//------------------------------------------------------------------------------ // Copyright (c) 2001-2002, Haiku, Inc. // // Permission is hereby granted, free of charge, to any person obtaining a // copy of this software and associated documentation files (the "Software"), // to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, // and/or sell copies of the Software, and to permit persons to whom the // Software is furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER // DEALINGS IN THE SOFTWARE. // // File Name: Angle.cpp // Author: DarkWyrm <bpmagic@columbus.rr.com> // Description: Angle class for speeding up trig functions // //------------------------------------------------------------------------------ #include "Angle.h" #include <math.h> #ifndef ANGLE_PI #define ANGLE_PI 3.14159265358979323846 #endif static bool sTablesInitialized = false; static float sSinTable[360]; static float sCosTable[360]; static float sTanTable[360]; /*! \brief Constructor \param angle Value in degrees */ Angle::Angle(float angle) : fAngleValue(angle) { _InitTrigTables(); } //! Constructor Angle::Angle() : fAngleValue(0) { _InitTrigTables(); } //! Empty destructor Angle::~Angle() { } //! Constrains angle to 0 <= angle <= 360 void Angle::Normalize() { // if the value of the angle is >=360 or <0, make it so that it is // within those bounds fAngleValue = fmodf(fAngleValue, 360); if (fAngleValue < 0) fAngleValue += 360; } /*! \brief Obtains the sine of the angle \return The sine of the angle */ float Angle::Sine() { return sSinTable[(int)fAngleValue]; } /*! \brief Calculates an angle given a float value \param value Number between 0 and 1 inclusive \return The angle obtained or 0 if value passed was invalid */ Angle Angle::InvSine(float value) { // Returns the inverse sine of a value in the range 0 <= value <= 1 via // reverse-lookup any value out of range causes the function to return 0 // Filter out bad values value = fabs(value); if (value > 1) return Angle(0); uint16 i = 90; while (value < sSinTable[i]) i--; // current sSinTable[i] is less than value. Pick the degree value which is closer // to the passed value if ((value - sSinTable[i]) > (sSinTable[i + 1] - value)) return Angle(i + 1); return Angle(i); // value is closer to previous } /*! \brief Obtains the cosine of the angle \return The cosine of the angle */ float Angle::Cosine(void) { return sCosTable[(int)fAngleValue]; } /*! \brief Calculates an angle given a float value \param value Number between 0 and 1 inclusive \return The angle obtained or 0 if value passed was invalid */ Angle Angle::InvCosine(float value) { // Returns the inverse cosine of a value in the range 0 <= value <= 1 via // reverse-lookup any value out of range causes the function to return 0 // Filter out bad values value = fabs(value); if (value > 1) return 0; uint16 i = 90; while (value > sCosTable[i]) i--; // current sCosTable[i] is less than value. Pick the degree value which is closer // to the passed value if ((value - sCosTable[i]) < (sCosTable[i + 1] - value)) return Angle(i + 1); return Angle(i); // value is closer to previous } /*! \brief Obtains the tangent of the angle \return The tangent of the angle */ float Angle::Tangent(int *status) { if (fAngleValue == 90 || fAngleValue == 270) { if (status) *status = 0; return 0.0; } return sTanTable[(int)fAngleValue]; } /*! \brief Returns the inverse tangent of a value given \param value Number between 0 and 1 inclusive \return The angle found or 0 if value was invalid */ Angle Angle::InvTangent(float value) { // Filter out bad values value = fabs(value); if (value > 1) return Angle(0); uint16 i = 90; while (value > sTanTable[i]) i--; if ((value - sTanTable[i]) < (sTanTable[i+1] - value)) return Angle(i+1); return Angle(i); // value is closer to previous } /*! \brief Returns a value based on what quadrant the angle is in \return - \c 1: 0 <= angle <90 - \c 2: 90 <= angle < 180 - \c 3: 180 <= angle < 270 - \c 4: 270 <= angle < 360 */ uint8 Angle::Quadrant() { // We can get away with not doing extra value checks because of the order in // which the checks are done. if (fAngleValue < 90) return 1; if (fAngleValue < 180) return 2; if (fAngleValue < 270) return 3; return 4; } /*! \brief Obtains the angle constrained to between 0 and 180 inclusive \return The constrained value */ Angle Angle::Constrain180() { // Constrains angle to 0 <= angle < 180 if (fAngleValue < 180) return Angle(fAngleValue); float value = fmodf(fAngleValue, 180);; if (value < 0) value += 180; return Angle(value); } /*! \brief Obtains the angle constrained to between 0 and 90 inclusive \return The constrained value */ Angle Angle::Constrain90() { // Constrains angle to 0 <= angle < 90 if (fAngleValue < 90) return Angle(fAngleValue); float value = fmodf(fAngleValue, 90);; if (value < 0) value += 90; return Angle(value); } /*! \brief Sets the angle's value and normalizes the value \param angle Value in degrees */ void Angle::SetValue(float angle) { fAngleValue = angle; Normalize(); } float Angle::Value() const { return fAngleValue; } //! Initializes the global trig tables void Angle::_InitTrigTables() { if (sTablesInitialized) return; sTablesInitialized = true; for(int32 i = 0; i < 90; i++) { double currentRadian = (i * ANGLE_PI) / 180.0; // Get these so that we can do some superfast assignments double sinValue = sin(currentRadian); double cosValue = cos(currentRadian); // Do 4 assignments, taking advantage of sin/cos symmetry sSinTable[i] = sinValue; sSinTable[i + 90] = cosValue; sSinTable[i + 180] = sinValue * -1; sSinTable[i + 270] = cosValue * -1; sCosTable[i] = cosValue; sCosTable[i + 90] = sinValue * -1; sCosTable[i + 180] = cosValue * -1; sCosTable[i + 270] = sinValue; double tanValue = sinValue / cosValue; sTanTable[i] = tanValue; sTanTable[i + 90] = tanValue; sTanTable[i + 180] = tanValue; sTanTable[i + 270] = tanValue; } } Angle& Angle::operator=(const Angle &from) { fAngleValue = from.fAngleValue; return *this; } Angle& Angle::operator=(const float &from) { fAngleValue = from; return *this; } Angle& Angle::operator=(const long &from) { fAngleValue = (float)from; return *this; } Angle& Angle::operator=(const int &from) { fAngleValue = (float)from; return *this; } bool Angle::operator==(const Angle &from) { return (fAngleValue == from.fAngleValue); } bool Angle::operator!=(const Angle &from) { return (fAngleValue != from.fAngleValue); } bool Angle::operator>(const Angle &from) { return (fAngleValue > from.fAngleValue); } bool Angle::operator<(const Angle &from) { return (fAngleValue < from.fAngleValue); } bool Angle::operator>=(const Angle &from) { return (fAngleValue >= from.fAngleValue); } bool Angle::operator<=(const Angle &from) { return (fAngleValue <= from.fAngleValue); }
