WebGL2 EXT_disjoint_timer_query_webgl2 limits test

README.md

WebGL2 EXT_disjoint_timer_query_webgl2 limits test

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index.css

/*bug-in-github-api-content-can-not-be-empty*/

index.html

/*bug-in-github-api-content-can-not-be-empty*/

index.js

async function main() {
  const gl = new OffscreenCanvas(300, 100).getContext('webgl2');;
  const prg = createProgram(gl, `
  void main() {
    gl_Position = vec4(0, 0, 0, 1);
    gl_PointSize = 128.0;
  }
  `, `
  precision mediump float;
  void main() {
    gl_FragColor = vec4(1, 0, 0, 1);
  }
  `);
  gl.useProgram(prg);

  // Example (1) -- uses beginQuery/endQuery.
  let ext = gl.getExtension('EXT_disjoint_timer_query_webgl2');
  if (!ext) {
    console.error('need EXT_disjoint_timer_query_webgl2');
  }

  async function makeAndUseQuery() {
    let query = gl.createQuery();
    gl.beginQuery(ext.TIME_ELAPSED_EXT, query);
    gl.clear(gl.COLOR_BUFFER_BIT);
    gl.drawArrays(gl.POINTS, 0, 1);
    gl.endQuery(ext.TIME_ELAPSED_EXT);

    // ...at some point in the future, after returning control to the browser and being called again:
    // (Note that this code might be called multiple times)
    for (;;) {
      await new Promise(resolve => setTimeout(resolve, 100));
      gl.flush();
      const available = gl.getQueryParameter(query, gl.QUERY_RESULT_AVAILABLE);
      const disjoint = gl.getParameter(ext.GPU_DISJOINT_EXT);
      if (available || disjoint) {
        break;
      }
    }

    return query;
  };

  const queries = [];
  for (;;) {
    const query = await makeAndUseQuery();
    const err = gl.getError();
    if (err !== 0) {
      console.log(err);
      break;
    }

    queries.push(query);
    if (queries.length % 100 == 0) {
      console.log('queries so far:', queries.length);
      await new Promise(resolve => setTimeout(resolve, 100));
    }
  }

  console.log('num queries:', queries.length);
}

function createShader(gl, type, src) {
  const shader = gl.createShader(type);
  gl.shaderSource(shader, src);
  gl.compileShader(shader);
  if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
    throw new Error(gl.getShaderInfoLog(shader));
  }
  return shader;
}

function createProgram(gl, vs, fs, tf) {
  const program = gl.createProgram();
  gl.attachShader(program, createShader(gl, gl.VERTEX_SHADER, vs));
  gl.attachShader(program, createShader(gl, gl.FRAGMENT_SHADER, fs));
  if (tf) {
     gl.transformFeedbackVaryings(program, tf, gl.INTERLEAVED_ATTRIBS); // gl.SEPARATE_ATTRIBS);
  }
  gl.linkProgram(program);
  if (!gl.getProgramParameter(program, gl.LINK_STATUS)) {
    throw new Error(gl.getProgramInfoLog(program));
  }
  return program;
}

main();

jsGist.json

{"name":"WebGL2 EXT_disjoint_timer_query_webgl2 limits test","settings":{},"filenames":["index.html","index.css","index.js"]}