Skip to content

Commit

Permalink
Improved TVT parsing (1 loop, not 2)
Browse files Browse the repository at this point in the history 
- also added draft of code so that each tvt has a tents property being an array of [peak, start, end] arrays, instead of named properties
  • Loading branch information
@Lorp
Lorp committed Nov 8, 2024
1 parent 470132e commit 13c44ff
Showing 1 changed file with 44 additions and 26 deletions.
70 changes: 44 additions & 26 deletions src/samsa-core.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@ const SAMSAGLOBAL = {
littleendian: endianness("LE"),
bigendian: endianness("BE"),
fingerprints: { WOFF2: 0x774f4632, TTF: 0x00010000, OTF: 0x4f54544f, true: 0x74727565 }, // 0x4f54544f/"OTTO" is for CFF fonts, 0x74727565/"true" is for Skia.ttf
stdGlyphNames: [".notdef",".null","nonmarkingreturn","space","exclam","quotedbl","numbersign","dollar","percent","ampersand","quotesingle","parenleft","parenright","asterisk","plus","comma","hyphen","period","slash","zero","one","two","three","four","five","six","seven","eight","nine","colon","semicolon","less","equal","greater","question","at","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","bracketleft","backslash","bracketright","asciicircum","underscore","grave","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","braceleft","bar","braceright","asciitilde","Adieresis","Aring","Ccedilla","Eacute","Ntilde","Odieresis","Udieresis","aacute","agrave","acircumflex","adieresis","atilde","aring","ccedilla","eacute","egrave","ecircumflex","edieresis","iacute","igrave","icircumflex","idieresis","ntilde","oacute","ograve","ocircumflex","odieresis","otilde","uacute","ugrave","ucircumflex","udieresis","dagger","degree","cent","sterling","section","bullet","paragraph","germandbls","registered","copyright","trademark","acute","dieresis","notequal","AE","Oslash","infinity","plusminus","lessequal","greaterequal","yen","mu","partialdiff","summation","product","pi","integral","ordfeminine","ordmasculine","Omega","ae","oslash","questiondown","exclamdown","logicalnot","radical","florin","approxequal","Delta","guillemotleft","guillemotright","ellipsis","nonbreakingspace","Agrave","Atilde","Otilde","OE","oe","endash","emdash","quotedblleft","quotedblright","quoteleft","quoteright","divide","lozenge","ydieresis","Ydieresis","fraction","currency","guilsinglleft","guilsinglright","fi","fl","daggerdbl","periodcentered","quotesinglbase","quotedblbase","perthousand","Acircumflex","Ecircumflex","Aacute","Edieresis","Egrave","Iacute","Icircumflex","Idieresis","Igrave","Oacute","Ocircumflex","apple","Ograve","Uacute","Ucircumflex","Ugrave","dotlessi","circumflex","tilde","macron","breve","dotaccent","ring","cedilla","hungarumlaut","ogonek","caron","Lslash","lslash","Scaron","scaron","Zcaron","zcaron","brokenbar","Eth","eth","Yacute","yacute","Thorn","thorn","minus","multiply","onesuperior","twosuperior","threesuperior","onehalf","onequarter","threequarters","franc","Gbreve","gbreve","Idotaccent","Scedilla","scedilla","Cacute","cacute","Ccaron","ccaron","dcroat"],
stdGlyphNames: [".notdef",".null","nonmarkingreturn","space","exclam","quotedbl","numbersign","dollar","percent","ampersand","quotesingle","parenleft","parenright","asterisk","plus","comma","hyphen","period","slash","zero","one","two","three","four","five","six","seven","eight","nine","colon","semicolon","less","equal","greater","question","at","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","bracketleft","backslash","bracketright","asciicircum","underscore","grave","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","braceleft","bar","braceright","asciitilde","Adieresis","Aring","Ccedilla","Eacute","Ntilde","Odieresis","Udieresis","aacute","agrave","acircumflex","adieresis","atilde","aring","ccedilla","eacute","egrave","ecircumflex","edieresis","iacute","igrave","icircumflex","idieresis","ntilde","oacute","ograve","ocircumflex","odieresis","otilde","uacute","ugrave","ucircumflex","udieresis","dagger","degree","cent","sterling","section","bullet","paragraph","germandbls","registered","copyright","trademark","acute","dieresis","notequal","AE","Oslash","infinity","plusminus","lessequal","greaterequal","yen","mu","partialdiff","summation","product","pi","integral","ordfeminine","ordmasculine","Omega","ae","oslash","questiondown","exclamdown","logicalnot","radical","florin","approxequal","Delta","guillemotleft","guillemotright","ellipsis","nonbreakingspace","Agrave","Atilde","Otilde","OE","oe","endash","emdash","quotedblleft","quotedblright","quoteleft","quoteright","divide","lozenge","ydieresis","Ydieresis","fraction","currency","guilsinglleft","guilsinglright","fi","fl","daggerdbl","periodcentered","quotesinglbase","quotedblbase","perthousand","Acircumflex","Ecircumflex","Aacute","Edieresis","Egrave","Iacute","Icircumflex","Idieresis","Igrave","Oacute","Ocircumflex","apple","Ograve","Uacute","Ucircumflex","Ugrave","dotlessi","circumflex","tilde","macron","breve","dotaccent","ring","cedilla","hungarumlaut","ogonek","caron","Lslash","lslash","Scaron","scaron","Zcaron","zcaron","brokenbar","Eth","eth","Yacute","yacute","Thorn","thorn","minus","multiply","onesuperior","twosuperior","threesuperior","onehalf","onequarter","threequarters","franc","Gbreve","gbreve","Idotaccent","Scedilla","scedilla","Cacute","cacute","Ccaron","ccaron","dcroat"], // 258 standard glyph names
};

// format codes
Expand Down Expand Up @@ -2780,28 +2780,54 @@ class SamsaBuffer extends DataView {
const _tupleCount = this.u16;
const tupleCount = _tupleCount & 0x0FFF;
const offsetToSerializedData = this.u16;
const bufS = new SamsaBuffer(this.buffer, tvtStart + offsetToSerializedData);
const sharedPointIds = _tupleCount & GVAR_SHARED_POINT_NUMBERS ? bufS.decodePointIds() : undefined; // get the shared pointIds

// create all the tuples
for (let t=0; t < tupleCount; t++) {
this.seekr(2); // serializedDataSize (we assume serializedData is packed, so we don’t use this)
const flags = this.u16; // tupleIndex in the spec
const tupleIndex = flags & 0x0FFF;
const tvt = {
serializedDataSize: this.u16,
flags: this.u16, // tupleIndex in the spec
numPoints: 0,
sharedTupleId: -1,
peak: [],
start: [],
end: [],
tents: [],
};

// move to a region representation, rather than peak, start, end arrays
// either
// region = [[p0,p1,p2,p3],[s0,s1,s2,s3],[e0,e1,e2,e3]]; // fewer objects in general
// TODO: move to a "region of tents" all-integer representation, rather than peak, start, end arrays
// either (for a 4-axis font):
// region = [[p0,p1,p2,p3],[s0,s1,s2,s3],[e0,e1,e2,e3]]; // fewer objects in general and maybe quicker to read
// or
// region = [[p0,s0,e0],[p1,s1,e1],[p2,s2,e2],[p3,s3,e3]]; // more intuitive, and usually axisCount is max 3 or 4
// region = [[p0,s0,e0],[p1,s1,e1],[p2,s2,e2],[p3,s3,e3]]; // more intuitive, and usually axisCount is max 3 or 4... each subarray is a "tent"
// also consider a single Int16Array
// use a switch on (tvt.flags & GVAR_EMBEDDED_PEAK_TUPLE & GVAR_INTERMEDIATE_REGION)

const tupleIndex = tvt.flags & 0x0FFF;
if (tvt.flags & GVAR_EMBEDDED_PEAK_TUPLE) {
/*
const tell = this.tell();
for (let a=0; a<axisCount; a++) {
const peak = (flags & GVAR_EMBEDDED_PEAK_TUPLE) ? gvar.sharedTuples[tupleIndex][a] : this.f214;
tvt.tents.push(peak > 0 ? [peak, 0, 1] : [peak, -1, 0]);
}
if (flags & GVAR_INTERMEDIATE_REGION) {
for (let a=0; a<axisCount; a++) {
tvt.tents[a][1] = this.f214; // start
}
for (let a=0; a<axisCount; a++) {
tvt.tents[a][2] = this.f214; // end
}
}
for (const tent of tvt.tents) {
if (!isValidTent(tent))
tent[0] = tent[1] = tent[2] = 0;
}
this.seek(tell);
console.log(tvt.tents);
*/

if (flags & GVAR_EMBEDDED_PEAK_TUPLE) {
for (let a=0; a<axisCount; a++) {
tvt.peak[a] = this.f214;
}
Expand All @@ -2811,7 +2837,7 @@ class SamsaBuffer extends DataView {
tvt.peak = gvar.sharedTuples[tupleIndex]; // set the whole peak array at once, TODO: it would be better if we thought in terms of regions, and assigned complete shared regions
}

if (tvt.flags & GVAR_INTERMEDIATE_REGION) {
if (flags & GVAR_INTERMEDIATE_REGION) {
for (let a=0; a<axisCount; a++) {
tvt.start[a] = this.f214;
}
Expand Down Expand Up @@ -2841,27 +2867,17 @@ class SamsaBuffer extends DataView {
tvt.start[a] = tvt.end[a] = tvt.peak[a] = 0;
}
}

tvts.push(tvt); // store the tvt
}

// is our position ok?
console.assert(this.tell() == tvtStart + offsetToSerializedData, "decodeTvts(): current offset is not ok (this.tell() != tvtStart + offsetToSerializedData)", this.tell(), tvtStart + offsetToSerializedData);

// get pointIds and deltas from the serialized data
this.seek(tvtStart + offsetToSerializedData); // jump to the serialized data explicitly
const sharedPointIds = _tupleCount & GVAR_SHARED_POINT_NUMBERS ? this.decodePointIds() : undefined; // get the shared pointIds
for (let t=0; t < tupleCount; t++) { // go thru each tuple
const tvt = tvts[t];
const pointIds = tvt.flags & GVAR_PRIVATE_POINT_NUMBERS ? this.decodePointIds() : sharedPointIds; // use private point ids or use the shared point ids
tvt.allPoints = pointIds.length == 0; // flag special case if all points are used, this triggers IUP!
// get pointIds and deltas from the serialized data
const pointIds = flags & GVAR_PRIVATE_POINT_NUMBERS ? bufS.decodePointIds() : sharedPointIds; // use private point ids or use the shared point ids
tvt.allPoints = pointIds.length == 0; // flag special case if all points are used (when unset this triggers IUP!)
const tupleNumPoints = tvt.allPoints ? glyph.points.length : pointIds.length; // how many deltas do we need?
const xDeltas = this.decodeDeltas(tupleNumPoints);
const yDeltas = this.decodeDeltas(tupleNumPoints);
const xDeltas = bufS.decodeDeltas(tupleNumPoints);
const yDeltas = bufS.decodeDeltas(tupleNumPoints);
tvt.deltas = [];
if (tvt.allPoints) {
for (let pt=0; pt < glyph.points.length; pt++) {
tvt.deltas[pt] = [xDeltas[pt], yDeltas[pt]];
tvt.deltas[pt] = [xDeltas[pt], yDeltas[pt]]; // TODO: try replacing this with tvt.deltas = [xDeltas, yDeltas] so there’s no copying, and having an extra array for IUP to map pointIds in array indices
}
}
else {
Expand All @@ -2876,6 +2892,8 @@ class SamsaBuffer extends DataView {
}
// after this, we no longer need pointIds, right? so it needn’t stick around as a property of the tvt (except for visualization)
}

tvts.push(tvt); // store the tvt
}
}
return tvts;
Expand Down

0 comments on commit 13c44ff

Please sign in to comment.