The avatar for @infowantstobeseen
T.J. Jankun-Kelly
Scientist, Designer, and Teacher. Assoc Prof of CompSci in visualization at Mississippi State University. Believes information wants to be seen. Loves Python. @dr_tj
Public
Computer Graphics
Edited
Sep 8, 2022
Importers
12 stars
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function in_triangle(pt, vert_a, vert_b, vert_c)
{
let [alpha, beta, gamma] = calc_barycentric(pt, vert_a, vert_b, vert_c);
// zed is our error tolerance. Occasionally, points will be negative but pretty
// much zero and thus we are in the triangle. zed corrects for this. Higher
// precision floats or tiny tiny pixels avoid or ignore this
if(alpha >= zed && beta >= zed && gamma >= zed )
return true;
else
return false;
}
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function fill_triangle(vert_a, vert_b, vert_c)
{
const pts = [];
let i_min = d3.min([vert_a, vert_b, vert_c], ([x,y]) => (Math.floor(x)));
let i_max = d3.max([vert_a, vert_b, vert_c], ([x,y]) => (Math.ceil(x)));
let j_min = d3.min([vert_a, vert_b, vert_c], ([x,y]) => (Math.floor(y)));
let j_max = d3.max([vert_a, vert_b, vert_c], ([x,y]) => (Math.ceil(y)));

for(let i = i_min; i <= i_max; ++i)
for(let j = j_min; j <= j_max; ++j)
if(in_triangle([i,j], vert_a, vert_b, vert_c)) pts.push([i,j]);
return pts;
}
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