SkPaint intercept API for SkTextBlob and horizontal text

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAutoKern.h"
 #include "SkChecksum.h"
 #include "SkColorFilter.h"
 #include "SkData.h"
 #include "SkDraw.h"
 #include "SkFontDescriptor.h"
 #include "SkGlyphCache.h"
 #include "SkImageFilter.h"
 #include "SkMaskFilter.h"
 #include "SkMaskGamma.h"
 #include "SkMutex.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkPaintDefaults.h"
 #include "SkPathEffect.h"
 #include "SkRasterizer.h"
 #include "SkScalar.h"
 #include "SkScalerContext.h"
 #include "SkShader.h"
 #include "SkStringUtils.h"
 #include "SkStroke.h"
+#include "SkStrokeRec.h"
+#include "SkSurfacePriv.h"
+#include "SkTextBlob.h"
+#include "SkTextBlobRunIterator.h"
 #include "SkTextFormatParams.h"
 #include "SkTextToPathIter.h"
 #include "SkTLazy.h"
 #include "SkTypeface.h"
-#include "SkStrokeRec.h"
-#include "SkSurfacePriv.h"
 #include "SkXfermode.h"
 
 static inline uint32_t set_clear_mask(uint32_t bits, bool cond, uint32_t mask) {
     return cond ? bits | mask : bits & ~mask;
 }
 
 // define this to get a printf for out-of-range parameter in setters
 // e.g. setTextSize(-1)
 //#define SK_REPORT_API_RANGE_CHECK
 
@@ skipping 1074 matching lines @@
     const SkPath*   iterPath;
     while (iter.next(&iterPath, &xpos)) {
         matrix.postTranslate(xpos - prevXPos, 0);
         if (iterPath) {
             path->addPath(*iterPath, matrix);
         }
         prevXPos = xpos;
     }
 }
 
-int SkPaint::getTextIntercepts(const void* textData, size_t length,
-                               SkScalar x, SkScalar y, const SkScalar bounds[2],
-                               SkScalar* array) const {
-    SkASSERT(length == 0 || textData != nullptr);
-    if (!length) {
-        return 0;
-    }
-
-    const char* text = (const char*) textData;
-    SkTextInterceptsIter iter(text, length, *this, bounds, x, y,
-            SkTextInterceptsIter::TextType::kText);
-    int count = 0;
-    while (iter.next(array, &count)) {
-    }
-    return count;
-}
-
 void SkPaint::getPosTextPath(const void* textData, size_t length,
                              const SkPoint pos[], SkPath* path) const {
     SkASSERT(length == 0 || textData != nullptr);
 
     const char* text = (const char*)textData;
     if (text == nullptr || length == 0 || path == nullptr) {
         return;
     }
 
     SkTextToPathIter    iter(text, length, *this, false);
     SkMatrix            matrix;
     SkPoint             prevPos;
     prevPos.set(0, 0);
 
     matrix.setScale(iter.getPathScale(), iter.getPathScale());
     path->reset();
 
     unsigned int    i = 0;
     const SkPath*   iterPath;
     while (iter.next(&iterPath, nullptr)) {
         matrix.postTranslate(pos[i].fX - prevPos.fX, pos[i].fY - prevPos.fY);
         if (iterPath) {
             path->addPath(*iterPath, matrix);
         }
         prevPos = pos[i];
         i++;
     }
 }
 
+template <SkTextInterceptsIter::TextType TextType, typename Func>
+int GetTextIntercepts(const SkPaint& paint, const void* text, size_t length,
+                      const SkScalar bounds[2], SkScalar* array, Func posMaker) {
+    SkASSERT(length == 0 || text != nullptr);
+    if (!length) {
+        return 0;
+    }
+
+    const SkPoint pos0 = posMaker(0);
+    SkTextInterceptsIter iter(static_cast<const char*>(text), length, paint, bounds,
+                              pos0.x(), pos0.y(), TextType);
+
+    int i = 0;
+    int count = 0;
+    while (iter.next(array, &count)) {
+        if (TextType == SkTextInterceptsIter::TextType::kPosText) {
+            const SkPoint pos = posMaker(++i);
+            iter.setPosition(pos.x(), pos.y());
+        }
+    }
+
+    return count;
+}
+
+int SkPaint::getTextIntercepts(const void* textData, size_t length,
+                               SkScalar x, SkScalar y, const SkScalar bounds[2],
+                               SkScalar* array) const {
+
+    return GetTextIntercepts<SkTextInterceptsIter::TextType::kText>(
+        *this, textData, length, bounds, array, [&x, &y] (int) -> SkPoint {
+            return SkPoint::Make(x, y);
+        });
+}
+
 int SkPaint::getPosTextIntercepts(const void* textData, size_t length, const SkPoint pos[],
                                   const SkScalar bounds[2], SkScalar* array) const {
-    SkASSERT(length == 0 || textData != nullptr);
-    if (!length) {
-        return 0;
+
+    return GetTextIntercepts<SkTextInterceptsIter::TextType::kPosText>(
+        *this, textData, length, bounds, array, [&pos] (int i) -> SkPoint {
+            return pos[i];
+        });
+}
+
+int SkPaint::getPosTextHIntercepts(const void* textData, size_t length, const SkScalar xpos[],
+                                   SkScalar constY, const SkScalar bounds[2],
+                                   SkScalar* array) const {
+
+    return GetTextIntercepts<SkTextInterceptsIter::TextType::kPosText>(
+        *this, textData, length, bounds, array, [&xpos, &constY] (int i) -> SkPoint {
+            return SkPoint::Make(xpos[i], constY);
+        });
+}
+
+int SkPaint::getTextBlobIntercepts(const SkTextBlob* blob, const SkScalar bounds[2],
+                                   SkScalar* intervals) const {
+    int count = 0;
+    SkPaint runPaint(*this);
+
+    SkTextBlobRunIterator it(blob);
+    while (!it.done()) {
+        it.applyFontToPaint(&runPaint);
+        const size_t runByteCount = it.glyphCount() * sizeof(SkGlyphID);
+        SkScalar* runIntervals = intervals ? intervals + count : nullptr;
+
+        switch (it.positioning()) {
+        case SkTextBlob::kDefault_Positioning:
+            count += runPaint.getTextIntercepts(it.glyphs(), runByteCount, it.offset().x(),
+                                                it.offset().y(), bounds, runIntervals);
+            break;
+        case SkTextBlob::kHorizontal_Positioning:
+            count += runPaint.getPosTextHIntercepts(it.glyphs(), runByteCount, it.pos(),
+                                                    it.offset().y(), bounds, runIntervals);
+            break;
+        case SkTextBlob::kFull_Positioning:
+            count += runPaint.getPosTextIntercepts(it.glyphs(), runByteCount,
+                                                   reinterpret_cast<const SkPoint*>(it.pos()),
+                                                   bounds, runIntervals);
+            break;
+        }
+
+        it.next();
     }
 
-    const char* text = (const char*) textData;
-    SkTextInterceptsIter iter(text, length, *this, bounds, pos[0].fX, pos[0].fY,
-            SkTextInterceptsIter::TextType::kPosText);
-    int i = 0;
-    int count = 0;
-    while (iter.next(array, &count)) {
-        i++;
-        iter.setPosition(pos[i].fX, pos[i].fY);
-    }
     return count;
 }
 
 SkRect SkPaint::getFontBounds() const {
     SkMatrix m;
     m.setScale(fTextSize * fTextScaleX, fTextSize);
     m.postSkew(fTextSkewX, 0);
 
     SkTypeface* typeface = this->getTypeface();
     if (nullptr == typeface) {
@@ skipping 1130 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     static_assert(offsetof(SkPaint, fBitfields) == 9 * sizeof(void*) + 6 * sizeof(uint32_t),
                   "SkPaint_notPackedTightly");
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }