50 lines
2.3 KiB
C++
50 lines
2.3 KiB
C++
/*
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* Aurora: https://github.com/pixelmatix/aurora
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* Copyright (c) 2014 Jason Coon
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*
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* Portions of this code are adapted from "Attractor" in "The Nature of Code" by Daniel Shiffman: http://natureofcode.com/
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* Copyright (c) 2014 Daniel Shiffman
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* http://www.shiffman.net
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy of
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* this software and associated documentation files (the "Software"), to deal in
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* the Software without restriction, including without limitation the rights to
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* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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* the Software, and to permit persons to whom the Software is furnished to do so,
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* subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include "Vector.h"
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class Attractor {
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public:
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float mass; // Mass, tied to size
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float G; // Gravitational Constant
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PVector location; // Location
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Attractor() {
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location = PVector(MATRIX_CENTRE_X, MATRIX_CENTRE_Y);
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mass = 10;
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G = .5;
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}
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PVector attract(Boid m) {
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PVector force = location - m.location; // Calculate direction of force
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float d = force.mag(); // Distance between objects
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d = constrain(d, 5.0, 32.0); // Limiting the distance to eliminate "extreme" results for very close or very far objects
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force.normalize(); // Normalize vector (distance doesn't matter here, we just want this vector for direction)
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float strength = (G * mass * m.mass) / (d * d); // Calculate gravitional force magnitude
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force *= strength; // Get force vector --> magnitude * direction
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return force;
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}
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};
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