Commit graph

8 commits

Author SHA1 Message Date
Bill Currie
6d75d91de2 [qfcc] Implement 2d PGA dot (inner) product
This has shown the need for more instructions, such as a 2d wedge
product and narrower swizzles. Also, making dot product produce a vector
instead of a scalar was a big mistake (works nicely in C, but not so
well in Ruamoko).
2023-08-24 00:19:58 +09:00
Bill Currie
469fdea0a1 [qfcc] Implement 2d PGA outer products
The specialization is really just in the layout.
2023-08-23 21:52:33 +09:00
Bill Currie
da1b797cb7 [qfcc] Get scalar promotion working again
The cleanup of the scalar expressions lost the type promotion so using
ints in expressions didn't always work.
2023-08-23 21:51:01 +09:00
Bill Currie
24c085c1bd [qfcc] Implement 3d-PGA wedge products
Not all possibilities have been tested yet, but the initial code looks
good even if it has a couple of excessive temporary variables.
2023-08-23 15:38:32 +09:00
Bill Currie
0d491ce68c [qfcc] Build multi-vector expressions correctly
Losing the other components and getting the offset wrong doesn't make
for a correct multi-vector expression when pulling apart a multi-vector
def.
2023-08-23 15:38:32 +09:00
Bill Currie
cfcacfbf28 [qfcc] Use scatter-gather for multivec expressions
This makes working with them much easier, and the type system reflects
what's in the multi-vector. Unfortunately, that does mean that large
algebras will wind up having a LOT of types, but it allows for efficient
storage of sparse multi-vectors:

    auto v = 4*(e1 + e032 + e123);

results in:

    0005 0213 1:0008<00000008>4:void     0:0000<00000000>?:invalid
              0:0044<00000044>4:void          assign (<void>), v
    0006 0213 1:000c<0000000c>4:void     0:0000<00000000>?:invalid
              0:0048<00000048>4:void          assign (<void>), {v + 4}

Where the two source vectors are:

    44:1 0 .imm float:18e [4, 0, 0, 0]
    48:1 0 .imm float:1aa [4, 0, 0, 4]

They just happen to be adjacent, but don't need to be.
2023-08-23 15:38:32 +09:00
Bill Currie
dfb719c92b [qfcc] Correct scaling and multivec sums
Scaling now works for multi-vector expressions, and always subtracting
even when addition is wanted doesn't work too well. However, now there's
the problem of multi-vectors very quickly becoming full algebra vectors,
which means certain things need a rethink.
2023-08-21 20:10:13 +09:00
Bill Currie
2e91b29580 [qfcc] Start work on implementing geometric algebra
This gets only some very basics working:
 * Algebra (multi-vector) types: eg @algebra(float(3,0,1)).
 * Algebra scopes (using either the above or @algebra(TYPE_NAME) where
   the above was used in a typedef.
 * Basis blades (eg, e12) done via procedural symbols that evaluate to
   suitable constants based on the basis group for the blade.
 * Addition and subtraction of multi-vectors (only partially tested).
 * Assignment of sub-algebra multi-vectors to full-algebra multi-vectors
   (missing elements zeroed).

There's still much work to be done, but I thought it time to get
something into git.
2023-08-21 17:58:20 +09:00