Fallback fonts for wasm

lib/src/rive_text_wasm.dart

@@ -15,6 +15,7 @@ late js.JsFunction _deleteFont;
 late js.JsFunction _makeGlyphPath;
 late js.JsFunction _deleteGlyphPath;
 late js.JsFunction _shapeText;
+late js.JsFunction _setFallbackFonts;
 late js.JsFunction _deleteShapeResult;
 late js.JsFunction _breakLines;
 late js.JsFunction _deleteLines;
@@ -505,18 +506,21 @@ Future<void> initFont() async {
   html.document.body!.append(script);
   await script.onLoad.first;
 
-  var init = js.context['RiveText'] as js.JsFunction;
-  var promise = init.apply(<dynamic>[]) as js.JsObject;
+  var initWasm = js.context['RiveText'] as js.JsFunction;
+  var promise = initWasm.apply(<dynamic>[]) as js.JsObject;
   var thenFunction = promise['then'] as js.JsFunction;
   var completer = Completer<void>();
   thenFunction.apply(
     <dynamic>[
       (js.JsObject module) {
+        var init = module['init'] as js.JsFunction;
+        init.apply(<dynamic>[]);
         _makeFont = module['makeFont'] as js.JsFunction;
         _deleteFont = module['deleteFont'] as js.JsFunction;
         _makeGlyphPath = module['makeGlyphPath'] as js.JsFunction;
         _deleteGlyphPath = module['deleteGlyphPath'] as js.JsFunction;
         _shapeText = module['shapeText'] as js.JsFunction;
+        _setFallbackFonts = module['setFallbackFonts'] as js.JsFunction;
         _deleteShapeResult = module['deleteShapeResult'] as js.JsFunction;
         _breakLines = module['breakLines'] as js.JsFunction;
         _deleteLines = module['deleteLines'] as js.JsFunction;
@@ -527,3 +531,16 @@ Future<void> initFont() async {
   );
   return completer.future;
 }
+
+void setFallbackFonts(List<Font> fonts) {
+  _setFallbackFonts.apply(
+    <dynamic>[
+      Uint32List.fromList(
+        fonts
+            .cast<FontWasm>()
+            .map((font) => font.fontPtr)
+            .toList(growable: false),
+      ),
+    ],
+  );
+}

macos/rive_text/rive_text.cpp

@@ -118,8 +118,6 @@ static rive::rcp<rive::Font> pickFallbackFont(rive::Span<const rive::Unichar> mi
         HBFont* font = static_cast<HBFont*>(fallbackFonts[i]);
         if (i == length - 1 || font->hasGlyph(missing))
         {
-            fprintf(stderr, "FONT COUNT IS: %d\n", font->debugging_refcnt());
-
             rive::rcp<rive::Font> rcFont = rive::rcp<rive::Font>(font);
             // because the font was released at load time, we need to give it an
             // extra ref whenever we bump it to a reference counted pointer.

premake5_rive_plugin.lua

@@ -219,7 +219,7 @@ do
         '-DANSI_DECLARATORS'
     }
 
-    filter {'system:macosx'}
+    filter {'not options:arch=wasm', 'system:macosx'}
     do
         files {
             'macos/rive_text/rive_text.cpp'

wasm/js/rive_text.js

@@ -1,7 +1,4 @@
 RiveText["onRuntimeInitialized"] = function () {
-  var HEAPU8 = RiveText["HEAPU8"];
-  var HEAPU32 = RiveText["HEAPU32"];
-  var HEAPF32 = RiveText["HEAPF32"];
   var nativeMakeGlyphPath = RiveText["makeGlyphPath"];
   var move = 0;
   var line = 1;
@@ -13,7 +10,7 @@ RiveText["onRuntimeInitialized"] = function () {
     var verbCount = glyph[3];
     var ptsPtr = glyph[1];
     var verbPtr = glyph[2];
-    var verbs = HEAPU8["subarray"](verbPtr, verbPtr + verbCount);
+    var verbs = RiveText["HEAPU8"]["subarray"](verbPtr, verbPtr + verbCount);
 
     let pointCount = 0;
     for (var verb of verbs) {
@@ -37,7 +34,10 @@ RiveText["onRuntimeInitialized"] = function () {
     return {
       "rawPath": glyph[0],
       "verbs": verbs,
-      "points": HEAPF32["subarray"](ptsStart, ptsStart + pointCount * 2),
+      "points": RiveText["HEAPF32"]["subarray"](
+        ptsStart,
+        ptsStart + pointCount * 2
+      ),
     };
   };
 
@@ -46,7 +46,7 @@ RiveText["onRuntimeInitialized"] = function () {
     var shapeResult = nativeShapeText(codeUnits, runsList);
     return {
       "rawResult": shapeResult,
-      "results": HEAPU8["subarray"](shapeResult),
+      "results": RiveText["HEAPU8"]["subarray"](shapeResult),
     };
   };
 
@@ -55,7 +55,7 @@ RiveText["onRuntimeInitialized"] = function () {
     var breakResult = nativeBreakLines(shape, width, align);
     return {
       "rawResult": breakResult,
-      "results": HEAPU8["subarray"](breakResult),
+      "results": RiveText["HEAPU8"]["subarray"](breakResult),
     };
   };
 };

wasm/rive_text_bindings.cpp

@@ -99,6 +99,41 @@ void deleteLines(WasmPtr lines)
     delete reinterpret_cast<rive::SimpleArray<rive::SimpleArray<rive::GlyphLine>>*>(lines);
 }
 
+std::vector<rive::Font*> fallbackFonts;
+
+void setFallbackFonts(emscripten::val fontsList)
+{
+    std::vector<int> fonts(fontsList["length"].as<unsigned>());
+    {
+        emscripten::val memoryView{emscripten::typed_memory_view(fonts.size(), fonts.data())};
+        memoryView.call<void>("set", fontsList);
+    }
+
+    fallbackFonts = std::vector<rive::Font*>();
+    for (auto fontPtr : fonts)
+    {
+        fallbackFonts.push_back(reinterpret_cast<rive::Font*>(fontPtr));
+    }
+}
+
+static rive::rcp<rive::Font> pickFallbackFont(rive::Span<const rive::Unichar> missing)
+{
+    size_t length = fallbackFonts.size();
+    for (size_t i = 0; i < length; i++)
+    {
+        HBFont* font = static_cast<HBFont*>(fallbackFonts[i]);
+        if (i == length - 1 || font->hasGlyph(missing))
+        {
+            rive::rcp<rive::Font> rcFont = rive::rcp<rive::Font>(font);
+            // because the font was released at load time, we need to give it an
+            // extra ref whenever we bump it to a reference counted pointer.
+            rcFont->ref();
+            return rcFont;
+        }
+    }
+    return nullptr;
+}
+
 WasmPtr shapeText(emscripten::val codeUnits, emscripten::val runsList)
 {
     std::vector<uint8_t> runsBytes(runsList["byteLength"].as<unsigned>());
@@ -121,12 +156,17 @@ WasmPtr shapeText(emscripten::val codeUnits, emscripten::val runsList)
     {
         auto result = (WasmPtr) new rive::SimpleArray<rive::Paragraph>(
             runs[0].font->shapeText(codeUnitArray, rive::Span(runs, runCount)));
-
         return result;
     }
     return {};
 }
 
+void init()
+{
+    fallbackFonts.clear();
+    HBFont::gFallbackProc = pickFallbackFont;
+}
+
 #ifdef DEBUG
 #define OFFSET_OF(type, member) ((int)(intptr_t) & (((type*)(void*)0)->member))
 void assertSomeAssumptions()
@@ -177,10 +217,12 @@ EMSCRIPTEN_BINDINGS(RiveText)
     function("deleteGlyphPath", &deleteGlyphPath);
 
     function("shapeText", &shapeText);
+    function("setFallbackFonts", &setFallbackFonts);
     function("deleteShapeResult", &deleteShapeResult);
 
     function("breakLines", &breakLines);
     function("deleteLines", &deleteLines);
+    function("init", &init);
 
 #ifdef DEBUG
     function("assertSomeAssumptions", &assertSomeAssumptions);