The grid calculations are modified from those of Inigo Quilez
(https://iquilezles.org/articles/filterableprocedurals/), but give very
nice results: when thin enough, the lines fade out nicely instead of
producing crazy moire patterns. Though currently disabled, the default
planes are the xy, yz and zx planes with colored axes.
The idea is the UI system can call into the renderer without knowing
anything about the renderer, and the renderer can do what it pleases to
create UI elements in the correct context (passes as a parameter).
Panels can be anchored to a widget in another hierarchy, allowing for
things like cascading menus. They can also be extended via referencing
them by name, allowing for subsystems to add items to an already panel
(eg, extending a menu).
SCR_UpdateScreen_Legacy now takes only the screen functions pointer (it
didn't need camera or realtime), and the camera sizzle code has been
moved into one place to make cleaning it up easier (when I get around to
auditing AngleVectors etc).
The intent is to use them for menus, tooltips and anything else along
those lines, but windows was a good starting point (and puts a border
along the top of the window too).
Canvas draw order is sorted by group then order within the group. As a
fallback, the canvas entity id is used to keep the sort stable, but
that's only as stable as the ids themselves (if the canvases are
destroyed and recreated, the ids may switch around).
This has use when the order of components in the pool affects draw order
(or has other significance), especially at the subpool level. I plan to
use it for fixing overlapping windows in imui.
Shaped text is cached using all the shaping parameters as well as the
text itself as a key. This makes text shaping a non-issue for imui when
the text is stable, taking my simple test from 120fps to 1000fps
(optimized build).
As I had long suspected, building large hierarchies is fiendishly
expensive (at least O(N^2)). However, this is because the hierarchies
are structured such that adding high-level nodes results in a lot of
copying due to the flattened (breadth-first) layout (which does make for
excellent breadth-first performance when working with a hierarchy).
Using tree mode allows adding new nodes to be O(1) (I guess O(N) for the
size of the sub-tree being added, but that's not supported yet) and
costs only an additional 8 bytes per node. Switching from flat mode to
tree mode is very cheap as only the additional tree-related indices need
to be fixed up (they're almost entirely ignored in flat mode). Switching
from tree to flat mode is a little more expensive as the entire tree
needs to be copied, but it seems to be an O(N) (size of the tree).
With this, building the style editor window went from about 25% to about
5% (and most of that is realloc!), with a 1.3% cost for switching from
tree mode to flat mode.
There's still a lot of work to do (supporting removal and tree inserts).
By default, horizontal and vertical layouts expand to fill their parent
in their on-axis direction (horizontally for horizontal layouts), but
fit to their child views in their off-axis.
Flexible space views take advantage of auto-expansion, pushing sibling
views such that the grandparent view is filled on the parent view's
on-axis, and the parent view is filled by the space in the parent view's
off-axis. Flexible views currently have a background fill, allowing them
to provide background filling of the overall view with minimal overdraw
(ancestor views don't need to have any fill at all).
The biggest change was splitting up the job resources into
per-render-pass resources, allowing individual render passes to
reallocate their resources without affecting any others. After that, it
was just getting translucency and capture working after a window resize.
This takes care of element order stability. It did need reworking the
mouse tracking code (including adding an active flag to views), but now
buttons seem to work correctly.
TextContent seems redundant at this stage since a text view is always
sized to its content, and PercentOfParent doesn't work yet. Pixels
definitely works and Null seems to work in that it does no sizing or
positioning. Vertical layout is supported but not yet tested, similar
for ChildrenSum, but I can have two buttons side by side.
It does almost nothing (just puts a non-function button on the screen),
but it will help develop the IMUI code and, of course, come to help with
debugging in general.
Both passage and simple text are supported, but only simple text has
been tested at this stage. However, as passage text was taken directly
from rua_gui.c and formed the basis for simple text rendering, I expect
it's at least close to working.
The same underlying mechanism is used for both simple text strings and
passages, but without the intervening hierarchy of paragraphs etc.
Results in only the one view for a simple text string.
