/// <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);
}