Jump to content

  • Log In with Google      Sign In   
  • Create Account

Ed Welch

Member Since 08 Jun 2009
Offline Last Active Nov 05 2014 01:52 PM

Topics I've Started

Panning camera so object is at edge of screen

16 September 2014 - 07:59 AM

I'm trying to write a formula to pan the camera enough so that an object is just visible at the edge of the screen.
So, in other words if the object is out of view to the right, I would change the x and y position of the camera, so that the object is just at the right edge of the screen (without changing camera angle or z co-ordinate).

Any tips how to do this would be greatly appreciated.



is glEnableVertexAttribArray redundant?

22 April 2014 - 05:48 PM

I can't seem to understand the purpose glEnableVertexAttribArray. I know it enables glVertexAttribPointer, but I can't see any case where you would want to call glVertexAttribPointer with the attribute disabled. If you don't want to send the attribute, then you would just not call glVertexAttribPointer at all.


13 March 2014 - 09:12 AM


For some reason I cannot find the official documentation of shadow2DProj function. In particular I want to know what the bias parameter does. Also, are there any differences to shadow2DProjExt (the opengl es extension)?

One reason why PowerVR is better than Tegra K1

25 February 2014 - 10:29 AM

I noticed something interesting in an article about the PowerVR architecture. The PowerVR 6 series has twice as many 16-bit float units than 32-bit float units, while the K1 has only 32-bit units. Now, if you write shaders for PowerVR you will notice that using lowp variables in your shaders makes it go a lot faster. The reason is, of coarse, because lowp (and mediump) use 16-bit floats. But speed isn't the only thing - the 16-bit float units also use less power. So, this power saving ability is simply not available at all on the Tegra K1.

How do you benchmark your game?

23 March 2013 - 10:37 AM

Do you think it's a good idea to use more metrics than just average frame rate when testing render performance? I mean 95th percentile, minimium frame rate, etc.