| /* |
| * Copyright 2016 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "GrColorSpaceXform.h" |
| #include "SkColorSpace.h" |
| #include "SkColorSpace_Base.h" |
| #include "SkMatrix44.h" |
| #include "SkSpinlock.h" |
| |
| class GrColorSpaceXformCache { |
| public: |
| using NewValueFn = std::function<sk_sp<GrColorSpaceXform>(void)>; |
| |
| GrColorSpaceXformCache() : fSequence(0) {} |
| |
| sk_sp<GrColorSpaceXform> findOrAdd(uint64_t key, NewValueFn newValue) { |
| int oldest = 0; |
| for (int i = 0; i < kEntryCount; ++i) { |
| if (fEntries[i].fKey == key) { |
| fEntries[i].fLastUse = fSequence++; |
| return fEntries[i].fXform; |
| } |
| if (fEntries[i].fLastUse < fEntries[oldest].fLastUse) { |
| oldest = i; |
| } |
| } |
| fEntries[oldest].fKey = key; |
| fEntries[oldest].fXform = newValue(); |
| fEntries[oldest].fLastUse = fSequence++; |
| return fEntries[oldest].fXform; |
| } |
| |
| private: |
| enum { kEntryCount = 32 }; |
| |
| struct Entry { |
| // The default Entry is "valid". Any 64-bit key that is the same 32-bit value repeated |
| // implies no xform is necessary, so nullptr should be returned. This particular case should |
| // never happen, but by initializing all entries with this data, we can avoid special cases |
| // for the array not yet being full. |
| Entry() : fKey(0), fXform(nullptr), fLastUse(0) {} |
| |
| uint64_t fKey; |
| sk_sp<GrColorSpaceXform> fXform; |
| uint64_t fLastUse; |
| }; |
| |
| Entry fEntries[kEntryCount]; |
| uint64_t fSequence; |
| }; |
| |
| GrColorSpaceXform::GrColorSpaceXform(const SkMatrix44& srcToDst) |
| : fSrcToDst(srcToDst) {} |
| |
| static SkSpinlock gColorSpaceXformCacheSpinlock; |
| |
| sk_sp<GrColorSpaceXform> GrColorSpaceXform::Make(SkColorSpace* src, SkColorSpace* dst) { |
| if (!src || !dst) { |
| // Invalid |
| return nullptr; |
| } |
| |
| if (src == dst) { |
| // Quick equality check - no conversion needed in this case |
| return nullptr; |
| } |
| |
| const SkMatrix44* toXYZD50 = as_CSB(src)->toXYZD50(); |
| const SkMatrix44* fromXYZD50 = as_CSB(dst)->fromXYZD50(); |
| if (!toXYZD50 || !fromXYZD50) { |
| // unsupported colour spaces -- cannot specify gamut as a matrix |
| return nullptr; |
| } |
| |
| uint32_t srcHash = as_CSB(src)->toXYZD50Hash(); |
| uint32_t dstHash = as_CSB(dst)->toXYZD50Hash(); |
| if (srcHash == dstHash) { |
| // Identical gamut - no conversion needed in this case |
| SkASSERT(*toXYZD50 == *as_CSB(dst)->toXYZD50() && "Hash collision"); |
| return nullptr; |
| } |
| |
| auto deferredResult = [fromXYZD50, toXYZD50]() { |
| SkMatrix44 srcToDst(SkMatrix44::kUninitialized_Constructor); |
| srcToDst.setConcat(*fromXYZD50, *toXYZD50); |
| return sk_make_sp<GrColorSpaceXform>(srcToDst); |
| }; |
| |
| if (gColorSpaceXformCacheSpinlock.tryAcquire()) { |
| static GrColorSpaceXformCache* gCache; |
| if (nullptr == gCache) { |
| gCache = new GrColorSpaceXformCache(); |
| } |
| |
| uint64_t key = static_cast<uint64_t>(srcHash) << 32 | static_cast<uint64_t>(dstHash); |
| sk_sp<GrColorSpaceXform> xform = gCache->findOrAdd(key, deferredResult); |
| gColorSpaceXformCacheSpinlock.release(); |
| return xform; |
| } else { |
| // Rather than wait for the spin lock, just bypass the cache |
| return deferredResult(); |
| } |
| } |
| |
| bool GrColorSpaceXform::Equals(const GrColorSpaceXform* a, const GrColorSpaceXform* b) { |
| if (a == b) { |
| return true; |
| } |
| |
| if (!a || !b) { |
| return false; |
| } |
| |
| return a->fSrcToDst == b->fSrcToDst; |
| } |
| |
| GrColor4f GrColorSpaceXform::apply(const GrColor4f& srcColor) { |
| GrColor4f result; |
| fSrcToDst.mapScalars(srcColor.fRGBA, result.fRGBA); |
| for (int i = 0; i < 4; ++i) { |
| result.fRGBA[i] = SkTPin(result.fRGBA[i], 0.0f, 1.0f); |
| } |
| return result; |
| } |