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/* -*- 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 "gfxTypes.h"
#include "gfxASurface.h"
#include "gfxPoint.h"
#include "gfxRect.h"
#include "gfxMatrix.h"
#include "gfxPattern.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 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 {
typedef mozilla::gfx::CapStyle CapStyle;
typedef mozilla::gfx::CompositionOp CompositionOp;
typedef mozilla::gfx::JoinStyle JoinStyle;
typedef mozilla::gfx::FillRule FillRule;
typedef mozilla::gfx::Float Float;
typedef mozilla::gfx::Path Path;
typedef mozilla::gfx::Pattern Pattern;
typedef mozilla::gfx::Rect Rect;
typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
typedef mozilla::gfx::Size Size;
NS_INLINE_DECL_REFCOUNTING(gfxContext)
public:
/**
* 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 already_AddRefed<gfxContext> CreateOrNull(
mozilla::gfx::DrawTarget* aTarget,
const mozilla::gfx::Point& aDeviceOffset = mozilla::gfx::Point());
/**
* Create a new gfxContext wrapping aTarget and preserving aTarget's
* transform. Note that the transform is moved from aTarget to the resulting
* gfxContext, aTarget will no longer have its transform.
* If aTarget is null or invalid, nullptr is returned. The caller
* is responsible for handling this scenario as appropriate.
*/
static already_AddRefed<gfxContext> CreatePreservingTransformOrNull(
mozilla::gfx::DrawTarget* aTarget);
mozilla::gfx::DrawTarget* GetDrawTarget() { return mDT; }
/**
* Returns the DrawTarget if it's actually a TextDrawTarget.
*/
mozilla::layout::TextDrawTarget* GetTextDrawer();
/**
** 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();
void Fill(const Pattern& aPattern);
/**
* Forgets the current path.
*/
void NewPath();
/**
* Closes the path, i.e. connects the last drawn point to the first one.
*
* Filling a path will implicitly close it.
*/
void ClosePath();
/**
* Returns the current path.
*/
already_AddRefed<Path> GetPath();
/**
* Sets the given path as the current path.
*/
void SetPath(Path* path);
/**
* Moves the pen to a new point without drawing a line.
*/
void MoveTo(const gfxPoint& pt);
/**
* Draws a line from the current point to pt.
*
* @see MoveTo
*/
void LineTo(const gfxPoint& pt);
// path helpers
/**
* Draws a line from start to end.
*/
void Line(const gfxPoint& start,
const gfxPoint& end); // XXX snapToPixels option?
/**
* 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& other);
void Multiply(const mozilla::gfx::Matrix& other);
/**
* Replaces the current transformation matrix with matrix.
*/
void SetMatrix(const mozilla::gfx::Matrix& matrix);
void SetMatrixDouble(const gfxMatrix& matrix);
/**
* Returns the current transformation matrix.
*/
mozilla::gfx::Matrix CurrentMatrix() const;
gfxMatrix CurrentMatrixDouble() const;
/**
* Converts a point from device to user coordinates using the inverse
* transformation matrix.
*/
gfxPoint DeviceToUser(const gfxPoint& point) const;
/**
* Converts a size from device to user coordinates. This does not apply
* translation components of the matrix.
*/
Size DeviceToUser(const Size& size) const;
/**
* 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& rect) const;
/**
* Converts a point from user to device coordinates using the transformation
* matrix.
*/
gfxPoint UserToDevice(const gfxPoint& point) const;
/**
* Converts a size from user to device coordinates. This does not apply
* translation components of the matrix.
*/
Size UserToDevice(const Size& size) const;
/**
* 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;
/**
* 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 mozilla::gfx::DeviceColor& 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(mozilla::gfx::DeviceColor& aColorOut);
/**
* 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(mozilla::gfx::DeviceColor& aColorOut) {
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);
/**
* Uses a pattern for drawing.
*/
void SetPattern(gfxPattern* pattern);
/**
* Get the source pattern (solid color, normal pattern, surface, etc)
*/
already_AddRefed<gfxPattern> GetPattern();
/**
** Painting
**/
/**
* Paints the current source surface/pattern everywhere in the current
* clip region.
*/
void Paint(Float alpha = 1.0);
/**
** Painting with a Mask
**/
/**
* Like Paint, except that it only draws the source where pattern is
* non-transparent.
*/
void Mask(mozilla::gfx::SourceSurface* aSurface, mozilla::gfx::Float aAlpha,
const mozilla::gfx::Matrix& aTransform);
void Mask(mozilla::gfx::SourceSurface* aSurface,
const mozilla::gfx::Matrix& aTransform) {
Mask(aSurface, 1.0f, aTransform);
}
void Mask(mozilla::gfx::SourceSurface* surface, float alpha = 1.0f,
const mozilla::gfx::Point& offset = mozilla::gfx::Point());
/**
** Line Properties
**/
void SetDash(const Float* dashes, int ndash, Float offset);
// 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);
/**
* Returns the currently set line width.
*
* @see SetLineWidth
*/
Float CurrentLineWidth() const;
/**
* Sets the line caps, i.e. how line endings are drawn.
*/
void SetLineCap(CapStyle cap);
CapStyle CurrentLineCap() const;
/**
* Sets the line join, i.e. how the connection between two lines is
* drawn.
*/
void SetLineJoin(JoinStyle join);
JoinStyle CurrentLineJoin() const;
void SetMiterLimit(Float limit);
Float CurrentMiterLimit() const;
/**
* 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 op);
CompositionOp CurrentOp() const;
void SetAntialiasMode(mozilla::gfx::AntialiasMode mode);
mozilla::gfx::AntialiasMode CurrentAntialiasMode() const;
/**
** 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 Rect& rect);
void Clip(const gfxRect& rect); // will clip to a rect
void SnappedClip(const gfxRect& rect); // snap rect and clip to the result
void Clip(Path* aPath);
void 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;
/**
* Returns true if the given rectangle is fully contained in the current clip.
* This is conservative; it may return false even when the given rectangle is
* fully contained by the current clip.
*/
bool ClipContainsRect(const gfxRect& aRect);
/**
* Exports the current clip using the provided exporter.
*/
bool ExportClip(ClipExporter& aExporter);
/**
* Groups
*/
void PushGroupForBlendBack(
gfxContentType content, mozilla::gfx::Float aOpacity = 1.0f,
mozilla::gfx::SourceSurface* aMask = nullptr,
const mozilla::gfx::Matrix& aMaskTransform = mozilla::gfx::Matrix());
/**
* Like PushGroupForBlendBack, but if the current surface is
* gfxContentType::COLOR and content is gfxContentType::COLOR_ALPHA, makes the
* pushed surface gfxContentType::COLOR instead and copies the contents of the
* current surface to the pushed surface. This is good for pushing opacity
* groups, since blending the group back to the current surface with some
* alpha applied will give the correct results and using an opaque pushed
* surface gives better quality and performance.
*/
void PushGroupAndCopyBackground(
gfxContentType content = gfxContentType::COLOR,
mozilla::gfx::Float aOpacity = 1.0f,
mozilla::gfx::SourceSurface* aMask = nullptr,
const mozilla::gfx::Matrix& aMaskTransform = mozilla::gfx::Matrix());
void PopGroupAndBlend();
mozilla::gfx::Point GetDeviceOffset() const;
void SetDeviceOffset(const mozilla::gfx::Point& 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
static mozilla::gfx::UserDataKey sDontUseAsSourceKey;
private:
/**
* Initialize this context from a DrawTarget.
* Strips any transform from aTarget.
* aTarget will be flushed in the gfxContext's destructor. Use the static
* ContextForDrawTargetNoTransform() when you want this behavior, as that
* version deals with null DrawTarget better.
*/
explicit gfxContext(
mozilla::gfx::DrawTarget* aTarget,
const mozilla::gfx::Point& aDeviceOffset = mozilla::gfx::Point());
~gfxContext();
friend class PatternFromState;
friend class GlyphBufferAzure;
typedef mozilla::gfx::Matrix Matrix;
typedef mozilla::gfx::DrawTarget DrawTarget;
typedef mozilla::gfx::sRGBColor sRGBColor;
typedef mozilla::gfx::DeviceColor DeviceColor;
typedef mozilla::gfx::StrokeOptions StrokeOptions;
typedef mozilla::gfx::PathBuilder PathBuilder;
typedef mozilla::gfx::SourceSurface SourceSurface;
struct AzureState {
AzureState()
: op(mozilla::gfx::CompositionOp::OP_OVER),
color(0, 0, 0, 1.0f),
aaMode(mozilla::gfx::AntialiasMode::SUBPIXEL),
patternTransformChanged(false)
#ifdef DEBUG
,
mContentChanged(false)
#endif
{
}
mozilla::gfx::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;
RefPtr<DrawTarget> drawTarget;
mozilla::gfx::AntialiasMode aaMode;
bool patternTransformChanged;
Matrix patternTransform;
DeviceColor fontSmoothingBackgroundColor;
// This is used solely for using minimal intermediate surface size.
mozilla::gfx::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();
void ChangeTransform(const mozilla::gfx::Matrix& aNewMatrix,
bool aUpdatePatternTransform = true);
Rect GetAzureDeviceSpaceClipBounds() const;
Matrix GetDTTransform() const;
bool mPathIsRect;
bool mTransformChanged;
Matrix mPathTransform;
Rect mRect;
RefPtr<PathBuilder> mPathBuilder;
RefPtr<Path> mPath;
Matrix mTransform;
nsTArray<AzureState> mStateStack;
AzureState& CurrentState() { return mStateStack[mStateStack.Length() - 1]; }
const AzureState& CurrentState() const {
return mStateStack[mStateStack.Length() - 1];
}
RefPtr<DrawTarget> mDT;
};
/**
* 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 gfxContextAutoSaveRestore {
public:
gfxContextAutoSaveRestore() : mContext(nullptr) {}
explicit gfxContextAutoSaveRestore(gfxContext* aContext)
: mContext(aContext) {
mContext->Save();
}
~gfxContextAutoSaveRestore() { Restore(); }
void SetContext(gfxContext* aContext) {
NS_ASSERTION(!mContext, "Not going to call Restore() on some 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 gfxContextMatrixAutoSaveRestore {
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 DrawTargetAutoDisableSubpixelAntialiasing {
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 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(gfxContext* aContext)
: mContext(aContext), mPattern(nullptr) {}
~PatternFromState() {
if (mPattern) {
mPattern->~Pattern();
}
}
operator mozilla::gfx::Pattern&();
private:
union {
mozilla::AlignedStorage2<mozilla::gfx::ColorPattern> mColorPattern;
mozilla::AlignedStorage2<mozilla::gfx::SurfacePattern> mSurfacePattern;
};
gfxContext* mContext;
mozilla::gfx::Pattern* mPattern;
};
/* 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 */