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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>Ahmet,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>The following function will return the angle in decimal degrees given 3 points on a flat plane. The three points create the angle. If you have two intersecting lines then the angle of any given corner is the center point where the lines intersect and two end points of the lines that complete an angle.<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><b><span style='font-size:9.5pt;font-family:Consolas'>// NOTE: the points must be fed to the function in clockwise order. <o:p></o:p></span></b></p><p class=MsoNormal style='text-autospace:none'><b><span style='font-size:9.5pt;font-family:Consolas'>// NOTE: the angle returned is an azimuth angle and not a trigonometric angle. Azimuth angles start with zero at north and increase clockwise whereas trigonometric angles zero starts to the right (east) on the x axis and increase going counter clockwise.<o:p></o:p></span></b></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>const double PI = 3.1415926535897932384626433;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>const double RAD2DEG = 180.0 / PI;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>double GetAngle(const double& x1, const double& y1, const double& x2, const double& y2, const double& x3, const double& y3)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double theta1 = atan2(y2 - y1, x2 - x1);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double theta2 = atan2(y2 - y3, x2 - x3);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double theta = (theta2 - theta1) * RAD2DEG;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> if (theta < 0) theta += 360.0;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> return theta;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><b><span style='font-size:9.5pt;font-family:Consolas'>// To get the intersection of two lines use:<o:p></o:p></span></b></p><p class=MsoNormal style='text-autospace:none'><b><span style='font-size:9.5pt;font-family:Consolas'>// NOTE: returns FALSE if the lines don’t intersect<o:p></o:p></span></b></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>struct Point<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double x;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double y;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>};<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>struct Line<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> Point point1;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> Point point2;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>};<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>BOOL GetLineIntersection(const Line& line1, const Line& line2, double& x, double& y)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double a1 = line1.point2.y - line1.point1.y;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double b1 = line1.point1.x - line1.point2.x;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double c1 = a1 * line1.point1.x + b1 * line1.point1.y;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double a2 = line2.point2.y - line2.point1.y;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double b2 = line2.point1.x - line2.point2.x;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double c2 = a2 * line2.point1.x + b2 * line2.point1.y;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> double determinant = a1 * b2 - a2 * b1;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> if (determinant == 0) return FALSE;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> x = (b2 * c1 - b1 * c2) / determinant;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> y = (a1 * c2 - a2 * c1) / determinant;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> return TRUE;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas;color:black'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas;color:black'>Best regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:9.5pt;font-family:Consolas;color:black'>Martin Chapman<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> gdal-dev [mailto:gdal-dev-bounces@lists.osgeo.org] <b>On Behalf Of </b>Ahmet Temiz<br><b>Sent:</b> Monday, November 11, 2019 7:07 AM<br><b>To:</b> gdal-dev<br><b>Subject:</b> [gdal-dev] angle of crossing two lines<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>Hi,<o:p></o:p></p></div><div><p class=MsoNormal>I need to know angle of crossing two lines.<o:p></o:p></p></div><div><p class=MsoNormal>which function can I use?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>regards<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <o:p></o:p></p><div><div><div><div><div><p class=MsoNormal>Ahmet Temiz<br>Jeoloji Müh.<br>Afet ve Acil Durum Yönetimi Başkanlığı<br>Bilgi İşlem Dairesi Başkanlığı-CBS Grubu<br><br><br>________________________<br><br>Ahmet Temiz<br>Geological Eng.<br>Information Systems - GIS Group<br>Disaster and Emergency Management<br>of Presidency<o:p></o:p></p></div></div></div></div></div></div></div></body></html>