 branches/purecfg/TODO 2011/04/14 15:54:24 824
+++ branches/purecfg/TODO 2011/05/03 15:20:16 1049
@@ 1,64 +1,33 @@
========================
SHORT TERM ============= (for curvaturebased 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
+NOTE: GLK's approximate ranking of 5 most important tagged with
+[GLK:1], [GLK:2], ...
+
+==============================
+other SHORT TERM ============= (including needed for LIC)
+==============================
+
+[GLK:1] Add sequence types (needed for evals & evecs)
+ syntax
+ types: ty '{' INT '}'
+ value construction: '{' e1 ',' … ',' en '}'
+ indexing: e '{' e '}'
IL support for higherorder tensor values (matrices, etc).
tensor construction [DONE]
tensor indexing [DONE]
tensor slicing
 verify that hessians work correctly

Outer products [DONE]

Add M dot v, v dot M, and M dot N [DONE]

Identity matrix [DONE up to code generation]

Zero tensor [DONE up to code generation]

trace [DONE]

extend norm (exp) to tensor[3,3]

extend implementation of scaling to work on higherorder tensors (it currently
just works on vectors)
+ verify that hessians work correctly [DONE]
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]

Infix "^" operator for pow() [DONE]

==============================
other SHORT TERM ============= (including needed for LIC)
==============================
+test/uninit.diderot:
+documents need for better compiler error messages when output variables
+are not initialized; the current messages are very cryptic
determinant ("det") for tensor[3,3]
Decide if we want to allow redefinitions of variables
 (as in vrlitecam.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
valuenumbering optimization
@@ 68,13 +37,55 @@
rgba = real{4}
==============================
MEDIUM TERM ================== (needed for streamlines & tractography)
+MEDIUM TERM ================== (including needed for streamlines & tractography)
==============================
+[GLK:1] evals & evecs for symmetric tensor[3,3] (requires sequences)
+
+[GLK:2] Save Diderot output to nrrd, instead of "mip.txt"
+ For grid of strands, save to similarlyshaped array
+ For list of strands, save to long 1D (or 2D for nonscalar output) list
+ For ragged things (like tractography output), will need to save both
+ complete list of values, as well as list of start indices and lengths
+ to index into complete list
+
+[GLK:3] Use of Teem's "hest" commandline parser for getting
+any input variables that are not defined in the source file
+
+[GLK:4] ability to declare a field in such a way so that probe
+positions are *always* clamped to the support of "inside";
+there are many cases where this is the sensible behavior.
+(could also have "repeat" declaration, to mimic GL_REPEAT texturing)
+
+extend norm (exp) to all tensor types [DONE for vectors and matrices]
+
ability to emit/track/record variables into dynamically resized
runtime buffer
evals & evecs for symmetric tensor[3,3]
+Want: allow X *= Y, X /= Y, X += Y, X = Y to mean what they do in C,
+provided that X*Y, X/Y, X+Y, XY are already supported.
+Nearly every Diderot program would be simplified by this.
+
+Want: nontrivial field expressions & functions:
+ image(2)[2] Vimg = load(...);
+ field#0(2)[] Vlen = Vimg ⊛ bspln3;
+to get a scalar field of vector length, or
+ field#2(2)[] F = Fimg ⊛ bspln3;
+ field#0(2)[] Gmag = ∇F;
+to get a scalar field of gradient magnitude, or
+ field#2(2)[] F = Fimg ⊛ bspln3;
+ field#0(2)[] Gmsq = ∇F•∇F;
+to get a scalar field of squared gradient magnitude, which is simpler
+to differentiate. However, there is value in having these, even if
+the differentiation of them is not supported (hence the indication
+of "field#0" for these above)
+
+Want: ability to apply "normalize" to a field itself, e.g.
+ field#0(2)[2] V = normalize(Vimg ⊛ ctmr);
+so that V(x) = normalize((Vimg ⊛ ctmr)(x)).
+Having this would simplify expression of standard LIC method, and
+would also help express other vector field expressions that arise
+in vector field feature exraction.
tensor fields: convolution on general tensor images
@@ 82,7 +93,10 @@
other MEDIUM TERM ============ (needed for particles)
==============================
runtime birth and death of strands
+[GLK:5] runtime death of strands; test/iso2d.diderot provides
+great initial test for "die" command.
+
+runtime birth of strands
"initially" supports lists
@@ 93,37 +107,41 @@
proper handling of stabilize method
Add support for code like
+test/vrkcomp2.diderot: 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 liverange of the result of the conditional.
+This will require duplication of the continuation of the conditional
+(but we should only duplicate over the liverange of the result of the
+conditional.
+
+add ":" for tensor dot product (contracts out two indices
+instead of one like •), valid for all pairs of tensors with
+at least two indices
==============================
other MEDIUM TERM ============
==============================
want: warnings when D (and likely I) is declared as a
variable name (now get confusing error messages now)
+want: warnings when "D" (reserved for differentiation) is declared as
+a variable name (get confusing error messages now)
support for Python interop and GUI
+Python/ctypes interface to runtime
+
==============================
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 strandinvariant variables
to global scope. Also prune out useless variables, which should include field variables after the
translation to midil.
+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 strandinvariant variables to global
+scope. Also prune out useless variables, which should include field
+variables after the translation to midil.
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)
@@ 135,28 +153,22 @@
"tensor comprehension" (like list comprehension)
Python/ctypes interface to runtimez

======================
BUGS =================
======================
test/mipcam.diderot:
 // generated C code looks like "(float)p_ui_00.5e0f"
 //real rayU = 2.0*camUmax*(real(ui)  0.5)/real(imgResU)  camUmax;

test/vrkcomp.diderot:
 // HEY (scoping BUG): the strand parameters (e.g. ui, vi) ...
+test/fields.diderot:
+Can't assign on field to another.
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/read2vecs.diderot:
+// HEY (BUG?) shouldn't it be a type error to load this 2D array of
+// 2vectors into a 2D *scalar* field? Instead, get:
+// uncaught exception Fail [Fail: Error in compiling lic.diderot]
+// raised at driver/main.sml:31.3931.76
+image(2)[] Vimg = load("../data/vorttest.nrrd");
test/zslice2.diderot:
// HEY (bug) bspln5 leads to problems ...
// uncaught exception Size [size]
// raised at ctarget/ctarget.sml:47.1547.19
//field#4(3)[] F = img ⊛ bspln5;

