We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
In order to save some texture memory in a multi-step process, I am thinking of binding an FBO in order to update a small part of it with the scissor test enabled.
As I am not performing a glClear() in that case, what is the expected penalty for loading the data into on-chip memory ? Will the GPU restrict the data fetch to only those tiles intersecting the scissor box (it is very small compared to the overall texture, less than 5%) ?