Working with Programmable Pipeline on Previous Fixed Pipeline Code

Hi everyone,
I’m working on an old data visualization code written on fixed pipeline (on OpenGL 1.1, using glBegin/glEnd blocks and Vertex2D, etc.). I need to update the graphical visualization methods to work with Shaders (and thus programmable pipeline). The problem is, as soon as I call glUseProgram() after creating the Shaders, everything becomes new! all background information are deleted (while on the same context) and an empty screen is presented with only Shader-drawn data. Is there anyway I can print my graph (drawn by vertex Shader) on the current screen (drawn by fixed pipeline and including axis, label and other info?)?

After you bound your program, did you ever unbind it, by calling glUseProgram with 0?

I cannot unbind it because later in my render function, I’ll need to use that program. Do you mean that I should place my render code inside a glUseProgram(handle) / glUseProgram(0) block and previous screen data will not be modified? I haven’t tried this, let me take a test run with your suggestion. thanks :slight_smile:

*** EDIT ***
It works perfectly Alfonse! you just saved me from weeks of code mapping, thanks :slight_smile: