00001 /********************************************************************* 00002 * Software License Agreement (BSD License) 00003 * 00004 * Copyright (c) 2017, laser_filters authors 00005 * All rights reserved. 00006 * 00007 * Redistribution and use in source and binary forms, with or without 00008 * modification, are permitted provided that the following conditions 00009 * are met: 00010 * 00011 * * Redistributions of source code must retain the above copyright 00012 * notice, this list of conditions and the following disclaimer. 00013 * * Redistributions in binary form must reproduce the above 00014 * copyright notice, this list of conditions and the following 00015 * disclaimer in the documentation and/or other materials provided 00016 * with the distribution. 00017 * * Neither the name of the Willow Garage nor the names of its 00018 * contributors may be used to endorse or promote products derived 00019 * from this software without specific prior written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00022 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00023 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00024 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 00025 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00026 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00027 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00028 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00029 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00030 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00031 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00032 * POSSIBILITY OF SUCH DAMAGE. 00033 *********************************************************************/ 00034 00035 /* 00036 \author Atsushi Watanabe (SEQSENSE, Inc.) 00037 */ 00038 00039 #ifndef SCAN_SHADOW_DETECTOR_H 00040 #define SCAN_SHADOW_DETECTOR_H 00041 00042 namespace laser_filters 00043 { 00044 class ScanShadowDetector 00045 { 00046 public: 00047 float min_angle_tan_, max_angle_tan_; // Filter angle thresholds 00048 00049 void configure(const float min_angle, const float max_angle) 00050 { 00051 min_angle_tan_ = tanf(min_angle); 00052 max_angle_tan_ = tanf(max_angle); 00053 00054 // Correct sign of tan around singularity points 00055 if (min_angle_tan_ < 0.0) 00056 min_angle_tan_ = -min_angle_tan_; 00057 if (max_angle_tan_ > 0.0) 00058 max_angle_tan_ = -max_angle_tan_; 00059 } 00060 bool isShadow(const float r1, const float r2, const float included_angle) 00061 { 00062 const float perpendicular_y_ = r2 * sinf(included_angle); 00063 const float perpendicular_x_ = r1 - r2 * cosf(included_angle); 00064 const float perpendicular_tan_ = fabs(perpendicular_y_) / perpendicular_x_; 00065 00066 if (perpendicular_tan_ > 0) 00067 { 00068 if (perpendicular_tan_ < min_angle_tan_) 00069 return true; 00070 } 00071 else 00072 { 00073 if (perpendicular_tan_ > max_angle_tan_) 00074 return true; 00075 } 00076 return false; 00077 } 00078 }; 00079 } 00080 00081 #endif //SCAN_SHADOW_DETECTOR_H