using UnityEngine;

// Sets up transformation matrices to scale&scroll water waves
// for the case where graphics card does not support vertex programs.
//
// Also disables reflection and/or refraction cameras if the shader
// falls back to non reflective/refractive one.

public class WaterWaveScroll : MonoBehaviour
{
    private string oldWaterMode = "";

    void Update()
    {
        if (!renderer)
            return;
        Material mat = renderer.material;
        if (!mat)
            return;

        Vector4 waveSpeed = mat.GetVector("WaveSpeed");
        float waveScale = mat.GetFloat("_WaveScale");
        float t = Time.time / 40.0f;

        Vector3 offset = new Vector3(t * waveSpeed.x, t * waveSpeed.y, 0);
        Vector3 scale = new Vector3(1.0f / waveScale, 1.0f / waveScale, 1);
        Matrix4x4 scrollMatrix = Matrix4x4.TRS(offset, Quaternion.identity, scale);
        mat.SetMatrix("_WaveMatrix", scrollMatrix);

        offset = new Vector3(t * waveSpeed.z, t * waveSpeed.w, 0);
        scrollMatrix = Matrix4x4.TRS(offset, Quaternion.identity, scale * 0.45f);
        mat.SetMatrix("_WaveMatrix2", scrollMatrix);

        // Get reflection mode from shader's tag
        string waterMode = mat.GetTag("WATERMODE", false);
        if (waterMode != oldWaterMode)
        {
            // If reflection mode changed, enable/disable
            // additional water cameras.
            Component[] reflCameras = GetComponentsInChildren(typeof(Camera));
            foreach (Camera cam in reflCameras)
            {
                cam.SendMessage("ExternalSetMode", waterMode, SendMessageOptions.DontRequireReceiver);
            }

            oldWaterMode = waterMode;
        }
    }
}