chromium/third_party/skia/src/base/SkQuads.cpp

/*
 * Copyright 2023 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "src/base/SkQuads.h"

#include "include/private/base/SkAssert.h"
#include "include/private/base/SkFloatingPoint.h"

#include <cmath>
#include <limits>

// Solve 0 = M * x + B. If M is 0, there are no solutions, unless B is also 0,
// in which case there are infinite solutions, so we just return 1 of them.
static int solve_linear(const double M, const double B, double solution[2]) { … }

// When B >> A, then the x^2 component doesn't contribute much to the output, so the second root
// will be very large, but have massive round off error. Because of the round off error, the
// second root will not evaluate to zero when substituted back into the quadratic equation. In
// the situation when B >> A, then just treat the quadratic as a linear equation.
static bool close_to_linear(double A, double B) { … }

double SkQuads::Discriminant(const double a, const double b, const double c) { … }

SkQuads::RootResult SkQuads::Roots(double A, double B, double C) { … }

static double zero_if_tiny(double x) { … }

int SkQuads::RootsReal(const double A, const double B, const double C, double solution[2]) { … }

double SkQuads::EvalAt(double A, double B, double C, double t) { … }