[Qt5-feedback] OpenGL ES 2.0 requirement

[gunnar.sletta at nokia.com]

>> 
>> A good software implementation of GL should not be any worse than our raster paint engine. Neither for battery nor for performance.
>> 
>> There are however fewer and fewer chips that ship without any GL capabilities, so over time (we are talking a year or two before this is mainstream technology after all), we expect GL to be common in most netbooks
> 
> OK, now I think I understand things better and I'm more OK with this.
> Indeed having a software renderer would solve the problem, at least in
> theory. This would need to be shipped with Qt though and be the same
> across platforms. Of course some implementation might be different.
> I'm not really sure about the speed it would achieve but that remains
> to be seen.  

It does indeed remain to be seen, as mesa today does not outperform our raster paint engine. That being said, in the end it boils down to filling triangles (running fragment shaders) and there is little reason why that should be any slower using a software implementation of GL compared to a software implementation of QPainter (which is what is currently used). All they do is fill pixels.