Add SkTypeface::getVariationDesignParameters

This adds a way for users to query the axis parameters for a typeface.

Change-Id: Idc2ac0d84bc7ae2ca484ae410cba5b01883418e5
Reviewed-on: https://skia-review.googlesource.com/137706
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Mike Reed <reed@google.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/include/core/SkFontParameters.h b/include/core/SkFontParameters.h
new file mode 100644
index 0000000000..7d3c407add
--- /dev/null
+++ b/include/core/SkFontParameters.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkFontParameters_DEFINED
+#define SkFontParameters_DEFINED
+
+#include "SkScalar.h"
+#include "SkTypes.h"
+
+struct SkFontParameters {
+    struct Variation {
+        // Parameters in a variation font axis.
+        struct Axis {
+            // Four character identifier of the font axis (weight, width, slant, italic...).
+            SkFourByteTag tag;
+            // Minimum value supported by this axis.
+            float min;
+            // Default value set by this axis.
+            float def;
+            // Maximum value supported by this axis. The maximum can equal the minimum.
+            float max;
+            // Return whether this axis is recommended to be remain hidden in user interfaces.
+            bool isHidden() const { return flags & HIDDEN; }
+            // Set this axis to be remain hidden in user interfaces.
+            void setHidden(bool hidden) { flags = hidden ? (flags | HIDDEN) : (flags & ~HIDDEN); }
+        private:
+            static constexpr uint16_t HIDDEN = 0x0001;
+            // Attributes for a font axis.
+            uint16_t flags;
+        };
+    };
+};
+
+#endif