Add some font functions to the C API

Cargo.lock

@@ -1397,6 +1397,7 @@ name = "pathfinder_c"
 version = "0.1.0"
 dependencies = [
  "cbindgen 0.8.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "font-kit 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.54 (registry+https://github.com/rust-lang/crates.io-index)",
  "pathfinder_canvas 0.1.0",

c/Cargo.toml

@@ -9,6 +9,7 @@ build = "build.rs"
 crate-type = ["staticlib"]
 
 [dependencies]
+font-kit = "0.2"
 gl = "0.6"
 libc = "0.2"
 

c/src/lib.rs

@@ -10,6 +10,7 @@
 
 //! C bindings to Pathfinder.
 
+use font_kit::handle::Handle;
 use gl;
 use pathfinder_canvas::{CanvasFontContext, CanvasRenderingContext2D, FillStyle, LineJoin};
 use pathfinder_canvas::{Path2D, TextMetrics};
@@ -55,6 +56,9 @@ pub const PF_RENDERER_OPTIONS_FLAGS_HAS_BACKGROUND_COLOR: u8 = 0x1;
 
 // Types
 
+// External: `font-kit`
+pub type FKHandleRef = *mut Handle;
+
 // `canvas`
 pub type PFCanvasRef = *mut CanvasRenderingContext2D;
 pub type PFPathRef = *mut Path2D;
@@ -154,6 +158,16 @@ pub unsafe extern "C" fn PFCanvasFontContextCreateWithSystemSource() -> PFCanvas
     Box::into_raw(Box::new(CanvasFontContext::from_system_source()))
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn PFCanvasFontContextCreateWithFonts(fonts: *const FKHandleRef,
+                                                            font_count: usize)
+                                                            -> PFCanvasFontContextRef {
+    let fonts = slice::from_raw_parts(fonts, font_count);
+    Box::into_raw(Box::new(CanvasFontContext::from_fonts(fonts.into_iter().map(|font| {
+        (**font).clone()
+    }))))
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn PFCanvasFontContextDestroy(font_context: PFCanvasFontContextRef) {
     drop(Box::from_raw(font_context))
@@ -250,6 +264,18 @@ pub unsafe extern "C" fn PFCanvasSetLineDashOffset(canvas: PFCanvasRef, new_offs
     (*canvas).set_line_dash_offset(new_offset)
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn PFCanvasSetFontByPostScriptName(canvas: PFCanvasRef,
+                                                         postscript_name: *const c_char,
+                                                         postscript_name_len: usize) {
+    (*canvas).set_font_by_postscript_name(to_rust_string(&postscript_name, postscript_name_len))
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn PFCanvasSetFontSize(canvas: PFCanvasRef, new_font_size: f32) {
+    (*canvas).set_font_size(new_font_size)
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn PFCanvasSetFillStyle(canvas: PFCanvasRef, fill_style: PFFillStyleRef) {
     (*canvas).set_fill_style(*fill_style)