twn_vec.h: add vec2_length(), remove legacy code

include/twn_vec.h

@@ -29,6 +29,10 @@ static inline Vec2 vec2_scale(Vec2 a, float s) {
     return (Vec2) { a.x * s, a.y * s };
 }
 
+static inline float vec2_length(Vec2 a) {
+    return sqrtf(a.x * a.x + a.y * a.y);
+}
+
 static inline Vec3 vec3_add(Vec3 a, Vec3 b) {
     return (Vec3) { a.x + b.x, a.y + b.y, a.z + b.z };
 }
@@ -98,10 +102,8 @@ static inline Vec3 vec3_rotate(Vec3 v, float angle, Vec3 axis) {
     return v;
 }
 
-#define m_vec2_from(p_any_vec2) (_Generic((p_any_vec2),       \
-                                    Vec2i:  vec2_from_vec2i,  \
-                                )(p_any_vec2))
 
+/* TODO: remove. */
 #define m_vec_add(p_any_vec0, p_any_vec1) (_Generic((p_any_vec0),   \
                                     Vec2:   vec2_add,               \
                                     Vec3:   vec3_add                \

src/rendering/twn_draw.c

@@ -414,6 +414,9 @@ void render(void) {
 
 
 void draw_camera(Vec3 position, float fov, Vec3 up, Vec3 direction) {
+    if (fabsf(0.0f - fov) < 0.00001f || fov > (M_PIf / 2))
+        log_warn("Invalid fov given (%f)", (double)fov);
+
     Camera const camera = {
         .fov = fov,
         .pos = position,
@@ -428,6 +431,9 @@ void draw_camera(Vec3 position, float fov, Vec3 up, Vec3 direction) {
 
 /* TODO: https://stackoverflow.com/questions/62493770/how-to-add-roll-in-camera-class */
 DrawCameraFromPrincipalAxesResult draw_camera_from_principal_axes(Vec3 position, float fov, float roll, float pitch, float yaw) {
+    if (fabsf(0.0f - fov) < 0.00001f || fov > (M_PIf / 2))
+        log_warn("Invalid fov given (%f)", (double)fov);
+
     (void)roll;
 
     float yawc, yaws, pitchc, pitchs;