font: freetype supports font variation settings

pkg/freetype/Library.zig

@@ -57,6 +57,11 @@ pub fn initMemoryFace(self: Library, data: []const u8, index: i32) Error!Face {
     return face;
 }
 
+/// Call when you're done with a loaded MM var.
+pub fn doneMMVar(self: Library, mm: *c.FT_MM_Var) void {
+    _ = c.FT_Done_MM_Var(self.handle, mm);
+}
+
 pub const Version = struct {
     major: i32,
     minor: i32,

pkg/freetype/face.zig

@@ -24,6 +24,12 @@ pub const Face = struct {
         return c.FT_HAS_COLOR(self.handle);
     }
 
+    /// A macro that returns true whenever a face object contains some
+    /// multiple masters.
+    pub fn hasMultipleMasters(self: Face) bool {
+        return c.FT_HAS_MULTIPLE_MASTERS(self.handle);
+    }
+
     /// A macro that returns true whenever a face object contains a scalable
     /// font face (true for TrueType, Type 1, Type 42, CID, OpenType/CFF,
     /// and PFR font formats).
@@ -95,6 +101,33 @@ pub const Face = struct {
         const res = c.FT_Get_Sfnt_Name(self.handle, @intCast(i), &name);
         return if (intToError(res)) |_| name else |err| err;
     }
+
+    /// Retrieve the font variation descriptor for a font.
+    pub fn getMMVar(self: Face) Error!*c.FT_MM_Var {
+        var result: *c.FT_MM_Var = undefined;
+        const res = c.FT_Get_MM_Var(self.handle, @ptrCast(&result));
+        return if (intToError(res)) |_| result else |err| err;
+    }
+
+    /// Get the design coordinates of the currently selected interpolated font.
+    pub fn getVarDesignCoordinates(self: Face, coords: []c.FT_Fixed) Error!void {
+        const res = c.FT_Get_Var_Design_Coordinates(
+            self.handle,
+            @intCast(coords.len),
+            coords.ptr,
+        );
+        return intToError(res);
+    }
+
+    /// Choose an interpolated font design through design coordinates.
+    pub fn setVarDesignCoordinates(self: Face, coords: []c.FT_Fixed) Error!void {
+        const res = c.FT_Set_Var_Design_Coordinates(
+            self.handle,
+            @intCast(coords.len),
+            coords.ptr,
+        );
+        return intToError(res);
+    }
 };
 
 /// An enumeration to specify indices of SFNT tables loaded and parsed by

pkg/freetype/freetype-zig.h

@@ -1,5 +1,6 @@
 #include <ft2build.h>
 #include FT_FREETYPE_H
 #include FT_TRUETYPE_TABLES_H
+#include <freetype/ftmm.h>
 #include <freetype/ftsnames.h>
 #include <freetype/ttnameid.h>