c30d540521
- Add Google Test via CMake FetchContent (v1.14.0) - Add clausen.hpp: Clausen integral, Lobachevsky function, Im(Li2) - Add hyper_ideal_utility.hpp: generalized and ideal-vertex hyperbolic tetrahedron volume formulas using Eigen for the 4x4 Gram determinant - Port ClausenTest (5 tests) and HyperIdealUtilityTest (8 tests) from Java/JUnit — all 13 pass with same tolerances as the Java originals - Fix pre-existing VIEWER/viewer case mismatch in CMakeLists.txt Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
93 lines
3.7 KiB
C++
93 lines
3.7 KiB
C++
// Port of de.varylab.discreteconformal.functional.HyperIdealUtilityTest (Java/JUnit).
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#include "hyper_ideal_utility.hpp"
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#include "clausen.hpp"
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#include <gtest/gtest.h>
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#include <cmath>
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using conformallab::calculateTetrahedronVolume;
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using conformallab::calculateTetrahedronVolumeWithIdealVertexAtGamma;
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using conformallab::Lobachevsky;
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constexpr double PI = 3.14159265358979323846264338328;
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// Regular tetrahedron at the Euclidean boundary (beta = arccos(1/3) for each
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// vertex angle) has volume 0 — it degenerates to a flat configuration.
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TEST(HyperIdealUtilityTest, VolumeEuclidean) {
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double b = std::acos(1.0 / 3.0);
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double V = calculateTetrahedronVolume(b, b, b, b, b, b);
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EXPECT_NEAR(0.0, V, 1e-7);
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}
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// Regular ideal tetrahedron with all angles pi/3.
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// Formula: sum of Lobachevsky values at each angle.
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TEST(HyperIdealUtilityTest, VolumeRegularIdeal1) {
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double b = PI / 3.0;
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double Ve = Lobachevsky(b) + Lobachevsky(b) + Lobachevsky(b);
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double V = calculateTetrahedronVolume(b, b, b, b, b, b);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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// Right-angled ideal tetrahedron (pi/2, pi/4, pi/4).
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TEST(HyperIdealUtilityTest, VolumeRegularIdeal2) {
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double bi = PI / 2.0, bj = PI / 4.0, bk = PI / 4.0;
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double Ve = Lobachevsky(bi) + Lobachevsky(bj) + Lobachevsky(bk);
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double V = calculateTetrahedronVolume(bi, bj, bk, bi, bj, bk);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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// Hyperideal octahedron: all angles 0, volume = 8*Л(pi/4).
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TEST(HyperIdealUtilityTest, VolumeOctahedron) {
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double Ve = 8.0 * Lobachevsky(PI / 4.0);
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double V = calculateTetrahedronVolume(0, 0, 0, 0, 0, 0);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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// Hyperideal tetrahedron with one hyperideal vertex.
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// Manual formula from the paper vs. general formula.
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TEST(HyperIdealUtilityTest, VolumeSingleHyperidealVertex) {
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double bi = PI / 5.0, bj = PI / 4.0, bk = PI / 4.0;
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double ai = (PI + bi - bj - bk) / 2.0;
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double aj = (PI + bj - bi - bk) / 2.0;
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double ak = (PI + bk - bi - bj) / 2.0;
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double aijk= (PI - bk - bi - bj) / 2.0;
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double Ve = 0.5 * (Lobachevsky(bi) + Lobachevsky(bj) + Lobachevsky(bk)
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+ Lobachevsky(ai) + Lobachevsky(aj) + Lobachevsky(ak)
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+ Lobachevsky(aijk));
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double V = calculateTetrahedronVolume(bi, bj, bk, ai, aj, ak);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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// A degenerate triangle (angle = pi) must give volume 0 without NaN.
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TEST(HyperIdealUtilityTest, VolumeWithDegenerateTriangle) {
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double V = calculateTetrahedronVolume(0.0, PI, 0.0, 0.0, 0.0, PI);
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EXPECT_NEAR(0.0, V, 1e-12);
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EXPECT_FALSE(std::isnan(V));
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}
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// The two volume formulas (general and ideal-vertex specialization) must agree
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// on the same input — numerical consistency check.
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TEST(HyperIdealUtilityTest, CompareGeneralAndIdealFormulaCase1) {
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constexpr double EPS = 0.1;
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double bi = PI / 3.0, bj = PI / 3.0, bk = PI / 3.0;
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double ai = PI / 3.0 - EPS, aj = PI / 3.0 - EPS, ak = PI / 3.0 - EPS;
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double Ve = calculateTetrahedronVolumeWithIdealVertexAtGamma(bi, bj, bk, ai, aj, ak);
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double V = calculateTetrahedronVolume(bi, bj, bk, ai, aj, ak);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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// Second consistency check with non-symmetric angles that sum to pi.
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TEST(HyperIdealUtilityTest, CompareGeneralAndIdealFormulaCase2) {
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double bi = 0.6623267054958116;
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double bj = 1.437248992086214;
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double bk = 1.0420169560077686;
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double ai = 0.6896178197389236;
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double aj = 0.5195634857410114;
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double ak = 0.6304500578493993;
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EXPECT_NEAR(PI, bi + bj + bk, 1e-12);
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double Ve = calculateTetrahedronVolumeWithIdealVertexAtGamma(bi, bj, bk, ai, aj, ak);
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double V = calculateTetrahedronVolume(bi, bj, bk, ai, aj, ak);
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EXPECT_NEAR(Ve, V, 1e-12);
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}
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