Add SkTypeface::makeClone.

This adds an method to typeface to allow users to create a copy of the
typeface with different arguments for its parameters. This is far more
efficient when animating a variation font.

Change-Id: Ie41a5b76bef8eaf05b56b65774eaf38aad0dc4cf
Reviewed-on: https://skia-review.googlesource.com/132934
Commit-Queue: Bruce Wang <brucewang@google.com>
Reviewed-by: Bruce Wang <brucewang@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>

1 files changed, 13 insertions, 5 deletions

diff --git a/gm/fontscalerdistortable.cpp b/gm/fontscalerdistortable.cpp
index 49d254de36..5778ce0200 100644
--- a/gm/fontscalerdistortable.cpp
+++ b/gm/fontscalerdistortable.cpp
@@ -35,8 +35,10 @@ protected:
         paint.setLCDRenderText(true);
         sk_sp<SkFontMgr> fontMgr(SkFontMgr::RefDefault());
 
-        std::unique_ptr<SkStreamAsset> distortable(GetResourceAsStream("fonts/Distortable.ttf"));
-        if (!distortable) {
+        std::unique_ptr<SkStreamAsset> distortableStream(GetResourceAsStream("fonts/Distortable.ttf"));
+        sk_sp<SkTypeface> distortable(MakeResourceAsTypeface("fonts/Distortable.ttf"));
+        
+        if (!distortableStream) {
             return;
         }
         const char* text = "abc";
@@ -48,13 +50,19 @@ protected:
                 SkScalar y = SkIntToScalar(20);
 
                 SkFourByteTag tag = SkSetFourByteTag('w','g','h','t');
-                SkScalar styleValue = SkDoubleToScalar(0.5 + (5*j + i) * ((2.0 - 0.5) / (2 * 5)));
+                SkScalar styleValue = SkDoubleToScalar(0.5 + (5 * j + i) * ((2.0 - 0.5) / (2 * 5)));
                 SkFontArguments::VariationPosition::Coordinate coordinates[] = {{tag, styleValue}};
                 SkFontArguments::VariationPosition position =
                         { coordinates, SK_ARRAY_COUNT(coordinates) };
-                paint.setTypeface(sk_sp<SkTypeface>(fontMgr->makeFromStream(
-                        distortable->duplicate(),
+                if (j == 0 && distortable) {
+                    paint.setTypeface(sk_sp<SkTypeface>(
+                        distortable->makeClone(
+                            SkFontArguments().setVariationDesignPosition(position))));
+                } else {
+                    paint.setTypeface(sk_sp<SkTypeface>(fontMgr->makeFromStream(
+                        distortableStream->duplicate(),
                         SkFontArguments().setVariationDesignPosition(position))));
+                }
 
                 SkAutoCanvasRestore acr(canvas, true);
                 canvas->translate(SkIntToScalar(30 + i * 100), SkIntToScalar(20));