Web G L Program
The WebGLProgram is part of the WebGL API and is a combination of two compiled
WebGLShader
s consisting of a vertex shader and a fragment shader (both written in GLSL). These are then linked into a usable program.var program = gl.createProgram();
// Attach pre-existing shaders
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
if ( !gl.getProgramParameter( program, gl.LINK_STATUS) ) {
var info = gl.getProgramInfoLog(program);
throw "Could not compile WebGL program. \n\n" + info;
}
See
WebGLShader
for information on creating the vertexShader
and fragmentShader
in the above example.Examples
Using the program
The steps to actually do some work with the program involve telling the GPU to use the program, bind the appropriate data and configuration options, and finally draw something to the screen.
// Use the program
gl.useProgram(program);
// Bind existing attribute data
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.enableVertexAttribArray(attributeLocation);
gl.vertexAttribPointer(attributeLocation, 3, gl.FLOAT, false, 0, 0);
// Draw a single triangle
gl.drawArrays(gl.TRIANGLES, 0, 3);
Deleting the program
If there is an error linking the program or you wish to delete an existing program, then it is as simple as running
WebGLRenderingContext.deleteProgram()
. This frees the memory of the linked program.gl.deleteProgram(program);
Specifications
Specification | Status | Comment |
---|---|---|
WebGL 1.0 The definition of 'WebGLProgram' in that specification. | Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | Servo |
---|---|---|---|---|---|---|---|
Basic Support | 9 | 12 | 4.0 | 11 | 12 | 5.1 | No support |
Available in workers | No support | No support | No support1 | No support | No support | No support | No support |
1. This feature is experimentally implemented since Firefox 44; to activate it, in about:config, set gfx.offscreencanvas.enabled to true
See also
WebGLShader
WebGLRenderingContext.attachShader()
WebGLRenderingContext.compileShader()
WebGLRenderingContext.createProgram()
WebGLRenderingContext.createShader()
WebGLRenderingContext.deleteProgram()
WebGLRenderingContext.deleteShader()
WebGLRenderingContext.detachShader()
WebGLRenderingContext.getAttachedShaders()
WebGLRenderingContext.getProgramParameter()
WebGLRenderingContext.getProgramInfoLog()
WebGLRenderingContext.getShaderParameter()
WebGLRenderingContext.getShaderPrecisionFormat()
WebGLRenderingContext.getShaderInfoLog()
WebGLRenderingContext.getShaderSource()
WebGLRenderingContext.isProgram()
WebGLRenderingContext.isShader()
WebGLRenderingContext.linkProgram()
WebGLRenderingContext.shaderSource()
WebGLRenderingContext.useProgram()
WebGLRenderingContext.validateProgram()
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