Following the suggestions of Hamish Todd, group 0 forms the planar
quaternions (with the "complex number" in the first two components) and
transflections in group 1.
e0 is created only if there are null vectors in the algebra, and the 3d
and 2d basis groups have been rearranged to compensate in the changed
ordering in the basis blade array.
I was aware in the beginning that the signs were probably incorrect, but
I had left them as I wasn't sure how they worked. Thanks to enki
(bivector community), I was pointed in the right direction for getting
the calculations right: the product of a basis blade with its dual
(x !x) must product the positive pseudo-scalar.
I guess I had forgotten that new_mv() does *NOT* initialize the
components. Things just happened to work (usually) because memory was
not getting recycled.
According to enki (bivector community) when there are more than one null
vector in a geometry, usually all vectors are null, and it was what to
do with multiple null vectors that caused me to balk at using e0 for the
null vector. However, using e0 for the null vector makes life much
easier, especially as that's what most of the literature does. There
are plenty of places, particularly in layout handling, that still need
adjustment for the change, but things seem to work (minus duals, but
they were broken in the first place, thus the discussion with enki).
Lexing . as a single character makes it impossible to enter fractions.
Unfortunately, this means that . as dot product requires white space on
either side.
Currently only PGA(3) is supported, but that's because the parser is
rather simple (recursive descent with a lame lexer), but it works well
enough for playing with geometric algebra without having to recompile
every time.
Wrap the strtod, strtof, strtol, strtoul functions, supporting the end
pointer as well (if not nil, the int offset of the end pointer relative
to the string start is returned).
Also, str_unmutable creates a return string from a mutable string
(copying it).
Meaning some leaks have been plugged, and some useful functions added:
loading a file (avoids polluting progs memory), setting the single
character lexeme string, and getting the line number.
I never liked the various hacks I had come up with for representing
resource handles in Ruamoko. Structs with an int were awkward to test,
pointers and ints could be modified, etc etc. The new @handle keyword (@
used to keep handle free for use) works just like struct, union and
enum in syntax, but creates an opaque type suitable for a 32-bit handle.
The backing type is a function so v6 progs can use it without (all the
necessary opcodes exist) and no modifications were needed for
type-checking in binary expressions, but only assignment and comparisons
are supported, and (of course) nil. Tested using cbuf_t and QFile: seems
to work as desired.
I had considered 64-bit handles, but really, if more than 4G resource
objects are needed, I'm not sure QF can handle the game. However, that
limit is per resource manager, not total.
This gives the resultant point the correct sign. Though the projective
divide would take care of the sign, this makes reading the point a
little less confusing (still need to sort out automatic blade reversals
for the likes of e31).
And other graphics versions too, of course. A lot of it feels rather
like a hack, but I think the entire canvas/console setup and console
related event handling may need a rethink (it's not horribly wrong, but
it doesn't feel right), particularly the initial sizing and binding for
toggling the console.
As the dot product is a metric product, using the metric is vital to
getting the correct results. This fixes the calculation of the closest
point on a line to a point other than the origin (and a whole pile of
other issues, I imagine).
Now that arrays work well enough for this case, no point in having the
workarounds (other than they're actually faster, but I'd like to
optimize *that* sometime).
I'm not 100% sure this is the best fix for the issue, but the way the
cbuf interpreter stack works (especially in the console code) meant that
the stack was built in the order opposite to how it could be safely
deleted with the existing function. Yeah, more leaks :P
Some of them, especially in rua_obj, were quite legitimate and even a
problem for thread-safety (rua_cmd is currently not thread-safe, but it
needs a lock, which I don't feel like doing at this stage).
This was mainly for the shutdown functions, thus allowing Sys_Shutdown
(and Sys_RegisterShutdown) to be per-thread, but it seemed like a good
idea to make everything per-thread.
Finally, hash links can be freed when the hash context is no longer
relevant. The context is created automatically when needed, and the
owner can delete the context when its done with the relevant hash
tables.
It should have been this way all along, and it seems I thought they were
when I did rua_gui.c as it already freed its resource block, which would
have been a double free (oops). Fixes an invalid write when shutting
down progs in qwaq-cmd (relevant change not committed).
qfot_basic_t is necessary for getting at the width of basic value types
(int, uint, float, long, ulong, double) in order to distinguish between
scalars and vectors of those types.
I had forgotten this when doing the Ruamoko VM and qfcc changes.
This will make it easy for client code to set up data needed by the
console before the console initializes. It already separates console
cvar setup and initialization, which has generally been a good thing.
Instead of creating new entities for the text views. This approximately
halves the number of entities required to display flowed text, but also
tests the ability to have an entity in multiple hierarchies (the goal of
the ECS component and system changes).
Font and text handling is very much part of user interface and at least
partially independent of rendering, but does fit it better with GUI than
genera UI (ie, both graphics and text mode), thus libQFgui as well as
libQFui are built in the ui directory.
The existing font related builtins have been moved into the ruamoko
client library.
While the libraries are probably getting a little out of hand, the
separation into its own directory is probably a good thing as an ECS
should not be tied to scenes. This should make the ECS more generally
useful.
This puts the hierarchy (transform) reference, animation, visibility,
renderer, active, and old_origin data in separate components. There are
a few bugs (crashes on grenade explosions in gl/glsl/vulkan, immediately
in sw, reasons known, missing brush models in vulkan).
While quake doesn't really need an ECS, the direction I want to take QF
does, and it does seem to have improved memory bandwidth a little
(uncertain). However, there's a lot more work to go (especially fixing
the above bugs), but this seems to be a good start.
The software renderer uses Bresenham's line slice algorithm as presented
by Michael Abrash in his Graphics Programming Black Book Special Edition
with the serial numbers filed off (as such, more just so *I* can read
the code easily), along with the Chen-Sutherland line clipping
algorithm. The other renderers were more or less trivial in comparison.
