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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#include <math.h>
#include "mozilla/Alignment.h"
#include "cairo.h"
#include "gfxContext.h"
#include "gfxMatrix.h"
#include "gfxUtils.h"
#include "gfxPattern.h"
#include "gfxPlatform.h"
#include "gfx2DGlue.h"
#include "mozilla/gfx/PathHelpers.h"
#include "mozilla/ProfilerLabels.h"
#include <algorithm>
#include "TextDrawTarget.h"
#if XP_WIN
# include "gfxWindowsPlatform.h"
# include "mozilla/gfx/DeviceManagerDx.h"
#endif
using namespace mozilla;
using namespace mozilla::gfx;
#ifdef DEBUG
# define CURRENTSTATE_CHANGED() mAzureState.mContentChanged = true;
#else
# define CURRENTSTATE_CHANGED()
#endif
PatternFromState::operator Pattern&() {
const gfxContext::AzureState& state = mContext->mAzureState;
if (state.pattern) {
return *state.pattern->GetPattern(
mContext->mDT,
state.patternTransformChanged ? &state.patternTransform : nullptr);
}
mPattern = new (mColorPattern.addr()) ColorPattern(state.color);
return *mPattern;
}
/* static */
UniquePtr<gfxContext> gfxContext::CreateOrNull(DrawTarget* aTarget) {
if (!aTarget || !aTarget->IsValid()) {
gfxCriticalNote << "Invalid target in gfxContext::CreateOrNull "
<< hexa(aTarget);
return nullptr;
}
return MakeUnique<gfxContext>(aTarget);
}
gfxContext::~gfxContext() {
while (!mSavedStates.IsEmpty()) {
Restore();
}
for (unsigned int c = 0; c < mAzureState.pushedClips.Length(); c++) {
mDT->PopClip();
}
}
mozilla::layout::TextDrawTarget* gfxContext::GetTextDrawer() const {
if (mDT->GetBackendType() == BackendType::WEBRENDER_TEXT) {
return static_cast<mozilla::layout::TextDrawTarget*>(&*mDT);
}
return nullptr;
}
void gfxContext::Save() {
mSavedStates.AppendElement(mAzureState);
mAzureState.pushedClips.Clear();
#ifdef DEBUG
mAzureState.mContentChanged = false;
#endif
}
void gfxContext::Restore() {
#ifdef DEBUG
// gfxContext::Restore is used to restore AzureState. We need to restore it
// only if it was altered. The following APIs do change the content of
// AzureState, a user should save the state before using them and restore it
// after finishing painting:
// 1. APIs to setup how to paint, such as SetColor()/SetAntialiasMode(). All
// gfxContext SetXXXX public functions belong to this category, except
// gfxContext::SetPath & gfxContext::SetMatrix.
// 2. Clip functions, such as Clip() or PopClip(). You may call PopClip()
// directly instead of using gfxContext::Save if the clip region is the
// only thing that you altered in the target context.
// 3. Function of setup transform matrix, such as Multiply() and
// SetMatrix(). Using gfxContextMatrixAutoSaveRestore is more recommended
// if transform data is the only thing that you are going to alter.
//
// You will hit the assertion message below if there is no above functions
// been used between a pair of gfxContext::Save and gfxContext::Restore.
// Considerate to remove that pair of Save/Restore if hitting that assertion.
//
// In the other hand, the following APIs do not alter the content of the
// current AzureState, therefore, there is no need to save & restore
// AzureState:
// 1. constant member functions of gfxContext.
// 2. Paint calls, such as Line()/Rectangle()/Fill(). Those APIs change the
// content of drawing buffer, which is not part of AzureState.
// 3. Path building APIs, such as SetPath()/MoveTo()/LineTo()/NewPath().
// Surprisingly, path information is not stored in AzureState either.
// Save current AzureState before using these type of APIs does nothing but
// make performance worse.
NS_ASSERTION(
mAzureState.mContentChanged || mAzureState.pushedClips.Length() > 0,
"The context of the current AzureState is not altered after "
"Save() been called. you may consider to remove this pair of "
"gfxContext::Save/Restore.");
#endif
for (unsigned int c = 0; c < mAzureState.pushedClips.Length(); c++) {
mDT->PopClip();
}
mAzureState = mSavedStates.PopLastElement();
ChangeTransform(mAzureState.transform, false);
}
// drawing
void gfxContext::Fill(const Pattern& aPattern) {
AUTO_PROFILER_LABEL("gfxContext::Fill", GRAPHICS);
CompositionOp op = GetOp();
if (mPathIsRect) {
MOZ_ASSERT(!mTransformChanged);
if (op == CompositionOp::OP_SOURCE) {
// Emulate cairo operator source which is bound by mask!
mDT->ClearRect(mRect);
mDT->FillRect(mRect, aPattern, DrawOptions(1.0f));
} else {
mDT->FillRect(mRect, aPattern, DrawOptions(1.0f, op, mAzureState.aaMode));
}
} else {
EnsurePath();
mDT->Fill(mPath, aPattern, DrawOptions(1.0f, op, mAzureState.aaMode));
}
}
// XXX snapToPixels is only valid when snapping for filled
// rectangles and for even-width stroked rectangles.
// For odd-width stroked rectangles, we need to offset x/y by
// 0.5...
void gfxContext::Rectangle(const gfxRect& rect, bool snapToPixels) {
Rect rec = ToRect(rect);
if (snapToPixels) {
gfxRect newRect(rect);
if (UserToDevicePixelSnapped(newRect, SnapOption::IgnoreScale)) {
gfxMatrix mat = CurrentMatrixDouble();
if (mat.Invert()) {
// We need the user space rect.
rec = ToRect(mat.TransformBounds(newRect));
} else {
rec = Rect();
}
}
}
if (!mPathBuilder && !mPathIsRect) {
mPathIsRect = true;
mRect = rec;
return;
}
EnsurePathBuilder();
mPathBuilder->MoveTo(rec.TopLeft());
mPathBuilder->LineTo(rec.TopRight());
mPathBuilder->LineTo(rec.BottomRight());
mPathBuilder->LineTo(rec.BottomLeft());
mPathBuilder->Close();
}
void gfxContext::SnappedClip(const gfxRect& rect) {
Rect rec = ToRect(rect);
gfxRect newRect(rect);
if (UserToDevicePixelSnapped(newRect, SnapOption::IgnoreScale)) {
gfxMatrix mat = CurrentMatrixDouble();
if (mat.Invert()) {
// We need the user space rect.
rec = ToRect(mat.TransformBounds(newRect));
} else {
rec = Rect();
}
}
Clip(rec);
}
bool gfxContext::UserToDevicePixelSnapped(gfxRect& rect,
SnapOptions aOptions) const {
if (mDT->GetUserData(&sDisablePixelSnapping)) {
return false;
}
// if we're not at 1.0 scale, don't snap, unless we're
// ignoring the scale. If we're not -just- a scale,
// never snap.
const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a, b) (fabs((a) - (b)) < epsilon)
Matrix mat = mAzureState.transform;
if (!aOptions.contains(SnapOption::IgnoreScale) &&
(!WITHIN_E(mat._11, 1.0) || !WITHIN_E(mat._22, 1.0) ||
!WITHIN_E(mat._12, 0.0) || !WITHIN_E(mat._21, 0.0))) {
return false;
}
#undef WITHIN_E
gfxPoint p1 = UserToDevice(rect.TopLeft());
gfxPoint p2 = UserToDevice(rect.TopRight());
gfxPoint p3 = UserToDevice(rect.BottomRight());
// Check that the rectangle is axis-aligned. For an axis-aligned rectangle,
// two opposite corners define the entire rectangle. So check if
// the axis-aligned rectangle with opposite corners p1 and p3
// define an axis-aligned rectangle whose other corners are p2 and p4.
// We actually only need to check one of p2 and p4, since an affine
// transform maps parallelograms to parallelograms.
if (!(p2 == gfxPoint(p1.x, p3.y) || p2 == gfxPoint(p3.x, p1.y))) {
return false;
}
if (aOptions.contains(SnapOption::PrioritizeSize)) {
// Snap the dimensions of the rect, to minimize distortion; only after that
// will we snap its position. In particular, this guarantees that a square
// remains square after snapping, which may not be the case if each edge is
// independently snapped to device pixels.
// Use the same rounding approach as gfx::BasePoint::Round.
rect.SizeTo(std::floor(rect.width + 0.5), std::floor(rect.height + 0.5));
// Find the top-left corner based on the original center and the snapped
// size, then snap this new corner to the grid.
gfxPoint center = (p1 + p3) / 2;
gfxPoint topLeft = center - gfxPoint(rect.width / 2.0, rect.height / 2.0);
topLeft.Round();
rect.MoveTo(topLeft);
} else {
p1.Round();
p3.Round();
rect.MoveTo(gfxPoint(std::min(p1.x, p3.x), std::min(p1.y, p3.y)));
rect.SizeTo(gfxSize(std::max(p1.x, p3.x) - rect.X(),
std::max(p1.y, p3.y) - rect.Y()));
}
return true;
}
bool gfxContext::UserToDevicePixelSnapped(gfxPoint& pt,
bool ignoreScale) const {
if (mDT->GetUserData(&sDisablePixelSnapping)) {
return false;
}
// if we're not at 1.0 scale, don't snap, unless we're
// ignoring the scale. If we're not -just- a scale,
// never snap.
const gfxFloat epsilon = 0.0000001;
#define WITHIN_E(a, b) (fabs((a) - (b)) < epsilon)
Matrix mat = mAzureState.transform;
if (!ignoreScale && (!WITHIN_E(mat._11, 1.0) || !WITHIN_E(mat._22, 1.0) ||
!WITHIN_E(mat._12, 0.0) || !WITHIN_E(mat._21, 0.0))) {
return false;
}
#undef WITHIN_E
pt = UserToDevice(pt);
pt.Round();
return true;
}
void gfxContext::SetDash(const Float* dashes, int ndash, Float offset,
Float devPxScale) {
CURRENTSTATE_CHANGED()
mAzureState.dashPattern.SetLength(ndash);
for (int i = 0; i < ndash; i++) {
mAzureState.dashPattern[i] = dashes[i] * devPxScale;
}
mAzureState.strokeOptions.mDashLength = ndash;
mAzureState.strokeOptions.mDashOffset = offset * devPxScale;
mAzureState.strokeOptions.mDashPattern =
ndash ? mAzureState.dashPattern.Elements() : nullptr;
}
bool gfxContext::CurrentDash(FallibleTArray<Float>& dashes,
Float* offset) const {
if (mAzureState.strokeOptions.mDashLength == 0 ||
!dashes.Assign(mAzureState.dashPattern, fallible)) {
return false;
}
*offset = mAzureState.strokeOptions.mDashOffset;
return true;
}
// clipping
void gfxContext::Clip(const Rect& rect) {
AzureState::PushedClip clip = {nullptr, rect, mAzureState.transform};
mAzureState.pushedClips.AppendElement(clip);
mDT->PushClipRect(rect);
NewPath();
}
void gfxContext::Clip(Path* aPath) {
mDT->PushClip(aPath);
AzureState::PushedClip clip = {aPath, Rect(), mAzureState.transform};
mAzureState.pushedClips.AppendElement(clip);
}
void gfxContext::Clip() {
if (mPathIsRect) {
MOZ_ASSERT(!mTransformChanged);
AzureState::PushedClip clip = {nullptr, mRect, mAzureState.transform};
mAzureState.pushedClips.AppendElement(clip);
mDT->PushClipRect(mRect);
} else {
EnsurePath();
mDT->PushClip(mPath);
AzureState::PushedClip clip = {mPath, Rect(), mAzureState.transform};
mAzureState.pushedClips.AppendElement(clip);
}
}
gfxRect gfxContext::GetClipExtents(ClipExtentsSpace aSpace) const {
Rect rect = GetAzureDeviceSpaceClipBounds();
if (rect.IsZeroArea()) {
return gfxRect(0, 0, 0, 0);
}
if (aSpace == eUserSpace) {
Matrix mat = mAzureState.transform;
mat.Invert();
rect = mat.TransformBounds(rect);
}
return ThebesRect(rect);
}
bool gfxContext::ExportClip(ClipExporter& aExporter) const {
ForAllClips([&](const AzureState::PushedClip& aClip) -> void {
gfx::Matrix transform = aClip.transform;
transform.PostTranslate(-GetDeviceOffset());
aExporter.BeginClip(transform);
if (aClip.path) {
aClip.path->StreamToSink(&aExporter);
} else {
aExporter.MoveTo(aClip.rect.TopLeft());
aExporter.LineTo(aClip.rect.TopRight());
aExporter.LineTo(aClip.rect.BottomRight());
aExporter.LineTo(aClip.rect.BottomLeft());
aExporter.Close();
}
aExporter.EndClip();
});
return true;
}
// rendering sources
bool gfxContext::GetDeviceColor(DeviceColor& aColorOut) const {
if (mAzureState.pattern) {
return mAzureState.pattern->GetSolidColor(aColorOut);
}
aColorOut = mAzureState.color;
return true;
}
already_AddRefed<gfxPattern> gfxContext::GetPattern() const {
RefPtr<gfxPattern> pat;
if (mAzureState.pattern) {
pat = mAzureState.pattern;
} else {
pat = new gfxPattern(mAzureState.color);
}
return pat.forget();
}
void gfxContext::Paint(Float alpha) const {
AUTO_PROFILER_LABEL("gfxContext::Paint", GRAPHICS);
Matrix mat = mDT->GetTransform();
mat.Invert();
Rect paintRect = mat.TransformBounds(Rect(Point(0, 0), Size(mDT->GetSize())));
mDT->FillRect(paintRect, PatternFromState(this), DrawOptions(alpha, GetOp()));
}
#ifdef MOZ_DUMP_PAINTING
void gfxContext::WriteAsPNG(const char* aFile) {
gfxUtils::WriteAsPNG(mDT, aFile);
}
void gfxContext::DumpAsDataURI() { gfxUtils::DumpAsDataURI(mDT); }
void gfxContext::CopyAsDataURI() { gfxUtils::CopyAsDataURI(mDT); }
#endif
void gfxContext::EnsurePath() {
if (mPathBuilder) {
mPath = mPathBuilder->Finish();
mPathBuilder = nullptr;
}
if (mPath) {
if (mTransformChanged) {
Matrix mat = mAzureState.transform;
mat.Invert();
mat = mPathTransform * mat;
mPathBuilder = mPath->TransformedCopyToBuilder(mat);
mPath = mPathBuilder->Finish();
mPathBuilder = nullptr;
mTransformChanged = false;
}
return;
}
EnsurePathBuilder();
mPath = mPathBuilder->Finish();
mPathBuilder = nullptr;
}
void gfxContext::EnsurePathBuilder() {
if (mPathBuilder && !mTransformChanged) {
return;
}
if (mPath) {
if (!mTransformChanged) {
mPathBuilder = mPath->CopyToBuilder();
mPath = nullptr;
} else {
Matrix invTransform = mAzureState.transform;
invTransform.Invert();
Matrix toNewUS = mPathTransform * invTransform;
mPathBuilder = mPath->TransformedCopyToBuilder(toNewUS);
}
return;
}
DebugOnly<PathBuilder*> oldPath = mPathBuilder.get();
if (!mPathBuilder) {
mPathBuilder = mDT->CreatePathBuilder(FillRule::FILL_WINDING);
if (mPathIsRect) {
mPathBuilder->MoveTo(mRect.TopLeft());
mPathBuilder->LineTo(mRect.TopRight());
mPathBuilder->LineTo(mRect.BottomRight());
mPathBuilder->LineTo(mRect.BottomLeft());
mPathBuilder->Close();
}
}
if (mTransformChanged) {
// This could be an else if since this should never happen when
// mPathBuilder is nullptr and mPath is nullptr. But this way we can
// assert if all the state is as expected.
MOZ_ASSERT(oldPath);
MOZ_ASSERT(!mPathIsRect);
Matrix invTransform = mAzureState.transform;
invTransform.Invert();
Matrix toNewUS = mPathTransform * invTransform;
RefPtr<Path> path = mPathBuilder->Finish();
if (!path) {
gfxCriticalError()
<< "gfxContext::EnsurePathBuilder failed in PathBuilder::Finish";
}
mPathBuilder = path->TransformedCopyToBuilder(toNewUS);
}
mPathIsRect = false;
}
CompositionOp gfxContext::GetOp() const {
if (mAzureState.op != CompositionOp::OP_SOURCE) {
return mAzureState.op;
}
if (mAzureState.pattern) {
if (mAzureState.pattern->IsOpaque()) {
return CompositionOp::OP_OVER;
} else {
return CompositionOp::OP_SOURCE;
}
} else {
if (mAzureState.color.a > 0.999) {
return CompositionOp::OP_OVER;
} else {
return CompositionOp::OP_SOURCE;
}
}
}
/* SVG font code can change the transform after having set the pattern on the
* context. When the pattern is set it is in user space, if the transform is
* changed after doing so the pattern needs to be converted back into userspace.
* We just store the old pattern transform here so that we only do the work
* needed here if the pattern is actually used.
* We need to avoid doing this when this ChangeTransform comes from a restore,
* since the current pattern and the current transform are both part of the
* state we know the new mAzureState's values are valid. But if we assume
* a change they might become invalid since patternTransformChanged is part of
* the state and might be false for the restored AzureState.
*/
void gfxContext::ChangeTransform(const Matrix& aNewMatrix,
bool aUpdatePatternTransform) {
if (aUpdatePatternTransform && (mAzureState.pattern) &&
!mAzureState.patternTransformChanged) {
mAzureState.patternTransform = GetDTTransform();
mAzureState.patternTransformChanged = true;
}
if (mPathIsRect) {
Matrix invMatrix = aNewMatrix;
invMatrix.Invert();
Matrix toNewUS = mAzureState.transform * invMatrix;
if (toNewUS.IsRectilinear()) {
mRect = toNewUS.TransformBounds(mRect);
mRect.NudgeToIntegers();
} else {
mPathBuilder = mDT->CreatePathBuilder(FillRule::FILL_WINDING);
mPathBuilder->MoveTo(toNewUS.TransformPoint(mRect.TopLeft()));
mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.TopRight()));
mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.BottomRight()));
mPathBuilder->LineTo(toNewUS.TransformPoint(mRect.BottomLeft()));
mPathBuilder->Close();
mPathIsRect = false;
}
// No need to consider the transform changed now!
mTransformChanged = false;
} else if ((mPath || mPathBuilder) && !mTransformChanged) {
mTransformChanged = true;
mPathTransform = mAzureState.transform;
}
mAzureState.transform = aNewMatrix;
mDT->SetTransform(GetDTTransform());
}
Rect gfxContext::GetAzureDeviceSpaceClipBounds() const {
Rect rect(mAzureState.deviceOffset.x + Float(mDT->GetRect().x),
mAzureState.deviceOffset.y + Float(mDT->GetRect().y),
Float(mDT->GetSize().width), Float(mDT->GetSize().height));
ForAllClips([&](const AzureState::PushedClip& aClip) -> void {
if (aClip.path) {
rect.IntersectRect(rect, aClip.path->GetBounds(aClip.transform));
} else {
rect.IntersectRect(rect, aClip.transform.TransformBounds(aClip.rect));
}
});
return rect;
}
template <typename F>
void gfxContext::ForAllClips(F&& aLambda) const {
for (const auto& state : mSavedStates) {
for (const auto& clip : state.pushedClips) {
aLambda(clip);
}
}
for (const auto& clip : mAzureState.pushedClips) {
aLambda(clip);
}
}