Tracking issue: new scaling system

[thebracket]

Making the next feature branch a scaling system. I'm hoping that this will resolve quite a few issues that have been reported, while not breaking the API (I'm not asking much, eh?). Since there's a lot of moving parts related to the two scaling systems (simply scaling consoles and growing/shrinking the terminal size dynamically), this deserves its own branch while the kinks are worked out.

Goals:

• Support gutters around the render area. This alleviates the window rounding seen with Big Sur (and in danger of hitting Win11 by the looks of it), and supports other scaling enhancements.
• Accurate font size in texture coordinates when blitting, to avoid the missing-pixel issues that have caused so many problems.
• Probably optional, but "perfect" scaling: add to the gutter until the size is a multiple of the font size, and then scale the font by a consistent amount (or expand/shrink the console by a fixed amount).

Developing will take place in the https://github.com/amethyst/bracket-lib/tree/scaling branch.

This directly affects the following issues:
#226 #220 #213 #178 #171

[thebracket]

The first commit to this branch sets up a new FontScaler type, which takes over the duties of calculating font sizes for all console types. It's actually pretty simple, but instead of each console doing the math - its now in one place. Using accurate math has fixed the issue with the bottom row of pixels not always rendering:

This has been applied to all OpenGL and WGPU supported consoles and is working well. It's actually slightly faster, too.

You'll also notice that the second commit is being used to add a gutter. This only applies to simple consoles at the moment, and only in OpenGL mode. So the adventurer isn't quite centered properly, because the secondary console doesn't have gutters yet. I also haven't applied it to other renderers or the input chain yet. Not a bad proof-of-concept, and performance is good.

[thebracket]

Hopefully the gif will work. The last patch:

• Sets the minimum window size to the natural size. This makes it easy to go back to the "normal" size and avoids scaling confusion.
• Divides the desired window size by the largest font size, and adds the remainder to an extra gutter. This keeps fonts scaling at natural levels on the x/y axes (no attempt at aspect ratio yet). This makes the result look better as you upscale it.

[thebracket]

Signing off for the day on this, but there's some solid progress. The bottom row not rendering issue appears to be fixed. Scaling windows works, and tries to pick reasonable sizes based on fonts to keep things looking decent. Added in an optimization (that probably doesn't really belong in this issue) to not update vertex/index buffers if a console hasn't changed between frames. On turn-based roguelikes, that's usually the case - so it saves quite a bit of cpu/gpu traffic. It remains to be seen if its worth the effort for real-time games.

This appears to work with consoles that change their character buffer size rather than scaling - but work remains to be done. There are also issues to resolve with WASM builds.

[thebracket]

OpenGL now has pretty nice aspect-ratio constrained scaling.

I've got some really odd behavior happening in WGPU. When you resize the window, holes appear in it - and moving the window instantly fixes it. Spying on the buffer in renderdoc shows that the buffer looks great - so it must be a problem with how the surface is reconfigured on move. Once I figure this out, I'll push the commit with this change.

[thebracket]

Haha. I guess it had to happen eventually... it works great on my Mac in wgpu, and on Linux. DX12 on Windows has the issue!

[thebracket]

More research indicates that its the driver! https://github.com/gfx-rs/wgpu/wiki/Known-Driver-Issues#intel--directx-12

[thebracket]

Now working on compatibility testing with the Hands-on Rust code-base.

• Flappy Dragon (bonus edition) works in both OpenGL and WGPU.
• dungeon_crawl_player works in both OpenGL and WGPU.
• dungeon_crawl_graphics works in OpenGL. Player rendering layer is broken in WGPU.

So I'll work on fixing that.

[thebracket]

More compatibility:

• dungeon_crawl_graphics now works with both GL and WebGPU.
• loot_tables and the final examples work with both GL and WebGPU.

So Hands-on Rust code now works with the latest builds. (I have to test that one first, since a large chunk of my livelihood comes from my book writing!)

Moving on to the Roguelike Tutorial. The most recent chapter compiles and runs great. Thanks to the new scheduling system, it consumes only 1% of CPU while running (Windows), spiking higher when you take a turn.

So I think this branch is good. :-)

[thebracket]

Woot - the new scaling system and associated enhancements are merged.

[thebracket]

Now that its merged, closing the tracking issue.