1 /* 2 * Copyright 2012 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "GrPath.h" 9 10 template<int NumBits> static uint64_t get_top_n_float_bits(float f) { 11 char* floatData = reinterpret_cast<char*>(&f); 12 uint32_t floatBits = *reinterpret_cast<uint32_t*>(floatData); 13 return floatBits >> (32 - NumBits); 14 } 15 16 GrResourceKey GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke) { 17 static const GrResourceKey::ResourceType gPathResourceType = GrResourceKey::GenerateResourceType(); 18 static const GrCacheID::Domain gPathDomain = GrCacheID::GenerateDomain(); 19 20 GrCacheID::Key key; 21 uint64_t* keyData = key.fData64; 22 keyData[0] = path.getGenerationID(); 23 keyData[1] = ComputeStrokeKey(stroke); 24 25 return GrResourceKey(GrCacheID(gPathDomain, key), gPathResourceType, 0); 26 } 27 28 uint64_t GrPath::ComputeStrokeKey(const SkStrokeRec& stroke) { 29 enum { 30 kStyleBits = 2, 31 kJoinBits = 2, 32 kCapBits = 2, 33 kWidthBits = 29, 34 kMiterBits = 29, 35 36 kJoinShift = kStyleBits, 37 kCapShift = kJoinShift + kJoinBits, 38 kWidthShift = kCapShift + kCapBits, 39 kMiterShift = kWidthShift + kWidthBits, 40 41 kBitCount = kMiterShift + kMiterBits 42 }; 43 44 SK_COMPILE_ASSERT(SkStrokeRec::kStyleCount <= (1 << kStyleBits), style_shift_will_be_wrong); 45 SK_COMPILE_ASSERT(SkPaint::kJoinCount <= (1 << kJoinBits), cap_shift_will_be_wrong); 46 SK_COMPILE_ASSERT(SkPaint::kCapCount <= (1 << kCapBits), miter_shift_will_be_wrong); 47 SK_COMPILE_ASSERT(kBitCount == 64, wrong_stroke_key_size); 48 49 if (!stroke.needToApply()) { 50 return SkStrokeRec::kFill_Style; 51 } 52 53 uint64_t key = stroke.getStyle(); 54 key |= stroke.getJoin() << kJoinShift; 55 key |= stroke.getCap() << kCapShift; 56 key |= get_top_n_float_bits<kWidthBits>(stroke.getWidth()) << kWidthShift; 57 key |= get_top_n_float_bits<kMiterBits>(stroke.getMiter()) << kMiterShift; 58 59 return key; 60 } 61
