WebGLShader

The WebGLShader is part of the WebGL API and can either be a vertex or a fragment shader. A WebGLProgram requires both types of shaders.

Description

To create a WebGLShader use WebGLRenderingContext.createShader, then hook up the GLSL source code using WebGLRenderingContext.shaderSource(), and finally invoke WebGLRenderingContext.compileShader() to finish and compile the shader. At this point the WebGLShader is still not in a usable form and must still be attached to a WebGLProgram.

function createShader (gl, sourceCode, type) {
  // Compiles either a shader of type gl.VERTEX_SHADER or gl.FRAGMENT_SHADER
  var shader = gl.createShader( type );
  gl.shaderSource( shader, sourceCode );
  gl.compileShader( shader );

  if ( !gl.getShaderParameter(shader, gl.COMPILE_STATUS) ) {
    var info = gl.getShaderInfoLog( shader );
    throw "Could not compile WebGL program. \n\n" + info;
  }
  return shader;
}

See WebGLProgram for information on attaching the shaders.

Examples

Creating a vertex shader

Note that there are many other strategies for writing and accessing shader source code strings. These example are for illustration purposes only.

var vertexShaderSource =
  "attribute vec4 position;\n"+
  "void main() {\n"+
  "  gl_Position = position;\n"+
  "}\n";

//Use the createShader function from the example above
var vertexShader = createShader(gl, vertexShaderSource, gl.VERTEX_SHADER)

Creating a fragment shader

var fragmentShaderSource =
  "void main() {\n"+
  "  gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);\n"+
  "}\n";

//Use the createShader function from the example above
var fragmentShader = createShader(gl, fragmentShaderSource, gl.FRAGMENT_SHADER)

Specifications

Specification Status Comment
WebGL 1.0
The definition of 'WebGLShader' in that specification.
Recommendation Initial definition.

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari Servo
Basic Support9124.011125.1No support
Available in workersNo supportNo supportNo support1No supportNo supportNo supportNo support
Feature Android Chrome for Android Edge Mobile Firefox for Android IE Mobile Opera Mobile Safari Mobile
Basic Support(Yes)25No support(Yes)11128.1
Available in workersNo supportNo supportNo supportNo supportNo supportNo supportNo support

1. This feature is experimentally implemented since Firefox 44; to activate it, in about:config, set gfx.offscreencanvas.enabled to true

See also

Document Tags and Contributors

 Contributors to this page: teoli, MrOpposite, zalomea, fscholz, gregtatum
 Last updated by: teoli,