========================
SHORT TERM ============= (for curvature-based VR)
========================
For RGB color output of 2D transfer function (indexed by
kappa1,kappa2), or for a 1D transfer function, will need
something akin to convolution on vector images
IL support for higher-order tensor values (matrices, etc).
tensor construction
tensor indexing and slicing
verify that hessians work correctly
Outer products
syntax [DONE]
typechecking
IL and codegen
Add M dot v, v dot M, and M dot N
Identity matrix [DONE up to code generation]
trace [DONE]
extend norm (|exp|) to tensor[3,3]
Use ∇⊗ etc. syntax
syntax [DONE]
typechecking
IL and codegen
Add sequence types
syntax
types: ty '{' INT '}'
value construction: '{' e1 ',' … ',' en '}'
indexing: e '{' e '}'
Infix dot product and cross product [DONE]
lerp on scalars and vectors [DONE]
==============================
other SHORT TERM ============= (including needed for LIC)
==============================
determinant ("det") for tensor[3,3]
Decide if we want to allow redefinitions of variables
(as in vr-lite-cam.diderot)
extend norm (|exp|) to all tensor types
extend normalize to all tensor types
vector fields: convolution on vector images
expand trace in mid to low translation
value-numbering optimization
Add type aliases for color types
rgb = real{3}
rgba = real{4}
==============================
MEDIUM TERM ================== (needed for streamlines & tractography)
==============================
ability to emit/track/record variables into dynamically re-sized
runtime buffer
evals & evecs for symmetric tensor[3,3]
tensor fields: convolution on general tensor images
==============================
other MEDIUM TERM ============ (needed for particles)
==============================
run-time birth and death of strands
"initially" supports lists
"initially" supports lists of positions output from
different initalization Diderot program
spatial data structure that permits strands' queries of neighbors
proper handling of stabilize method
Add support for code like
(F1 if x else F2)@pos
This will require duplication of the continuation of the conditional (but we should only
duplicate over the live-range of the result of the conditional.
==============================
LONG TERM ====================
==============================
Better handling of variables that determines the scope of a variable based on its actual use,
instead of where the user defined it. So, for example, we should lift strand-invariant variables
to global scope. Also prune out useless variables, which should include field variables after the
translation to mid-il.
co- vs contra- index distinction
add ":" for tensor dot product (contracts out two indices
instead of one like •), valid for all pairs of tensors with
at least two indices
some indication of tensor symmetry
(have to identify the group of index permutations that are symmetries)
dot works on all tensors
outer works on all tensors
Einstein summation notation
"tensor comprehension" (like list comprehension)
======================
BUGS =================
======================
test/mip-cam.diderot:
// generated C code looks like "(float)p_ui_0--0.5e0f"
//real rayU = 2.0*camUmax*(real(ui) - -0.5)/real(imgResU) - camUmax;
test/vr-kcomp.diderot:
// HEY (scoping BUG): the strand parameters (e.g. ui, vi) ...
test/zslice2.diderot:
// but is this not valid syntax for creating field in one shot?
//field#2(3)[] F = (load("../data/zimg112.nrrd")) ⊛ bspln3;
// It is valid syntax, but there is a bug in the conversion from HighIL to MidIL
test/zslice2.diderot:
// HEY (bug) bspln5 leads to problems ...
// uncaught exception Size [size]
// raised at c-target/c-target.sml:47.15-47.19
//field#4(3)[] F = img ⊛ bspln5;