splash/tests/unit_tests/graphics/camera.cpp

#include <doctest.h>

#include "./graphics/camera.h"

using namespace Splash;

/*************/
TEST_CASE("Testing Camera::checkPointsCoplanar with coplanar points")
{
    // Test case: 3 points forming a plane (e.g., a triangle)
    std::vector<glm::dvec3> points = {
        {0.0, 0.0, 0.0},
        {1.0, 0.0, 0.0},
        {0.0, 1.0, 0.0}
    };

    // Expected: coplanar with small tolerance
    CHECK(Camera::checkPointsCoplanar(points, 0.1f));
    CHECK(Camera::checkPointsCoplanar(points, 0.01f));
}

/*************/
TEST_CASE("Testing Camera::checkPointsCoplanar with non-coplanar points")
{
    // Test case: 4 points forming a tetrahedron (non-coplanar)
    std::vector<glm::dvec3> points = {
        {0.0, 0.0, 0.0},
        {1.0, 0.0, 0.0},
        {0.0, 1.0, 0.0},
        {0.0, 0.0, 1.0}
    };

    // Should fail with any reasonable tolerance
    CHECK_FALSE(Camera::checkPointsCoplanar(points, 0.1f));
    CHECK_FALSE(Camera::checkPointsCoplanar(points, 0.01f));
}

/*************/
TEST_CASE("Testing Camera::checkPointsCoplanar with edge cases")
{
    // Case 1: Fewer than 3 points
    std::vector<glm::dvec3> points1 = {{0.0, 0.0, 0.0}};
    CHECK_FALSE(Camera::checkPointsCoplanar(points1, 0.1f));

    std::vector<glm::dvec3> points2 = {{0.0, 0.0, 0.0}, {1.0, 0.0, 0.0}};
    CHECK_FALSE(Camera::checkPointsCoplanar(points2, 0.1f));

    // Case 2: All points are collinear (should still be coplanar, but normal is undefined)
    std::vector<glm::dvec3> points3 = {
        {0.0, 0.0, 0.0},
        {1.0, 0.0, 0.0},
        {2.0, 0.0, 0.0}
    };
    CHECK(Camera::checkPointsCoplanar(points3, 0.1f)); // Coplanar (in a plane), but normal may be unstable

    // Case 3: Degenerate (all points same)
    std::vector<glm::dvec3> points4 = {
        {0.0, 0.0, 0.0},
        {0.0, 0.0, 0.0},
        {0.0, 0.0, 0.0}
    };
    CHECK_FALSE(Camera::checkPointsCoplanar(points4, 0.1f));
}

/*************/
TEST_CASE("Testing Camera::checkPointsCoplanar with noisy 4-point set and tolerance")
{
    // Define a base plane with noise to each point
    std::vector<glm::dvec3> noisyPoints = {
        {0.0 + 0.01, 0.0 + 0.01, 0.0 - 0.02},
        {1.0 - 0.01, 0.0 + 0.01, 0.0 - 0.02},
        {0.0 + 0.01, 1.0 - 0.01, 0.0 + 0.02},
        {1.0 + 0.01, 1.0 - 0.01, 0.0 - 0.02}
    };

    // Test with tolerance = 10% of diameter (should pass)
    CHECK(Camera::checkPointsCoplanar(noisyPoints, 0.1));

    // Test with tolerance = 0.1% of diameter (should fail)
    CHECK_FALSE(Camera::checkPointsCoplanar(noisyPoints, 0.001));
}