hopefully correct camera

src/camera.rs

@@ -23,14 +23,22 @@ impl OrbitalCamera {
 	}
 
 	pub fn transform(&self) -> Mat4 {
+		// for yaw=0, pitch=0:
+		// X -> -Z
+		// Y -> -X
+		// Z -> Y
 		Mat4::from_translation(vec3(0., 0., self.distance))
-			* Mat4::from_euler(glam::EulerRot::ZXZ, 0., PI / 2., -PI / 2.)
-			* Mat4::from_euler(
-				glam::EulerRot::ZYZ,
-				0.,
-				self.position_pitch,
-				-self.position_yaw,
-			)
+			* Mat4::from_cols_array_2d(&[
+				[0., 0., -1., 0.],
+				[-1., 0., 0., 0.],
+				[0., 1., 0., 0.],
+				[0., 0., 0., 1.],
+			]) * Mat4::from_euler(
+			glam::EulerRot::ZYZ,
+			0.,
+			self.position_pitch,
+			-self.position_yaw,
+		)
 	}
 }
 
@@ -68,7 +76,7 @@ mod tests {
 	#[test]
 	fn test_orbital_camera_forward() {
 		const EPSILON: f32 = 1e-5;
-		for pitch in [0., 30., 45., 89., 90.] {
+		for pitch in [0., 30., 45., 89., -30., -45., -89.] {
 			for yaw in [0., 30., 45., 89., 90.] {
 				let camera = camera_deg(yaw, pitch);
 				let pos = camera.position();
@@ -91,6 +99,12 @@ mod tests {
 					abs_diff_eq!(mapped, vec3(0., 0., 1.), epsilon = EPSILON),
 					"origin not mapped to (0, 0, 1): yaw={yaw:?}°, pitch={pitch:?}°, pos={pos:?}, mapped={mapped:?}"
 				);
+
+				let mapped = tfm.transform_vector3(vec3(0., 0., 1.));
+				assert!(
+					mapped.y > 0.,
+					"up is not up: yaw={yaw:?}°, pitch={pitch:?}°, pos={pos:?}, mapped={mapped:?}"
+				);
 			}
 		}
 	}