Add strikeout metrics for macosunderline-strikethrough

Macos doesn't provide their own strikeout metrics, so instead of using
the font metrics a fallback is used.

Since this seems to be stored separately on freetype too, there might be
a different way to get strikeout position and thickness (without CoreText)

2 files changed, 23 insertions, 16 deletions

diff --git a/font/Cargo.lock b/font/Cargo.lock
index 86d0f8ce..25ed3c7c 100644
--- a/font/Cargo.lock
+++ b/font/Cargo.lock
@@ -28,16 +28,16 @@ dependencies = [
 
 [[package]]
 name = "core-foundation"
-version = "0.4.6"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "core-foundation-sys 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation-sys 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "core-foundation-sys"
-version = "0.4.6"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -45,22 +45,22 @@ dependencies = [
 
 [[package]]
 name = "core-graphics"
-version = "0.12.4"
+version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bitflags 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "core-foundation 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "core-text"
-version = "8.0.0"
+version = "9.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "core-foundation 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "core-graphics 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.36 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -87,10 +87,10 @@ dependencies = [
 name = "font"
 version = "0.1.0"
 dependencies = [
- "core-foundation 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "core-foundation-sys 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "core-graphics 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "core-text 8.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation-sys 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-text 9.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.16.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype-rs 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -259,10 +259,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum cc 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "deaf9ec656256bb25b404c51ef50097207b9cbb29c933d31f92cae5a8a0ffee0"
 "checksum cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c819a1287eb618df47cc647173c5c4c66ba19d888a6e50d605672aed3140de"
 "checksum cmake 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)" = "56d741ea7a69e577f6d06b36b7dff4738f680593dc27a701ffa8506b73ce28bb"
-"checksum core-foundation 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "8047f547cd6856d45b1cdd75ef8d2f21f3d0e4bf1dab0a0041b0ae9a5dda9c0e"
-"checksum core-foundation-sys 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "152195421a2e6497a8179195672e9d4ee8e45ed8c465b626f1606d27a08ebcd5"
-"checksum core-graphics 0.12.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8de78908c558a9ba526877d165635c9eaed0818a785a93efddde1c5bfd2ce5d1"
-"checksum core-text 8.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bcad23756dd1dc4b47bf6a914ace27aadb8fa68889db5837af2308d018d0467c"
+"checksum core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "286e0b41c3a20da26536c6000a280585d519fd07b3956b43aed8a79e9edce980"
+"checksum core-foundation-sys 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "716c271e8613ace48344f723b60b900a93150271e5be206212d052bbc0883efa"
+"checksum core-graphics 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fb0ed45fdc32f9ab426238fba9407dfead7bacd7900c9b4dd3f396f46eafdae3"
+"checksum core-text 9.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2bd581c37283d0c23311d179aefbb891f2324ee0405da58a26e8594ab76e5748"
 "checksum euclid 0.16.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b8d33ed9630f5f7a86abb0849e96a585922cc5a640478a36f05f74d96a22655f"
 "checksum expat-sys 2.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "c470ccb972f2088549b023db8029ed9da9426f5affbf9b62efff7009ab8ed5b1"
 "checksum foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f6f339eb8adc052cd2ca78910fda869aefa38d22d5cb648e6485e4d3fc06f3b1"
diff --git a/font/src/darwin/mod.rs b/font/src/darwin/mod.rs
index 89858f77..19c05d5a 100644
--- a/font/src/darwin/mod.rs
+++ b/font/src/darwin/mod.rs
@@ -422,8 +422,13 @@ impl Font {
         let descent = self.ct_font.descent() as f64;
         let leading = self.ct_font.leading() as f64;
         let line_height = (ascent + descent + leading + 0.5).floor();
+
+        // Strikeout and underline metrics
+        // CoreText doesn't provide strikeout so we provide our own
         let underline_position = self.ct_font.underline_position() as f32;
         let underline_thickness = self.ct_font.underline_thickness() as f32;
+        let strikeout_position = line_height as f32 / 2. + descent as f32;
+        let strikeout_thickness = underline_thickness;
 
         Metrics {
             average_advance: average_advance,
@@ -431,6 +436,8 @@ impl Font {
             descent: -(self.ct_font.descent() as f32),
             underline_position,
             underline_thickness,
+            strikeout_position,
+            strikeout_thickness,
         }
     }