/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrShape_DEFINED
#define GrShape_DEFINED
#include "GrStyle.h"
#include "SkPath.h"
#include "SkPathPriv.h"
#include "SkRRect.h"
#include "SkTemplates.h"
#include "SkTLazy.h"
/**
* Represents a geometric shape (rrect or path) and the GrStyle that it should be rendered with.
* It is possible to apply the style to the GrShape to produce a new GrShape where the geometry
* reflects the styling information (e.g. is stroked). It is also possible to apply just the
* path effect from the style. In this case the resulting shape will include any remaining
* stroking information that is to be applied after the path effect.
*
* Shapes can produce keys that represent only the geometry information, not the style. Note that
* when styling information is applied to produce a new shape then the style has been converted
* to geometric information and is included in the new shape's key. When the same style is applied
* to two shapes that reflect the same underlying geometry the computed keys of the stylized shapes
* will be the same.
*
* Currently this can only be constructed from a path, rect, or rrect though it can become a path
* applying style to the geometry. The idea is to expand this to cover most or all of the geometries
* that have SkCanvas::draw APIs.
*/
class GrShape {
public:
// Keys for paths may be extracted from the path data for small paths. Clients aren't supposed
// to have to worry about this. This value is exposed for unit tests.
static constexpr int kMaxKeyFromDataVerbCnt = 10;
GrShape() { this->initType(Type::kEmpty); }
explicit GrShape(const SkPath& path) : GrShape(path, GrStyle::SimpleFill()) {}
explicit GrShape(const SkRRect& rrect) : GrShape(rrect, GrStyle::SimpleFill()) {}
explicit GrShape(const SkRect& rect) : GrShape(rect, GrStyle::SimpleFill()) {}
GrShape(const SkPath& path, const GrStyle& style) : fStyle(style) {
this->initType(Type::kPath, &path);
this->attemptToSimplifyPath();
}
GrShape(const SkRRect& rrect, const GrStyle& style)
: fStyle(style) {
this->initType(Type::kRRect);
fRRectData.fRRect = rrect;
fRRectData.fInverted = false;
fRRectData.fStart = DefaultRRectDirAndStartIndex(rrect, style.hasPathEffect(),
&fRRectData.fDir);
this->attemptToSimplifyRRect();
}
GrShape(const SkRRect& rrect, SkPath::Direction dir, unsigned start, bool inverted,
const GrStyle& style)
: fStyle(style) {
this->initType(Type::kRRect);
fRRectData.fRRect = rrect;
fRRectData.fInverted = inverted;
if (style.pathEffect()) {
fRRectData.fDir = dir;
fRRectData.fStart = start;
if (fRRectData.fRRect.getType() == SkRRect::kRect_Type) {
fRRectData.fStart = (fRRectData.fStart + 1) & 0b110;
} else if (fRRectData.fRRect.getType() == SkRRect::kOval_Type) {
fRRectData.fStart &= 0b110;
}
} else {
fRRectData.fStart = DefaultRRectDirAndStartIndex(rrect, false, &fRRectData.fDir);
}
this->attemptToSimplifyRRect();
}
GrShape(const SkRect& rect, const GrStyle& style)
: fStyle(style) {
this->initType(Type::kRRect);
fRRectData.fRRect = SkRRect::MakeRect(rect);
fRRectData.fInverted = false;
fRRectData.fStart = DefaultRectDirAndStartIndex(rect, style.hasPathEffect(),
&fRRectData.fDir);
this->attemptToSimplifyRRect();
}
GrShape(const SkPath& path, const SkPaint& paint) : fStyle(paint) {
this->initType(Type::kPath, &path);
this->attemptToSimplifyPath();
}
GrShape(const SkRRect& rrect, const SkPaint& paint)
: fStyle(paint) {
this->initType(Type::kRRect);
fRRectData.fRRect = rrect;
fRRectData.fInverted = false;
fRRectData.fStart = DefaultRRectDirAndStartIndex(rrect, fStyle.hasPathEffect(),
&fRRectData.fDir);
this->attemptToSimplifyRRect();
}
GrShape(const SkRect& rect, const SkPaint& paint)
: fStyle(paint) {
this->initType(Type::kRRect);
fRRectData.fRRect = SkRRect::MakeRect(rect);
fRRectData.fInverted = false;
fRRectData.fStart = DefaultRectDirAndStartIndex(rect, fStyle.hasPathEffect(),
&fRRectData.fDir);
this->attemptToSimplifyRRect();
}
GrShape(const GrShape&);
GrShape& operator=(const GrShape& that);
~GrShape() { this->changeType(Type::kEmpty); }
const GrStyle& style() const { return fStyle; }
/**
* Returns a shape that has either applied the path effect or path effect and stroking
* information from this shape's style to its geometry. Scale is used when approximating the
* output geometry and typically is computed from the view matrix
*/
GrShape applyStyle(GrStyle::Apply apply, SkScalar scale) const {
return GrShape(*this, apply, scale);
}
/** Returns the unstyled geometry as a rrect if possible. */
bool asRRect(SkRRect* rrect, SkPath::Direction* dir, unsigned* start, bool* inverted) const {
if (Type::kRRect != fType) {
return false;
}
if (rrect) {
*rrect = fRRectData.fRRect;
}
if (dir) {
*dir = fRRectData.fDir;
}
if (start) {
*start = fRRectData.fStart;
}
if (inverted) {
*inverted = fRRectData.fInverted;
}
return true;
}
/**
* If the unstyled shape is a straight line segment, returns true and sets pts to the endpoints.
* An inverse filled line path is still considered a line.
*/
bool asLine(SkPoint pts[2], bool* inverted) const {
if (fType != Type::kLine) {
return false;
}
if (pts) {
pts[0] = fLineData.fPts[0];
pts[1] = fLineData.fPts[1];
}
if (inverted) {
*inverted = fLineData.fInverted;
}
return true;
}
/** Returns the unstyled geometry as a path. */
void asPath(SkPath* out) const {
switch (fType) {
case Type::kEmpty:
out->reset();
break;
case Type::kRRect:
out->reset();
out->addRRect(fRRectData.fRRect, fRRectData.fDir, fRRectData.fStart);
// Below matches the fill type that attemptToSimplifyPath uses.
if (fRRectData.fInverted) {
out->setFillType(kDefaultPathInverseFillType);
} else {
out->setFillType(kDefaultPathFillType);
}
break;
case Type::kLine:
out->reset();
out->moveTo(fLineData.fPts[0]);
out->lineTo(fLineData.fPts[1]);
if (fLineData.fInverted) {
out->setFillType(kDefaultPathInverseFillType);
} else {
out->setFillType(kDefaultPathFillType);
}
break;
case Type::kPath:
*out = this->path();
break;
}
}
/**
* Returns whether the geometry is empty. Note that applying the style could produce a
* non-empty shape.
*/
bool isEmpty() const { return Type::kEmpty == fType; }
/**
* Gets the bounds of the geometry without reflecting the shape's styling. This ignores
* the inverse fill nature of the geometry.
*/
SkRect bounds() const;
/**
* Gets the bounds of the geometry reflecting the shape's styling (ignoring inverse fill
* status).
*/
SkRect styledBounds() const;
/**
* Is this shape known to be convex, before styling is applied. An unclosed but otherwise
* convex path is considered to be closed if they styling reflects a fill and not otherwise.
* This is because filling closes all contours in the path.
*/
bool knownToBeConvex() const {
switch (fType) {
case Type::kEmpty:
return true;
case Type::kRRect:
return true;
case Type::kLine:
return true;
case Type::kPath:
// SkPath.isConvex() really means "is this path convex were it to be closed" and
// thus doesn't give the correct answer for stroked paths, hence we also check
// whether the path is either filled or closed. Convex paths may only have one
// contour hence isLastContourClosed() is a sufficient for a convex path.
return (this->style().isSimpleFill() || this->path().isLastContourClosed()) &&
this->path().isConvex();
}
return false;
}
/** Is the pre-styled geometry inverse filled? */
bool inverseFilled() const {
bool ret = false;
switch (fType) {
case Type::kEmpty:
ret = false;
break;
case Type::kRRect:
ret = fRRectData.fInverted;
break;
case Type::kLine:
ret = fLineData.fInverted;
break;
case Type::kPath:
ret = this->path().isInverseFillType();
break;
}
// Dashing ignores inverseness. We should have caught this earlier. skbug.com/5421
SkASSERT(!(ret && this->style().isDashed()));
return ret;
}
/**
* Might applying the styling to the geometry produce an inverse fill. The "may" part comes in
* because an arbitrary path effect could produce an inverse filled path. In other cases this
* can be thought of as "inverseFilledAfterStyling()".
*/
bool mayBeInverseFilledAfterStyling() const {
// An arbitrary path effect can produce an arbitrary output path, which may be inverse
// filled.
if (this->style().hasNonDashPathEffect()) {
return true;
}
return this->inverseFilled();
}
/**
* Is it known that the unstyled geometry has no unclosed contours. This means that it will
* not have any caps if stroked (modulo the effect of any path effect).
*/
bool knownToBeClosed() const {
switch (fType) {
case Type::kEmpty:
return true;
case Type::kRRect:
return true;
case Type::kLine:
return false;
case Type::kPath:
// SkPath doesn't keep track of the closed status of each contour.
return SkPathPriv::IsClosedSingleContour(this->path());
}
return false;
}
uint32_t segmentMask() const {
switch (fType) {
case Type::kEmpty:
return 0;
case Type::kRRect:
if (fRRectData.fRRect.getType() == SkRRect::kOval_Type) {
return SkPath::kConic_SegmentMask;
} else if (fRRectData.fRRect.getType() == SkRRect::kRect_Type) {
return SkPath::kLine_SegmentMask;
}
return SkPath::kLine_SegmentMask | SkPath::kConic_SegmentMask;
case Type::kLine:
return SkPath::kLine_SegmentMask;
case Type::kPath:
return this->path().getSegmentMasks();
}
return 0;
}
/**
* Gets the size of the key for the shape represented by this GrShape (ignoring its styling).
* A negative value is returned if the shape has no key (shouldn't be cached).
*/
int unstyledKeySize() const;
bool hasUnstyledKey() const { return this->unstyledKeySize() >= 0; }
/**
* Writes unstyledKeySize() bytes into the provided pointer. Assumes that there is enough
* space allocated for the key and that unstyledKeySize() does not return a negative value
* for this shape.
*/
void writeUnstyledKey(uint32_t* key) const;
private:
enum class Type {
kEmpty,
kRRect,
kLine,
kPath,
};
void initType(Type type, const SkPath* path = nullptr) {
fType = Type::kEmpty;
this->changeType(type, path);
}
void changeType(Type type, const SkPath* path = nullptr) {
bool wasPath = Type::kPath == fType;
fType = type;
bool isPath = Type::kPath == type;
SkASSERT(!path || isPath);
if (wasPath && !isPath) {
fPathData.fPath.~SkPath();
} else if (!wasPath && isPath) {
if (path) {
new (&fPathData.fPath) SkPath(*path);
} else {
new (&fPathData.fPath) SkPath();
}
} else if (isPath && path) {
fPathData.fPath = *path;
}
// Whether or not we use the path's gen ID is decided in attemptToSimplifyPath.
fPathData.fGenID = 0;
}
SkPath& path() {
SkASSERT(Type::kPath == fType);
return fPathData.fPath;
}
const SkPath& path() const {
SkASSERT(Type::kPath == fType);
return fPathData.fPath;
}
/** Constructor used by the applyStyle() function */
GrShape(const GrShape& parentShape, GrStyle::Apply, SkScalar scale);
/**
* Determines the key we should inherit from the input shape's geometry and style when
* we are applying the style to create a new shape.
*/
void setInheritedKey(const GrShape& parentShape, GrStyle::Apply, SkScalar scale);
void attemptToSimplifyPath();
void attemptToSimplifyRRect();
void attemptToSimplifyLine();
// Defaults to use when there is no distinction between even/odd and winding fills.
static constexpr SkPath::FillType kDefaultPathFillType = SkPath::kEvenOdd_FillType;
static constexpr SkPath::FillType kDefaultPathInverseFillType =
SkPath::kInverseEvenOdd_FillType;
static constexpr SkPath::Direction kDefaultRRectDir = SkPath::kCW_Direction;
static constexpr unsigned kDefaultRRectStart = 0;
static unsigned DefaultRectDirAndStartIndex(const SkRect& rect, bool hasPathEffect,
SkPath::Direction* dir) {
*dir = kDefaultRRectDir;
// This comes from SkPath's interface. The default for adding a SkRect is counter clockwise
// beginning at index 0 (which happens to correspond to rrect index 0 or 7).
if (!hasPathEffect) {
// It doesn't matter what start we use, just be consistent to avoid redundant keys.
return kDefaultRRectStart;
}
// In SkPath a rect starts at index 0 by default. This is the top left corner. However,
// we store rects as rrects. RRects don't preserve the invertedness, but rather sort the
// rect edges. Thus, we may need to modify the rrect's start index to account for the sort.
bool swapX = rect.fLeft > rect.fRight;
bool swapY = rect.fTop > rect.fBottom;
if (swapX && swapY) {
// 0 becomes start index 2 and times 2 to convert from rect the rrect indices.
return 2 * 2;
} else if (swapX) {
*dir = SkPath::kCCW_Direction;
// 0 becomes start index 1 and times 2 to convert from rect the rrect indices.
return 2 * 1;
} else if (swapY) {
*dir = SkPath::kCCW_Direction;
// 0 becomes start index 3 and times 2 to convert from rect the rrect indices.
return 2 * 3;
}
return 0;
}
static unsigned DefaultRRectDirAndStartIndex(const SkRRect& rrect, bool hasPathEffect,
SkPath::Direction* dir) {
// This comes from SkPath's interface. The default for adding a SkRRect to a path is
// clockwise beginning at starting index 6.
static constexpr unsigned kPathRRectStartIdx = 6;
*dir = kDefaultRRectDir;
if (!hasPathEffect) {
// It doesn't matter what start we use, just be consistent to avoid redundant keys.
return kDefaultRRectStart;
}
return kPathRRectStartIdx;
}
Type fType;
union {
struct {
SkRRect fRRect;
SkPath::Direction fDir;
unsigned fStart;
bool fInverted;
} fRRectData;
struct {
SkPath fPath;
// Gen ID of the original path (fPath may be modified)
int32_t fGenID;
} fPathData;
struct {
SkPoint fPts[2];
bool fInverted;
} fLineData;
};
GrStyle fStyle;
SkAutoSTArray<8, uint32_t> fInheritedKey;
};
#endif