71 lines
1.9 KiB
C
71 lines
1.9 KiB
C
/*
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* Copyright 2011-2014 hasufell
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*
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* This file is part of a hasufell project.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation version 2 of the License only.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file bezier.c
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* This file provides operations and informational functions
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* on the bezier data type which is defined in bezier.h.
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* @brief operations on bezier curves
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*/
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#include "bezier.h"
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#include "vector.h"
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#include <stdint.h>
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#include <stdlib.h>
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/**
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* Calculate a point on the bezier curve according to the
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* bezier vertices. If section is set to 0.5 then it will
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* return the vector to the point in the middle of the curve.
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*
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* @param obj the object holding the bezier vertices information
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* @param section the section which will be applied to all
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* lines between the bezier vertices
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* @return the vector to the calculated point
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*/
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vector *calculate_bezier_point(bez_curv *bez, float section)
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{
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vector vec_arr[bez->deg];
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bez_curv new_bez;
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for (uint32_t i = 0; i < bez->deg; i++) {
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vector new_vec;
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SUB_VECTORS(&(bez->vec[i + 1]), &(bez->vec[i]), &new_vec);
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VECTOR_LEN_SCAL_MUL(&new_vec, section, &new_vec);
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ADD_VECTORS(&new_vec, &(bez->vec[i]), &new_vec);
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vec_arr[i] = new_vec;
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}
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new_bez.vec = vec_arr;
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new_bez.deg = bez->deg - 1;
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if (new_bez.deg > 0) {
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return calculate_bezier_point(&new_bez, section);
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} else {
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vector *result_vector = malloc(sizeof(*result_vector));
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*result_vector = vec_arr[0];
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return result_vector;
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}
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}
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