chromium/third_party/skia/src/utils/SkShadowUtils.cpp

/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/

#include "include/utils/SkShadowUtils.h"

#include "include/core/SkBlendMode.h"
#include "include/core/SkBlender.h"
#include "include/core/SkBlurTypes.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkMaskFilter.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPath.h"
#include "include/core/SkPoint.h"
#include "include/core/SkPoint3.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkVertices.h"
#include "include/private/SkIDChangeListener.h"
#include "include/private/base/SkFloatingPoint.h"
#include "include/private/base/SkTPin.h"
#include "include/private/base/SkTemplates.h"
#include "include/private/base/SkTo.h"
#include "src/base/SkRandom.h"
#include "src/core/SkBlurMask.h"
#include "src/core/SkColorFilterPriv.h"
#include "src/core/SkDevice.h"
#include "src/core/SkDrawShadowInfo.h"
#include "src/core/SkPathPriv.h"
#include "src/core/SkResourceCache.h"
#include "src/core/SkVerticesPriv.h"

#if !defined(SK_ENABLE_OPTIMIZE_SIZE)
#include "src/utils/SkShadowTessellator.h"
#endif

#if defined(SK_GANESH)
#include "src/gpu/ganesh/GrStyle.h"
#include "src/gpu/ganesh/geometry/GrStyledShape.h"
#endif

#include <algorithm>
#include <cstring>
#include <functional>
#include <memory>
#include <new>
#include <utility>

usingnamespaceskia_private;

class SkRRect;

///////////////////////////////////////////////////////////////////////////////////////////////////

#if !defined(SK_ENABLE_OPTIMIZE_SIZE)
namespace {

uint64_t resource_cache_shared_id() { … }

/** Factory for an ambient shadow mesh with particular shadow properties. */
struct AmbientVerticesFactory { … };

/** Factory for an spot shadow mesh with particular shadow properties. */
struct SpotVerticesFactory { … };

/**
 * This manages a set of tessellations for a given shape in the cache. Because SkResourceCache
 * records are immutable this is not itself a Rec. When we need to update it we return this on
 * the FindVisitor and let the cache destroy the Rec. We'll update the tessellations and then add
 * a new Rec with an adjusted size for any deletions/additions.
 */
class CachedTessellations : public SkRefCnt { … };

/**
 * A record of shadow vertices stored in SkResourceCache of CachedTessellations for a particular
 * path. The key represents the path's geometry and not any shadow params.
 */
class CachedTessellationsRec : public SkResourceCache::Rec { … };

/**
 * Used by FindVisitor to determine whether a cache entry can be reused and if so returns the
 * vertices and a translation vector. If the CachedTessellations does not contain a suitable
 * mesh then we inform SkResourceCache to destroy the Rec and we return the CachedTessellations
 * to the caller. The caller will update it and reinsert it back into the cache.
 */
template <typename FACTORY>
struct FindContext { … };

/**
 * Function called by SkResourceCache when a matching cache key is found. The FACTORY and matrix of
 * the FindContext are used to determine if the vertices are reusable. If so the vertices and
 * necessary translation vector are set on the FindContext.
 */
template <typename FACTORY>
bool FindVisitor(const SkResourceCache::Rec& baseRec, void* ctx) { … }

class ShadowedPath { … };

// This creates a domain of keys in SkResourceCache used by this file.
static void* kNamespace;

// When the SkPathRef genID changes, invalidate a corresponding GrResource described by key.
class ShadowInvalidator : public SkIDChangeListener { … };

/**
 * Draws a shadow to 'canvas'. The vertices used to draw the shadow are created by 'factory' unless
 * they are first found in SkResourceCache.
 */
template <typename FACTORY>
bool draw_shadow(const FACTORY& factory,
                 std::function<void(const SkVertices*, SkBlendMode, const SkPaint&,
                 SkScalar tx, SkScalar ty, bool)> drawProc, ShadowedPath& path, SkColor color) { … }
}  // namespace

static bool tilted(const SkPoint3& zPlaneParams) { … }
#endif // SK_ENABLE_OPTIMIZE_SIZE

void SkShadowUtils::ComputeTonalColors(SkColor inAmbientColor, SkColor inSpotColor,
                                       SkColor* outAmbientColor, SkColor* outSpotColor) { … }

static bool fill_shadow_rec(const SkPath& path, const SkPoint3& zPlaneParams,
                            const SkPoint3& lightPos, SkScalar lightRadius,
                            SkColor ambientColor, SkColor spotColor,
                            uint32_t flags, const SkMatrix& ctm, SkDrawShadowRec* rec) { … }

// Draw an offset spot shadow and outlining ambient shadow for the given path.
void SkShadowUtils::DrawShadow(SkCanvas* canvas, const SkPath& path, const SkPoint3& zPlaneParams,
                               const SkPoint3& lightPos, SkScalar lightRadius,
                               SkColor ambientColor, SkColor spotColor,
                               uint32_t flags) { … }

bool SkShadowUtils::GetLocalBounds(const SkMatrix& ctm, const SkPath& path,
                                   const SkPoint3& zPlaneParams, const SkPoint3& lightPos,
                                   SkScalar lightRadius, uint32_t flags, SkRect* bounds) { … }

//////////////////////////////////////////////////////////////////////////////////////////////

static bool validate_rec(const SkDrawShadowRec& rec) { … }

void SkDevice::drawShadow(const SkPath& path, const SkDrawShadowRec& rec) { … }