using System.IO;
using UnityEngine;

// Attach this to a camera and position it. You can use "Align With View" from the "Game Object" menu to help with this.
// Check the snap box to take a picture. It will log the path to the console.
// It works in Editor mode too, no need to play the scene.

[ExecuteInEditMode]
public class CameraSnap : MonoBehaviour {
    public int resolutionX = 2048;
    public int resolutionY = 2048;
    public float fieldOfView = 23.9f;
    public bool snap = false;
    
    private byte[] texToPNG(Texture tex) {
        if (tex == null) {
            Debug.Log("No texture");
            return null;
        }
        RenderTexture prev = RenderTexture.active;
        RenderTexture.active = RenderTexture.GetTemporary(tex.width, tex.height, 0, RenderTextureFormat.ARGB32, RenderTextureReadWrite.sRGB);
        Graphics.Blit(tex, RenderTexture.active);
        Texture2D readTex = new Texture2D(tex.width, tex.height, TextureFormat.RGBA32, false);
        readTex.ReadPixels(new Rect(0, 0, tex.width, tex.height), 0, 0);
        readTex.Apply();
        RenderTexture.ReleaseTemporary(RenderTexture.active);
        RenderTexture.active = prev;
        return readTex.EncodeToPNG();
    }
    
    public void Capture() {
        Camera cam = GetComponent<Camera>();
        cam.fieldOfView = fieldOfView;
        cam.aspect = (float)resolutionX / (float)resolutionY;
        cam.stereoTargetEye = StereoTargetEyeMask.None;
        cam.clearFlags = CameraClearFlags.SolidColor;
        cam.backgroundColor = new Color(0f, 0f, 0f, 0f);
        cam.useOcclusionCulling = false;
        cam.allowHDR = true;
        cam.allowMSAA = true;
        RenderTexture active = RenderTexture.active;
        cam.targetTexture = RenderTexture.GetTemporary(resolutionX, resolutionY, 24, RenderTextureFormat.ARGB32, RenderTextureReadWrite.sRGB);
        RenderTexture.active = cam.targetTexture;
        cam.Render();
        string filename =  Application.persistentDataPath + "/Photo-" + System.DateTime.Now.ToString("yyyyMMddHHmmss") + ".png";
        byte[] png = texToPNG(cam.targetTexture);
        if (png != null) {
            File.WriteAllBytes(filename, png);
            Debug.Log(filename);
        }
        RenderTexture.active = active;
        active = cam.targetTexture;
        cam.targetTexture = null;
        RenderTexture.ReleaseTemporary(active);
    }

    public void Update() {
        if (snap) {
            snap = false;
            Capture();
        }
    }
}