add size limit for using glyphcache. above that, draw using paths

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 "SkAnnotation.h"
@@ skipping 407 matching lines @@
     GEN_ID_INC;
 
     bool isNoDraw = annotation && annotation->isNoDraw();
     fPrivFlags = SkSetClearMask(fPrivFlags, isNoDraw, kNoDrawAnnotation_PrivFlag);
 
     return annotation;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
+static SkScalar mag2(SkScalar x, SkScalar y) {
+    return x * x + y * y;
+}
+
+static bool tooBig(const SkMatrix& m, SkScalar ma2max) {
+    return  mag2(m[SkMatrix::kMScaleX], m[SkMatrix::kMSkewY]) > ma2max
+            ||
+            mag2(m[SkMatrix::kMSkewX], m[SkMatrix::kMScaleY]) > ma2max;
+}
+
+bool SkPaint::TooBigToUseCache(const SkMatrix& ctm, const SkMatrix& textM) {
+    SkASSERT(!ctm.hasPerspective());
+    SkASSERT(!textM.hasPerspective());
+
+    SkMatrix matrix;
+    matrix.setConcat(ctm, textM);
+    return tooBig(matrix, MaxCacheSize2());
+}
+
+bool SkPaint::tooBigToUseCache(const SkMatrix& ctm) const {
+    SkMatrix textM;
+    return TooBigToUseCache(ctm, *this->setTextMatrix(&textM));
+}
+
+bool SkPaint::tooBigToUseCache() const {
+    SkMatrix textM;
+    return tooBig(*this->setTextMatrix(&textM), MaxCacheSize2());
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
 #include "SkGlyphCache.h"
 #include "SkUtils.h"
 
 static void DetachDescProc(SkTypeface* typeface, const SkDescriptor* desc,
                            void* context) {
     *((SkGlyphCache**)context) = SkGlyphCache::DetachCache(typeface, desc);
 }
 
 #ifdef SK_BUILD_FOR_ANDROID
 const SkGlyph& SkPaint::getUnicharMetrics(SkUnichar text,
@@ skipping 627 matching lines @@
 }
 
 SkScalar SkPaint::measureText(const void* textData, size_t length,
                               SkRect* bounds, SkScalar zoom) const {
     const char* text = (const char*)textData;
     SkASSERT(text != NULL || length == 0);
 
     SkScalar                            scale = 0;
     SkAutoRestorePaintTextSizeAndFrame  restore(this);
 
-    if (this->isLinearText()) {
+    if (this->isLinearText() || this->tooBigToUseCache()) {
         scale = fTextSize / kCanonicalTextSizeForPaths;
         // this gets restored by restore
         ((SkPaint*)this)->setTextSize(SkIntToScalar(kCanonicalTextSizeForPaths));
     }
 
     SkMatrix zoomMatrix, *zoomPtr = NULL;
     if (zoom) {
         zoomMatrix.setScale(zoom, zoom);
         zoomPtr = &zoomMatrix;
     }
@@ skipping 194 matching lines @@
 
     SkASSERT(NULL != textData);
 
     if (NULL == widths && NULL == bounds) {
         return this->countText(textData, byteLength);
     }
 
     SkAutoRestorePaintTextSizeAndFrame  restore(this);
     SkScalar                            scale = 0;
 
-    if (this->isLinearText()) {
+    if (this->isLinearText() || this->tooBigToUseCache()) {
         scale = fTextSize / kCanonicalTextSizeForPaths;
         // this gets restored by restore
         ((SkPaint*)this)->setTextSize(SkIntToScalar(kCanonicalTextSizeForPaths));
     }
 
     SkAutoGlyphCache    autoCache(*this, NULL, NULL);
     SkGlyphCache*       cache = autoCache.getCache();
     SkMeasureCacheProc  glyphCacheProc;
     glyphCacheProc = this->getMeasureCacheProc(kForward_TextBufferDirection,
                                                NULL != bounds);
@@ skipping 1248 matching lines @@
             case SkXfermode::kPlus_Mode:
                 return 0 == this->getAlpha();
             case SkXfermode::kDst_Mode:
                 return true;
             default:
                 break;
         }
     }
     return false;
 }