/*! * * \file src/math/math.cpp * \brief Vector and Matrix math * * \author Mongoose * \author xythobuz */ #include #include #include #include #include "math/Vector3d.h" #include "math/Matrix.h" #include "math/math.h" bool equalEpsilon(vec_t a, vec_t b) { vec_t epsilon = FLT_EPSILON; if (fabs(a - b) <= (fmax(fabs(a), fabs(b)) * epsilon)) return true; return false; } int intersectionLinePolygon(vec3_t intersect, vec3_t p1, vec3_t p2, vec3_t *polygon) { assert(polygon != NULL); // vec3_t normal, a, b; Vector3d a, b, normal, pA, pB; vec_t d, denominator, mu; pA = Vector3d(p1); pB = Vector3d(p2); // Find normal a = Vector3d(polygon[1]) - Vector3d(polygon[0]); b = Vector3d(polygon[2]) - Vector3d(polygon[0]); normal = Vector3d::cross(a, b); normal.normalize(); // find D d = (normal.mVec[0] * polygon[0][0] - normal.mVec[1] * polygon[0][1] - normal.mVec[2] * polygon[0][2]); // line segment parallel to plane? a = pB - pA; denominator = Vector3d::dot(normal, a); if (denominator > 0.0) return 0; // Line segment contains intercept point? mu = -((d + Vector3d::dot(normal, pA)) / denominator); if (mu < 0.0 || mu > 1.0) return 0; b = pA + (a * mu); intersect[0] = b.mVec[0]; intersect[1] = b.mVec[1]; intersect[2] = b.mVec[2]; // See if the intercept is bound by polygon by winding number // assume convex polygons here for sure double theta = Vector3d::dot(b - Vector3d(polygon[0]), normal); // b = intersect if (theta >= 90.0) // Yeah I know return 0; return 1; } vec_t distance(const vec3_t a, const vec3_t b) { return sqrtf(((b[0] - a[0]) * (b[0] - a[0])) + ((b[1] - a[1]) * (b[1] - a[1])) + ((b[2] - a[2]) * (b[2] - a[2]))); } void midpoint(const vec3_t a, const vec3_t b, vec3_t mid) { mid[0] = (a[0] + b[0]) / 2.0f; mid[1] = (a[1] + b[1]) / 2.0f; mid[2] = (a[2] + b[2]) / 2.0f; } vec_t randomNum(vec_t from, vec_t to) { return from + ((to - from) * rand() / (RAND_MAX + 1.0f)); }