Revision: 36578
Initial Code
Initial URL
Initial Description
Initial Title
Initial Tags
Initial Language
at November 23, 2010 13:58 by browny
Initial Code
struct Vector { double x, y; }; double getRotateAngle(Vector vec1, Vector vec2) { const double epsilon = 1.0e-6; const double PI = acos(-1.0); // 180 degree double angle = 0; // normalize Vector norVec1, norVec2; norVec1.x = vec1.x / sqrt(pow(vec1.x, 2) + pow(vec1.y, 2)); norVec1.y = vec1.y / sqrt(pow(vec1.x, 2) + pow(vec1.y, 2)); norVec2.x = vec2.x / sqrt(pow(vec2.x, 2) + pow(vec2.y, 2)); norVec2.y = vec2.y / sqrt(pow(vec2.x, 2) + pow(vec2.y, 2)); // dot product double dotProd = (norVec1.x * norVec2.x) + (norVec1.y * norVec2.y); if ( abs(dotProd - 1.0) <= epsilon ) angle = 0; else if ( abs(dotProd + 1.0) <= epsilon ) angle = PI; else { double cross = 0; angle = acos(dotProd); //cross product (clockwise or counter-clockwise) cross = (norVec1.x * norVec2.y) - (norVec2.x * norVec1.y); if (cross < 0) // vec1 rotate clockwise to vec2 angle = 2 * PI - angle; } return angle*(180 / PI); }
Initial URL
http://www.cnblogs.com/lsmdiao0812/archive/2010/05/05/1728122.html
Initial Description
Initial Title
Get the directional rotation angle between 2 vectors
Initial Tags
Initial Language
C++