Texture real time modification

How is it possible to draw in an active texture (modify pixels, make it transparent, draw a bitmap line…) : glTexSubImage2D, FBO Frame Buffer Object…?? Is it possible to modify the bitmap data directly within the GPU and which operations are necessary to actualize the texture if necessary ? Thanks

You can directly render to a texture by using framebuffer objects (ARB_framebuffer_object). That’s the most efficient way.

However, if your source data comes from application data you might want to take a look at pixel unpack buffer (ARB_pixel_buffer_object) which allows you to upload your data into a buffer object (GPU memory) and then upload from there asynchronously using glTexSubImage2D.

Thanks a lot, I’ll try it!