[skottie] Text line height support

Change-Id: Id5b52e7586aa42400162fd227add28d6ebf3ac11
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212728
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>

modules/skottie/src/SkottieTest.cpp

@@ -256,6 +256,7 @@ DEF_TEST(Skottie_Shaper_HAlign, reporter) {
             const skottie::Shaper::TextDesc desc = {
                 typeface,
                 tsize.text_size,
+                tsize.text_size,
                 talign.align,
                 skottie::Shaper::VAlign::kTopBaseline,
             };
@@ -316,6 +317,7 @@ DEF_TEST(Skottie_Shaper_VAlign, reporter) {
             const skottie::Shaper::TextDesc desc = {
                 typeface,
                 tsize.text_size,
+                tsize.text_size,
                 SkTextUtils::Align::kCenter_Align,
                 talign.align,
             };

modules/skottie/src/text/SkottieShaper.cpp

@@ -102,7 +102,11 @@ public:
     }
 
     void commitLine() override {
-        fOffset += { 0, fMaxRunDescent + fMaxRunLeading - fMaxRunAscent };
+        // Observe explicit line height, if specified; otherwise use line metrics.
+        const auto lh = fDesc.fLineHeight > 0
+                ? fDesc.fLineHeight
+                : fMaxRunDescent + fMaxRunLeading - fMaxRunAscent;
+        fOffset.fY += lh;
     }
 
     Shaper::Result makeBlob() {

modules/skottie/src/text/SkottieShaper.h

@@ -40,7 +40,8 @@ public:
 
     struct TextDesc {
         const sk_sp<SkTypeface>&  fTypeface;
-        SkScalar                  fTextSize;
+        SkScalar                  fTextSize,
+                                  fLineHeight; // when 0, use natural/computed line height.
         SkTextUtils::Align        fHAlign;
         VAlign                    fVAlign;
     };

modules/skottie/src/text/TextAdapter.cpp

@@ -45,6 +45,7 @@ void TextAdapter::apply() {
     const Shaper::TextDesc text_desc = {
         fText.fTypeface,
         fText.fTextSize,
+        fText.fLineHeight,
         fText.fHAlign,
         fText.fVAlign,
     };

modules/skottie/src/text/TextValue.cpp

@@ -17,6 +17,7 @@ bool TextValue::operator==(const TextValue &other) const {
         && fText == other.fText
         && fTextSize == other.fTextSize
         && fStrokeWidth == other.fStrokeWidth
+        && fLineHeight == other.fLineHeight
         && fHAlign == other.fHAlign
         && fVAlign == other.fVAlign
         && fBox == other.fBox
@@ -48,6 +49,7 @@ bool ValueTraits<TextValue>::FromJSON(const skjson::Value& jv,
     }
     v->fText.set(text->begin(), text->size());
     v->fTextSize = **text_size;
+    v->fLineHeight = ParseDefault<float>((*jtxt)["lh"], 0);
 
     static constexpr SkTextUtils::Align gAlignMap[] = {
         SkTextUtils::kLeft_Align,  // 'j': 0

modules/skottie/src/text/TextValue.h

@@ -19,7 +19,8 @@ struct TextValue {
     sk_sp<SkTypeface>  fTypeface;
     SkString           fText;
     float              fTextSize    = 0,
-                       fStrokeWidth = 0;
+                       fStrokeWidth = 0,
+                       fLineHeight  = 0;
     SkTextUtils::Align fHAlign      = SkTextUtils::kLeft_Align;
     Shaper::VAlign     fVAlign      = Shaper::VAlign::kTop;
     SkRect             fBox         = SkRect::MakeEmpty();