Slick Forums

hi, simple question and sorry if its a bit obvious but how do you set the line type to dashed or dotted for shapes?
specifically for circles, and they'll be fairly rapidly expanding and contracting so the solution needs to be flexible

thanks

You could achieve this with GL stippling.


More info and other pattern examples:
http://fly.cc.fer.hr/~unreal/theredbook/chapter02.html

Problems:

• It's deprecated OpenGL, which means it won't be very well supported by drivers in the future.
• Drivers will tend to implement it slightly differently; so don't expect your dotted lines to look identical on all systems.

thanks, shame there's not a 'cleaner' way but i had to get into OpenGL sometime

Speaking of which, besides performance how would you guys say direct oGL calls might improve a slick game, and are there any other resources (info) focusing only on the Slick-compatible/useful parts?

For a start: a wider range of blend modes, sorting sprites based on the depth buffer (i.e. hardware), masking with the stencil buffer, collision detection done on GPU, dynamic shadows/lighting, explosion effects, blurring/depth of field, normal mapping, etc. These are all possible using lower level OpenGL/GLSL alongside Slick.

Unfortunately, there aren't many resources yet. But Slick is not doing a whole lot that would interfere with low-level GL calls, so pretty much anything can be "compatible." You just need to take a few precautions before you start using GL.

• If you're using ScalableGame, you should account for the scaling factor at all times (vertices, matrix transforms, etc).
• Slick caches the last bound texture to avoid redundant glBindTexture/glEnable calls. If you change these states using low-level OpenGL, you should use TextureImpl.unbind() (which clears the last bound texture) or TextureImpl.bindNone() (which clears the last bound texture, and then glDisables texturing).
• Organize your code like so:
  
  Code:
  ... Slick code ... //don't use GL11/etc. calls here
  Renderer.get().flush(); //flush the renderer before using GL11 calls
  ... GL code, e.g. glBlendFunc ...
• When you change a state/attribute (like viewport), generally it would be a good idea to change it back before continuing Slick rendering. For example, if you're changing depth/alpha/blending, use glPushAttrib to revert the state.
• When in doubt, use SlickCallable to be extra safe (at the expense of performance; it requires a lot of state changes).