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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPoint3_DEFINED
#define SkPoint3_DEFINED
#include "SkPoint.h"
struct SK_API SkPoint3 {
SkScalar fX, fY, fZ;
static SkPoint3 Make(SkScalar x, SkScalar y, SkScalar z) {
SkPoint3 pt;
pt.set(x, y, z);
return pt;
}
SkScalar x() const { return fX; }
SkScalar y() const { return fY; }
SkScalar z() const { return fZ; }
void set(SkScalar x, SkScalar y, SkScalar z) { fX = x; fY = y; fZ = z; }
friend bool operator==(const SkPoint3& a, const SkPoint3& b) {
return a.fX == b.fX && a.fY == b.fY && a.fZ == b.fZ;
}
friend bool operator!=(const SkPoint3& a, const SkPoint3& b) {
return !(a == b);
}
/** Returns the Euclidian distance from (0,0,0) to (x,y,z)
*/
static SkScalar Length(SkScalar x, SkScalar y, SkScalar z);
/** Return the Euclidian distance from (0,0,0) to the point
*/
SkScalar length() const { return SkPoint3::Length(fX, fY, fZ); }
/** Set the point (vector) to be unit-length in the same direction as it
already points. If the point has a degenerate length (i.e., nearly 0)
then set it to (0,0,0) and return false; otherwise return true.
*/
bool normalize();
/** Return a new point whose X, Y and Z coordinates are scaled.
*/
SkPoint3 makeScale(SkScalar scale) const {
SkPoint3 p;
p.set(scale * fX, scale * fY, scale * fZ);
return p;
}
/** Scale the point's coordinates by scale.
*/
void scale(SkScalar value) {
fX *= value;
fY *= value;
fZ *= value;
}
/** Return a new point whose X, Y and Z coordinates are the negative of the
original point's
*/
SkPoint3 operator-() const {
SkPoint3 neg;
neg.fX = -fX;
neg.fY = -fY;
neg.fZ = -fZ;
return neg;
}
/** Returns a new point whose coordinates are the difference between
a and b (i.e., a - b)
*/
friend SkPoint3 operator-(const SkPoint3& a, const SkPoint3& b) {
SkPoint3 v;
v.set(a.fX - b.fX, a.fY - b.fY, a.fZ - b.fZ);
return v;
}
/** Returns a new point whose coordinates are the sum of a and b (a + b)
*/
friend SkPoint3 operator+(const SkPoint3& a, const SkPoint3& b) {
SkPoint3 v;
v.set(a.fX + b.fX, a.fY + b.fY, a.fZ + b.fZ);
return v;
}
/** Add v's coordinates to the point's
*/
void operator+=(const SkPoint3& v) {
fX += v.fX;
fY += v.fY;
fZ += v.fZ;
}
/** Subtract v's coordinates from the point's
*/
void operator-=(const SkPoint3& v) {
fX -= v.fX;
fY -= v.fY;
fZ -= v.fZ;
}
/** Returns true if fX, fY, and fZ are measurable values.
@return true for values other than infinities and NaN
*/
bool isFinite() const {
SkScalar accum = 0;
accum *= fX;
accum *= fY;
accum *= fZ;
// accum is either NaN or it is finite (zero).
SkASSERT(0 == accum || SkScalarIsNaN(accum));
// value==value will be true iff value is not NaN
// TODO: is it faster to say !accum or accum==accum?
return !SkScalarIsNaN(accum);
}
/** Returns the dot product of a and b, treating them as 3D vectors
*/
static SkScalar DotProduct(const SkPoint3& a, const SkPoint3& b) {
return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
}
SkScalar dot(const SkPoint3& vec) const {
return DotProduct(*this, vec);
}
};
typedef SkPoint3 SkVector3;
typedef SkPoint3 SkColor3f;
#endif
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