Eu estava lendo tutoriais deAqui.

<script class = "WebGL">
var gl;
function initGL() {
  // Get A WebGL context
  var canvas = document.getElementById("canvas");
  gl = getWebGLContext(canvas);
  if (!gl) {
    return;
  }
}
var positionLocation;
var resolutionLocation;
var colorLocation;
var translationLocation;
var rotationLocation;
var translation = [50,50];
var rotation = [0, 1];
var angle = 0;
function initShaders() {
  // setup GLSL program
  vertexShader = createShaderFromScriptElement(gl, "2d-vertex-shader");
  fragmentShader = createShaderFromScriptElement(gl, "2d-fragment-shader");
  program = createProgram(gl, [vertexShader, fragmentShader]);
  gl.useProgram(program);

  // look up where the vertex data needs to go.
  positionLocation = gl.getAttribLocation(program, "a_position");

  // lookup uniforms
  resolutionLocation = gl.getUniformLocation(program, "u_resolution");
  colorLocation = gl.getUniformLocation(program, "u_color");
  translationLocation = gl.getUniformLocation(program, "u_translation");
    rotationLocation = gl.getUniformLocation(program, "u_rotation");

  // set the resolution
  gl.uniform2f(resolutionLocation, canvas.width, canvas.height);
}
function initBuffers() {
  // Create a buffer.
  var buffer = gl.createBuffer();
  gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
  gl.enableVertexAttribArray(positionLocation);
  gl.vertexAttribPointer(positionLocation, 2, gl.FLOAT, false, 0, 0);

  // Set Geometry.
  setGeometry(gl);
}

function setColor(red, green, blue) {
    gl.uniform4f(colorLocation, red, green, blue, 1);
}
// Draw the scene.
function drawScene() {
    // Clear the canvas.
    gl.clear(gl.COLOR_BUFFER_BIT);

    // Set the translation.
    gl.uniform2fv(translationLocation, translation);
    // Set the rotation.
    gl.uniform2fv(rotationLocation, rotation);

    // Draw the geometry.
    gl.drawArrays(gl.TRIANGLES, 0, 6);
}


// Fill the buffer with the values that define a letter 'F'.
function setGeometry(gl) {
/*Assume size1 is declared*/
    var vertices = [
         -size1/2, -size1/2,
         -size1/2, size1/2,
         size1/2, size1/2,
         size1/2, size1/2,
         size1/2, -size1/2,
         -size1/2, -size1/2 ];
      gl.bufferData(
         gl.ARRAY_BUFFER,
         new Float32Array(vertices),
         gl.STATIC_DRAW);
}
function animate() {
    translation[0] += 0.01;
    translation[1] += 0.01;
    angle += 0.01;
    rotation[0] = Math.cos(angle);
    rotation[1] = Math.sin(angle);
}
function tick() {
    requestAnimFrame(tick);
    drawScene();
    animate();
}
function start() {

    initGL();
    initShaders();
    initBuffers();
    setColor(0.2, 0.5, 0.5);
    tick();
}

</script>

<!-- vertex shader -->
<script id="2d-vertex-shader" type="x-shader/x-vertex">
    attribute vec2 a_position;

    uniform vec2 u_resolution;
    uniform vec2 u_translation;
    uniform vec2 u_rotation;
    void main() {
        vec2 rotatedPosition = vec2(
        a_position.x * u_rotation.y + a_position.y * u_rotation.x,
        a_position.y * u_rotation.y - a_position.x * u_rotation.x);

       // Add in the translation.
       vec2 position = rotatedPosition + u_translation;

       // convert the position from pixels to 0.0 to 1.0
       vec2 zeroToOne = position / u_resolution;

       // convert from 0->1 to 0->2
       vec2 zeroToTwo = zeroToOne * 2.0;

       // convert from 0->2 to -1->+1 (clipspace)
       vec2 clipSpace = zeroToTwo - 1.0;

       gl_Position = vec4(clipSpace, 0, 1);
    }
</script>
<!-- fragment shader -->
<script id="2d-fragment-shader" type="x-shader/x-fragment">
    precision mediump float;

    uniform vec4 u_color;

    void main() {
       gl_FragColor = u_color;
    }
</script>

Meu programa WebGL para 1 forma funciona assim:

Obtenha um contexto (gl) do elemento canvas.inicializar buffers com a forma do meu objetodrawScene() : uma chamada paragl.drawArrays()Se houver animação, uma função de atualização, que atualiza os ângulos, as posições e, em seguida,drawScene() ambos emtick(), para que seja chamado repetidamente.

Agora, quando eu preciso de mais de uma forma, devo preencher o buffer único de uma vez com muitos objetos e depois usá-lo para chamar mais tardedrawScene() desenhando todos os objetos de uma só vez[OU] devo repetir ligar para oinitBuffer edrawScene() derequestAnimFrame().