WebGL shaders are programs running on the GPU to handle graphics rendering details. 1. It is divided into two types: vertex shader and chip shader; 2. Write in GLSL language to control vertex position and pixel color; 3. Implement high-performance visual effects in the front end, such as particle system, 3D effects, etc.; 4. Get the WebGL context, compile and link shaders, set buffers and draw; 5. Common application scenarios include dynamic background, data visualization, 3D model rendering; 6. Optimization suggestions include controlling frame rate, reducing CPU and GPU communication, using texture maps reasonably, and paying attention to accuracy issues. After mastering it, it can effectively improve the front-end interactive experience.

WebGL shaders look tall and elegant, but in fact it is not that difficult to understand. It is essentially a program running on the GPU to handle the details of graphics rendering. WebGL shaders are used in front-end development, mainly to achieve high-performance and rich visual interaction experiences, such as particle systems, 3D effects, dynamic backgrounds, etc.

What are WebGL Shaders?

WebGL is a built-in API for browsers that allows us to perform hardware-accelerated 2D and 3D graphics rendering on web pages. Shaders (shaders) are the key part, and it is divided into two types:

• Vertex Shader : Controls the position of each vertex.
• Fragment Shader : Determines the color of each pixel.

They are written in a language called GLSL (OpenGL Shading Language), which looks a bit like C. Although the syntax is different, the logical structure is very clear.

If you have done Canvas drawing, you can think of it as a more underlying, more performant way.

How to get started with WebGL Shaders?

To use WebGL shaders in front-end projects, you need the following steps:

• Get WebGL context
• Write and compile vertex and fragment shader code
• Link to a shader program
• Set buffer data and draw

Here is a simple example of creating a full-screen red background:

 const canvas = document.createElement('canvas');
document.body.appendChild(canvas);
const gl = canvas.getContext('webgl');

// Vertex Shader const vertexShaderSource = `
attribute vec2 a_position;
void main() {
  gl_Position = vec4(a_position, 0, 1);
}
`;

// Const fragmentShaderSource = `
precision medium float;
void main() {
  gl_FragColor = vec4(1, 0, 0, 1); // red}
`;

function createShader(gl, type, source) {
  const shader = gl.createShader(type);
  gl.shaderSource(shader, source);
  gl.compileShader(shader);
  return shader;
}

const vertexShader = createShader(gl, gl.VERTEX_SHADER, vertexShaderSource);
const fragmentShader = createShader(gl, gl.FRAGMENT_SHADER, fragmentShaderSource);

const program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);

gl.useProgram(program);

// Set vertex data const positionBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, positionBuffer);
const positions = [
  -1, -1,
   1, -1,
  -1, 1,
   1, 1,
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);

const aPositionLoc = gl.getAttribLocation(program, 'a_position');
gl.enableVertexAttribArray(aPositionLoc);
gl.vertexAttribPointer(aPositionLoc, 2, gl.FLOAT, false, 0, 0);

gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4);

Although this code is a bit long, every step is very basic and suitable for beginner learning.

Common application scenarios and optimization suggestions

The most common uses of WebGL shaders include:

• Dynamic background (such as flowing starry sky, water ripples)
• Data visualization (thermogram, particle simulation)
• 3D model rendering (combined with Three.js and other libraries)

Optimization suggestions:

• Use requestAnimationFrame to control frame rate to avoid lag
• Minimize frequent communication between CPU and GPU
• Use texture maps reasonably instead of complex calculations
• Pay attention to accuracy issues, especially on mobile devices, it is safer to use mediump instead of highp

In addition, you can use some online tools when debugging shaders, such as The Book of Shaders or Shadertoy . There are many ready-made examples in these places, which can be directly referenced and learned.

Let's summarize

WebGL shaders are not mysterious, it is a very practical technical direction in front-end graphics programming. At first, I may feel that it is a bit of a threshold, but as long as I master the basic process and debugging methods, I can produce many cool effects. Whether it is doing interactive pages or data visualization, it is worth a try.

Basically that's it, let's try it.

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