glsl-light-direction

GLSL function for computing lighting direction. Designed for use as a shader component with glslify and glsl-light.

install

To make avaialble in your project

npm install glsl-light-direction --save

example

Define a light in your shader

pragma glslify: Light = require('glsl-light')
uniform Light light;

Then compute light direction from the vertex position

pragma glslify: direction = require('glsl-light-direction')
vec3 dir = direction(light, position);

algorithm

The calculated direction depends on the position parameter of the light, a vec4 in homogenous coordinates. The fourth element determines whether the light is directional or not.

• If the fourth element is 0.0, the direction will be the normalized light position.
• If the fourth element is 1.0, the direction will point from the light to the vertex.

API

direction(light, position)

Parameters

• light : struct instance of glsl-light
• position : vec4 position of the light

Returns

• vec3 the computed light direction