Whats holding ~100% D GUI back?

[Gregor Mückl]

On Friday, 29 November 2019 at 06:02:40 UTC, Ola Fosheim Grostad 
wrote:
> On Friday, 29 November 2019 at 05:16:08 UTC, Jab wrote:
>> IIRC GPUs are limited in what they can do in parallel, so if 
>> you only need to do 1 things for a specific job the rest of 
>> the GPU isn't really being fully utilized.
>
> GPUs have used a VLIW design, but are moving to RISC as a 
> result of the GPGPU trend. So, becoming more like simple CPUs. 
> But what you get and what you get to access will vary based on 
> API and hardware. (AI and raytracing will likely cause more 
> changes in the future too.)
>

GPUs are vector processors, typically 16 wide SIMD. The shaders 
and compute kernels for then are written from a single-"threaded" 
perspective, but this is converted to SIMD qith one "thread" 
really being a single value in the 16 wide register. This has all 
kinds of implications for things like branching and memory 
accesses. Thus forum is not rhe place to go into them.

> So you need a CPU software renderer to fall back on, GPU 
> rendering is more of an optimization in addition to CPU 
> rendering. But more and more is moving to the GPU.
>
> Look at the roadmap for Skia to get an idea.

Yes, proper drawing of common 2d graphics primitives is hard.