Guide to viaWebGL

viaWebGL attributes

Options	Type	About	Default
vShader	String	path/to/*.glsl or shader code	'vShader.glsl'
fShader	String	path/to/*.glsl or shader code	'fShader.glsl'
tile_size	String	glsl uniform vec2	'u_tile_size'
tile_pos	String	glsl varying vec2	'a_tile_pos'
pos	String	glsl varying vec2	'a_pos'
height	Number	value of u_tile_size.y	128
width	Number	value of u_tile_size.x	128
container	HTMLDivElement	Draw here on viaGL.init	none
gl-drawing	Function	Set to custom gl-handler	(e) => e
gl-loaded	Function	Set to custom gl-handler	(e) => e
onclick	String	viaGL.onclick = 'toggle'	none

viaWebGL methods

#viaGL = new viaWebGL(<options>) Returns viaWebGL (chainable)

Pass <options> keys for any viaWebGL attributes.

##viaGL.init(<source>) Returns viaWebGL (chainable)

Parameters	Type	About
source	HTMLImageElement	Draw source to container via shaders
Call when all viaGL attributes have been set as needed.

##viaGL.toCanvas(source) Returns HTMLCanvasElement

Parameters	Type	About
source	HTMLImageElement or HTMLCanvasElement	Return canvas via shaders
Call after viaGL.init() to return a canvas of source via the shaders.

###gl-handler(viaGL, event-object) Returns None

Parameter	Type	About
viaGL	viaWebGL	Get or set any viaGL attributes
event-object	Object	See event-object type chart below

• Assign viaGL['gl-loaded'] = gl-handler to write webGL once with shaders
• Assign viaGL['gl-drawing'] = gl-handler to write webGL per draw call

event-object type chart	called on 'tile-drawing'	called on 'tile-loaded'
event 'gl-loaded'	WebGLProgram	WebGLProgram
event 'gl-drawing'	HTMLCanvasElement	HTMLImageElement