////////////////////////////////////////////////////////////////////// // LibFile: vectors.scad // Vector math functions. // To use, add the following lines to the beginning of your file: // ``` // use // ``` ////////////////////////////////////////////////////////////////////// // Section: Vector Manipulation // Function: is_vector() // Usage: // is_vector(v, [length]); // Description: // Returns true if v is a list of finite numbers. // Arguments: // v = The value to test to see if it is a vector. // length = If given, make sure the vector is `length` items long. // Example: // is_vector(4); // Returns false // is_vector([4,true,false]); // Returns false // is_vector([3,4,INF,5]); // Returns false // is_vector([3,4,5,6]); // Returns true // is_vector([3,4,undef,5]); // Returns false // is_vector([3,4,5],3); // Returns true // is_vector([3,4,5],4); // Returns true // is_vector([]); // Returns false function is_vector(v,length) = is_list(v) && is_num(0*(v*v)) && (is_undef(length)||len(v)==length); // Function: add_scalar() // Usage: // add_scalar(v,s); // Description: // Given a vector and a scalar, returns the vector with the scalar added to each item in it. // If given a list of vectors, recursively adds the scalar to the each vector. // Arguments: // v = The initial list of values. // s = A scalar value to add to every item in the vector. // Example: // add_scalar([1,2,3],3); // Returns: [4,5,6] // add_scalar([[1,2,3],[3,4,5]],3); // Returns: [[4,5,6],[6,7,8]] function add_scalar(v,s) = [for (x=v) is_list(x)? add_scalar(x,s) : x+s]; // Function: vang() // Usage: // theta = vang([X,Y]); // theta_phi = vang([X,Y,Z]); // Description: // Given a 2D vector, returns the angle in degrees counter-clockwise from X+ on the XY plane. // Given a 3D vector, returns [THETA,PHI] where THETA is the number of degrees counter-clockwise from X+ on the XY plane, and PHI is the number of degrees up from the X+ axis along the XZ plane. function vang(v) = len(v)==2? atan2(v.y,v.x) : let(res=xyz_to_spherical(v)) [res[1], 90-res[2]]; // Function: vmul() // Description: // Element-wise vector multiplication. Multiplies each element of vector `v1` by // the corresponding element of vector `v2`. Returns a vector of the products. // Arguments: // v1 = The first vector. // v2 = The second vector. // Example: // vmul([3,4,5], [8,7,6]); // Returns [24, 28, 30] function vmul(v1, v2) = [for (i = [0:1:len(v1)-1]) v1[i]*v2[i]]; // Function: vdiv() // Description: // Element-wise vector division. Divides each element of vector `v1` by // the corresponding element of vector `v2`. Returns a vector of the quotients. // Arguments: // v1 = The first vector. // v2 = The second vector. // Example: // vdiv([24,28,30], [8,7,6]); // Returns [3, 4, 5] function vdiv(v1, v2) = [for (i = [0:1:len(v1)-1]) v1[i]/v2[i]]; // Function: vabs() // Description: Returns a vector of the absolute value of each element of vector `v`. // Arguments: // v = The vector to get the absolute values of. // Example: // vabs([-1,3,-9]); // Returns: [1,3,9] function vabs(v) = [for (x=v) abs(x)]; // Function: vfloor() // Description: // Returns the given vector after performing a `floor()` on all items. function vfloor(v) = [for (x=v) floor(x)]; // Function: vceil() // Description: // Returns the given vector after performing a `ceil()` on all items. function vceil(v) = [for (x=v) ceil(x)]; // Function: unit() // Usage: // unit(v, [error]); // Description: // Returns the unit length normalized version of vector v. If passed a zero-length vector, // asserts an error unless `error` is given, in which case the value of `error` is returned. // Arguments: // v = The vector to normalize. // error = If given, and input is a zero-length vector, this value is returned. Default: Assert error on zero-length vector. // Examples: // unit([10,0,0]); // Returns: [1,0,0] // unit([0,10,0]); // Returns: [0,1,0] // unit([0,0,10]); // Returns: [0,0,1] // unit([0,-10,0]); // Returns: [0,-1,0] // unit([0,0,0],[1,2,3]); // Returns: [1,2,3] // unit([0,0,0]); // Asserts an error. function unit(v, error=[[["ASSERT"]]]) = assert(is_vector(v), str("Expected a vector. Got: ",v)) norm(v)=EPSILON) : error) : v/norm(v); // Function: vector_angle() // Usage: // vector_angle(v1,v2); // vector_angle(PT1,PT2,PT3); // vector_angle([PT1,PT2,PT3]); // Description: // If given a single list of two vectors, like `vector_angle([V1,V2])`, returns the angle between the two vectors V1 and V2. // If given a single list of three points, like `vector_angle([A,B,C])`, returns the angle between the line segments AB and BC. // If given two vectors, like `vector_angle(V1,V2)`, returns the angle between the two vectors V1 and V2. // If given three points, like `vector_angle(A,B,C)`, returns the angle between the line segments AB and BC. // Arguments: // v1 = First vector or point. // v2 = Second vector or point. // v3 = Third point in three point mode. // Examples: // vector_angle(UP,LEFT); // Returns: 90 // vector_angle(RIGHT,LEFT); // Returns: 180 // vector_angle(UP+RIGHT,RIGHT); // Returns: 45 // vector_angle([10,10], [0,0], [10,-10]); // Returns: 90 // vector_angle([10,0,10], [0,0,0], [-10,10,0]); // Returns: 120 // vector_angle([[10,0,10], [0,0,0], [-10,10,0]]); // Returns: 120 function vector_angle(v1,v2,v3) = let( vecs = !is_undef(v3)? [v1-v2,v3-v2] : !is_undef(v2)? [v1,v2] : len(v1) == 3? [v1[0]-v1[1],v1[2]-v1[1]] : len(v1) == 2? v1 : assert(false, "Bad arguments to vector_angle()"), is_valid = is_vector(vecs[0]) && is_vector(vecs[1]) && vecs[0]*0 == vecs[1]*0 ) assert(is_valid, "Bad arguments to vector_angle()") let( norm0 = norm(vecs[0]), norm1 = norm(vecs[1]) ) assert(norm0>0 && norm1>0,"Zero length vector given to vector_angle()") // NOTE: constrain() corrects crazy FP rounding errors that exceed acos()'s domain. acos(constrain((vecs[0]*vecs[1])/(norm0*norm1), -1, 1)); // Function: vector_axis() // Usage: // vector_axis(v1,v2); // vector_axis(PT1,PT2,PT3); // vector_axis([PT1,PT2,PT3]); // Description: // If given a single list of two vectors, like `vector_axis([V1,V2])`, returns the vector perpendicular the two vectors V1 and V2. // If given a single list of three points, like `vector_axis([A,B,C])`, returns the vector perpendicular the line segments AB and BC. // If given two vectors, like `vector_axis(V1,V1)`, returns the vector perpendicular the two vectors V1 and V2. // If given three points, like `vector_axis(A,B,C)`, returns the vector perpendicular the line segments AB and BC. // Arguments: // v1 = First vector or point. // v2 = Second vector or point. // v3 = Third point in three point mode. // Examples: // vector_axis(UP,LEFT); // Returns: [0,-1,0] (FWD) // vector_axis(RIGHT,LEFT); // Returns: [0,-1,0] (FWD) // vector_axis(UP+RIGHT,RIGHT); // Returns: [0,1,0] (BACK) // vector_axis([10,10], [0,0], [10,-10]); // Returns: [0,0,-1] (DOWN) // vector_axis([10,0,10], [0,0,0], [-10,10,0]); // Returns: [-0.57735, -0.57735, 0.57735] // vector_axis([[10,0,10], [0,0,0], [-10,10,0]]); // Returns: [-0.57735, -0.57735, 0.57735] function vector_axis(v1,v2=undef,v3=undef) = (is_list(v1) && is_list(v1[0]) && is_undef(v2) && is_undef(v3))? ( assert(is_vector(v1.x)) assert(is_vector(v1.y)) len(v1)==3? assert(is_vector(v1.z)) vector_axis(v1.x, v1.y, v1.z) : len(v1)==2? vector_axis(v1.x, v1.y) : assert(false, "Bad arguments.") ) : (is_vector(v1) && is_vector(v2) && is_vector(v3))? vector_axis(v1-v2, v3-v2) : (is_vector(v1) && is_vector(v2) && is_undef(v3))? let( eps = 1e-6, v1 = point3d(v1/norm(v1)), v2 = point3d(v2/norm(v2)), v3 = (norm(v1-v2) > eps && norm(v1+v2) > eps)? v2 : (norm(vabs(v2)-UP) > eps)? UP : RIGHT ) unit(cross(v1,v3)) : assert(false, "Bad arguments."); // vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap