/
Cylinder.js
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/
Cylinder.js
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import gl from "../gl.js";
import Vao from "../Vao.js";
import Geometry from "../data/Geometry.js";
import Renderable from "../rendering/Renderable.js";
function Cylinder(mat, sides=6, tRadius=0.5, bRadius=0.5, h=1, botBuild=true){
var data = Cylinder.vertData(sides, tRadius, bRadius, h, botBuild),
vao = Vao.standardRenderable("Cylinder", 3, data.vertices, null, null, data.index),
model = new Renderable("Cylinder", vao, mat);
//model.drawMode = gl.ctx.TRIANGLES;
return model;
}
Cylinder.vertData = function(sides=6, tRadius=0.5, bRadius=0.5, h=1, botBuild=true){
var geo = new Geometry(),
PIH = Math.PI * 0.5,
inc = Math.PI * 2 / sides,
tYPos = h,
bYPos = 0,
bFace = [],
tFace = [],
i, a, b, rad;
if(!botBuild){
tYPos = h * 0.5;
bYPos = -tYPos;
}
//Bottom Face
geo.addVert(0,bYPos,0);
for(i=0; i < sides; i++){
rad = PIH + inc * i;
a = bRadius * Math.cos(rad);
b = bRadius * Math.sin(rad);
geo.addVert(a, bYPos, b);
bFace.push(i+1);
}
//Top Face
var tcIdx = geo.verts.length;
geo.addVert(0,tYPos,0);
for(i=0; i < sides; i++){
rad = PIH + inc * i;
a = tRadius * Math.cos(rad);
b = tRadius * Math.sin(rad);
geo.addVert(a, tYPos, b);
tFace.push(tcIdx+i+1);
}
//Build Faces
geo.triangleWallLoop( tFace, bFace );
geo.triangleCircle( tcIdx, tFace );
geo.triangleCircle( 0, bFace.reverse() );
return { vertices:geo.vertexArray(), index:geo.faceArray() };
}
export default Cylinder;