ViewDesignEngine/tests/curves/test_bezier.cpp

#include <gtest/gtest.h>
#include "vde/curves/bezier_curve.h"

using namespace vde::curves;

TEST(BezierTest, LinearEvaluateAtMidpoint) {
    BezierCurve curve({Point3D(0,0,0), Point3D(2,0,0)});
    Point3D p = curve.evaluate(0.5);
    EXPECT_NEAR(p.x(), 1.0, 1e-6);
}

TEST(BezierTest, QuadraticEvaluateAtEndpoints) {
    BezierCurve curve({Point3D(0,0,0), Point3D(1,1,0), Point3D(2,0,0)});
    EXPECT_NEAR((curve.evaluate(0.0) - Point3D(0,0,0)).norm(), 0.0, 1e-6);
    EXPECT_NEAR((curve.evaluate(1.0) - Point3D(2,0,0)).norm(), 0.0, 1e-6);
}

TEST(BezierTest, LinearDerivative) {
    BezierCurve curve({Point3D(0,0,0), Point3D(2,0,0)});
    Vector3D d = curve.derivative(0.5, 1);
    EXPECT_NEAR(d.x(), 2.0, 1e-6);
    EXPECT_NEAR(d.y(), 0.0, 1e-6);
}

TEST(BezierTest, QuadraticDerivative) {
    BezierCurve curve({Point3D(0,0,0), Point3D(1,2,0), Point3D(3,0,0)});
    Vector3D d = curve.derivative(0.5, 1);
    EXPECT_GT(d.norm(), 0.0);
}

TEST(BezierTest, Split) {
    BezierCurve curve({Point3D(0,0,0), Point3D(2,0,0)});
    auto [c1, c2] = curve.split(0.5);
    EXPECT_EQ(c1.degree(), 1);
    EXPECT_EQ(c2.degree(), 1);
    EXPECT_NEAR((c1.evaluate(1.0) - Point3D(1,0,0)).norm(), 0.0, 1e-6);
}