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, 42 insertions, 0 deletions

diff --git a/tests/TypefaceTest.cpp b/tests/TypefaceTest.cpp
index 757f3a5e44..cc04fa24ce 100644
--- a/tests/TypefaceTest.cpp
+++ b/tests/TypefaceTest.cpp
@@ -226,6 +226,43 @@ DEF_TEST(Typeface, reporter) {
     REPORTER_ASSERT(reporter, SkTypeface::Equal(t2.get(), nullptr));
 }
 
+DEF_TEST(TypefaceAxesParameters, reporter) {
+    std::unique_ptr<SkStreamAsset> distortable(GetResourceAsStream("fonts/Distortable.ttf"));
+    if (!distortable) {
+        REPORT_FAILURE(reporter, "distortable", SkString());
+        return;
+    }
+    constexpr int numberOfAxesInDistortable = 1;
+    constexpr SkScalar minAxisInDistortable = 0.5;
+    constexpr SkScalar defAxisInDistortable = 1;
+    constexpr SkScalar maxAxisInDistortable = 2;
+    constexpr bool axisIsHiddenInDistortable = false;
+
+    sk_sp<SkFontMgr> fm = SkFontMgr::RefDefault();
+
+    SkFontArguments params;
+    sk_sp<SkTypeface> typeface = fm->makeFromStream(std::move(distortable), params);
+
+    if (!typeface) {
+        // Not all SkFontMgr can makeFromStream().
+        return;
+    }
+
+    SkFontParameters::Variation::Axis parameter[numberOfAxesInDistortable];
+    int count = typeface->getVariationDesignParameters(parameter, SK_ARRAY_COUNT(parameter));
+    if (count == -1) {
+        return;
+    }
+
+    REPORTER_ASSERT(reporter, count == SK_ARRAY_COUNT(parameter));
+    REPORTER_ASSERT(reporter, parameter[0].min == minAxisInDistortable);
+    REPORTER_ASSERT(reporter, parameter[0].def == defAxisInDistortable);
+    REPORTER_ASSERT(reporter, parameter[0].max == maxAxisInDistortable);
+    REPORTER_ASSERT(reporter, parameter[0].tag == SkSetFourByteTag('w','g','h','t'));
+    REPORTER_ASSERT(reporter, parameter[0].isHidden() == axisIsHiddenInDistortable);
+
+}
+
 namespace {
 
 class EmptyTypeface : public SkTypeface {
@@ -264,6 +301,11 @@ protected:
     {
         return 0;
     }
+    int onGetVariationDesignParameters(SkFontParameters::Variation::Axis parameters[],
+                                       int parameterCount) const override
+    {
+        return 0;
+    }
     int onGetTableTags(SkFontTableTag tags[]) const override { return 0; }
     size_t onGetTableData(SkFontTableTag, size_t, size_t, void*) const override { return 0; }
 };