I resolved my problem! I wanted to verify the texture coordinate using a shader. I found that the texture coordinate looked ok in the color output of the fragment shaders. and I decided to use a...

I forgot to say that the pixel is being rendered on the entire quad(The entire screen). It's like OpenGL is setting the same texture coordinate for all the vertices.

Even if I create and apply my own texture on the quad it shows only one pixel of the texture. If I test the same code on my own executable it works perfectly.

For my project I need to create a plugin for Unity3D to render into an another window the exact same thing than the in-game rendering of the editor.

I use the same OpenGL context than unity,...