gl-spikes3d
Draws axis spikes compatible with gl-axes3d. This can be useful to illustrate selections or specific points in a point cloud
Example
var shell = require("gl-now")({ clearColor: [0,0,0,0], tickRate: 5 })
var camera = require("game-shell-orbit-camera")(shell)
var mat4 = require("gl-matrix").mat4
var createAxes = require("gl-axes")
var createSpikes = require("gl-spikes")
//Bounds on function to plot
var bounds = [[-1,-1,-1], [1,1,1]]
//camera.lookAt([-15,20,-15], [0,0,0], [0, 1, 0])
camera.lookAt([2, 2, 2], [0,0,0], [0,1,0])
//State variables
var axes, spikes
shell.on("gl-init", function() {
var gl = shell.gl
axes = createAxes(gl, {
bounds: bounds,
tickSpacing: [0.1,0.1,0.1],
textSize: 0.05
})
spikes = createSpikes(gl, {
bounds: bounds,
colors: [[1,0,0,1], [0,1,0,1], [0,0,1,1]],
position: [0,0,0]
})
})
shell.on("gl-render", function() {
var gl = shell.gl
gl.enable(gl.DEPTH_TEST)
//Compute camera parameters
var cameraParameters = {
view: camera.view(),
projection: mat4.perspective(
mat4.create(),
Math.PI/4.0,
shell.width/shell.height,
0.1,
1000.0)
}
//Update spike position
var t = 0.001*Date.now()
spikes.position = [Math.cos(t), Math.sin(t), Math.cos(2*t+0.1)]
//Draw objects
axes.draw(cameraParameters)
spikes.draw(cameraParameters)
})
Install
npm install gl-spikes
API
var spikes = require('gl-spikes')(gl, options)
Creates a new spike object.
-
gl
is a WebGL context -
options
is a list of optional parameters which are passed along
Methods
spikes.draw(camera)
Draws the axis spikes using the given camera coordinates.
-
camera.model
is the model matrix for the camera -
camera.view
is the view matrix -
camera.projection
is the projection matrix
spikes.update(options)
Updates the parameters of the axes spikes. options
is an object with the following properties:
-
position
the position of the spike ball in data coordinates -
bounds
the bounds of the axes object -
colors
an array of 3 length 4 arrays encoding the RGBA colors for the spikes along the x/y/z directions -
enabled
an array of 3 flags which if set turns on or off the spikes -
drawSides
an array of 3 flag which if set turns on or off the projected spikes in each data plane -
lineWidth
an array of 3 numbers giving the thickness of the spikes for each axis
spikes.dispose()
Destroys the spike object and releases all associated resources.
Credits
(c) 2014 Mikola Lysenko. MIT License