feat(harfbuzz): initial Skia integration (revery-ui#927)

* Integrated Skia into Harfbuzz

* Fixed dune build errors

* Rename hb_face_from_bytes -> hb_face_from_data

* Add suppression for fontconfig

* Remove duplicate file

* Change CI command for HarfbuzzCLI

* Use String_val in rehb_face_from_bytes

* String_val => Bp_val

* Harfbuzz: return NULL -> CAMLreturn(Val_error("File not found"))

* Remove Cstubs include

* Fix CLI not building on Windows

* Add OS to script

.ci/esy-build-steps.yml

@@ -13,8 +13,8 @@ steps:
     displayName: 'esy @test run'
   - script: esy @examples install
     displayName: 'esy @examples install'
-  - script: esy @examples x HarfbuzzCli
-    displayName: 'esy @examples x HarfbuzzCli'
+  - script: esy @examples run-harfbuzz
+    displayName: 'esy @examples run-harfbuzz'
   - script: esy @examples x FontQuery -family=Arial
     displayName: 'esy @examples x FontQuery -family=Arial'
   - script: esy @examples x SkiaCli

examples.json

@@ -1,7 +1,8 @@
 {
   "source": "./package.json",
   "scripts": {
-      "run": "esy x Examples"
+      "run": "esy @examples x Examples",
+      "run-harfbuzz": "esy @examples x bash -c run-harfbuzz.sh #{os}"
   },
   "override": {
       "build": ["dune build -p font-manager,harfbuzz,skia,Revery,ReveryExamples -j4"],

examples/harfbuzz-cli/HarfbuzzCli.re

@@ -1,4 +1,5 @@
 open Harfbuzz;
+open Skia;
 
 Printexc.record_backtrace(true);
 
@@ -13,12 +14,15 @@ let getExecutingDirectory = () =>
   isNative ? Filename.dirname(Sys.argv[0]) ++ Filename.dir_sep : "";
 
 let run = () => {
-  let fontPath = getExecutingDirectory() ++ "Roboto-Regular.ttf";
-  let result = Harfbuzz.hb_new_face(fontPath);
+  let fontManager = FontManager.makeDefault();
+  let style = FontStyle.make(400, 5, Upright);
+  let maybeTypeface =
+    FontManager.matchFamilyStyle(fontManager, "Arial", style);
+  let result = maybeTypeface |> Option.map(face => hb_face_from_skia(face));
 
   switch (result) {
-  | Error(msg) => failwith(msg)
-  | Ok(font) =>
+  | Some(Error(msg)) => failwith(msg)
+  | Some(Ok(font)) =>
     let show = ({glyphId, cluster}: hb_shape) =>
       Printf.sprintf("GlyphID: %d Cluster: %d", glyphId, cluster);
 
@@ -30,6 +34,7 @@ let run = () => {
     renderString("abc");
     renderString("!=ajga");
     renderString("a==>b");
+  | None => failwith("Font Arial not found!")
   };
 };
 

examples/harfbuzz-cli/dune

@@ -3,3 +3,8 @@
  (package ReveryExamples)
  (public_name HarfbuzzCli)
  (libraries bigarray harfbuzz reason-native-crash-utils.asan))
+
+(install
+ (section bin)
+ (package ReveryExamples)
+ (files run-harfbuzz.sh))

examples/harfbuzz-cli/run-harfbuzz.sh

@@ -0,0 +1,6 @@
+set -e
+
+CWD=$(dirname $0)
+if [[ $1 == 'windows' ]]; then executable="HarfbuzzCli.exe"; else executable="HarfbuzzCli"; fi
+
+LSAN_OPTIONS=suppressions=lsan.supp $CWD/$executable

lsan.supp

@@ -0,0 +1,2 @@
+# Add suppression for libfontconfig, which has known leaks
+leak:*libfontconfig*

src/Font/FontCache.re

@@ -66,7 +66,7 @@ let load: string => result(t, string) =
       let assetPath = Environment.getAssetPath(fontName);
 
       let skiaTypeface = Skia.Typeface.makeFromFile(assetPath, 0);
-      let harfbuzzFace = Harfbuzz.hb_new_face(assetPath);
+      let harfbuzzFace = Harfbuzz.hb_face_from_path(assetPath);
 
       let metricsCache = MetricsLruHash.create(~initialSize=8, 64);
       let shapeCache =

src/reason-harfbuzz/Harfbuzz.re

@@ -5,15 +5,18 @@ type hb_shape = {
 
 module Internal = {
   type face;
-  external hb_new_face: string => result(face, string) = "rehb_new_face";
+  external hb_face_from_path: string => result(face, string) =
+    "rehb_face_from_path";
+  external hb_face_from_data: (string, int) => result(face, string) =
+    "rehb_face_from_bytes";
   external hb_destroy_face: face => unit = "rehb_destroy_face";
   external hb_shape: (face, string) => array(hb_shape) = "rehb_shape";
 };
 
 type hb_face = {face: Internal.face};
 
-let hb_new_face = str => {
-  switch (Internal.hb_new_face(str)) {
+let hb_face_from_path = str => {
+  switch (Internal.hb_face_from_path(str)) {
   | Error(msg) => Error(msg)
   | Ok(face) =>
     let ret = {face: face};
@@ -25,4 +28,24 @@ let hb_new_face = str => {
   };
 };
 
+let hb_new_face = str => hb_face_from_path(str);
+
+let hb_face_from_skia = sk_typeface => {
+  let stream = Skia.Typeface.toStream(sk_typeface);
+  let length = Skia.Stream.getLength(stream);
+  let data = Skia.Data.makeFromStream(stream, length);
+  let bytes = Skia.Data.makeString(data);
+
+  switch (Internal.hb_face_from_data(bytes, String.length(bytes))) {
+  | Error(_) as e => e
+  | Ok(face) =>
+    let ret = {face: face};
+
+    let finalise = ({face}) => Internal.hb_destroy_face(face);
+
+    Gc.finalise(finalise, ret);
+    Ok(ret);
+  };
+};
+
 let hb_shape = ({face}, str) => Internal.hb_shape(face, str);

src/reason-harfbuzz/Harfbuzz.rei

@@ -5,5 +5,10 @@ type hb_shape = {
   cluster: int,
 };
 
+let hb_face_from_path: string => result(hb_face, string);
+let hb_face_from_skia: Skia.Typeface.t => result(hb_face, string);
+
+[@ocaml.deprecated "Deprecated in favor of hb_face_from_path"]
 let hb_new_face: string => result(hb_face, string);
+
 let hb_shape: (hb_face, string) => array(hb_shape);

src/reason-harfbuzz/dune

@@ -1,6 +1,7 @@
 (library
  (name harfbuzz)
  (public_name harfbuzz)
+ (libraries skia ctypes)
  (library_flags
   (:include flags.sexp))
  (c_flags (:include c_flags.sexp))

src/reason-harfbuzz/harfbuzz.cpp

@@ -9,6 +9,7 @@
 #include <hb-ot.h>
 #include <hb.h>
 
+
 /* #define TEST_FONT "E:/FiraCode-Regular.ttf" */
 /* #define TEST_FONT "E:/Hasklig-Medium.otf" */
 /* #define TEST_FONT "E:/Cassandra.ttf" */
@@ -36,21 +37,7 @@ CAMLprim value Val_error(const char *szMsg) {
 
 /* Use native open type implementation to load font
   https://github.com/harfbuzz/harfbuzz/issues/255 */
-hb_font_t *get_font_ot(const char *filename, int size) {
-  FILE *file = fopen(filename, "rb");
-
-  if (!file) {
-    return NULL;
-  }
-
-  fseek(file, 0, SEEK_END);
-  unsigned int length = ftell(file);
-  fseek(file, 0, SEEK_SET);
-
-  char *data = (char *)malloc(length);
-  fread(data, length, 1, file);
-  fclose(file);
-
+hb_font_t *get_font_ot(char *data, int length, int size) {
   hb_blob_t *blob =
       hb_blob_create(data, length, HB_MEMORY_MODE_WRITABLE, (void *)data, free);
   hb_face_t *face = hb_face_create(blob, 0);
@@ -76,14 +63,46 @@ CAMLprim value rehb_destroy_face(value vFont) {
   CAMLreturn(Val_unit);
 }
 
-CAMLprim value rehb_new_face(value vString) {
+CAMLprim value rehb_face_from_path(value vString) {
   CAMLparam1(vString);
   CAMLlocal1(ret);
 
   const char *szFont = String_val(vString);
+
+  FILE *file = fopen(szFont, "rb");
+
+  if (!file) {
+    CAMLreturn(Val_error("File does not exist"));
+  }
+
+  fseek(file, 0, SEEK_END);
+  unsigned int length = ftell(file);
+  fseek(file, 0, SEEK_SET);
+
+  char *data = (char *)malloc(length);
+  fread(data, length, 1, file);
+  fclose(file);
+
+  hb_font_t *hb_font;
+  hb_font = get_font_ot(data, length, 12 /*iSize*/ * 64);
+
+  if (!hb_font) {
+    ret = Val_error("Unable to load font");
+  } else {
+    ret = Val_success((value)hb_font);
+  }
+  CAMLreturn(ret);
+}
+
+CAMLprim value rehb_face_from_bytes(value vPtr, value vLength) {
+  CAMLparam2(vPtr, vLength);
+  CAMLlocal1(ret);
+
+  char *data = Bp_val(vPtr);
+  int length = Int_val(vLength);
 
   hb_font_t *hb_font;
-  hb_font = get_font_ot(szFont, 12 /*iSize*/ * 64);
+  hb_font = get_font_ot(data, length, 12 /*iSize*/ * 64);
 
   if (!hb_font) {
     ret = Val_error("Unable to load font");