0;i<GposScriptCount;i++)
* {
* uint GposTag = GsubScriptList.GetScriptTag(GposTable,i);
* if (TagInfo.IsNewTag(Scripts,GposTag)) GposNewTags++;
* }
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* int CurrentScriptIndex=GposScriptCount;
*
* //Allocate new array to fit all tags
* TagInfo[] tmp = Scripts;
* Scripts = new TagInfo[GsubScriptCount+GposNewTags];
* Array.Copy(tmp,0,Scripts,0,tmp.Length);
*
* for(i=0;i<GposScriptCount;i++)
* {
* uint GposTag = GsubScriptList.GetScriptTag(GposTable,i);
* if (TagInfo.IsNewTag(Scripts,GposTag))
* {
* Scripts[CurrentScriptIndex].Tag=GposTag;
* Scripts[CurrentScriptIndex].TagFlags
* = TagInfoFlags.Positioning;
++CurrentScriptIndex;
* }
* else
* {
* int ScriptIndex = TagInfo.GetTagIndex(Scripts,GposTag);
* Scripts[ScriptIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentScriptIndex==Scripts.Length);
* }
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*
*
* ///<summary>
* /// Enumerates language systems for script
* /// </summary>
* internal static OpenTypeLayoutResult GetLangSysList (
* IOpenTypeFont Font, // In: Font access interface
* uint ScriptTag, // In: Script tag
* out TagInfo[] LangSystems // Out: Array of LangSystems for Script
* )
* {
* ushort i;
* ushort GposNewTags;
*
* LangSystems=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ScriptTable GsubScript;
* ScriptTable GposScript;
* ushort GsubLangSysCount;
* ushort GposLangSysCount;
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScript = GsubScriptList.FindScript(GsubTable,ScriptTag);
* }
* else
* {
* GsubScript = new ScriptTable(FontTable.InvalidOffset);
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScript = GposScriptList.FindScript(GposTable,ScriptTag);
* }
* else
* {
* GposScript = new ScriptTable(FontTable.InvalidOffset);
* }
*
* if (GsubScript.IsNull && GposScript.IsNull)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (!GsubScript.IsNull)
* {
* GsubLangSysCount = GsubScript.GetLangSysCount(GsubTable);
* }
* else
* {
* GsubLangSysCount = 0;
* }
*
* if (!GposScript.IsNull)
* {
* GposLangSysCount = GposScript.GetLangSysCount(GposTable);
* }
* else
* {
* GposLangSysCount = 0;
* }
*
* //This is true in most cases that there is no new tags in GPOS.
* //So, we allocate this array then check GPOS for new tags
* ushort CurrentLangSysIndex;
*
* if (GsubScript.IsDefaultLangSysExists(GsubTable))
* {
* LangSystems = new TagInfo[GsubLangSysCount+1];
* LangSystems[0].Tag = (uint)OpenTypeTags.dflt;
* LangSystems[0].TagFlags = TagInfoFlags.Substitution;
* CurrentLangSysIndex = 1;
* }
* else
* {
* LangSystems = new TagInfo[GsubLangSysCount];
* CurrentLangSysIndex = 0;
* }
*
* for(i=0; i<GsubLangSysCount; i++)
* {
* LangSystems[CurrentLangSysIndex].Tag = GsubScript.GetLangSysTag(GsubTable,i);
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Substitution;
++CurrentLangSysIndex;
* }
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
*
* if (!GposScript.IsNull)
* {
* if (GposScript.IsDefaultLangSysExists(GposTable) &&
* TagInfo.IsNewTag(LangSystems,(uint)OpenTypeTags.dflt))
* {
++GposNewTags;
* }
*
* for(i=0;i<GposLangSysCount;i++)
* {
* uint GposTag = GsubScript.GetLangSysTag(GposTable,i);
* if (TagInfo.IsNewTag(LangSystems,GposTag))
* {
++GposNewTags;
* }
* }
* }
*
* Debug.Assert(CurrentLangSysIndex==LangSystems.Length);
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* //Allocate new array to fit all tags
* TagInfo[] tmp = LangSystems;
* LangSystems = new TagInfo[GsubLangSysCount+GposNewTags];
* Array.Copy(tmp,0,LangSystems,0,tmp.Length);
*
* if (GposScript.IsDefaultLangSysExists(GposTable))
* {
* if (TagInfo.IsNewTag(LangSystems,(uint)OpenTypeTags.dflt))
* {
* LangSystems[CurrentLangSysIndex].Tag = (uint)OpenTypeTags.dflt;
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentLangSysIndex;
* }
* else
* {
* int LangSysIndex = TagInfo.GetTagIndex(LangSystems,(uint)OpenTypeTags.dflt);
* LangSystems[LangSysIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* for(i=0;i<GposLangSysCount;i++)
* {
* uint GposTag = GposScript.GetLangSysTag(GposTable,i);
*
* if (TagInfo.IsNewTag(LangSystems,GposTag))
* {
* LangSystems[CurrentLangSysIndex].Tag = GposTag;
* LangSystems[CurrentLangSysIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentLangSysIndex;
* }
* else
* {
* int LangSysIndex = TagInfo.GetTagIndex(LangSystems,GposTag);
* LangSystems[LangSysIndex].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentLangSysIndex==LangSystems.Length);
* }
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*
*
* /// <summary>
* /// Enumerates features in a language system
* /// </summary>
* internal static OpenTypeLayoutResult GetFeatureList (
* IOpenTypeFont Font, // In: Font access interface
* uint ScriptTag, // In: Script tag
* uint LangSysTag, // In: LangSys tag
* out TagInfo[] Features // Out: Array of features
* )
* {
* ushort i;
* ushort GposNewTags;
*
* Features=null; // Assignment required, because of out attribute.
* // This value should be owerwritten later.
*
* try
* {
* FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
* FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
*
* GSUBHeader GsubHeader = new GSUBHeader(0);
* GPOSHeader GposHeader = new GPOSHeader(0);
*
* ScriptList GsubScriptList;
* ScriptList GposScriptList;
* ScriptTable GsubScript;
* ScriptTable GposScript;
* LangSysTable GsubLangSys;
* LangSysTable GposLangSys;
* ushort GsubFeatureCount;
* ushort GposFeatureCount;
* FeatureList GsubFeatureList;
* FeatureList GposFeatureList;
*
*
* if (GsubTable.IsNotPresent && GposTable.IsNotPresent)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubTable.IsPresent)
* {
* GsubScriptList = GsubHeader.GetScriptList(GsubTable);
* GsubScript = GsubScriptList.FindScript(GsubTable,ScriptTag);
* GsubLangSys = GsubScript.FindLangSys(GsubTable,LangSysTag);
* GsubFeatureList = GsubHeader.GetFeatureList(GsubTable);
* }
* else
* {
* GsubScript = new ScriptTable(FontTable.InvalidOffset);
* GsubLangSys = new LangSysTable(FontTable.InvalidOffset);
* GsubFeatureList = new FeatureList(FontTable.InvalidOffset);
* }
*
* if (GposTable.IsPresent)
* {
* GposScriptList = GposHeader.GetScriptList(GposTable);
* GposScript = GposScriptList.FindScript(GposTable,ScriptTag);
* GposLangSys = GposScript.FindLangSys(GposTable,LangSysTag);
* GposFeatureList = GposHeader.GetFeatureList(GposTable);
* }
* else
* {
* GposScript = new ScriptTable(FontTable.InvalidOffset);
* GposLangSys = new LangSysTable(FontTable.InvalidOffset);
* GposFeatureList = new FeatureList(FontTable.InvalidOffset);
* }
*
* if (GsubScript.IsNull && GposScript.IsNull)
* {
* return OpenTypeLayoutResult.ScriptNotFound;
* }
*
* if (GsubLangSys.IsNull && GposLangSys.IsNull)
* {
* return OpenTypeLayoutResult.LangSysNotFound;
* }
*
* if (!GsubLangSys.IsNull)
* {
* GsubFeatureCount = GsubLangSys.FeatureCount(GsubTable);
* }
* else
* {
* GsubFeatureCount = 0;
* }
*
* if (!GposLangSys.IsNull)
* {
* GposFeatureCount = GposLangSys.FeatureCount(GposTable);
* }
* else
* {
* GposFeatureCount = 0;
* }
*
* Features = new TagInfo[GsubFeatureCount];
* int CurrentFeatureIndex = 0;
*
* for(i=0; i<GsubFeatureCount; i++)
* {
* ushort FeatureIndex = GsubLangSys.GetFeatureIndex(GsubTable,i);
* Features[CurrentFeatureIndex].Tag = GsubFeatureList.FeatureTag(GsubTable,FeatureIndex);
* Features[CurrentFeatureIndex].TagFlags = TagInfoFlags.Substitution;
++CurrentFeatureIndex;
* }
*
* Debug.Assert(CurrentFeatureIndex==Features.Length);
*
* //Check GPOS for tags that is not in GSUB
* GposNewTags=0;
* if (!GposLangSys.IsNull)
* {
* for(i=0;i<GposFeatureCount;i++)
* {
* ushort FeatureIndex = GposLangSys.GetFeatureIndex(GposTable,i);
* uint GposTag = GposFeatureList.FeatureTag(GposTable,FeatureIndex);
* if (TagInfo.IsNewTag(Features,GposTag))
* {
++GposNewTags;
* }
* }
* }
*
* //append new tags to ScriptTags if any exists
* if (GposNewTags>0)
* {
* //Allocate new array to fit all tags
* TagInfo[] tmp = Features;
* Features = new TagInfo[GsubFeatureCount+GposNewTags];
* Array.Copy(tmp,0,Features,0,tmp.Length);
*
* for(i=0;i<GposFeatureCount;i++)
* {
* ushort FeatureIndex = GposLangSys.GetFeatureIndex(GposTable,i);
* uint GposTag = GposFeatureList.FeatureTag(GposTable,FeatureIndex);
*
* if (TagInfo.IsNewTag(Features,GposTag))
* {
* Features[CurrentFeatureIndex].Tag = GposTag;
* Features[CurrentFeatureIndex].TagFlags = TagInfoFlags.Positioning;
++CurrentFeatureIndex;
* }
* else
* {
* int Index = TagInfo.GetTagIndex(Features,GposTag);
* Features[Index].TagFlags |= TagInfoFlags.Positioning;
* }
* }
*
* Debug.Assert(CurrentFeatureIndex==Features.Length);
* }
*
*
* }
* catch (FileFormatException)
* {
* return OpenTypeLayoutResult.BadFontTable;
* }
*
* return OpenTypeLayoutResult.Success;
* }
*/
/// <summary>
/// Substitutes glyphs according to features defined in the font.
/// </summary>
/// <param name="Font">In: Font access interface</param>
/// <param name="workspace">In: Workspace for layout engine</param>
/// <param name="ScriptTag">In: Script tag</param>
/// <param name="LangSysTag">In: LangSys tag</param>
/// <param name="FeatureSet">In: List of features to apply</param>
/// <param name="featureCount">In: Actual number of features in <paramref name="FeatureSet"/></param>
/// <param name="featureSetOffset">In: offset of input characters inside FeatureSet</param>
/// <param name="CharCount">In: Characters count (i.e. <paramref name="Charmap"/>.Length);</param>
/// <param name="Charmap">In/out: Char to glyph mapping</param>
/// <param name="Glyphs">In/out: List of GlyphInfo structs</param>
/// <returns>Substitution result</returns>
internal static OpenTypeLayoutResult SubstituteGlyphs(
IOpenTypeFont Font, // In: Font access interface
OpenTypeLayoutWorkspace workspace, // In: Workspace for layout engine
uint ScriptTag, // In: Script tag
uint LangSysTag, // In: LangSys tag
Feature[] FeatureSet, // In: List of features to apply
int featureCount, // In: Actual number of features in FeatureSet
int featureSetOffset,
int CharCount, // In: Characters count (i.e. Charmap.Length);
UshortList Charmap, // In/out: Char to glyph mapping
GlyphInfoList Glyphs // In/out: List of GlyphInfo structs
)
{
try
{
FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
if (!GsubTable.IsPresent)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
GSUBHeader GsubHeader = new GSUBHeader(0);
ScriptList ScriptList = GsubHeader.GetScriptList(GsubTable);
ScriptTable Script = ScriptList.FindScript(GsubTable, ScriptTag);
if (Script.IsNull)
{
return(OpenTypeLayoutResult.ScriptNotFound);
}
LangSysTable LangSys = Script.FindLangSys(GsubTable, LangSysTag);
if (LangSys.IsNull)
{
return(OpenTypeLayoutResult.LangSysNotFound);
}
FeatureList FeatureList = GsubHeader.GetFeatureList(GsubTable);
LookupList LookupList = GsubHeader.GetLookupList(GsubTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GSUB,
GsubTable,
new LayoutMetrics(), //it is not needed for substitution
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
null,
null
);
}
catch (FileFormatException)
{
return(OpenTypeLayoutResult.BadFontTable);
}
return(OpenTypeLayoutResult.Success);
}
private static void GetNextEnabledGlyphRange(
Feature[] FeatureSet, // In: List of features to apply
int featureCount, // In: Actual nubmer of features in FeatureSet
int featureSetOffset, // In: offset of input chars inside feature set
FontTable Table, // Layout table (GSUB or GPOS)
OpenTypeLayoutWorkspace workspace, // workspace with compiled feature set
LangSysTable LangSys, // Language system
FeatureList Features, // List of Features in layout table
ushort lookupIndex, // List of lokups definitions in layout table
int CharCount, // Characters count (i.e. Charmap.Length);
UshortList Charmap, // Character to glyph mapping
int StartChar,
int StartGlyph,
int GlyphRunLength,
out int FirstChar, // First char in enabled range
out int AfterLastChar, // next char after enabled range
out int FirstGlyph, // First char in enabled range
out int AfterLastGlyph, // next char after enabled range
out uint Parameter // applied feature parameter
)
{
FirstChar = int.MaxValue;
AfterLastChar = int.MaxValue;
FirstGlyph = StartGlyph;
AfterLastGlyph = GlyphRunLength;
Parameter = 0;
if (workspace.IsRequiredFeatureFlagSet(lookupIndex))
{
FirstChar = StartChar;
AfterLastChar = CharCount;
FirstGlyph = StartGlyph;
AfterLastGlyph = GlyphRunLength;
return;
}
for(int feature=0; feature < featureCount; feature++)
{
if (!workspace.IsFeatureFlagSet(lookupIndex,feature))
{
continue;
}
Feature featureDescription = FeatureSet[feature];
// Shift values from the feature by specified offset and
// work with these values from here
int featureStart = featureDescription.StartIndex - featureSetOffset;
if (featureStart < 0)
{
featureStart = 0;
}
int featureAfterEnd = featureDescription.StartIndex + featureDescription.Length
- featureSetOffset;
if (featureAfterEnd > CharCount)
{
featureAfterEnd = CharCount;
}
//If feature is disabled there should not be any flag set
Debug.Assert(featureDescription.Parameter != 0);
if (featureAfterEnd <= StartChar)
{
continue;
}
if (featureStart < FirstChar ||
(
featureStart == FirstChar &&
featureAfterEnd >= AfterLastChar
)
)
{
FirstChar = featureStart;
AfterLastChar = featureAfterEnd;
Parameter = featureDescription.Parameter;
continue;
}
}
//No ranges found
if (FirstChar == int.MaxValue)
{
FirstGlyph = GlyphRunLength;
AfterLastGlyph = GlyphRunLength;
}
else
{
if (StartGlyph > Charmap[FirstChar])
FirstGlyph = StartGlyph;
else
FirstGlyph = Charmap[FirstChar];
if (AfterLastChar < CharCount)
AfterLastGlyph = Charmap[AfterLastChar];
else
AfterLastGlyph = GlyphRunLength;
}
}
private static void CompileFeatureSet(
Feature[] FeatureSet, // In: List of features to apply
int featureCount, // In: Actual number of features in FeatureSet
int featureSetOffset, //In: Offset of character input sequence inside feature set
int charCount, // In: number of characters in the input string
FontTable Table, // In: Layout table (GSUB or GPOS)
LangSysTable LangSys, // In: Language system
FeatureList Features, // In: List of Features in layout table
int lookupCount, // In: number of lookup in layout table
OpenTypeLayoutWorkspace workspace // In: workspace with compiled feature set
)
{
workspace.InitLookupUsageFlags(lookupCount, featureCount);
//Set lookup uasge flags for required feature
FeatureTable requiredFeatureTable = LangSys.RequiredFeature(Table, Features);
if (!requiredFeatureTable.IsNull)
{
int featureLookupCount = requiredFeatureTable.LookupCount(Table);
for(ushort lookup = 0; lookup < featureLookupCount; lookup++)
{
workspace.SetRequiredFeatureFlag(requiredFeatureTable.LookupIndex(Table,lookup));
}
}
//Set lookup usage flags for each feature in the FeatureSet
for(int feature = 0; feature < featureCount; feature++)
{
Feature featureDescription = FeatureSet[feature];
//Filter out features which:
// Not enabled or applied completely before or after input characters
if (featureDescription.Parameter == 0 ||
featureDescription.StartIndex >= (featureSetOffset + charCount) ||
(featureDescription.StartIndex+featureDescription.Length) <= featureSetOffset
)
{
continue;
}
FeatureTable featureTable = LangSys.FindFeature( Table,
Features,
featureDescription.Tag);
if (featureTable.IsNull)
{
continue;
}
int featureLookupCount = featureTable.LookupCount(Table);
for(ushort lookup = 0; lookup < featureLookupCount; lookup++)
{
workspace.SetFeatureFlag(featureTable.LookupIndex(Table,lookup), feature);
}
}
}
public static void ApplyFeatures(
IOpenTypeFont Font,
OpenTypeLayoutWorkspace workspace,
OpenTypeTags TableTag,
FontTable Table,
LayoutMetrics Metrics,
LangSysTable LangSys,
FeatureList Features,
LookupList Lookups,
Feature[] FeatureSet,
int featureCount,
int featureSetOffset,
int CharCount,
UshortList Charmap,
GlyphInfoList GlyphInfo,
int* Advances,
LayoutOffset* Offsets
)
{
UpdateGlyphFlags(Font, GlyphInfo, 0, GlyphInfo.Length, false, GlyphFlags.NotChanged);
// if client did not supply us with workspace
// we will create our own (temporarily)
if (workspace == null)
{
workspace = new OpenTypeLayoutWorkspace();
}
ushort lookupCount=Lookups.LookupCount(Table);
//Compile feature set
CompileFeatureSet(
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Table,
LangSys,
Features,
lookupCount,
workspace
);
OpenTypeLayoutCache.InitCache(Font, TableTag, GlyphInfo, workspace);
for(ushort lookupIndex = 0; lookupIndex < lookupCount; lookupIndex++)
{
if (!workspace.IsAggregatedFlagSet(lookupIndex))
{
continue;
}
int firstChar=0,
afterLastChar=0,
firstGlyph=0,
afterLastGlyph=0;
OpenTypeLayoutCache.FindNextLookup(workspace,
GlyphInfo,
lookupIndex,
out lookupIndex,
out firstGlyph);
// We need to check this again, because FindNextLookup will change lookupIndex
if (lookupIndex >= lookupCount)
{
break;
}
if (!workspace.IsAggregatedFlagSet(lookupIndex))
{
continue;
}
LookupTable lookup = Lookups.Lookup(Table, lookupIndex);
uint parameter=0;
bool isLookupReversal = IsLookupReversal(TableTag, lookup.LookupType());
while(firstGlyph < GlyphInfo.Length) // While we have ranges to work on
{
if (!OpenTypeLayoutCache.FindNextGlyphInLookup(workspace, lookupIndex, isLookupReversal, ref firstGlyph, ref afterLastGlyph))
{
firstGlyph = afterLastGlyph;
}
if (firstGlyph < afterLastGlyph) // Apply lookup while in one range
{
int nextGlyph;
int oldLength = GlyphInfo.Length;
int glyphsAfterLastChar = oldLength - afterLastGlyph;
bool match = ApplyLookup(
Font, // In: Font access interface
TableTag, // Layout table tag (GSUB or GPOS)
Table, // Layout table (GSUB or GPOS)
Metrics, // In: LayoutMetrics
lookup, // Lookup definition structure
CharCount,
Charmap, // In: Char to glyph mapping
GlyphInfo, // In/out: List of GlyphInfo structs
Advances, // In/out: Glyph adv.widths
Offsets, // In/out: Glyph offsets
firstGlyph, // where to apply it
afterLastGlyph, // how long is a context we can use
parameter, // lookup parameter
0, // Nesting level for contextual lookups
out nextGlyph // out: next glyph index
// !!!: for reversal lookup, should
// return new afterLastGlyph
);
if (match)
{
//Adjust range end if length changed,
// for reversal changes happens beyond afterLast, no change needed
if (!isLookupReversal)
{
OpenTypeLayoutCache.OnGlyphsChanged(workspace, GlyphInfo, oldLength, firstGlyph, nextGlyph);
afterLastGlyph = GlyphInfo.Length - glyphsAfterLastChar;
firstGlyph = nextGlyph;
}
else
{
OpenTypeLayoutCache.OnGlyphsChanged(workspace, GlyphInfo, oldLength, nextGlyph, afterLastGlyph);
afterLastGlyph = nextGlyph;
}
}
else
{
if (isLookupReversal)
afterLastGlyph = nextGlyph;
else
firstGlyph = nextGlyph;
}
}
else // End of range. Get next
{
GetNextEnabledGlyphRange(
FeatureSet,
featureCount,
featureSetOffset,
Table,
workspace,
LangSys,
Features,
lookupIndex,
CharCount,
Charmap,
afterLastChar,
afterLastGlyph,
GlyphInfo.Length,
out firstChar,
out afterLastChar,
out firstGlyph,
out afterLastGlyph,
out parameter);
}
}
}
}
internal static OpenTypeLayoutResult SubstituteGlyphs(
IOpenTypeFont Font, // In: Font access interface
OpenTypeLayoutWorkspace workspace, // In: Workspace for layout engine
uint ScriptTag, // In: Script tag
uint LangSysTag, // In: LangSys tag
Feature[] FeatureSet, // In: List of features to apply
int featureCount, // In: Actual number of features in FeatureSet
int featureSetOffset,
int CharCount, // In: Characters count (i.e. Charmap.Length);
UshortList Charmap, // In/out: Char to glyph mapping
GlyphInfoList Glyphs // In/out: List of GlyphInfo structs
)
{
try
{
FontTable GsubTable = Font.GetFontTable(OpenTypeTags.GSUB);
if (!GsubTable.IsPresent) {return OpenTypeLayoutResult.ScriptNotFound;}
GSUBHeader GsubHeader = new GSUBHeader(0);
ScriptList ScriptList = GsubHeader.GetScriptList(GsubTable);
ScriptTable Script = ScriptList.FindScript(GsubTable,ScriptTag);
if (Script.IsNull) {return OpenTypeLayoutResult.ScriptNotFound;}
LangSysTable LangSys = Script.FindLangSys(GsubTable,LangSysTag);
if (LangSys.IsNull) {return OpenTypeLayoutResult.LangSysNotFound;}
FeatureList FeatureList = GsubHeader.GetFeatureList(GsubTable);
LookupList LookupList = GsubHeader.GetLookupList(GsubTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GSUB,
GsubTable,
new LayoutMetrics(), //it is not needed for substitution
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
null,
null
);
}
catch (FileFormatException)
{
return OpenTypeLayoutResult.BadFontTable;
}
return OpenTypeLayoutResult.Success;
}
internal static OpenTypeLayoutResult PositionGlyphs(
IOpenTypeFont Font,
OpenTypeLayoutWorkspace workspace,
uint ScriptTag,
uint LangSysTag,
LayoutMetrics Metrics,
Feature[] FeatureSet,
int featureCount,
int featureSetOffset,
int CharCount,
UshortList Charmap,
GlyphInfoList Glyphs,
int* Advances,
LayoutOffset* Offsets
)
{
try
{
FontTable GposTable = Font.GetFontTable(OpenTypeTags.GPOS);
if (!GposTable.IsPresent) {return OpenTypeLayoutResult.ScriptNotFound;}
GPOSHeader GposHeader = new GPOSHeader(0);
ScriptList ScriptList = GposHeader.GetScriptList(GposTable);
ScriptTable Script = ScriptList.FindScript(GposTable,ScriptTag);
if (Script.IsNull) {return OpenTypeLayoutResult.ScriptNotFound;}
LangSysTable LangSys = Script.FindLangSys(GposTable,LangSysTag);
if (LangSys.IsNull) {return OpenTypeLayoutResult.LangSysNotFound;}
FeatureList FeatureList = GposHeader.GetFeatureList(GposTable);
LookupList LookupList = GposHeader.GetLookupList(GposTable);
LayoutEngine.ApplyFeatures(
Font,
workspace,
OpenTypeTags.GPOS,
GposTable,
Metrics,
LangSys,
FeatureList,
LookupList,
FeatureSet,
featureCount,
featureSetOffset,
CharCount,
Charmap,
Glyphs,
Advances,
Offsets
);
}
catch (FileFormatException)
{
return OpenTypeLayoutResult.BadFontTable;
}
return OpenTypeLayoutResult.Success;
}
