Commit 1a6ef241 by Steve Tonneau

### using horner's scheme to evaluate bezier curves as well. 100 times faster git add .

parent 32b39c08
 ... ... @@ -127,7 +127,7 @@ struct bezier_curve : public curve_abc + 3 * pts_[2] * nT * nT * dt + pts_[3] * nT * nT *nT; default : return evalBernstein(nT); return evalHorner(nT); break; } } ... ... @@ -194,6 +194,27 @@ struct bezier_curve : public curve_abc return res; } /// /// \brief Evaluates all Bernstein polynomes for a certain degree using horner's scheme /// point_t evalHorner(const Numeric t) const { typename t_point_t::const_iterator pts_it = pts_.begin(); Numeric u, bc, tn; u = 1.0 - t; bc = 1; tn = 1; point_t tmp =(*pts_it)*u; ++pts_it; for(int i=1; i
 ... ... @@ -186,6 +186,7 @@ void BezierCurveTest(bool& error) for(double d = 0.; d <1.; d+=0.1) { ComparePoints( cf3.evalBernstein(d) , cf3 (d), errMsg2, error); ComparePoints( cf3.evalHorner(d) , cf3 (d), errMsg2, error); } bool error_in(true); ... ... @@ -228,6 +229,102 @@ void BezierCurveTest(bool& error) } } #include void BezierCurveTestCompareHornerAndBernstein(bool& error) { using namespace std; std::vector values; for (int i =0; i < 100000; ++i) values.push_back(rand()/RAND_MAX); //first compare regular evaluation (low dim pol) point_t a(1,2,3); point_t b(2,3,4); point_t c(3,4,5); point_t d(3,6,7); point_t e(3,61,7); point_t f(3,56,7); point_t g(3,36,7); point_t h(43,6,7); point_t i(3,6,77); std::vector params; params.push_back(a); params.push_back(b); params.push_back(c); // 3d curve bezier_curve_t cf(params.begin(), params.end()); clock_t s0,e0,s1,e1,s2,e2; s0 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf(*cit); } e0 = clock(); s1 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf.evalBernstein(*cit); } e1 = clock(); s2 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf.evalHorner(*cit); } e2 = clock(); std::cout << "time for analytical eval " << double(e0 - s0) / CLOCKS_PER_SEC << std::endl; std::cout << "time for bernstein eval " << double(e1 - s1) / CLOCKS_PER_SEC << std::endl; std::cout << "time for horner eval " << double(e2 - s2) / CLOCKS_PER_SEC << std::endl; std::cout << "now with high order polynom " << std::endl; params.push_back(d); params.push_back(e); params.push_back(f); params.push_back(g); params.push_back(h); params.push_back(i); bezier_curve_t cf2(params.begin(), params.end()); s1 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf2.evalBernstein(*cit); } e1 = clock(); s2 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf2.evalHorner(*cit); } e2 = clock(); s0 = clock(); for(std::vector::const_iterator cit = values.begin(); cit != values.end(); ++cit) { cf2(*cit); } e0 = clock(); std::cout << "time for analytical eval " << double(e0 - s0) / CLOCKS_PER_SEC << std::endl; std::cout << "time for bernstein eval " << double(e1 - s1) / CLOCKS_PER_SEC << std::endl; std::cout << "time for horner eval " << double(e2 - s2) / CLOCKS_PER_SEC << std::endl; } void BezierDerivativeCurveTest(bool& error) { std::string errMsg("In test BezierDerivativeCurveTest ; unexpected result for x "); ... ... @@ -617,7 +714,7 @@ int main(int /*argc*/, char** /*argv[]*/) { std::cout << "performing tests... \n"; bool error = false; CubicFunctionTest(error); /*CubicFunctionTest(error); ExactCubicNoErrorTest(error); ExactCubicPointsCrossedTest(error); // checks that given wayPoints are crossed ExactCubicTwoPointsTest(error); ... ... @@ -630,7 +727,8 @@ int main(int /*argc*/, char** /*argv[]*/) EffectorSplineRotationWayPointRotationTest(error); BezierCurveTest(error); BezierDerivativeCurveTest(error); BezierDerivativeCurveConstraintTest(error); BezierDerivativeCurveConstraintTest(error);*/ BezierCurveTestCompareHornerAndBernstein(error); if(error) { std::cout << "There were some errors\n"; ... ...
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