Unless your sprites are perfectly rectangular, you'll have to deal with alphachannel for them. As you know, Construct has two modes for rendering: point and linear sampling. First one suits well for retro styled games with sprites having (essentially) 1-bit alpha, and the second for pretty much all the rest, with sprites having a smoother alpha channel. (I mean that 1-bit alpha suits point sampling, and full 8-bit alpha goes well with linear sampling)
The problem is that neither is suited for zooming things up a lot. With point sampling you get huge pixels, and with linear sampling you get an ugly blurred mess. And if you, say, double your sprites' resolution to fight that, you'll spend a lot of VRAM, 4 times more than before.
There is a way to get smooth (without huge pixels showing up) but crisp (without messy blurriness) edges. It has some limitations, though, and that's the exact reason why it isn't used every time by everyone.
Here's the original article: http://www.valvesoftware.com/publicatio ... cation.pdf
Hey, if it's good enough for Valve and their Team Fortress 2, then it's good enough for us, right?
Anyway, if you're too lazy to read the article and figure the limitations out by yourself (and you should be!
), here they are:
The image should be monochrome (not necessarily black, just one flat color), and the result will be aliased.
The upside is that you don't need any shaders, it's basically a 0.0 effect. All it takes is a proper alphachannel, and two render state flags.
Good news: you can also get rid of the aliasing with a very simple shader.
Better yet, if your sprites are cartoony, that is, use a low number of distinct flat colors, you can still benefit from this technique.
You see, according to the four color theorem
, you can separate said sprites into four layers each, so that on every layer differently colored areas do not touch. Of course, drawing 4 sprites instead of just one means 4 times greater load on the GPU, but that's still much less of an performance impact than most shaders make.
Examples of usage will hopefully follow soon.