move intercepts call to textblob

Bug: skia:
Change-Id: Ic7cd8ec1b33bd278ed489cbc1ccca35bd4776e27
Reviewed-on: https://skia-review.googlesource.com/c/175833
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

Author: reed-at-google

gm/texteffects.cpp

@@ -45,11 +45,11 @@ static void find_intercepts(const char* text, size_t len, SkScalar x, SkScalar y
 
     SkScalar uPos = uWidth;
     SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
-    int count = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
+    int count = blob->getIntercepts(bounds, nullptr, &paint);
     SkASSERT(!(count % 2));
     if (count) {
         intersections->setCount(count);
-        paint.getTextBlobIntercepts(blob.get(), bounds, intersections->begin());
+        blob->getIntercepts(bounds, intersections->begin(), &paint);
         for (int i = 0; i < count; ++i) {
             (*intersections)[i] += x;
         }
@@ -95,11 +95,11 @@ static void find_intercepts(const char* text, size_t len, const SkPoint* pos, co
 
     SkScalar uPos = pos[0].fY + uWidth;
     SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
-    int count = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
+    int count = blob->getIntercepts(bounds, nullptr, &paint);
     SkASSERT(!(count % 2));
     if (count) {
         intersections->setCount(count);
-        paint.getTextBlobIntercepts(blob.get(), bounds, intersections->begin());
+        blob->getIntercepts(bounds, intersections->begin(), &paint);
     }
 }
 
@@ -227,12 +227,12 @@ DEF_SIMPLE_GM(fancyblobunderline, canvas, 1480, 1380) {
 
             const SkScalar uPos = uWidth;
             const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
-            const int interceptCount = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
+            const int interceptCount = blob->getIntercepts(bounds, nullptr, &paint);
             SkASSERT(!(interceptCount % 2));
 
             SkTDArray<SkScalar> intercepts;
             intercepts.setCount(interceptCount);
-            paint.getTextBlobIntercepts(blob.get(), bounds, intercepts.begin());
+            blob->getIntercepts(bounds, intercepts.begin(), &paint);
 
             const SkScalar start = blob->bounds().left();
             const SkScalar end = blob->bounds().right();

include/core/SkTextBlob.h

@@ -51,6 +51,21 @@ class SK_API SkTextBlob final : public SkNVRefCnt<SkTextBlob> {
     */
     uint32_t uniqueID() const { return fUniqueID; }
 
+    /** Returns the number of intervals that intersect bounds.
+        bounds describes a pair of lines parallel to the text advance.
+        The return count is zero or a multiple of two, and is at most twice the number of glyphs in
+        the the blob.
+
+        Pass nullptr for intervals to determine the size of the interval array.
+
+        @param bounds     lower and upper line parallel to the advance
+        @param intervals  returned intersections; may be nullptr
+        @param paint      specifies stroking, patheffect that may affect the result; may be nullptr
+        @return           number of intersections; may be zero
+     */
+    int getIntercepts(const SkScalar bounds[2], SkScalar intervals[],
+                      const SkPaint* paint = nullptr) const;
+
     /** Creates SkTextBlob with a single run.
 
         font contains attributes used to define the run text.

src/core/SkTextBlob.cpp

@@ -587,6 +587,15 @@ sk_sp<SkTextBlob> SkTextBlobBuilder::make() {
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
+int SkTextBlob::getIntercepts(const SkScalar bounds[2], SkScalar intervals[],
+                              const SkPaint* paint) const {
+    SkPaint defaultPaint;
+    if (!paint) {
+        paint = &defaultPaint;
+    }
+    return paint->getTextBlobIntercepts(this, bounds, intervals);
+}
+
 void SkTextBlobPriv::Flatten(const SkTextBlob& blob, SkWriteBuffer& buffer) {
     buffer.writeRect(blob.fBounds);