About to pull out my hair

[linuxgurugamer]

I'm having a very strange problem with Texture2D.  I'm trying to save the image of a window to a file.  First, here is the code:

Spoiler

        void OnGUI()
        {
            graphWindow.OnGUI();
            if (graphWindow.saveScreen)
            {
                graphWindow.saveScreen = false;
                StartCoroutine(ScreenshotEncode());
            }
        }

        IEnumerator ScreenshotEncode()
        {
            // wait for graphics to render
            yield return new WaitForEndOfFrame();

            // create a texture to pass to encoding
            // First texture will capture the entire screen
            // Second texture is the destination for the final image
            // GraphWindow.wnd_rect is the Rect of the window which is being captured (obtained from GUILayout.Window)
            Texture2D texture = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, false);
            Texture2D destTexture = new Texture2D((int)GraphWindow.wnd_rect.width, (int)GraphWindow.wnd_rect.height, TextureFormat.RGB24, false);

            // put buffer into texture
#if false
            // This would read the pixels of the desired Rect and put directly into destTexture
            destTexture.ReadPixels(GraphWindow.wnd_rect, 0, 0);
#else
            // Read the entire screen
            texture.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);

            // Now copy the texture of the wnd_rect to the destTexture
            int x = (int)GraphWindow.wnd_rect.x;
            int y = (int)GraphWindow.wnd_rect.y;
            Graphics.CopyTexture(texture, 0, 0, x,y, (int)GraphWindow.wnd_rect.width, (int)GraphWindow.wnd_rect.height,
                destTexture, 0, 0, 0, 0);
#endif

            byte[] bytes = destTexture.EncodeToPNG();
            string filePath = KSPUtil.ApplicationRootPath + "Screenshots/";
            Log.Info("filePath: " + filePath);
            FileInfo file = new System.IO.FileInfo(filePath);

            const string fname = "ResonantOrbit";
            int i = 0;
            while (File.Exists(filePath + fname + i.ToString() + ".png"))
                i++;
            File.WriteAllBytes(filePath + fname + i.ToString() + ".png", bytes);

            bytes = texture.EncodeToPNG();
            File.WriteAllBytes(filePath + fname+ "Screenshot" + i.ToString() + ".png", bytes);

            DestroyObject(texture);
            Destroy(destTexture);
            Log.Info("Exiting coroutine");
        }

 

This is a case of a picture is worth a thousand words.  I've tried many different variations, all with the same results.  The really wierd thing is that if I set y to a constant (ie: 200), then it will always copy from the vertical height of 200.

First test:

and this is the screenshot saved at the same time:

 

Second test, I moved the window a bit:

and the screenshot:

 

[xEvilReeperx]

You've nearly got it. Your issue is that your window rect is in screen space (0,0 = top left) while ReadPixels (and CopyTexture) expects pixel space (0,0 = bottom left)

Convert to pixel space by inverting the y coordinate (Screen.height - y) and subtracting out the window height to get the bottom-left corner of the window

[KSPAddon(KSPAddon.Startup.MainMenu, false)]
class CaptureWindowScreenshot : MonoBehaviour
{
    private Rect _windowRect = new Rect(Screen.width * 0.5f, Screen.height * 0.5f - 200, 200f, 50f);
    private readonly GUILayoutOption[] _defaultOptions = new GUILayoutOption[0];
    private GUI.WindowFunction _windowFunc;
    private bool _capture = false;

    private void Awake()
    {
        _windowFunc = DrawWindow;
    }

    private void OnGUI()
    {
        _windowRect = KSPUtil.ClampRectToScreen(GUILayout.Window(GetInstanceID(), _windowRect, _windowFunc, "Test Window", _defaultOptions));

        if (_capture && Event.current.type == EventType.Repaint)
        {
            _capture = false;
            StartCoroutine(Capture());
        }
    }

    private IEnumerator Capture()
    {
        yield return new WaitForEndOfFrame();

        var pixelRect = _windowRect; // copy values

        pixelRect.y = Mathf.Max(Screen.height - _windowRect.y - _windowRect.height, 0f);

        var captureTex = new Texture2D(Mathf.CeilToInt(pixelRect.width), Mathf.CeilToInt(pixelRect.height));

        captureTex.ReadPixels(pixelRect, 0, 0, false);

        captureTex.SaveToDisk("window.png"); // your preferred method here

        Destroy(captureTex);
    }

    private void DrawWindow(int winid)
    {
        for (int i = 0; i < 5; ++i)
            GUILayout.Label("Text goes here", _defaultOptions);

        GUILayout.Space(5f);

        if (GUILayout.Button("Capture this window", _defaultOptions))
            _capture = true;

        GUI.DragWindow();
    }
}

 

Edited August 24, 2018 by xEvilReeperx
added example code

[linuxgurugamer]

Thank you @xEvilReeperx

[linuxgurugamer]

@xEvilReeperx would you have any idea how to get (on the fly) an image of a planet?  What I'd like to do would be to use an image of the planet itself in the chart, rather than a solid circle.

Thanks in advance

[Thomas P.]

Feel free to take a look at the KittopiaTech code, I have a basic planet thumbnail generator there. I cannot guarantee proper lighting, it seems to work fine just after the main menu scene was loaded, so KittopiaTech generates them there and caches them.

https://github.com/Kopernicus/KittopiaTech/blob/master/src/UI/PlanetSelector.cs#L131-L168

https://github.com/Kopernicus/KittopiaTech/blob/master/src/RuntimePreviewGenerator.cs

Solid bodies and gas planets work fine, Stars are very... white

[linuxgurugamer]

I'll try it, but a problem is that it's looking for "ScaledSpaceOnDemand", which I'm guessing is from Kopernicus???

Seems to work, except all the planets are extremely dark, as if there was no lighting.

I copied your code exactly, and am saving it to a file in my tests.

The only change was disabling that code for the ScaledSpaceOnDemand.

Any ideas?

[linuxgurugamer]

Oh, I think I see.  I was testing in the editor, and there are no light sources.  I'll have to try it in flight

[linuxgurugamer]

Ok, in flight scene, I did get better images.

So what I'm going to do is to generate and save the images to files, so that I don't keep them around the whole time