chromium/third_party/skia/src/core/SkPoint3.cpp

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkPoint3.h"
#include "include/private/base/SkFloatingPoint.h"

#include <cmath>

// Returns the square of the Euclidian distance to (x,y,z).
static inline float get_length_squared(float x, float y, float z) { … }

// Calculates the square of the Euclidian distance to (x,y,z) and stores it in
// *lengthSquared.  Returns true if the distance is judged to be "nearly zero".
//
// This logic is encapsulated in a helper method to make it explicit that we
// always perform this check in the same manner, to avoid inconsistencies
// (see http://code.google.com/p/skia/issues/detail?id=560 ).
static inline bool is_length_nearly_zero(float x, float y, float z, float *lengthSquared) { … }

SkScalar SkPoint3::Length(SkScalar x, SkScalar y, SkScalar z) { … }

/*
 *  We have to worry about 2 tricky conditions:
 *  1. underflow of magSq (compared against nearlyzero^2)
 *  2. overflow of magSq (compared w/ isfinite)
 *
 *  If we underflow, we return false. If we overflow, we compute again using
 *  doubles, which is much slower (3x in a desktop test) but will not overflow.
 */
bool SkPoint3::normalize() { … }