Get Ganja.js to display planes

This commit is contained in:
Aaron Fenyes 2024-06-27 21:45:41 -07:00
parent 8eb1ebb8d2
commit 242d630cc6
2 changed files with 36 additions and 4 deletions

View File

@ -123,12 +123,24 @@ mutable struct ConstructionViewer
end
end
mprod(v, w) =
v[1]*w[1] + v[2]*w[2] + v[3]*w[3] + v[4]*w[4] - v[5]*w[5]
function display!(viewer::ConstructionViewer, elements::Matrix)
# load elements
elements_full = [
[0; elt; fill(0, 26)]
for elt in eachcol(elements)
]
elements_full = []
for elt in eachcol(elements)
if mprod(elt, elt) < 0.5
elt_full = [0; elt; fill(0, 26)]
else
# `elt` is a spacelike vector, representing a generalized sphere, so we
# take its Hodge dual before passing it to Ganja.js. the dual represents
# the same generalized sphere, but Ganja.js only displays planes when
# they're represented by vectors in grade 4 rather than grade 1
elt_full = [fill(0, 26); -elt[5]; -elt[4]; elt[3]; -elt[2]; elt[1]; 0]
end
push!(elements_full, elt_full)
end
@js viewer.win elements = $elements_full.map((elt) -> @new CGA3(elt))
# generate palette. this is Gadfly's `default_discrete_colors` palette,

View File

@ -28,6 +28,25 @@
CGA3.inline(() => Math.sqrt(0.5)*(-1e1 - 1e2 + 1e3 + 1e5))(),
CGA3.inline(() => -Math.sqrt(3)*1e4 + Math.sqrt(2)*1e5)()
];
/*
these blocks of commented-out code can be used to confirm that a spacelike
vector and its Hodge dual represent the same generalized sphere
*/
/*let elements = [
CGA3.inline(() => Math.sqrt(0.5)*!( 1e1 + 1e2 + 1e3 + 1e5))(),
CGA3.inline(() => Math.sqrt(0.5)*!( 1e1 - 1e2 - 1e3 + 1e5))(),
CGA3.inline(() => Math.sqrt(0.5)*!(-1e1 + 1e2 - 1e3 + 1e5))(),
CGA3.inline(() => Math.sqrt(0.5)*!(-1e1 - 1e2 + 1e3 + 1e5))(),
CGA3.inline(() => !(-Math.sqrt(3)*1e4 + Math.sqrt(2)*1e5))()
];*/
/*let elements = [
CGA3.inline(() => 1e1 + 1e5)(),
CGA3.inline(() => 1e2 + 1e5)(),
CGA3.inline(() => 1e3 + 1e5)(),
CGA3.inline(() => -1e4 + 1e5)(),
CGA3.inline(() => Math.sqrt(0.5)*(1e1 + 1e2 + 1e3 + 1e5))(),
CGA3.inline(() => Math.sqrt(0.5)*!(1e1 + 1e2 + 1e3 - 0.01e4 + 1e5))()
];*/
// set up palette
var colorIndex;
@ -66,6 +85,7 @@
// de-noise
for (let k = 6; k < elements[n].length; ++k) {
/*for (let k = 0; k < 26; ++k) {*/
elements[n][k] = 0;
}
}