gecko-dev/gfx/thebes/gfxBlur.cpp
Nicholas Nethercote a02611e830 Bug 1276824 (part 1) - Rename gfxContext::ForDrawTarget{,WithTransform}(). r=milan.
The new names Create{,PreservingTransform}OrNull() better communicate that
these functions (a) do object creation, and (b) are fallible.

--HG--
extra : rebase_source : a36bd9a2bcdfae281868959403f811f2bc690ad4
2016-06-07 09:39:56 +10:00

1090 lines
38 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "gfxBlur.h"
#include "gfx2DGlue.h"
#include "gfxContext.h"
#include "gfxPlatform.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Blur.h"
#include "mozilla/gfx/PathHelpers.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsExpirationTracker.h"
#include "nsClassHashtable.h"
#include "gfxUtils.h"
using namespace mozilla;
using namespace mozilla::gfx;
gfxAlphaBoxBlur::gfxAlphaBoxBlur()
{
}
gfxAlphaBoxBlur::~gfxAlphaBoxBlur()
{
mContext = nullptr;
}
gfxContext*
gfxAlphaBoxBlur::Init(const gfxRect& aRect,
const IntSize& aSpreadRadius,
const IntSize& aBlurRadius,
const gfxRect* aDirtyRect,
const gfxRect* aSkipRect)
{
mozilla::gfx::Rect rect(Float(aRect.x), Float(aRect.y),
Float(aRect.width), Float(aRect.height));
IntSize spreadRadius(aSpreadRadius.width, aSpreadRadius.height);
IntSize blurRadius(aBlurRadius.width, aBlurRadius.height);
UniquePtr<Rect> dirtyRect;
if (aDirtyRect) {
dirtyRect = MakeUnique<Rect>(Float(aDirtyRect->x),
Float(aDirtyRect->y),
Float(aDirtyRect->width),
Float(aDirtyRect->height));
}
UniquePtr<Rect> skipRect;
if (aSkipRect) {
skipRect = MakeUnique<Rect>(Float(aSkipRect->x),
Float(aSkipRect->y),
Float(aSkipRect->width),
Float(aSkipRect->height));
}
mBlur = MakeUnique<AlphaBoxBlur>(rect, spreadRadius, blurRadius, dirtyRect.get(), skipRect.get());
size_t blurDataSize = mBlur->GetSurfaceAllocationSize();
if (blurDataSize == 0)
return nullptr;
IntSize size = mBlur->GetSize();
// Make an alpha-only surface to draw on. We will play with the data after
// everything is drawn to create a blur effect.
mData = MakeUniqueFallible<unsigned char[]>(blurDataSize);
if (!mData) {
return nullptr;
}
memset(mData.get(), 0, blurDataSize);
RefPtr<DrawTarget> dt =
gfxPlatform::GetPlatform()->CreateDrawTargetForData(mData.get(), size,
mBlur->GetStride(),
SurfaceFormat::A8);
if (!dt || !dt->IsValid()) {
return nullptr;
}
IntRect irect = mBlur->GetRect();
gfxPoint topleft(irect.TopLeft().x, irect.TopLeft().y);
mContext = gfxContext::CreateOrNull(dt);
MOZ_ASSERT(mContext); // already checked for target above
mContext->SetMatrix(gfxMatrix::Translation(-topleft));
return mContext;
}
void
DrawBlur(gfxContext* aDestinationCtx,
SourceSurface* aBlur,
const IntPoint& aTopLeft,
const Rect* aDirtyRect)
{
DrawTarget *dest = aDestinationCtx->GetDrawTarget();
RefPtr<gfxPattern> thebesPat = aDestinationCtx->GetPattern();
Pattern* pat = thebesPat->GetPattern(dest, nullptr);
Matrix oldTransform = dest->GetTransform();
Matrix newTransform = oldTransform;
newTransform.PreTranslate(aTopLeft.x, aTopLeft.y);
// Avoid a semi-expensive clip operation if we can, otherwise
// clip to the dirty rect
if (aDirtyRect) {
dest->PushClipRect(*aDirtyRect);
}
dest->SetTransform(newTransform);
dest->MaskSurface(*pat, aBlur, Point(0, 0));
dest->SetTransform(oldTransform);
if (aDirtyRect) {
dest->PopClip();
}
}
already_AddRefed<SourceSurface>
gfxAlphaBoxBlur::DoBlur(DrawTarget* aDT, IntPoint* aTopLeft)
{
mBlur->Blur(mData.get());
*aTopLeft = mBlur->GetRect().TopLeft();
return aDT->CreateSourceSurfaceFromData(mData.get(),
mBlur->GetSize(),
mBlur->GetStride(),
SurfaceFormat::A8);
}
void
gfxAlphaBoxBlur::Paint(gfxContext* aDestinationCtx)
{
if (!mContext)
return;
DrawTarget *dest = aDestinationCtx->GetDrawTarget();
if (!dest) {
NS_WARNING("Blurring not supported for Thebes contexts!");
return;
}
Rect* dirtyRect = mBlur->GetDirtyRect();
IntPoint topLeft;
RefPtr<SourceSurface> mask = DoBlur(dest, &topLeft);
if (!mask) {
NS_ERROR("Failed to create mask!");
return;
}
DrawBlur(aDestinationCtx, mask, topLeft, dirtyRect);
}
IntSize gfxAlphaBoxBlur::CalculateBlurRadius(const gfxPoint& aStd)
{
mozilla::gfx::Point std(Float(aStd.x), Float(aStd.y));
IntSize size = AlphaBoxBlur::CalculateBlurRadius(std);
return IntSize(size.width, size.height);
}
struct BlurCacheKey : public PLDHashEntryHdr {
typedef const BlurCacheKey& KeyType;
typedef const BlurCacheKey* KeyTypePointer;
enum { ALLOW_MEMMOVE = true };
IntSize mMinSize;
IntSize mBlurRadius;
Color mShadowColor;
BackendType mBackend;
RectCornerRadii mCornerRadii;
bool mIsInset;
// Only used for inset blurs
bool mHasBorderRadius;
IntSize mInnerMinSize;
BlurCacheKey(IntSize aMinSize, IntSize aBlurRadius,
RectCornerRadii* aCornerRadii, const Color& aShadowColor,
BackendType aBackendType)
: BlurCacheKey(aMinSize, IntSize(0, 0),
aBlurRadius, aCornerRadii,
aShadowColor, false,
false, aBackendType)
{}
explicit BlurCacheKey(const BlurCacheKey* aOther)
: mMinSize(aOther->mMinSize)
, mBlurRadius(aOther->mBlurRadius)
, mShadowColor(aOther->mShadowColor)
, mBackend(aOther->mBackend)
, mCornerRadii(aOther->mCornerRadii)
, mIsInset(aOther->mIsInset)
, mHasBorderRadius(aOther->mHasBorderRadius)
, mInnerMinSize(aOther->mInnerMinSize)
{ }
explicit BlurCacheKey(IntSize aOuterMinSize, IntSize aInnerMinSize,
IntSize aBlurRadius,
const RectCornerRadii* aCornerRadii,
const Color& aShadowColor, bool aIsInset,
bool aHasBorderRadius, BackendType aBackendType)
: mMinSize(aOuterMinSize)
, mBlurRadius(aBlurRadius)
, mShadowColor(aShadowColor)
, mBackend(aBackendType)
, mCornerRadii(aCornerRadii ? *aCornerRadii : RectCornerRadii())
, mIsInset(aIsInset)
, mHasBorderRadius(aHasBorderRadius)
, mInnerMinSize(aInnerMinSize)
{ }
static PLDHashNumber
HashKey(const KeyTypePointer aKey)
{
PLDHashNumber hash = 0;
hash = AddToHash(hash, aKey->mMinSize.width, aKey->mMinSize.height);
hash = AddToHash(hash, aKey->mBlurRadius.width, aKey->mBlurRadius.height);
hash = AddToHash(hash, HashBytes(&aKey->mShadowColor.r,
sizeof(aKey->mShadowColor.r)));
hash = AddToHash(hash, HashBytes(&aKey->mShadowColor.g,
sizeof(aKey->mShadowColor.g)));
hash = AddToHash(hash, HashBytes(&aKey->mShadowColor.b,
sizeof(aKey->mShadowColor.b)));
hash = AddToHash(hash, HashBytes(&aKey->mShadowColor.a,
sizeof(aKey->mShadowColor.a)));
for (int i = 0; i < 4; i++) {
hash = AddToHash(hash, aKey->mCornerRadii[i].width, aKey->mCornerRadii[i].height);
}
hash = AddToHash(hash, (uint32_t)aKey->mBackend);
if (aKey->mIsInset) {
hash = AddToHash(hash, aKey->mInnerMinSize.width, aKey->mInnerMinSize.height);
hash = AddToHash(hash, HashBytes(&aKey->mHasBorderRadius, sizeof(bool)));
}
return hash;
}
bool
KeyEquals(KeyTypePointer aKey) const
{
if (aKey->mMinSize == mMinSize &&
aKey->mBlurRadius == mBlurRadius &&
aKey->mCornerRadii == mCornerRadii &&
aKey->mShadowColor == mShadowColor &&
aKey->mBackend == mBackend) {
if (mIsInset) {
return (mHasBorderRadius == aKey->mHasBorderRadius) &&
(mInnerMinSize == aKey->mInnerMinSize);
}
return true;
}
return false;
}
static KeyTypePointer
KeyToPointer(KeyType aKey)
{
return &aKey;
}
};
/**
* This class is what is cached. It need to be allocated in an object separated
* to the cache entry to be able to be tracked by the nsExpirationTracker.
* */
struct BlurCacheData {
BlurCacheData(SourceSurface* aBlur, IntMargin aExtendDestBy, const BlurCacheKey& aKey)
: mBlur(aBlur)
, mExtendDest(aExtendDestBy)
, mKey(aKey)
{}
BlurCacheData(const BlurCacheData& aOther)
: mBlur(aOther.mBlur)
, mExtendDest(aOther.mExtendDest)
, mKey(aOther.mKey)
{ }
nsExpirationState *GetExpirationState() {
return &mExpirationState;
}
nsExpirationState mExpirationState;
RefPtr<SourceSurface> mBlur;
IntMargin mExtendDest;
BlurCacheKey mKey;
};
/**
* This class implements a cache with no maximum size, that retains the
* SourceSurfaces used to draw the blurs.
*
* An entry stays in the cache as long as it is used often.
*/
class BlurCache final : public nsExpirationTracker<BlurCacheData,4>
{
public:
BlurCache()
: nsExpirationTracker<BlurCacheData, 4>(GENERATION_MS, "BlurCache")
{
}
virtual void NotifyExpired(BlurCacheData* aObject)
{
RemoveObject(aObject);
mHashEntries.Remove(aObject->mKey);
}
BlurCacheData* Lookup(const IntSize aMinSize,
const IntSize& aBlurRadius,
RectCornerRadii* aCornerRadii,
const Color& aShadowColor,
BackendType aBackendType)
{
BlurCacheData* blur =
mHashEntries.Get(BlurCacheKey(aMinSize, aBlurRadius,
aCornerRadii, aShadowColor,
aBackendType));
if (blur) {
MarkUsed(blur);
}
return blur;
}
BlurCacheData* LookupInsetBoxShadow(const IntSize aOuterMinSize,
const IntSize aInnerMinSize,
const IntSize& aBlurRadius,
const RectCornerRadii* aCornerRadii,
const Color& aShadowColor,
const bool& aHasBorderRadius,
BackendType aBackendType)
{
bool insetBoxShadow = true;
BlurCacheKey key(aOuterMinSize, aInnerMinSize,
aBlurRadius, aCornerRadii,
aShadowColor, insetBoxShadow,
aHasBorderRadius, aBackendType);
BlurCacheData* blur = mHashEntries.Get(key);
if (blur) {
MarkUsed(blur);
}
return blur;
}
// Returns true if we successfully register the blur in the cache, false
// otherwise.
bool RegisterEntry(BlurCacheData* aValue)
{
nsresult rv = AddObject(aValue);
if (NS_FAILED(rv)) {
// We are OOM, and we cannot track this object. We don't want stall
// entries in the hash table (since the expiration tracker is responsible
// for removing the cache entries), so we avoid putting that entry in the
// table, which is a good things considering we are short on memory
// anyway, we probably don't want to retain things.
return false;
}
mHashEntries.Put(aValue->mKey, aValue);
return true;
}
protected:
static const uint32_t GENERATION_MS = 1000;
/**
* FIXME use nsTHashtable to avoid duplicating the BlurCacheKey.
* https://bugzilla.mozilla.org/show_bug.cgi?id=761393#c47
*/
nsClassHashtable<BlurCacheKey, BlurCacheData> mHashEntries;
};
static BlurCache* gBlurCache = nullptr;
static IntSize
ComputeMinSizeForShadowShape(RectCornerRadii* aCornerRadii,
IntSize aBlurRadius,
IntMargin& aSlice,
const IntSize& aRectSize)
{
float cornerWidth = 0;
float cornerHeight = 0;
if (aCornerRadii) {
RectCornerRadii corners = *aCornerRadii;
for (size_t i = 0; i < 4; i++) {
cornerWidth = std::max(cornerWidth, corners[i].width);
cornerHeight = std::max(cornerHeight, corners[i].height);
}
}
aSlice = IntMargin(ceil(cornerHeight) + aBlurRadius.height,
ceil(cornerWidth) + aBlurRadius.width,
ceil(cornerHeight) + aBlurRadius.height,
ceil(cornerWidth) + aBlurRadius.width);
IntSize minSize(aSlice.LeftRight() + 1,
aSlice.TopBottom() + 1);
// If aRectSize is smaller than minSize, the border-image approach won't
// work; there's no way to squeeze parts of the min box-shadow source
// image such that the result looks correct. So we need to adjust minSize
// in such a way that we can later draw it without stretching in the affected
// dimension. We also need to adjust "slice" to ensure that we're not trying
// to slice away more than we have.
if (aRectSize.width < minSize.width) {
minSize.width = aRectSize.width;
aSlice.left = 0;
aSlice.right = 0;
}
if (aRectSize.height < minSize.height) {
minSize.height = aRectSize.height;
aSlice.top = 0;
aSlice.bottom = 0;
}
MOZ_ASSERT(aSlice.LeftRight() <= minSize.width);
MOZ_ASSERT(aSlice.TopBottom() <= minSize.height);
return minSize;
}
void
CacheBlur(DrawTarget& aDT,
const IntSize& aMinSize,
const IntSize& aBlurRadius,
RectCornerRadii* aCornerRadii,
const Color& aShadowColor,
IntMargin aExtendDest,
SourceSurface* aBoxShadow)
{
BlurCacheKey key(aMinSize, aBlurRadius, aCornerRadii, aShadowColor, aDT.GetBackendType());
BlurCacheData* data = new BlurCacheData(aBoxShadow, aExtendDest, key);
if (!gBlurCache->RegisterEntry(data)) {
delete data;
}
}
// Blurs a small surface and creates the mask.
static already_AddRefed<SourceSurface>
CreateBlurMask(const IntSize& aMinSize,
RectCornerRadii* aCornerRadii,
IntSize aBlurRadius,
IntMargin& aExtendDestBy,
IntMargin& aSliceBorder,
DrawTarget& aDestDrawTarget)
{
gfxAlphaBoxBlur blur;
IntRect minRect(IntPoint(), aMinSize);
gfxContext* blurCtx = blur.Init(ThebesRect(Rect(minRect)), IntSize(),
aBlurRadius, nullptr, nullptr);
if (!blurCtx) {
return nullptr;
}
DrawTarget* blurDT = blurCtx->GetDrawTarget();
ColorPattern black(Color(0.f, 0.f, 0.f, 1.f));
if (aCornerRadii) {
RefPtr<Path> roundedRect =
MakePathForRoundedRect(*blurDT, Rect(minRect), *aCornerRadii);
blurDT->Fill(roundedRect, black);
} else {
blurDT->FillRect(Rect(minRect), black);
}
IntPoint topLeft;
RefPtr<SourceSurface> result = blur.DoBlur(&aDestDrawTarget, &topLeft);
if (!result) {
return nullptr;
}
IntRect expandedMinRect(topLeft, result->GetSize());
aExtendDestBy = expandedMinRect - minRect;
aSliceBorder += aExtendDestBy;
MOZ_ASSERT(aSliceBorder.LeftRight() <= expandedMinRect.width);
MOZ_ASSERT(aSliceBorder.TopBottom() <= expandedMinRect.height);
return result.forget();
}
static already_AddRefed<SourceSurface>
CreateBoxShadow(SourceSurface* aBlurMask, const Color& aShadowColor)
{
IntSize blurredSize = aBlurMask->GetSize();
gfxPlatform* platform = gfxPlatform::GetPlatform();
RefPtr<DrawTarget> boxShadowDT =
platform->CreateOffscreenContentDrawTarget(blurredSize, SurfaceFormat::B8G8R8A8);
if (!boxShadowDT) {
return nullptr;
}
ColorPattern shadowColor(ToDeviceColor(aShadowColor));
boxShadowDT->MaskSurface(shadowColor, aBlurMask, Point(0, 0));
return boxShadowDT->Snapshot();
}
static already_AddRefed<SourceSurface>
GetBlur(gfxContext* aDestinationCtx,
const IntSize& aRectSize,
const IntSize& aBlurRadius,
RectCornerRadii* aCornerRadii,
const Color& aShadowColor,
IntMargin& aExtendDestBy,
IntMargin& aSlice)
{
if (!gBlurCache) {
gBlurCache = new BlurCache();
}
IntSize minSize =
ComputeMinSizeForShadowShape(aCornerRadii, aBlurRadius, aSlice, aRectSize);
// We can get seams using the min size rect when drawing to the destination rect
// if we have a non-pixel aligned destination transformation. In those cases,
// fallback to just rendering the destination rect.
Matrix destMatrix = ToMatrix(aDestinationCtx->CurrentMatrix());
bool useDestRect = !destMatrix.IsRectilinear() || destMatrix.HasNonIntegerTranslation();
if (useDestRect) {
minSize = aRectSize;
}
DrawTarget& destDT = *aDestinationCtx->GetDrawTarget();
BlurCacheData* cached = gBlurCache->Lookup(minSize, aBlurRadius,
aCornerRadii, aShadowColor,
destDT.GetBackendType());
if (cached && !useDestRect) {
// See CreateBlurMask() for these values
aExtendDestBy = cached->mExtendDest;
aSlice = aSlice + aExtendDestBy;
RefPtr<SourceSurface> blur = cached->mBlur;
return blur.forget();
}
RefPtr<SourceSurface> blurMask =
CreateBlurMask(minSize, aCornerRadii, aBlurRadius, aExtendDestBy, aSlice,
destDT);
if (!blurMask) {
return nullptr;
}
RefPtr<SourceSurface> boxShadow = CreateBoxShadow(blurMask, aShadowColor);
if (!boxShadow) {
return nullptr;
}
if (useDestRect) {
// Since we're just going to paint the actual rect to the destination
aSlice.SizeTo(0, 0, 0, 0);
} else {
CacheBlur(destDT, minSize, aBlurRadius, aCornerRadii, aShadowColor,
aExtendDestBy, boxShadow);
}
return boxShadow.forget();
}
void
gfxAlphaBoxBlur::ShutdownBlurCache()
{
delete gBlurCache;
gBlurCache = nullptr;
}
static Rect
RectWithEdgesTRBL(Float aTop, Float aRight, Float aBottom, Float aLeft)
{
return Rect(aLeft, aTop, aRight - aLeft, aBottom - aTop);
}
static void
RepeatOrStretchSurface(DrawTarget& aDT, SourceSurface* aSurface,
const Rect& aDest, const Rect& aSrc, Rect& aSkipRect)
{
if (aSkipRect.Contains(aDest)) {
return;
}
if ((!aDT.GetTransform().IsRectilinear() &&
aDT.GetBackendType() != BackendType::CAIRO) ||
(aDT.GetBackendType() == BackendType::DIRECT2D1_1)) {
// Use stretching if possible, since it leads to less seams when the
// destination is transformed. However, don't do this if we're using cairo,
// because if cairo is using pixman it won't render anything for large
// stretch factors because pixman's internal fixed point precision is not
// high enough to handle those scale factors.
// Calling FillRect on a D2D backend with a repeating pattern is much slower
// than DrawSurface, so special case the D2D backend here.
aDT.DrawSurface(aSurface, aDest, aSrc);
return;
}
SurfacePattern pattern(aSurface, ExtendMode::REPEAT,
Matrix::Translation(aDest.TopLeft() - aSrc.TopLeft()),
SamplingFilter::GOOD, RoundedToInt(aSrc));
aDT.FillRect(aDest, pattern);
}
static void
DrawCorner(DrawTarget& aDT, SourceSurface* aSurface,
const Rect& aDest, const Rect& aSrc, Rect& aSkipRect)
{
if (aSkipRect.Contains(aDest)) {
return;
}
aDT.DrawSurface(aSurface, aDest, aSrc);
}
static void
DrawBoxShadows(DrawTarget& aDestDrawTarget, SourceSurface* aSourceBlur,
Rect aDstOuter, Rect aDstInner, Rect aSrcOuter, Rect aSrcInner,
Rect aSkipRect)
{
// Corners: top left, top right, bottom left, bottom right
DrawCorner(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstOuter.Y(), aDstInner.X(),
aDstInner.Y(), aDstOuter.X()),
RectWithEdgesTRBL(aSrcOuter.Y(), aSrcInner.X(),
aSrcInner.Y(), aSrcOuter.X()),
aSkipRect);
DrawCorner(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstOuter.Y(), aDstOuter.XMost(),
aDstInner.Y(), aDstInner.XMost()),
RectWithEdgesTRBL(aSrcOuter.Y(), aSrcOuter.XMost(),
aSrcInner.Y(), aSrcInner.XMost()),
aSkipRect);
DrawCorner(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstInner.YMost(), aDstInner.X(),
aDstOuter.YMost(), aDstOuter.X()),
RectWithEdgesTRBL(aSrcInner.YMost(), aSrcInner.X(),
aSrcOuter.YMost(), aSrcOuter.X()),
aSkipRect);
DrawCorner(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstInner.YMost(), aDstOuter.XMost(),
aDstOuter.YMost(), aDstInner.XMost()),
RectWithEdgesTRBL(aSrcInner.YMost(), aSrcOuter.XMost(),
aSrcOuter.YMost(), aSrcInner.XMost()),
aSkipRect);
// Edges: top, left, right, bottom
RepeatOrStretchSurface(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstOuter.Y(), aDstInner.XMost(),
aDstInner.Y(), aDstInner.X()),
RectWithEdgesTRBL(aSrcOuter.Y(), aSrcInner.XMost(),
aSrcInner.Y(), aSrcInner.X()),
aSkipRect);
RepeatOrStretchSurface(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstInner.Y(), aDstInner.X(),
aDstInner.YMost(), aDstOuter.X()),
RectWithEdgesTRBL(aSrcInner.Y(), aSrcInner.X(),
aSrcInner.YMost(), aSrcOuter.X()),
aSkipRect);
RepeatOrStretchSurface(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstInner.Y(), aDstOuter.XMost(),
aDstInner.YMost(), aDstInner.XMost()),
RectWithEdgesTRBL(aSrcInner.Y(), aSrcOuter.XMost(),
aSrcInner.YMost(), aSrcInner.XMost()),
aSkipRect);
RepeatOrStretchSurface(aDestDrawTarget, aSourceBlur,
RectWithEdgesTRBL(aDstInner.YMost(), aDstInner.XMost(),
aDstOuter.YMost(), aDstInner.X()),
RectWithEdgesTRBL(aSrcInner.YMost(), aSrcInner.XMost(),
aSrcOuter.YMost(), aSrcInner.X()),
aSkipRect);
}
/***
* We draw a blurred a rectangle by only blurring a smaller rectangle and
* splitting the rectangle into 9 parts.
* First, a small minimum source rect is calculated and used to create a blur
* mask since the actual blurring itself is expensive. Next, we use the mask
* with the given shadow color to create a minimally-sized box shadow of the
* right color. Finally, we cut out the 9 parts from the box-shadow source and
* paint each part in the right place, stretching the non-corner parts to fill
* the space between the corners.
*/
/* static */ void
gfxAlphaBoxBlur::BlurRectangle(gfxContext* aDestinationCtx,
const gfxRect& aRect,
RectCornerRadii* aCornerRadii,
const gfxPoint& aBlurStdDev,
const Color& aShadowColor,
const gfxRect& aDirtyRect,
const gfxRect& aSkipRect)
{
IntSize blurRadius = CalculateBlurRadius(aBlurStdDev);
IntRect rect = RoundedToInt(ToRect(aRect));
IntMargin extendDestBy;
IntMargin slice;
RefPtr<SourceSurface> boxShadow = GetBlur(aDestinationCtx,
rect.Size(), blurRadius,
aCornerRadii, aShadowColor,
extendDestBy, slice);
if (!boxShadow) {
return;
}
DrawTarget& destDrawTarget = *aDestinationCtx->GetDrawTarget();
destDrawTarget.PushClipRect(ToRect(aDirtyRect));
// Copy the right parts from boxShadow into destDrawTarget. The middle parts
// will be stretched, border-image style.
Rect srcOuter(Point(), Size(boxShadow->GetSize()));
Rect srcInner = srcOuter;
srcInner.Deflate(Margin(slice));
rect.Inflate(extendDestBy);
Rect dstOuter(rect);
Rect dstInner(rect);
dstInner.Deflate(Margin(slice));
Rect skipRect = ToRect(aSkipRect);
if (srcInner.IsEqualInterior(srcOuter)) {
MOZ_ASSERT(dstInner.IsEqualInterior(dstOuter));
// The target rect is smaller than the minimal size so just draw the surface
destDrawTarget.DrawSurface(boxShadow, dstInner, srcInner);
} else {
DrawBoxShadows(destDrawTarget, boxShadow, dstOuter, dstInner,
srcOuter, srcInner, skipRect);
// Middle part
RepeatOrStretchSurface(destDrawTarget, boxShadow,
RectWithEdgesTRBL(dstInner.Y(), dstInner.XMost(),
dstInner.YMost(), dstInner.X()),
RectWithEdgesTRBL(srcInner.Y(), srcInner.XMost(),
srcInner.YMost(), srcInner.X()),
skipRect);
}
// A note about anti-aliasing and seems between adjacent parts:
// We don't explicitly disable anti-aliasing in the DrawSurface calls above,
// so if there's a transform on destDrawTarget that is not pixel-aligned,
// there will be seams between adjacent parts of the box-shadow. It's hard to
// avoid those without the use of an intermediate surface.
// You might think that we could avoid those by just turning of AA, but there
// is a problem with that: Box-shadow rendering needs to clip out the
// element's border box, and we'd like that clip to have anti-aliasing -
// especially if the element has rounded corners! So we can't do that unless
// we have a way to say "Please anti-alias the clip, but don't antialias the
// destination rect of the DrawSurface call".
// On OS X there is an additional problem with turning off AA: CoreGraphics
// will not just fill the pixels that have their pixel center inside the
// filled shape. Instead, it will fill all the pixels which are partially
// covered by the shape. So for pixels on the edge between two adjacent parts,
// all those pixels will be painted to by both parts, which looks very bad.
destDrawTarget.PopClip();
}
static already_AddRefed<Path>
GetBoxShadowInsetPath(DrawTarget* aDrawTarget,
const Rect aOuterRect, const Rect aInnerRect,
const bool aHasBorderRadius, const RectCornerRadii& aInnerClipRadii)
{
/***
* We create an inset path by having two rects.
*
* -----------------------
* | ________________ |
* | | | |
* | | | |
* | ------------------ |
* |_____________________|
*
* The outer rect and the inside rect. The path
* creates a frame around the content where we draw the inset shadow.
*/
RefPtr<PathBuilder> builder =
aDrawTarget->CreatePathBuilder(FillRule::FILL_EVEN_ODD);
AppendRectToPath(builder, aOuterRect, true);
if (aHasBorderRadius) {
AppendRoundedRectToPath(builder, aInnerRect, aInnerClipRadii, false);
} else {
AppendRectToPath(builder, aInnerRect, false);
}
return builder->Finish();
}
static void
FillDestinationPath(gfxContext* aDestinationCtx,
const Rect aDestinationRect,
const Rect aShadowClipRect,
const Color& aShadowColor,
const bool aHasBorderRadius,
const RectCornerRadii& aInnerClipRadii)
{
// When there is no blur radius, fill the path onto the destination
// surface.
aDestinationCtx->SetColor(aShadowColor);
DrawTarget* destDrawTarget = aDestinationCtx->GetDrawTarget();
RefPtr<Path> shadowPath = GetBoxShadowInsetPath(destDrawTarget, aDestinationRect,
aShadowClipRect, aHasBorderRadius,
aInnerClipRadii);
aDestinationCtx->SetPath(shadowPath);
aDestinationCtx->Fill();
}
static void
CacheInsetBlur(const IntSize aMinOuterSize,
const IntSize aMinInnerSize,
const IntSize& aBlurRadius,
const RectCornerRadii* aCornerRadii,
const Color& aShadowColor,
const bool& aHasBorderRadius,
BackendType aBackendType,
SourceSurface* aBoxShadow)
{
bool isInsetBlur = true;
BlurCacheKey key(aMinOuterSize, aMinInnerSize,
aBlurRadius, aCornerRadii,
aShadowColor, isInsetBlur,
aHasBorderRadius, aBackendType);
IntMargin extendDestBy(0, 0, 0, 0);
BlurCacheData* data = new BlurCacheData(aBoxShadow, extendDestBy, key);
if (!gBlurCache->RegisterEntry(data)) {
delete data;
}
}
already_AddRefed<mozilla::gfx::SourceSurface>
gfxAlphaBoxBlur::GetInsetBlur(const mozilla::gfx::Rect aOuterRect,
const mozilla::gfx::Rect aWhitespaceRect,
const bool aIsDestRect,
const mozilla::gfx::Color& aShadowColor,
const mozilla::gfx::IntSize& aBlurRadius,
const bool aHasBorderRadius,
const RectCornerRadii& aInnerClipRadii,
DrawTarget* aDestDrawTarget)
{
if (!gBlurCache) {
gBlurCache = new BlurCache();
}
IntSize outerSize((int)aOuterRect.width, (int)aOuterRect.height);
IntSize whitespaceSize((int)aWhitespaceRect.width, (int)aWhitespaceRect.height);
BlurCacheData* cached =
gBlurCache->LookupInsetBoxShadow(outerSize, whitespaceSize,
aBlurRadius, &aInnerClipRadii,
aShadowColor, aHasBorderRadius,
aDestDrawTarget->GetBackendType());
if (cached && !aIsDestRect) {
// So we don't forget the actual cached blur
RefPtr<SourceSurface> cachedBlur = cached->mBlur;
return cachedBlur.forget();
}
// If we can do a min rect, the whitespace rect will be expanded in Init to
// aOuterRect.
Rect blurRect = aIsDestRect ? aOuterRect : aWhitespaceRect;
IntSize zeroSpread(0, 0);
gfxContext* minGfxContext = Init(ThebesRect(blurRect),
zeroSpread, aBlurRadius,
nullptr, nullptr);
if (!minGfxContext) {
return nullptr;
}
// This is really annoying. When we create the AlphaBoxBlur, the gfxContext
// has a translation applied to it that is the topLeft point. This is actually
// the rect we gave it plus the blur radius. The rects we give this for the outer
// and whitespace rects are based at (0, 0). We could either translate those rects
// when we don't have a destination rect or ignore the translation when using
// the dest rect. The dest rects layout gives us expect this translation.
if (!aIsDestRect) {
minGfxContext->SetMatrix(gfxMatrix());
}
DrawTarget* minDrawTarget = minGfxContext->GetDrawTarget();
// Fill in the path between the inside white space / outer rects
// NOT the inner frame
RefPtr<Path> maskPath =
GetBoxShadowInsetPath(minDrawTarget, aOuterRect,
aWhitespaceRect, aHasBorderRadius,
aInnerClipRadii);
Color black(0.f, 0.f, 0.f, 1.f);
minGfxContext->SetColor(black);
minGfxContext->SetPath(maskPath);
minGfxContext->Fill();
// Create the A8 mask
IntPoint topLeft;
RefPtr<SourceSurface> minMask = DoBlur(minDrawTarget, &topLeft);
if (!minMask) {
return nullptr;
}
// Fill in with the color we actually wanted
RefPtr<SourceSurface> minInsetBlur = CreateBoxShadow(minMask, aShadowColor);
if (!minInsetBlur) {
return nullptr;
}
if (!aIsDestRect) {
CacheInsetBlur(outerSize, whitespaceSize,
aBlurRadius, &aInnerClipRadii,
aShadowColor, aHasBorderRadius,
aDestDrawTarget->GetBackendType(),
minInsetBlur);
}
return minInsetBlur.forget();
}
/***
* We create our minimal rect with 2 rects.
* The first is the inside whitespace rect, that is "cut out"
* from the box. This is (1). This must be the size
* of the blur radius + corner radius so we can have a big enough
* inside cut.
*
* The second (2) is one blur radius surrounding the inner
* frame of (1). This is the amount of blur space required
* to get a proper blend.
*
* B = one blur size
* W = one blur + corner radii - known as inner margin
* ___________________________________
* | |
* | | | |
* | (2) | (1) | (2) |
* | B | W | B |
* | | | |
* | | | |
* | | |
* |________________________________|
*/
static void GetBlurMargins(const bool aHasBorderRadius,
const RectCornerRadii& aInnerClipRadii,
const IntSize aBlurRadius,
Margin& aOutBlurMargin,
Margin& aOutInnerMargin)
{
float cornerWidth = 0;
float cornerHeight = 0;
if (aHasBorderRadius) {
for (size_t i = 0; i < 4; i++) {
cornerWidth = std::max(cornerWidth, aInnerClipRadii[i].width);
cornerHeight = std::max(cornerHeight, aInnerClipRadii[i].height);
}
}
// Only the inside whitespace size cares about the border radius size.
// Outer sizes only care about blur.
int width = cornerWidth + aBlurRadius.width;
int height = cornerHeight + aBlurRadius.height;
aOutInnerMargin.SizeTo(height, width, height, width);
aOutBlurMargin.SizeTo(aBlurRadius.height, aBlurRadius.width,
aBlurRadius.height, aBlurRadius.width);
}
static bool
GetInsetBoxShadowRects(const Margin aBlurMargin,
const Margin aInnerMargin,
const Rect aShadowClipRect,
const Rect aDestinationRect,
Rect& aOutWhitespaceRect,
Rect& aOutOuterRect)
{
// We always copy (2 * blur radius) + corner radius worth of data to the destination rect
// This covers the blend of the path + the actual blur
// Need +1 so that we copy the edges correctly as we'll copy
// over the min box shadow corners then the +1 for the edges between
// Note, the (x,y) coordinates are from the blur margin
// since the frame outside the whitespace rect is 1 blur radius extra space.
Rect insideWhiteSpace(aBlurMargin.left,
aBlurMargin.top,
aInnerMargin.LeftRight() + 1,
aInnerMargin.TopBottom() + 1);
// If the inner white space rect is larger than the shadow clip rect
// our approach does not work as we'll just copy one corner
// and cover the destination. In those cases, fallback to the destination rect
bool useDestRect = (aShadowClipRect.width <= aInnerMargin.LeftRight()) ||
(aShadowClipRect.height <= aInnerMargin.TopBottom());
if (useDestRect) {
aOutWhitespaceRect = aShadowClipRect;
aOutOuterRect = aDestinationRect;
} else {
aOutWhitespaceRect = insideWhiteSpace;
aOutOuterRect = aOutWhitespaceRect;
aOutOuterRect.Inflate(aBlurMargin);
}
return useDestRect;
}
void
gfxAlphaBoxBlur::BlurInsetBox(gfxContext* aDestinationCtx,
const Rect aDestinationRect,
const Rect aShadowClipRect,
const IntSize aBlurRadius,
const IntSize aSpreadRadius,
const Color& aShadowColor,
bool aHasBorderRadius,
const RectCornerRadii& aInnerClipRadii,
const Rect aSkipRect,
const Point aShadowOffset)
{
if ((aBlurRadius.width == 0 && aBlurRadius.height == 0)
|| aShadowClipRect.IsEmpty()) {
FillDestinationPath(aDestinationCtx, aDestinationRect, aShadowClipRect,
aShadowColor, aHasBorderRadius, aInnerClipRadii);
return;
}
DrawTarget* destDrawTarget = aDestinationCtx->GetDrawTarget();
Margin innerMargin;
Margin blurMargin;
GetBlurMargins(aHasBorderRadius, aInnerClipRadii, aBlurRadius,
blurMargin, innerMargin);
Rect whitespaceRect;
Rect outerRect;
bool useDestRect = GetInsetBoxShadowRects(blurMargin, innerMargin, aShadowClipRect,
aDestinationRect, whitespaceRect, outerRect);
RefPtr<SourceSurface> minBlur = GetInsetBlur(outerRect, whitespaceRect, useDestRect, aShadowColor,
aBlurRadius, aHasBorderRadius, aInnerClipRadii,
destDrawTarget);
if (!minBlur) {
return;
}
if (useDestRect) {
IntSize blurSize = minBlur->GetSize();
Rect srcBlur(0, 0, blurSize.width, blurSize.height);
Rect destBlur = aDestinationRect;
// The blur itself expands the rect by the blur margin, so we
// have to mimic that here.
destBlur.Inflate(blurMargin);
MOZ_ASSERT(srcBlur.Size() == destBlur.Size());
destDrawTarget->DrawSurface(minBlur, destBlur, srcBlur);
} else {
Rect srcOuter(outerRect);
Rect srcInner(srcOuter);
srcInner.Deflate(blurMargin); // The outer color fill
srcInner.Deflate(innerMargin); // The inner whitespace
// The shadow clip rect already takes into account the spread radius
Rect outerFillRect(aShadowClipRect);
outerFillRect.Inflate(blurMargin);
FillDestinationPath(aDestinationCtx, aDestinationRect, outerFillRect, aShadowColor, false, RectCornerRadii());
// Inflate once for the frame around the whitespace
Rect destRect(aShadowClipRect);
destRect.Inflate(blurMargin);
// Deflate for the blurred in white space
Rect destInnerRect(aShadowClipRect);
destInnerRect.Deflate(innerMargin);
DrawBoxShadows(*destDrawTarget, minBlur,
destRect, destInnerRect,
srcOuter, srcInner,
aSkipRect);
}
}