I have come across a need to make small incremental changes to a texture for piloting data in real time. What i want to do is draw a line on a existing texture without clearing the entire texture.
So far the only way i see of doing it is to draw the existing texture in to another texture, then draw that texture in to the original one and draw a line on top. The other way i see of doing it is to keep it as a image in CPU memory and do all the drawing on that while occasionally updating the image to GPU memory.
Is there a easier or more optimized way of doing that?