Why does webrender take nearly 100 MB of RAM when rendering text?

[fasihrana]

I've been working on a GUI framework with webrender as the rendering engine. I've noticed that the RAM consumption is about 100MB when I start rendering text. This happens on both Windows and Ubuntu. I understand that text rendering is quite complex and calculation intensive, but doesn't 100MB RAM seem a bit too much? Maybe I'm doing something?

You can find the code sample here: fasihrana/skryn.

With text rendering:

Without text rendering:

The difference between both these runs is that for the run without text rendering I've commented out the following line:
line 166: map.insert(c, (gi[i], gd));

[gw3583]

This is probably caused by the lazy allocation of the texture atlas.

WR will only start allocating memory for the texture cache once an image / glyph is placed in it for the first time. Unfortunately, the texture cache is currently a large, fixed size. The downside is that there is an immediate jump to a large memory usage - but on the plus side, there generally won't be any further allocations made, even as you add thousands more glyphs / images.

There is some ongoing work by @bholley to make the texture cache start out much smaller, and grow as required, which should fix this.

[fasihrana]

Thanks for that explanation.

[gw3583]

The texture cache now starts very small and grows as required, so I think this will be resolved.