So I just finished the functionality for a scene for my upcoming game, and I'm about to optimize it for mobile and memory use. It's a scene where the main character's flying through some ethereal portal thingy, where I've faked 3-dimensional depth to the best of my abilities. No video, all in-engine.
Youtube's compression isn't kind to the footage, so I recommend checking it at max quality.
I achieved the effect with lots of instances of the same 128x128 texture uncropped. As C2 doesn't have the draw canvas feature, the tunnel's composed of about 100+ instances of the same sprite on screen at once. I have painful experience with overdraw, and want to reduce it as much as possible.
I know I can crop it, but in return I need to introduce a lot more math per sprite to ensure it renders with the correct proportions due to inconsistent frame size.
My big questions are:
-Is an empty alpha equally expensive to draw as an alpha with lets say 50 % opacity?
-If the alpha is empty, do I save much performance beyond just memory by cropping 30 % of the 128x128 texture?