Proposal-1778: Updating Transform.rotated() docs and test cases.

doc/classes/Transform.xml

@@ -168,7 +168,8 @@
  <argument index="1" name="phi" type="float">
  </argument>
  <description>
- Rotates the transform around the given axis by the given angle (in radians), using matrix multiplication. The axis must be a normalized vector.
+ Returns a new transform created by rotating around the given axis by the given angle (in radians). The axis must be a normalized vector.
+ The axis of rotation goes through (0, 0, 0) in local space, so the transform's origin will also rotate. If you want to change the transform's orientation while keeping it in place, consider calling [code]rotated[/code] on the transform's basis instead.
  </description>
  </method>
  <method name="scaled">

tests/test_math.h

@@ -31,11 +31,55 @@
 #ifndef TEST_MATH_H
 #define TEST_MATH_H
 
-#include "core/os/main_loop.h"
+#include "core/math/math_defs.h"
+#include "core/math/math_funcs.h"
+#include "core/math/transform.h"
+#include "core/os/os.h"
+
+#include <math.h>
+#include <stdio.h>
+
+#include "tests/test_macros.h"
 
 namespace TestMath {
 
 MainLoop *test();
 }
 
+TEST_CASE("[Transform] Rotate around global origin") {
+ // Start with the default orientation, but not centered on the origin.
+ // Rotating should rotate both our basis and the origin.
+ Transform transform = Transform();
+ transform.origin = Vector3(0, 0, 1);
+
+ Transform expected = Transform();
+ expected.origin = Vector3(0, 0, -1);
+ expected.basis.set_axis(0, Vector3(-1, 0, 0));
+ expected.basis.set_axis(2, Vector3(0, 0, -1));
+
+ Transform rotated_transform = transform.rotated(Vector3(0, 1, 0), Math_PI);
+ REQUIRE(rotated_transform.is_equal_approx(expected));
+
+ // Make sure that the rotated transform isn't sharing references with the original transform.
+ REQUIRE(&rotated_transform.basis != &transform.basis);
+ REQUIRE(&rotated_transform.origin != &transform.origin);
+}
+
+TEST_CASE("[Transform] Rotate in-place") {
+ // Start with the default orientation, centered on the origin.
+ // Rotating should rotate us around the origin, so the origin shouldn't change.
+ Transform transform = Transform();
+
+ Transform expected = Transform();
+ expected.basis.set_axis(0, Vector3(-1, 0, 0));
+ expected.basis.set_axis(2, Vector3(0, 0, -1));
+
+ Transform rotated_transform = transform.rotated(Vector3(0, 1, 0), Math_PI);
+ REQUIRE(rotated_transform.is_equal_approx(expected));
+
+ // Make sure that the rotated transform isn't sharing references with the original transform.
+ REQUIRE(&rotated_transform.basis != &transform.basis);
+ REQUIRE(&rotated_transform.origin != &transform.origin);
+}
+
 #endif