[Ohrrpgce] SVN: teeemcee/7792 Fix Select slices updating child visibility when drawing instead of refr

[subversion at HamsterRepublic.com]

teeemcee
2016-03-12 20:05:27 -0800 (Sat, 12 Mar 2016)
1750
Fix Select slices updating child visibility when drawing instead of refreshing

This change affects when a script will see up-to-date visibility of select
child slices. You still need to do something to cause the slice to be refreshed.
This also affects "slice at pixel" and "find colliding slice" called with
visibleonly=true.

ChildRefresh is now called even on non-visible slices by DrawSlice, but it
takes an additional visibleonly argument to skip refreshing the size and
position in that case. This is both to avoid unneeded processing for hidden
slices and to exactly match the previous behaviour for non-select slices
(although I really hope noone is relying on the size of hidden slices not being
updated!)

Slices shouldn't modify themselves when drawn, aside from calling ChildRefresh,
so that we can draw slices more or less than expected without breaking anything
as long as they're refreshed somehow (e.g. RefreshSliceTreeScreenPos()).
For example, slice velocity is applied in AdvanceSlice, not DrawSlice.
In future this will allow things like frame skpping and drawing slices multiple
times on small wrapping maps.

Unfortunately other slice types don't entirely obey the pure-draw-function rule.
Both rect and sprite slices delay loading styles or sprites until the first
draw, which causes modifications.
Even worse, auto-advancing dissolving sprites advance when being drawn; which
is definitely the wrong place to do so.
Text slices toggle .insert_tog and recompute .line_count when drawn. The latter
doesn't directly affect drawing but is related to the bug that the height of
text slices isn't recomputed when their .line_count changes (e.g. because their
width changes), because that's only done when ChangeTextSlice is called.
---
U   wip/ohrhelp/sliceedit_browse_slicetype.txt
U   wip/slices.bas
U   wip/slices.bi