All right then, thanks. Please indulge me further...
Is the r2t/glCopyTexImage2D approach suitable for say erasing parts of an image? I actually need this for the opposite reason of most other people - instead of needing to draw stuff onto an image and have that on the image forever I need to start off with an image and remove sections of it randomly.
This image is then used for pixel perfect collision detection...
Additionally I presume if I were to take a r2t approach (if it is even suitable) I would need to chop it up into square sized textures for this to work (as the image can be many thousands of pixels wide or high)?
If you want to have r2t then use the glCopyTexImage2D approach (faster than Grabimage) or the FBO approach (very driver and gfx card dependent)
Is the r2t/glCopyTexImage2D approach suitable for say erasing parts of an image? I actually need this for the opposite reason of most other people - instead of needing to draw stuff onto an image and have that on the image forever I need to start off with an image and remove sections of it randomly.
This image is then used for pixel perfect collision detection...
Additionally I presume if I were to take a r2t approach (if it is even suitable) I would need to chop it up into square sized textures for this to work (as the image can be many thousands of pixels wide or high)?