make sure that our up vector really is up in an axis before picking a world plane (#5459)

Author: JeffM2501

src/rcamera.h

@@ -255,8 +255,8 @@ void CameraMoveForward(Camera *camera, float distance, bool moveInWorldPlane)
     if (moveInWorldPlane)
     {
         // Project vector onto world plane (the plane defined by the up vector)
-        if (fabsf(camera->up.z) > 0) forward.z = 0;
-        else if (fabsf(camera->up.x) > 0) forward.x = 0;
+        if (fabsf(camera->up.z) > 0.7071f) forward.z = 0;
+        else if (fabsf(camera->up.x) > 0.7071f) forward.x = 0;
         else forward.y = 0;
 
         forward = Vector3Normalize(forward);
@@ -291,8 +291,8 @@ void CameraMoveRight(Camera *camera, float distance, bool moveInWorldPlane)
     if (moveInWorldPlane)
     {
         // Project vector onto world plane (the plane defined by the up vector)
-        if (fabsf(camera->up.z) > 0) right.z = 0;
-        else if (fabsf(camera->up.x) > 0) right.x = 0;
+        if (fabsf(camera->up.z) > 0.7071f) right.z = 0;
+        else if (fabsf(camera->up.x) > 0.7071f) right.x = 0;
         else right.y = 0;
 
         right = Vector3Normalize(right);