Nanogl-state NPM

nanogl-state

Efficient webgl context state configuration. (3Ko gzipped)

Design to efficiently keep track of the actual context state, and reduce api call by skip useless ones.

Example

Rendering alpha blended and opaque primitves

var GLState = require( 'nanogl-state' );

// create the state machine from a gl context
// glStage will be sync with the actuel gl state
var glState = new GLState( gl );


// create a config to change glCullFace for both opaques and blended
var cfgG = GLState.config()
  .cullFace( gl.FRONT );


// create a configuration to enable DEPTH_TEST
var cfgA = GLState.config()
  .enableDepthTest()
  .enableCullface();

// create another config for alpha blending and depth test

var cfgB = GLState.config()
  .enableBlend()
  .blendFunc( gl.SRC_ALPHA, gl.ONE_MINUS_DRC_ALPHA )
  .enableDepthTest()
  .enableCullface()
  .depthMask( false );



// somewhere in your render loop
function render(){
  // context in default state

  // add the cullFace cfg to the stack
  glState.push( cfgG );

  // add cfgA to the stack, apply the complete stack to the context, then pop cfgA
  glState.now( cfgA );
  renderOpaqueStuffs();


  // apply the cfgB, enable DEPTH_TEST and CULL_FACE are skipped since they are already enabled
  glState.now( cfgB );
  renderBlendableStuffs();

  // pop the cullFace config (cfgG)
  glState.pop();

  // sync the glState and the actual gl context
  glState.apply();

  // here we are back to the default state
}