blob: 3a66865c6e5d3448eaeaefce22db731364340519 [file] [log] [blame]
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrPath.h"
template<int NumBits> static uint64_t get_top_n_float_bits(float f) {
char* floatData = reinterpret_cast<char*>(&f);
uint32_t floatBits = *reinterpret_cast<uint32_t*>(floatData);
return floatBits >> (32 - NumBits);
}
void GrPath::ComputeKey(const SkPath& path, const SkStrokeRec& stroke, GrUniqueKey* key) {
static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
GrUniqueKey::Builder builder(key, kDomain, 3);
*reinterpret_cast<uint64_t*>(&builder[0]) = ComputeStrokeKey(stroke);
builder[2] = path.getGenerationID();
}
uint64_t GrPath::ComputeStrokeKey(const SkStrokeRec& stroke) {
enum {
kStyleBits = 2,
kJoinBits = 2,
kCapBits = 2,
kWidthBits = 29,
kMiterBits = 29,
kJoinShift = kStyleBits,
kCapShift = kJoinShift + kJoinBits,
kWidthShift = kCapShift + kCapBits,
kMiterShift = kWidthShift + kWidthBits,
kBitCount = kMiterShift + kMiterBits
};
SK_COMPILE_ASSERT(SkStrokeRec::kStyleCount <= (1 << kStyleBits), style_shift_will_be_wrong);
SK_COMPILE_ASSERT(SkPaint::kJoinCount <= (1 << kJoinBits), cap_shift_will_be_wrong);
SK_COMPILE_ASSERT(SkPaint::kCapCount <= (1 << kCapBits), miter_shift_will_be_wrong);
SK_COMPILE_ASSERT(kBitCount == 64, wrong_stroke_key_size);
if (!stroke.needToApply()) {
return SkStrokeRec::kFill_Style;
}
uint64_t key = stroke.getStyle();
key |= stroke.getJoin() << kJoinShift;
key |= stroke.getCap() << kCapShift;
key |= get_top_n_float_bits<kWidthBits>(stroke.getWidth()) << kWidthShift;
key |= get_top_n_float_bits<kMiterBits>(stroke.getMiter()) << kMiterShift;
return key;
}