/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "Matrix.h" #include "Quaternion.h" #include "Tools.h" #include <algorithm> #include <ostream> #include <math.h> #include <float.h> // for FLT_EPSILON #include "mozilla/FloatingPoint.h" // for UnspecifiedNaN using namespace std; namespace mozilla { namespace gfx { /* Force small values to zero. We do this to avoid having sin(360deg) * evaluate to a tiny but nonzero value. */ double FlushToZero(double aVal) { // XXX Is double precision really necessary here if (-FLT_EPSILON < aVal && aVal < FLT_EPSILON) { return 0.0f; } else { return aVal; } } /* Computes tan(aTheta). For values of aTheta such that tan(aTheta) is * undefined or very large, SafeTangent returns a manageably large value * of the correct sign. */ double SafeTangent(double aTheta) { // XXX Is double precision really necessary here const double kEpsilon = 0.0001; /* tan(theta) = sin(theta)/cos(theta); problems arise when * cos(theta) is too close to zero. Limit cos(theta) to the * range [-1, -epsilon] U [epsilon, 1]. */ double sinTheta = sin(aTheta); double cosTheta = cos(aTheta); if (cosTheta >= 0 && cosTheta < kEpsilon) { cosTheta = kEpsilon; } else if (cosTheta < 0 && cosTheta >= -kEpsilon) { cosTheta = -kEpsilon; } return FlushToZero(sinTheta / cosTheta); } std::ostream& operator<<(std::ostream& aStream, const Matrix& aMatrix) { return aStream << "[ " << aMatrix._11 << " " << aMatrix._12 << "; " << aMatrix._21 << " " << aMatrix._22 << "; " << aMatrix._31 << " " << aMatrix._32 << "; ]"; } Matrix Matrix::Rotation(Float aAngle) { Matrix newMatrix; Float s = sinf(aAngle); Float c = cosf(aAngle); newMatrix._11 = c; newMatrix._12 = s; newMatrix._21 = -s; newMatrix._22 = c; return newMatrix; } Rect Matrix::TransformBounds(const Rect &aRect) const { int i; Point quad[4]; Float min_x, max_x; Float min_y, max_y; quad[0] = TransformPoint(aRect.TopLeft()); quad[1] = TransformPoint(aRect.TopRight()); quad[2] = TransformPoint(aRect.BottomLeft()); quad[3] = TransformPoint(aRect.BottomRight()); min_x = max_x = quad[0].x; min_y = max_y = quad[0].y; for (i = 1; i < 4; i++) { if (quad[i].x < min_x) min_x = quad[i].x; if (quad[i].x > max_x) max_x = quad[i].x; if (quad[i].y < min_y) min_y = quad[i].y; if (quad[i].y > max_y) max_y = quad[i].y; } return Rect(min_x, min_y, max_x - min_x, max_y - min_y); } Matrix& Matrix::NudgeToIntegers() { NudgeToInteger(&_11); NudgeToInteger(&_12); NudgeToInteger(&_21); NudgeToInteger(&_22); NudgeToInteger(&_31); NudgeToInteger(&_32); return *this; } } // namespace gfx } // namespace mozilla