SaraP
102 lines
4.7 KiB
C
102 lines
4.7 KiB
C
/*****************************************************************************/
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/* */
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/* Copyright (C) 2003--2023 M. Held */
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/* */
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/* This code is not in the public domain. All rights reserved! Please make */
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/* sure to read the full copyright statement contained in "README.txt" or in */
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/* the "main" file of this code, such as "main.cc". */
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/* */
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/*****************************************************************************/
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/* */
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/* Written by: Martin Held */
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/* */
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/* E-Mail: held@cs.sbg.ac.at */
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/* Fax Mail: (+43 662) 8044-611 */
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/* Voice Mail: (+43 662) 8044-6304 */
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/* Snail Mail: Martin Held */
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/* FB Informatik */
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/* Universitaet Salzburg */
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/* A-5020 Salzburg, Austria */
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/* */
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/*****************************************************************************/
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#ifndef VRONI_APPROX_H
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#define VRONI_APPROX_H
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inline void ApproxArc(const coord & p1, const coord & p2,
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double_arg xc3, double_arg yc3, double_arg radius,
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vr_bool ccw_orientation, double_arg apx_absolute,
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vronivector<coord> & apx_vtx, int & max_num_apx_vtx,
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double_arg max_incr, int & number)
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{
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double incr;
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/* */
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/* determine the start angle and end angle of the arc */
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/* */
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double angle_s = atan2(p1.y - yc3, p1.x - xc3);
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double angle_e = atan2(p2.y - yc3, p2.x - xc3);
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if (angle_s < 0.0) angle_s += M_2PI;
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if (angle_e < 0.0) angle_e += M_2PI;
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if (angle_e < angle_s) angle_e += M_2PI;
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/* */
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/* determine the angular increment incr: we will insert points at */
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/* the angles angle_s + 0.5 * incr, angle_s + 1.5 * incr, ..., */
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/* angle_e - 0.5 * incr (for a CCW arc). */
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/* */
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if (apx_absolute > 0.0) {
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incr = acos(radius / (radius + apx_absolute));
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incr = Min(incr, max_incr);
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}
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else {
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incr = max_incr;
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}
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incr *= 10.0;
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assert(gt(incr, ZERO));
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double diff = (angle_e - angle_s);
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incr = diff / (2.0 * incr);
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number = REAL_TO_INT(Ceiling(incr));
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if (number <= 0) number = 1;
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incr = diff / ((double) (number));
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/* */
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/* the new pnts will lie at a distance lgth from the arc's center */
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/* */
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// double lgth = radius / cos(incr / 2.0);
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double lgth = radius;
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double alpha;
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if (ccw_orientation) {
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alpha = angle_s + incr / 2.0;
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}
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else {
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alpha = angle_e - incr / 2.0;
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incr = - incr;
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}
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/* */
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/* allocate memory for the new vertices to be computed */
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/* */
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if (number > max_num_apx_vtx) {
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max_num_apx_vtx = number;
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gentlyResizeSTLVector(apx_vtx, max_num_apx_vtx, "approx:apx_vtx");
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}
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/* */
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/* compute and store the new pnts and segs */
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/* */
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//printf("p1.x = %20.16f, p1.y = %20.16f\n", p1.x, p1.y);
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//printf("p2.x = %20.16f, p2.y = %20.16f\n", p2.x, p2.y);
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for (int k = 0; k < number; ++k) {
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assert(k <= max_num_apx_vtx);
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apx_vtx[k].x = xc3 + lgth * cos(alpha);
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apx_vtx[k].y = yc3 + lgth * sin(alpha);
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//printf("alpha = %20.16f\n", alpha);
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alpha += incr;
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}
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}
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#endif
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