1 files changed, 45 insertions, 0 deletions
diff --git a/modules/ray/ray_euler.h b/modules/ray/ray_euler.h
new file mode 100644
index 0000000..86f5221
--- /dev/null
+++ b/modules/ray/ray_euler.h
@@ -0,0 +1,45 @@
+#ifndef _RAY_EULER_H
+#define _RAY_EULER_H
+
+#include <math.h>
+
+#include "ray_3f.h"
+
+
+/* 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_t;
+
+
+/* convenience macro for converting degrees to radians */
+#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;
+}
+
+#endif