title: Drawing points in top of texture openGL
body: <p>I have a texture drawn in a GLcontrol and I want to draw points on top of it. Instead, I get the full texture set to the colour of the point I want to draw. I guess that I have to disable the texture format and enable the points drawings, but cant reach the solution...</p>
  
  <p>Here is the draw function:
  Basically the point to draw is ROI[0], but instead drawing just the point I got the image shown below (the image is grayscale before drawing "the point").</p>
  
  <pre><code>private: void drawImg(int img){
  
           int w=this-&gt;glControl_create_grid-&gt;Width;
           int h=this-&gt;glControl_create_grid-&gt;Height;
           GL::MatrixMode(MatrixMode::Projection);
  
           GL::LoadIdentity();
           GL::Ortho(0, w, 0, h, -1, 1); // Bottom-left corner pixel has coordinate (0, 0)
           GL::Viewport(0, 0, w, h); // Use all of the glControl painting area
  
           GL::Clear(ClearBufferMask::ColorBufferBit | ClearBufferMask::DepthBufferBit);
           GL::ClearColor(Color::LightGray);
           GL::MatrixMode(MatrixMode::Modelview);
           GL::LoadIdentity();
  
           GL::Enable(EnableCap::Texture2D);
           GL::BindTexture(TextureTarget::Texture2D, img);
           OpenTK::Graphics::OpenGL::ErrorCode error=GL::GetError();
               GL::Begin(BeginMode::Quads);
                  GL::TexCoord2(0, 0);
                  GL::Vertex2(0 ,h);
  
                  GL::TexCoord2(1, 0);
                  GL::Vertex2(w, h);
  
                  GL::TexCoord2(1, 1);
                  GL::Vertex2(w, 0);
  
                  GL::TexCoord2(0, 1);
                  GL::Vertex2(0, 0);
              GL::End();
              GL::Disable(EnableCap::Texture2D);
              if (ROI[0].x!=0||ROI[0].y!=0){
                  GL::Color3(Color::Red);
                  GL::Begin(BeginMode::Points);
                  GL::Vertex2(ROI[0].x,ROI[0].y);
                  GL::End();
              }
  
  
      }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/aSwtt.png" alt="enter image description here"></p>
  
  <p>What should I change in my code? I can't seem to achieve it....</p>