From 8a6fc54ccdba233b2951b8933798c03915739afd Mon Sep 17 00:00:00 2001 From: Jihyun Yu Date: Sat, 21 Aug 2021 16:57:59 +0900 Subject: Curve2D/Curve3D: exact linear interpolation While calculating interpolated points, intervals between two baked points has been assummed to be `baked_interval`. The assumption could cause significant error in some extreme cases (for example #7088). To improve accuracy, `baked_dist_cache` is introduced, which stores distance from starting point for each baked points. `interpolate_baked` now returns exact linear-interpolated position along baked points. --- tests/test_curve.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'tests') diff --git a/tests/test_curve.h b/tests/test_curve.h index 7eeee86f32..e079905e35 100644 --- a/tests/test_curve.h +++ b/tests/test_curve.h @@ -216,6 +216,41 @@ TEST_CASE("[Curve] Custom curve with linear tangents") { Math::is_equal_approx(curve->interpolate_baked(0.7), (real_t)0.8), "Custom free curve should return the expected baked value at offset 0.7 after removing point at invalid index 10."); } + +TEST_CASE("[Curve2D] Linear sampling should return exact value") { + Ref curve = memnew(Curve2D); + int len = 2048; + + curve->add_point(Vector2(0, 0)); + curve->add_point(Vector2((float)len, 0)); + + float baked_length = curve->get_baked_length(); + CHECK((float)len == baked_length); + + for (int i = 0; i < len; i++) { + float expected = (float)i; + Vector2 pos = curve->interpolate_baked(expected); + CHECK_MESSAGE(pos.x == expected, "interpolate_baked should return exact value"); + } +} + +TEST_CASE("[Curve3D] Linear sampling should return exact value") { + Ref curve = memnew(Curve3D); + int len = 2048; + + curve->add_point(Vector3(0, 0, 0)); + curve->add_point(Vector3((float)len, 0, 0)); + + float baked_length = curve->get_baked_length(); + CHECK((float)len == baked_length); + + for (int i = 0; i < len; i++) { + float expected = (float)i; + Vector3 pos = curve->interpolate_baked(expected); + CHECK_MESSAGE(pos.x == expected, "interpolate_baked should return exact value"); + } +} + } // namespace TestCurve #endif // TEST_CURVE_H -- cgit v1.2.3