ray: implement all orders in ray_euler_basis()

Originally I only implemented pitch->yaw->roll, and being new to all this
didn't fully appreciate the limitation that resulted in.

This adds all six permutations of pitch/yaw/roll, the scene must specify
the desired order when setting up the camera with the euler angles, see
the enum in ray_euler.h.

1 files changed, 14 insertions, 26 deletions

diff --git a/src/modules/ray/ray_euler.h b/src/modules/ray/ray_euler.h
index 86f5221..3a74cab 100644
--- a/src/modules/ray/ray_euler.h
+++ b/src/modules/ray/ray_euler.h
@@ -5,12 +5,22 @@
 
 #include "ray_3f.h"
 
+/* Desired order to apply euler angle rotations */
+typedef enum ray_euler_order_t {
+	RAY_EULER_ORDER_PYR,
+	RAY_EULER_ORDER_YRP,
+	RAY_EULER_ORDER_RPY,
+	RAY_EULER_ORDER_PRY,
+	RAY_EULER_ORDER_RYP,
+	RAY_EULER_ORDER_YPR,
+} ray_euler_order_t;
 
 /* euler angles are convenient for describing orientation */
 typedef struct ray_euler_t {
-	float	pitch;	/* pitch in radiasn */
-	float	yaw;	/* yaw in radians */
-	float	roll;	/* roll in radians */
+	ray_euler_order_t	order;	/* order to apply rotations in */
+	float			pitch;	/* pitch in radiasn */
+	float			yaw;	/* yaw in radians */
+	float			roll;	/* roll in radians */
 } ray_euler_t;
 
 
@@ -18,28 +28,6 @@ typedef struct ray_euler_t {
 #define RAY_EULER_DEGREES(_deg) \
 	(_deg * (2 * M_PI / 360.0f))
 
-
-/* produce basis vectors from euler angles */
-static inline void ray_euler_basis(ray_euler_t *e, ray_3f_t *forward, ray_3f_t *up, ray_3f_t *left)
-{
-	float	cos_yaw = cosf(e->yaw);
-	float	sin_yaw = sinf(e->yaw);
-	float	cos_roll = cosf(e->roll);
-	float	sin_roll = sinf(e->roll);
-	float	cos_pitch = cosf(e->pitch);
-	float	sin_pitch = sinf(e->pitch);
-
-	forward->x = sin_yaw;
-	forward->y = -sin_pitch * cos_yaw;
-	forward->z = cos_pitch * cos_yaw;
-
-	up->x = -cos_yaw * sin_roll;
-	up->y = -sin_pitch * sin_yaw * sin_roll + cos_pitch * cos_roll;
-	up->z = cos_pitch * sin_yaw * sin_roll + sin_pitch * cos_roll;
-
-	left->x = cos_yaw * cos_roll;
-	left->y = sin_pitch * sin_yaw * cos_roll + cos_pitch * sin_roll;
-	left->z = -cos_pitch * sin_yaw * cos_roll + sin_pitch * sin_roll;
-}
+void ray_euler_basis(ray_euler_t *e, ray_3f_t *forward, ray_3f_t *up, ray_3f_t *left);
 
 #endif