Camera

Functions

get_active_camera

Get the currently active camera entity.

EntityHandle get_active_camera(ScriptContext* ctx);

Returns the active camera handle, or NULL_ENTITY_HANDLE if none is set.

set_active_camera

Switch the rendering to a different camera entity.

bool set_active_camera(ScriptContext* ctx, EntityHandle camera);

Parameter	Type	Description
camera	EntityHandle	Entity with CameraComponent

Returns true if the entity exists and has a CameraComponent.

get_camera_fov

Get the camera's field of view in degrees.

bool get_camera_fov(ScriptContext* ctx, EntityHandle entity, float* out_fov);

Parameter	Type	Description
entity	EntityHandle	Camera entity
out_fov	float*	Output FOV in degrees (caller-allocated)

set_camera_fov

Set the camera's field of view (clamped to 1-179 degrees).

bool set_camera_fov(ScriptContext* ctx, EntityHandle entity, float fov);

Parameter	Type	Description
entity	EntityHandle	Camera entity
fov	float	FOV in degrees

---

Example: Camera Switcher

static EntityHandle cam_fps;
static EntityHandle cam_third;
static bool first_person = true;

void OnStart(ScriptContext* ctx) {
    cam_fps = ctx->find_entity_by_name(ctx, "FPSCamera");
    cam_third = ctx->find_entity_by_name(ctx, "ThirdPersonCamera");
    ctx->set_active_camera(ctx, cam_fps);
}

void OnUpdate(ScriptContext* ctx) {
    // Toggle camera with Tab
    if (ctx->is_key_pressed(ctx, 258)) {
        first_person = !first_person;
        ctx->set_active_camera(ctx,
            first_person ? cam_fps : cam_third);
    }
}

Example: Zoom with FOV

static float base_fov = 60.0f;
static float zoom_fov = 20.0f;

void OnUpdate(ScriptContext* ctx) {
    EntityHandle cam = ctx->get_active_camera(ctx);

    // Hold right-click to zoom
    float fov = ctx->is_mouse_button_down(ctx, 1) ? zoom_fov : base_fov;
    ctx->set_camera_fov(ctx, cam, fov);
}

---

Camera Effect Helpers

Razorbill includes pure math utility functions in math_utils.hpp for common camera effects. These can be used in scripts by including the header:

#include <eng/sdk/math_utils.hpp>

smooth_damp

Smoothly interpolates a value toward a target, with velocity tracking for natural deceleration:

float smooth_damp(float current, float target, float& velocity,
                  float smooth_time, float dt);

Use for smooth camera follow, gradual FOV transitions, or any value that should ease toward a target.

look_at_rotation

Compute a quaternion rotation that points from one position toward another:

void look_at_rotation(const float from[3], const float to[3],
                      float out_quat[4]);

quat_slerp

Spherical linear interpolation between two quaternion rotations:

void quat_slerp(const float a[4], const float b[4],
                float t, float out[4]);

camera_shake

Generate Perlin noise-based camera shake offsets:

void camera_shake(float intensity, float frequency, float time,
                  float out_offset[3]);

Example: Smooth Follow Camera

static EntityHandle target;
static float smooth_vel_x = 0, smooth_vel_y = 0, smooth_vel_z = 0;

void OnStart(ScriptContext* ctx) {
    target = ctx->find_entity_by_name(ctx, "Player");
}

void OnUpdate(ScriptContext* ctx) {
    float dt = ctx->get_delta_time();
    float target_pos[3], cam_pos[3];
    ctx->get_position(target, target_pos);
    ctx->get_position(ctx->self, cam_pos);

    // Follow with offset, smoothed
    float goal_x = target_pos[0];
    float goal_y = target_pos[1] + 5.0f;
    float goal_z = target_pos[2] + 8.0f;

    cam_pos[0] = smooth_damp(cam_pos[0], goal_x, smooth_vel_x, 0.3f, dt);
    cam_pos[1] = smooth_damp(cam_pos[1], goal_y, smooth_vel_y, 0.3f, dt);
    cam_pos[2] = smooth_damp(cam_pos[2], goal_z, smooth_vel_z, 0.3f, dt);

    ctx->set_position(ctx->self, cam_pos);

    // Look at target
    float look_rot[4];
    look_at_rotation(cam_pos, target_pos, look_rot);
    ctx->set_rotation(ctx->self, look_rot);
}