/* -*- 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 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 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 GetPath() { EnsurePath(); RefPtr 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; 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 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& 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 pattern; Matrix transform; struct PushedClip { RefPtr path; Rect rect; Matrix transform; }; CopyableTArray pushedClips; CopyableTArray 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 mPathBuilder; RefPtr mPath; AzureState mAzureState; nsTArray mSavedStates; // Iterate over all clips in the saved and current states, calling aLambda // with each of them. template void ForAllClips(F&& aLambda) const; const AzureState& CurrentState() const { return mAzureState; } RefPtr 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 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 */