/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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/. */
#ifndef GFX_CONTEXT_H
#define GFX_CONTEXT_H
#include "gfx2DGlue.h"
#include "gfxPattern.h"
#include "gfxUtils.h"
#include "nsTArray.h"
#include "mozilla/EnumSet.h"
#include "mozilla/gfx/2D.h"
typedef struct _cairo cairo_t;
class GlyphBufferAzure;
namespace mozilla {
namespace gfx {
struct RectCornerRadii;
}
// namespace gfx
namespace layout {
class TextDrawTarget;
}
// namespace layout
}
// namespace mozilla
class ClipExporter;
/* This class lives on the stack and allows gfxContext users to easily, and
* performantly get a gfx::Pattern to use for drawing in their current context.
*/
class PatternFromState {
public:
explicit PatternFromState(
const gfxContext* aContext)
: mContext(aContext), mPattern(nullptr) {}
~PatternFromState() {
if (mPattern) {
mPattern->~Pattern();
}
}
operator mozilla::gfx::Pattern&();
private:
mozilla::AlignedStorage2<mozilla::gfx::ColorPattern> mColorPattern;
const gfxContext* mContext;
mozilla::gfx::Pattern* mPattern;
};
/**
* This is the main class for doing actual drawing. It is initialized using
* a surface and can be drawn on. It manages various state information like
* a current transformation matrix (CTM), a current path, current color,
* etc.
*
* All drawing happens by creating a path and then stroking or filling it.
* The functions like Rectangle and Arc do not do any drawing themselves.
* When a path is drawn (stroked or filled), it is filled/stroked with a
* pattern set by SetPattern or SetColor.
*
* Note that the gfxContext takes coordinates in device pixels,
* as opposed to app units.
*/
class gfxContext final {
#ifdef DEBUG
# define CURRENTSTATE_CHANGED() mAzureState.mContentChanged =
true;
#else
# define CURRENTSTATE_CHANGED()
#endif
typedef mozilla::gfx::BackendType BackendType;
typedef mozilla::gfx::CapStyle CapStyle;
typedef mozilla::gfx::CompositionOp CompositionOp;
typedef mozilla::gfx::DeviceColor DeviceColor;
typedef mozilla::gfx::DrawOptions DrawOptions;
typedef mozilla::gfx::DrawTarget DrawTarget;
typedef mozilla::gfx::JoinStyle JoinStyle;
typedef mozilla::gfx::FillRule FillRule;
typedef mozilla::gfx::
Float Float;
typedef mozilla::gfx::Matrix Matrix;
typedef mozilla::gfx::Path Path;
typedef mozilla::gfx::Pattern Pattern;
typedef mozilla::gfx::Point Point;
typedef mozilla::gfx::Rect Rect;
typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
typedef mozilla::gfx::Size Size;
public:
/**
* Initialize this context from a DrawTarget, which must be non-null.
* Strips any transform from aTarget, unless aPreserveTransform is true.
* aTarget will be flushed in the gfxContext's destructor.
*/
MOZ_NONNULL(2)
explicit gfxContext(DrawTarget* aTarget,
const Point& aDeviceOffset = Point())
: mDT(aTarget) {
mAzureState.deviceOffset = aDeviceOffset;
mDT->SetTransform(GetDTTransform());
}
MOZ_NONNULL(2)
gfxContext(DrawTarget* aTarget,
bool aPreserveTransform) : mDT(aTarget) {
if (aPreserveTransform) {
SetMatrix(aTarget->GetTransform());
}
else {
mDT->SetTransform(GetDTTransform());
}
}
~gfxContext();
/**
* Initialize this context from a DrawTarget.
* Strips any transform from aTarget.
* aTarget will be flushed in the gfxContext's destructor.
* If aTarget is null or invalid, nullptr is returned. The caller
* is responsible for handling this scenario as appropriate.
*/
static mozilla::UniquePtr<gfxContext> CreateOrNull(DrawTarget* aTarget);
DrawTarget* GetDrawTarget()
const {
return mDT; }
/**
* Returns the DrawTarget if it's actually a TextDrawTarget.
*/
mozilla::layout::TextDrawTarget* GetTextDrawer()
const;
/**
** State
**/
// XXX document exactly what bits are saved
void Save();
void Restore();
/**
** Paths & Drawing
**/
/**
* Fill the current path according to the current settings.
*
* Does not consume the current path.
*/
void Fill() { Fill(PatternFromState(
this)); }
void Fill(
const Pattern& aPattern);
/**
* Forgets the current path.
*/
void NewPath() {
mPath = nullptr;
mPathBuilder = nullptr;
mPathIsRect =
false;
mTransformChanged =
false;
}
/**
* Returns the current path.
*/
already_AddRefed<Path> GetPath() {
EnsurePath();
RefPtr<Path> path(mPath);
return path.forget();
}
/**
* Sets the given path as the current path.
*/
void SetPath(Path* path) {
MOZ_ASSERT(path->GetBackendType() == mDT->GetBackendType() ||
path->GetBackendType() == BackendType::RECORDING ||
(mDT->GetBackendType() == BackendType::DIRECT2D1_1 &&
path->GetBackendType() == BackendType::DIRECT2D));
mPath = path;
mPathBuilder = nullptr;
mPathIsRect =
false;
mTransformChanged =
false;
}
/**
* Draws the rectangle given by rect.
*/
void Rectangle(
const gfxRect& rect) {
return Rectangle(rect,
false); }
void SnappedRectangle(
const gfxRect& rect) {
return Rectangle(rect,
true); }
private:
void Rectangle(
const gfxRect& rect,
bool snapToPixels);
public:
/**
** Transformation Matrix manipulation
**/
/**
* Post-multiplies 'other' onto the current CTM, i.e. this
* matrix's transformation will take place before the previously set
* transformations.
*/
void Multiply(
const gfxMatrix& aMatrix) { Multiply(ToMatrix(aMatrix)); }
void Multiply(
const Matrix& aOther) {
CURRENTSTATE_CHANGED()
ChangeTransform(aOther * mAzureState.transform);
}
/**
* Replaces the current transformation matrix with matrix.
*/
void SetMatrix(
const Matrix& aMatrix) {
CURRENTSTATE_CHANGED()
ChangeTransform(aMatrix);
}
void SetMatrixDouble(
const gfxMatrix& aMatrix) {
SetMatrix(ToMatrix(aMatrix));
}
void SetCrossProcessPaintScale(
float aScale) {
MOZ_ASSERT(mCrossProcessPaintScale == 1.0f,
"Should only be initialized once");
mCrossProcessPaintScale = aScale;
}
float GetCrossProcessPaintScale()
const {
return mCrossProcessPaintScale; }
/**
* Returns the current transformation matrix.
*/
Matrix CurrentMatrix()
const {
return mAzureState.transform; }
gfxMatrix CurrentMatrixDouble()
const {
return ThebesMatrix(CurrentMatrix());
}
/**
* Converts a point from device to user coordinates using the inverse
* transformation matrix.
*/
gfxPoint DeviceToUser(
const gfxPoint& aPoint)
const {
return ThebesPoint(
mAzureState.transform.Inverse().TransformPoint(ToPoint(aPoint)));
}
/**
* Converts a size from device to user coordinates. This does not apply
* translation components of the matrix.
*/
Size DeviceToUser(
const Size& aSize)
const {
return mAzureState.transform.Inverse().TransformSize(aSize);
}
/**
* Converts a rectangle from device to user coordinates; this has the
* same effect as using DeviceToUser on both the rectangle's point and
* size.
*/
gfxRect DeviceToUser(
const gfxRect& aRect)
const {
return ThebesRect(
mAzureState.transform.Inverse().TransformBounds(ToRect(aRect)));
}
/**
* Converts a point from user to device coordinates using the transformation
* matrix.
*/
gfxPoint UserToDevice(
const gfxPoint& aPoint)
const {
return ThebesPoint(mAzureState.transform.TransformPoint(ToPoint(aPoint)));
}
/**
* Converts a size from user to device coordinates. This does not apply
* translation components of the matrix.
*/
Size UserToDevice(
const Size& aSize)
const {
const auto& mtx = mAzureState.transform;
return Size(aSize.width * mtx._11 + aSize.height * mtx._12,
aSize.width * mtx._21 + aSize.height * mtx._22);
}
/**
* Converts a rectangle from user to device coordinates. The
* resulting rectangle is the minimum device-space rectangle that
* encloses the user-space rectangle given.
*/
gfxRect UserToDevice(
const gfxRect& rect)
const {
return ThebesRect(mAzureState.transform.TransformBounds(ToRect(rect)));
}
/**
* Takes the given rect and tries to align it to device pixels. If
* this succeeds, the method will return true, and the rect will
* be in device coordinates (already transformed by the CTM). If it
* fails, the method will return false, and the rect will not be
* changed.
*
* aOptions parameter:
* If IgnoreScale is set, then snapping will take place even if the CTM
* has a scale applied. Snapping never takes place if there is a rotation
* in the CTM.
*
* If PrioritizeSize is set, the rect's dimensions will first be snapped
* and then its position aligned to device pixels, rather than snapping
* the position of each edge independently.
*/
enum class SnapOption : uint8_t {
IgnoreScale = 1,
PrioritizeSize = 2,
};
using SnapOptions = mozilla::EnumSet<SnapOption>;
bool UserToDevicePixelSnapped(gfxRect& rect, SnapOptions aOptions = {})
const;
/**
* Takes the given point and tries to align it to device pixels. If
* this succeeds, the method will return true, and the point will
* be in device coordinates (already transformed by the CTM). If it
* fails, the method will return false, and the point will not be
* changed.
*
* If ignoreScale is true, then snapping will take place even if
* the CTM has a scale applied. Snapping never takes place if
* there is a rotation in the CTM.
*/
bool UserToDevicePixelSnapped(gfxPoint& pt,
bool ignoreScale =
false)
const;
/**
** Painting sources
**/
/**
* Set a solid color to use for drawing. This color is in the device color
* space and is not transformed.
*/
void SetDeviceColor(
const DeviceColor& aColor) {
CURRENTSTATE_CHANGED()
mAzureState.pattern = nullptr;
mAzureState.color = aColor;
}
/**
* Gets the current color. It's returned in the device color space.
* returns false if there is something other than a color
* set as the current source (pattern, surface, etc)
*/
bool GetDeviceColor(DeviceColor& aColorOut)
const;
/**
* Returns true if color is neither opaque nor transparent (i.e. alpha is not
* 0 or 1), and false otherwise. If true, aColorOut is set on output.
*/
bool HasNonOpaqueNonTransparentColor(DeviceColor& aColorOut)
const {
return GetDeviceColor(aColorOut) && 0.f < aColorOut.a && aColorOut.a < 1.f;
}
/**
* Set a solid color in the sRGB color space to use for drawing.
* If CMS is not enabled, the color is treated as a device-space color
* and this call is identical to SetDeviceColor().
*/
void SetColor(
const mozilla::gfx::sRGBColor& aColor) {
CURRENTSTATE_CHANGED()
mAzureState.pattern = nullptr;
mAzureState.color = ToDeviceColor(aColor);
}
/**
* Uses a pattern for drawing.
*/
void SetPattern(gfxPattern* pattern) {
CURRENTSTATE_CHANGED()
mAzureState.patternTransformChanged =
false;
mAzureState.pattern = pattern;
}
/**
* Get the source pattern (solid color, normal pattern, surface, etc)
*/
already_AddRefed<gfxPattern> GetPattern()
const;
/**
** Painting
**/
/**
* Paints the current source surface/pattern everywhere in the current
* clip region.
*/
void Paint(
Float alpha = 1.0)
const;
/**
** Line Properties
**/
// Set the dash pattern, applying devPxScale to convert passed-in lengths
// to device pixels (used by the SVGUtils::SetupStrokeGeometry caller,
// which has the desired dash pattern in CSS px).
void SetDash(
const Float* dashes,
int ndash,
Float offset,
Float devPxScale);
// Return true if dashing is set, false if it's not enabled or the
// context is in an error state. |offset| can be nullptr to mean
// "don't care".
bool CurrentDash(FallibleTArray<
Float>& dashes,
Float* offset)
const;
/**
* Sets the line width that's used for line drawing.
*/
void SetLineWidth(
Float width) {
CURRENTSTATE_CHANGED()
mAzureState.strokeOptions.mLineWidth = width;
}
/**
* Returns the currently set line width.
*
* @see SetLineWidth
*/
Float CurrentLineWidth()
const {
return mAzureState.strokeOptions.mLineWidth;
}
/**
* Sets the line caps, i.e. how line endings are drawn.
*/
void SetLineCap(CapStyle cap) {
CURRENTSTATE_CHANGED()
mAzureState.strokeOptions.mLineCap = cap;
}
CapStyle CurrentLineCap()
const {
return mAzureState.strokeOptions.mLineCap; }
/**
* Sets the line join, i.e. how the connection between two lines is
* drawn.
*/
void SetLineJoin(JoinStyle join) {
CURRENTSTATE_CHANGED()
mAzureState.strokeOptions.mLineJoin = join;
}
JoinStyle CurrentLineJoin()
const {
return mAzureState.strokeOptions.mLineJoin;
}
void SetMiterLimit(
Float limit) {
CURRENTSTATE_CHANGED()
mAzureState.strokeOptions.mMiterLimit = limit;
}
Float CurrentMiterLimit()
const {
return mAzureState.strokeOptions.mMiterLimit;
}
/**
* Sets the operator used for all further drawing. The operator affects
* how drawing something will modify the destination. For example, the
* OVER operator will do alpha blending of source and destination, while
* SOURCE will replace the destination with the source.
*/
void SetOp(CompositionOp aOp) {
CURRENTSTATE_CHANGED()
mAzureState.op = aOp;
}
CompositionOp CurrentOp()
const {
return mAzureState.op; }
void SetAntialiasMode(mozilla::gfx::AntialiasMode aMode) {
CURRENTSTATE_CHANGED()
mAzureState.aaMode = aMode;
}
mozilla::gfx::AntialiasMode CurrentAntialiasMode()
const {
return mAzureState.aaMode;
}
/**
** Clipping
**/
/**
* Clips all further drawing to the current path.
* This does not consume the current path.
*/
void Clip();
/**
* Helper functions that will create a rect path and call Clip().
* Any current path will be destroyed by these functions!
*/
void Clip(
const gfxRect& aRect) { Clip(ToRect(aRect)); }
void Clip(
const Rect& rect);
// will clip to a rect
void SnappedClip(
const gfxRect& rect);
// snap rect and clip to the result
void Clip(Path* aPath);
void PopClip() {
MOZ_ASSERT(!mAzureState.pushedClips.IsEmpty());
mAzureState.pushedClips.RemoveLastElement();
mDT->PopClip();
}
enum ClipExtentsSpace {
eUserSpace = 0,
eDeviceSpace = 1,
};
/**
* According to aSpace, this function will return the current bounds of
* the clip region in user space or device space.
*/
gfxRect GetClipExtents(ClipExtentsSpace aSpace = eUserSpace)
const;
/**
* Exports the current clip using the provided exporter.
*/
bool ExportClip(ClipExporter& aExporter)
const;
/**
* Groups
*/
void PushGroupForBlendBack(gfxContentType content,
Float aOpacity = 1.0f,
mozilla::gfx::SourceSurface* aMask = nullptr,
const Matrix& aMaskTransform = Matrix())
const {
mDT->PushLayer(content == gfxContentType::COLOR, aOpacity, aMask,
aMaskTransform);
}
void PopGroupAndBlend()
const { mDT->PopLayer(); }
Point GetDeviceOffset()
const {
return mAzureState.deviceOffset; }
void SetDeviceOffset(
const Point& aOffset) {
mAzureState.deviceOffset = aOffset;
}
#ifdef MOZ_DUMP_PAINTING
/**
* Debug functions to encode the current surface as a PNG and export it.
*/
/**
* Writes a binary PNG file.
*/
void WriteAsPNG(
const char* aFile);
/**
* Write as a PNG encoded Data URL to stdout.
*/
void DumpAsDataURI();
/**
* Copy a PNG encoded Data URL to the clipboard.
*/
void CopyAsDataURI();
#endif
private:
friend class PatternFromState;
friend class GlyphBufferAzure;
typedef mozilla::gfx::sRGBColor sRGBColor;
typedef mozilla::gfx::StrokeOptions StrokeOptions;
typedef mozilla::gfx::PathBuilder PathBuilder;
typedef mozilla::gfx::SourceSurface SourceSurface;
struct AzureState {
AzureState()
: op(CompositionOp::OP_OVER),
color(0, 0, 0, 1.0f),
aaMode(mozilla::gfx::AntialiasMode::SUBPIXEL),
patternTransformChanged(
false)
#ifdef DEBUG
,
mContentChanged(
false)
#endif
{
}
CompositionOp op;
DeviceColor color;
RefPtr<gfxPattern> pattern;
Matrix transform;
struct PushedClip {
RefPtr<Path> path;
Rect rect;
Matrix transform;
};
CopyableTArray<PushedClip> pushedClips;
CopyableTArray<
Float> dashPattern;
StrokeOptions strokeOptions;
mozilla::gfx::AntialiasMode aaMode;
bool patternTransformChanged;
Matrix patternTransform;
// This is used solely for using minimal intermediate surface size.
Point deviceOffset;
#ifdef DEBUG
// Whether the content of this AzureState changed after construction.
bool mContentChanged;
#endif
};
// This ensures mPath contains a valid path (in user space!)
void EnsurePath();
// This ensures mPathBuilder contains a valid PathBuilder (in user space!)
void EnsurePathBuilder();
CompositionOp GetOp()
const;
void ChangeTransform(
const Matrix& aNewMatrix,
bool aUpdatePatternTransform =
true);
Rect GetAzureDeviceSpaceClipBounds()
const;
Matrix GetDTTransform()
const {
Matrix mat = mAzureState.transform;
mat.PostTranslate(-mAzureState.deviceOffset);
return mat;
}
bool mPathIsRect =
false;
bool mTransformChanged =
false;
Matrix mPathTransform;
Rect mRect;
RefPtr<PathBuilder> mPathBuilder;
RefPtr<Path> mPath;
AzureState mAzureState;
nsTArray<AzureState> mSavedStates;
// Iterate over all clips in the saved and current states, calling aLambda
// with each of them.
template <
typename F>
void ForAllClips(F&& aLambda)
const;
const AzureState& CurrentState()
const {
return mAzureState; }
RefPtr<DrawTarget>
const mDT;
float mCrossProcessPaintScale = 1.0f;
#ifdef DEBUG
# undef CURRENTSTATE_CHANGED
#endif
};
/**
* Sentry helper class for functions with multiple return points that need to
* call Save() on a gfxContext and have Restore() called automatically on the
* gfxContext before they return.
*/
class MOZ_STACK_CLASS gfxContextAutoSaveRestore final {
public:
gfxContextAutoSaveRestore() : mContext(nullptr) {}
explicit gfxContextAutoSaveRestore(gfxContext* aContext)
: mContext(aContext) {
mContext->Save();
}
~gfxContextAutoSaveRestore() { Restore(); }
void SetContext(gfxContext* aContext) {
MOZ_ASSERT(!mContext,
"no context?");
mContext = aContext;
mContext->Save();
}
void EnsureSaved(gfxContext* aContext) {
MOZ_ASSERT(!mContext || mContext == aContext,
"wrong context");
if (!mContext) {
mContext = aContext;
mContext->Save();
}
}
void Restore() {
if (mContext) {
mContext->Restore();
mContext = nullptr;
}
}
private:
gfxContext* mContext;
};
/**
* Sentry helper class for functions with multiple return points that need to
* back up the current matrix of a context and have it automatically restored
* before they return.
*/
class MOZ_STACK_CLASS gfxContextMatrixAutoSaveRestore final {
public:
gfxContextMatrixAutoSaveRestore() : mContext(nullptr) {}
explicit gfxContextMatrixAutoSaveRestore(gfxContext* aContext)
: mContext(aContext), mMatrix(aContext->CurrentMatrix()) {}
~gfxContextMatrixAutoSaveRestore() {
if (mContext) {
mContext->SetMatrix(mMatrix);
}
}
void SetContext(gfxContext* aContext) {
NS_ASSERTION(!mContext,
"Not going to restore the matrix on some context!");
mContext = aContext;
mMatrix = aContext->CurrentMatrix();
}
void Restore() {
if (mContext) {
mContext->SetMatrix(mMatrix);
mContext = nullptr;
}
}
const mozilla::gfx::Matrix& Matrix() {
MOZ_ASSERT(mContext,
"mMatrix doesn't contain a useful matrix");
return mMatrix;
}
bool HasMatrix()
const {
return !!mContext; }
private:
gfxContext* mContext;
mozilla::gfx::Matrix mMatrix;
};
class MOZ_STACK_CLASS gfxGroupForBlendAutoSaveRestore final {
public:
using Float = mozilla::gfx::
Float;
using Matrix = mozilla::gfx::Matrix;
explicit gfxGroupForBlendAutoSaveRestore(gfxContext* aContext)
: mContext(aContext) {}
~gfxGroupForBlendAutoSaveRestore() {
if (mPushedGroup) {
mContext->PopGroupAndBlend();
}
}
void PushGroupForBlendBack(gfxContentType aContent,
Float aOpacity = 1.0f,
mozilla::gfx::SourceSurface* aMask = nullptr,
const Matrix& aMaskTransform = Matrix()) {
MOZ_ASSERT(!mPushedGroup,
"Already called PushGroupForBlendBack once");
mContext->PushGroupForBlendBack(aContent, aOpacity, aMask, aMaskTransform);
mPushedGroup =
true;
}
private:
gfxContext* mContext;
bool mPushedGroup =
false;
};
class MOZ_STACK_CLASS gfxClipAutoSaveRestore final {
public:
using Rect = mozilla::gfx::Rect;
explicit gfxClipAutoSaveRestore(gfxContext* aContext) : mContext(aContext) {}
void Clip(
const gfxRect& aRect) { Clip(ToRect(aRect)); }
void Clip(
const Rect& aRect) {
MOZ_ASSERT(!mClipped,
"Already called Clip once");
mContext->Clip(aRect);
mClipped =
true;
}
void TransformedClip(
const gfxMatrix& aTransform,
const gfxRect& aRect) {
MOZ_ASSERT(!mClipped,
"Already called Clip once");
if (aTransform.IsSingular()) {
return;
}
gfxContextMatrixAutoSaveRestore matrixAutoSaveRestore(mContext);
mContext->Multiply(aTransform);
mContext->Clip(aRect);
mClipped =
true;
}
~gfxClipAutoSaveRestore() {
if (mClipped) {
mContext->PopClip();
}
}
private:
gfxContext* mContext;
bool mClipped =
false;
};
class MOZ_STACK_CLASS DrawTargetAutoDisableSubpixelAntialiasing final {
public:
typedef mozilla::gfx::DrawTarget DrawTarget;
DrawTargetAutoDisableSubpixelAntialiasing(DrawTarget* aDT,
bool aDisable)
: mSubpixelAntialiasingEnabled(
false) {
if (aDisable) {
mDT = aDT;
mSubpixelAntialiasingEnabled = mDT->GetPermitSubpixelAA();
mDT->SetPermitSubpixelAA(
false);
}
}
~DrawTargetAutoDisableSubpixelAntialiasing() {
if (mDT) {
mDT->SetPermitSubpixelAA(mSubpixelAntialiasingEnabled);
}
}
private:
RefPtr<DrawTarget> mDT;
bool mSubpixelAntialiasingEnabled;
};
/* This interface should be implemented to handle exporting the clip from a
* context.
*/
class ClipExporter :
public mozilla::gfx::PathSink {
public:
virtual void BeginClip(
const mozilla::gfx::Matrix& aMatrix) = 0;
virtual void EndClip() = 0;
};
#endif /* GFX_CONTEXT_H */
