skia2/include/core/SkRRect.h

319 lines
10 KiB
C++

/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkRRect_DEFINED
#define SkRRect_DEFINED
#include "SkRect.h"
#include "SkPoint.h"
class SkPath;
class SkMatrix;
// Path forward:
// core work
// add validate method (all radii positive, all radii sums < rect size, etc.)
// add contains(SkRect&) - for clip stack
// add contains(SkRRect&) - for clip stack
// add heart rect computation (max rect inside RR)
// add 9patch rect computation
// add growToInclude(SkPath&)
// analysis
// use growToInclude to fit skp round rects & generate stats (RRs vs. real paths)
// check on # of rectorus's the RRs could handle
// rendering work
// update SkPath.addRRect() to only use quads
// add GM and bench
// further out
// detect and triangulate RRectorii rather than falling back to SW in Ganesh
//
/** \class SkRRect
The SkRRect class represents a rounded rect with a potentially different
radii for each corner. It does not have a constructor so must be
initialized with one of the initialization functions (e.g., setEmpty,
setRectRadii, etc.)
This class is intended to roughly match CSS' border-*-*-radius capabilities.
This means:
If either of a corner's radii are 0 the corner will be square.
Negative radii are not allowed (they are clamped to zero).
If the corner curves overlap they will be proportionally reduced to fit.
*/
class SK_API SkRRect {
public:
/**
* Enum to capture the various possible subtypes of RR. Accessed
* by type(). The subtypes become progressively less restrictive.
*/
enum Type {
// !< Internal indicator that the sub type must be computed.
kUnknown_Type = -1,
// !< The RR is empty
kEmpty_Type,
//!< The RR is actually a (non-empty) rect (i.e., at least one radius
//!< at each corner is zero)
kRect_Type,
//!< The RR is actually a (non-empty) oval (i.e., all x radii are equal
//!< and >= width/2 and all the y radii are equal and >= height/2
kOval_Type,
//!< The RR is non-empty and all the x radii are equal & all y radii
//!< are equal but it is not an oval (i.e., there are lines between
//!< the curves) nor a rect (i.e., both radii are non-zero)
kSimple_Type,
//!< The RR is non-empty and the two left x radii are equal, the two top
//!< y radii are equal, and the same for the right and bottom but it is
//!< neither an rect, oval, nor a simple RR. It is called "nine patch"
//!< because the centers of the corner ellipses form an axis aligned
//!< rect with edges that divide the RR into an 9 rectangular patches:
//!< an interior patch, four edge patches, and four corner patches.
kNinePatch_Type,
//!< A fully general (non-empty) RR. Some of the x and/or y radii are
//!< different from the others and there must be one corner where
//!< both radii are non-zero.
kComplex_Type,
};
/**
* Returns the RR's sub type.
*/
Type getType() const {
SkDEBUGCODE(this->validate();)
if (kUnknown_Type == fType) {
this->computeType();
}
SkASSERT(kUnknown_Type != fType);
return fType;
}
Type type() const { return this->getType(); }
inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
inline bool isRect() const { return kRect_Type == this->getType(); }
inline bool isOval() const { return kOval_Type == this->getType(); }
inline bool isSimple() const { return kSimple_Type == this->getType(); }
inline bool isSimpleCircular() const {
return this->isSimple() && fRadii[0].fX == fRadii[0].fY;
}
inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
inline bool isComplex() const { return kComplex_Type == this->getType(); }
bool allCornersCircular() const;
SkScalar width() const { return fRect.width(); }
SkScalar height() const { return fRect.height(); }
/**
* Set this RR to the empty rectangle (0,0,0,0) with 0 x & y radii.
*/
void setEmpty() {
fRect.setEmpty();
memset(fRadii, 0, sizeof(fRadii));
fType = kEmpty_Type;
SkDEBUGCODE(this->validate();)
}
/**
* Set this RR to match the supplied rect. All radii will be 0.
*/
void setRect(const SkRect& rect) {
if (rect.isEmpty()) {
this->setEmpty();
return;
}
fRect = rect;
memset(fRadii, 0, sizeof(fRadii));
fType = kRect_Type;
SkDEBUGCODE(this->validate();)
}
/**
* Set this RR to match the supplied oval. All x radii will equal half the
* width and all y radii will equal half the height.
*/
void setOval(const SkRect& oval) {
if (oval.isEmpty()) {
this->setEmpty();
return;
}
SkScalar xRad = SkScalarHalf(oval.width());
SkScalar yRad = SkScalarHalf(oval.height());
fRect = oval;
for (int i = 0; i < 4; ++i) {
fRadii[i].set(xRad, yRad);
}
fType = kOval_Type;
SkDEBUGCODE(this->validate();)
}
/**
* Initialize the RR with the same radii for all four corners.
*/
void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);
/**
* Initialize the rr with one radius per-side.
*/
void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
SkScalar rightRad, SkScalar bottomRad);
/**
* Initialize the RR with potentially different radii for all four corners.
*/
void setRectRadii(const SkRect& rect, const SkVector radii[4]);
// The radii are stored in UL, UR, LR, LL order.
enum Corner {
kUpperLeft_Corner,
kUpperRight_Corner,
kLowerRight_Corner,
kLowerLeft_Corner
};
const SkRect& rect() const { return fRect; }
const SkVector& radii(Corner corner) const { return fRadii[corner]; }
const SkRect& getBounds() const { return fRect; }
/**
* When a rrect is simple, all of its radii are equal. This returns one
* of those radii. This call requires the rrect to be non-complex.
*/
const SkVector& getSimpleRadii() const {
SkASSERT(!this->isComplex());
return fRadii[0];
}
friend bool operator==(const SkRRect& a, const SkRRect& b) {
return a.fRect == b.fRect &&
SkScalarsEqual(a.fRadii[0].asScalars(),
b.fRadii[0].asScalars(), 8);
}
friend bool operator!=(const SkRRect& a, const SkRRect& b) {
return a.fRect != b.fRect ||
!SkScalarsEqual(a.fRadii[0].asScalars(),
b.fRadii[0].asScalars(), 8);
}
/**
* Call inset on the bounds, and adjust the radii to reflect what happens
* in stroking: If the corner is sharp (no curvature), leave it alone,
* otherwise we grow/shrink the radii by the amount of the inset. If a
* given radius becomes negative, it is pinned to 0.
*
* It is valid for dst == this.
*/
void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;
void inset(SkScalar dx, SkScalar dy) {
this->inset(dx, dy, this);
}
/**
* Call outset on the bounds, and adjust the radii to reflect what happens
* in stroking: If the corner is sharp (no curvature), leave it alone,
* otherwise we grow/shrink the radii by the amount of the inset. If a
* given radius becomes negative, it is pinned to 0.
*
* It is valid for dst == this.
*/
void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
this->inset(-dx, -dy, dst);
}
void outset(SkScalar dx, SkScalar dy) {
this->inset(-dx, -dy, this);
}
/**
* Translate the rrect by (dx, dy).
*/
void offset(SkScalar dx, SkScalar dy) {
fRect.offset(dx, dy);
}
/**
* Returns true if 'rect' is wholy inside the RR, and both
* are not empty.
*/
bool contains(const SkRect& rect) const;
SkDEBUGCODE(void validate() const;)
enum {
kSizeInMemory = 12 * sizeof(SkScalar)
};
/**
* Write the rrect into the specified buffer. This is guaranteed to always
* write kSizeInMemory bytes, and that value is guaranteed to always be
* a multiple of 4. Return kSizeInMemory.
*/
size_t writeToMemory(void* buffer) const;
/**
* Reads the rrect from the specified buffer
*
* If the specified buffer is large enough, this will read kSizeInMemory bytes,
* and that value is guaranteed to always be a multiple of 4.
*
* @param buffer Memory to read from
* @param length Amount of memory available in the buffer
* @return number of bytes read (must be a multiple of 4) or
* 0 if there was not enough memory available
*/
size_t readFromMemory(const void* buffer, size_t length);
/**
* Transform by the specified matrix, and put the result in dst.
*
* @param matrix SkMatrix specifying the transform. Must only contain
* scale and/or translate, or this call will fail.
* @param dst SkRRect to store the result. It is an error to use this,
* which would make this function no longer const.
* @return true on success, false on failure. If false, dst is unmodified.
*/
bool transform(const SkMatrix& matrix, SkRRect* dst) const;
#ifdef SK_DEVELOPER
/**
* Prints the rrect using SkDebugf. This is intended for Skia development debugging. Don't
* rely on the existence of this function or the formatting of its output.
*/
void dump() const;
#endif
private:
SkRect fRect;
// Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[]
SkVector fRadii[4];
mutable Type fType;
// TODO: add padding so we can use memcpy for flattening and not copy
// uninitialized data
void computeType() const;
bool checkCornerContainment(SkScalar x, SkScalar y) const;
// to access fRadii directly
friend class SkPath;
};
#endif