| /* |
| * 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 "include/core/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) { |
| return { a.fX - b.fX, a.fY - b.fY, a.fZ - b.fZ }; |
| } |
| |
| /** Returns a new point whose coordinates are the sum of a and b (a + b) |
| */ |
| friend SkPoint3 operator+(const SkPoint3& a, const SkPoint3& b) { |
| return { a.fX + b.fX, a.fY + b.fY, a.fZ + b.fZ }; |
| } |
| |
| /** 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; |
| } |
| |
| friend SkPoint3 operator*(SkScalar t, SkPoint3 p) { |
| return { t * p.fX, t * p.fY, t * p.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); |
| } |
| |
| /** Returns the cross product of a and b, treating them as 3D vectors |
| */ |
| static SkPoint3 CrossProduct(const SkPoint3& a, const SkPoint3& b) { |
| SkPoint3 result; |
| result.fX = a.fY*b.fZ - a.fZ*b.fY; |
| result.fY = a.fZ*b.fX - a.fX*b.fZ; |
| result.fZ = a.fX*b.fY - a.fY*b.fX; |
| |
| return result; |
| } |
| |
| SkPoint3 cross(const SkPoint3& vec) const { |
| return CrossProduct(*this, vec); |
| } |
| }; |
| |
| typedef SkPoint3 SkVector3; |
| typedef SkPoint3 SkColor3f; |
| |
| #endif |