added transforms

src/transform.h

@@ -0,0 +1,43 @@
+#ifndef _fencer_transform_h
+#define _fencer_transform_h
+
+#include "vmath.h"
+
+typedef struct Transform Transform;
+struct Transform {
+    Vector position;
+    Vector scale;
+    float rotation;
+};
+
+#define IdentityTransform (Transform){ZeroVector, OneVector, 0.0f}
+
+static inline
+Transform transform_apply(Transform a, Transform b) {
+    return (Transform) {
+        .position = vaddf(a.position, b.position),
+        .scale = vmulf(a.scale, b.scale),
+        .rotation = a.rotation + b.rotation
+    };
+}
+
+static inline
+Transform transform_invert(Transform a) {
+    return (Transform) {
+        .position = vinvf(a.position),
+        .scale = vreciprocalf(a.scale),
+        .rotation = -a.rotation
+    };
+}
+
+static inline
+Vector transform_direction(Transform* self, Vector direction) {
+    return vmulf(vrotatef(direction, self->rotation), self->scale);
+}
+
+static inline
+Vector transform_point(Transform* self, Vector position) {
+    return vaddf(transform_direction(self, position), self->position);
+}
+
+#endif // !_fencer_transform_h