WebGLProgram
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).
To create a WebGLProgram
, call the GL context's createProgram()
function. After attaching the shader programs using attachShader()
, you link them into a usable program. This is shown in the code below.
js
const 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)) {
const 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.
js
// 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.
js
gl.deleteProgram(program);
Specifications
Specification |
---|
WebGL Specification # 5.6 |
Browser compatibility
BCD tables only load in the browser
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()