A flexible wrapper for gl-vao and gl-buffer that you can use to set up renderable WebGL geometries from a variety of different formats.
Creates a new geometry attached to the WebGL canvas context gl
.
Define a new attribute value, for example using a simplicial complex:
var createGeometry = require('gl-geometry')
var bunny = require('bunny')
var geom = createGeometry(gl)
.attr('positions', bunny)
The following vertex formats are supported and will be normalized:
-
Arrays of arrays, e.g.
[[0, 0, 0], [1, 0, 0], [1, 1, 0]]
. -
Flat arrays, e.g.
[0, 0, 0, 1, 0, 0, 1, 1, 0]
. -
Typed arrays, preferably a
Float32Array
. -
1-dimensional ndarrays.
-
simplicial complexes, i.e. an object with a
positions
array and acells
array. The former is a list of unique vertices in the mesh (if you've used three.js, thinkTHREE.Vector3
), and the latter is an index mapping these vertices to faces (THREE.Face3
) in the mesh. It looks something like this:{ "positions": [ [0.0, 0.0, 0.0], [1.5, 0.0, 0.0], [1.5, 1.5, 0.0], [0.0, 1.5, 0.0] ], "cells": [ [0, 1, 2], [1, 2, 3] ] }
Pass a simplicial complex's cells
property here in any of the above formats
to use it as your index when drawing the geometry. For example:
var createGeometry = require('gl-geometry')
var bunny = require('bunny')
bunny.normals = normals.vertexNormals(
bunny.cells
, bunny.positions
)
var geom = createGeometry(gl)
.attr('positions', bunny.positions)
.attr('normals', bunny.normals)
.faces(bunny.cells)
Binds the underlying VAO โ this must
be called before calling geom.draw
. Optionally, you can pass in a
gl-shader or
glslify shader instance to
automatically set up your attribute locations for you.
Draws the geometry to the screen using the currently bound shader.
Optionally, you can pass in the drawing mode, which should be one of the following:
gl.POINTS
gl.LINES
gl.LINE_STRIP
gl.LINE_LOOP
gl.TRIANGLES
gl.TRIANGLE_STRIP
gl.TRIANGLE_FAN
The default value is gl.TRIANGLES
. You're also able to pass in a start
and
stop
range for the points you want to render, just the same as you would
with gl.drawArrays
or gl.drawElements
.
Unbinds the underlying VAO. This must be done when you're finished drawing, unless you're binding to another gl-geometry or gl-vao instance.
- ArrayBuffer and Typed Arrays
- The WebGL Context
- simplicial-complex
- ndarray
- gl-shader
- gl-buffer
- gl-vao
MIT. See LICENSE.md for details.