[SOLVED] Graphic Glitch

Graphics
1

A player of my game got a weird graphic glitch:

http://i.imgur.com/vl0vPIo.png

This is his bug description:

“One glitch causes the audio to cut out. And the fullscreen and windowed versions both have their own unique visual glitches. Windowed cuts off the bottom of the screen while fullscreen.
Whenever something moves between the bottom screen and top screen, it
creates weird imprints, which you can see to the far right and the left.
It’s really odd. And it happens ALWAYS. Not just sometimes.”

And the drone(ship) we saw under the first one is not a duplicate/repetition. It’s the rest of the spritesheet

The game looks like this usually :

http://visumeca.com/wp-content/uploads/2015/12/scr05.png

Anyone have this problem? Any advices to solve this?
I use the latest version of Monogame.

2

What screen resolution did the player use? That small image doesn’t scale up correctly to any common resolution.
What screen resolution did you use? Is it the image size of 1366x768?

3

The “imprints” they refer to look like what happens when you move a texture over an area that does not get cleared at the beginning of the Draw().

4

Right now i don’t have the screen resolution the player used.

The default resolution of the game is 1366x768. So the game is stretched according to player resolution.

5

A friend suggested to clear backbuffer and rendertarget before to draw.

6

Clearing the backbuffer is usually not necessary if you can guarantee you’re going to redraw the entire viewport, but that appears to be the issue here.

Do you draw some of that UI aligned to anything other than the top left of the viewport? For example, taking a negative offset from the bottom of the viewport?

7

So, i added
GraphicsDevice.Clear(Color.Black);
before
spriteBatch.Begin();

I think it is possible taht some of the UI is aligned to the bottom. I guess I should position everything according to corner top left?

8

Well, the problem came from the fact i was handling only 16:9 screen ratios by using a unique uniform scale factor instead of a scale factor for the width and another for the height.
So when a player with a 1440x900 px resolution was launching the game, things were messed up.

9

Good to see you found the issue.