mdx-m3-viewer/src/viewer/gl/program.js

A browser WebGL model viewer. Mainly focused on models of the games Warcraft 3 and Starcraft 2.

/**
 * A wrapper around a WebGL shader program.
 */
export default class ShaderProgram {
  /**
   * @param {WebGLRenderingContext} gl
   * @param {ShaderUnit} vertexShader
   * @param {ShaderUnit} fragmentShader
   */
  constructor(gl, vertexShader, fragmentShader) {
    let id = gl.createProgram();
    let uniforms = {};
    let attribs = {};

    /** @member {boolean} */
    this.ok = false;
    /** @member {WebGLProgram} */
    this.webglResource = id;
    /** @member {Array<ShaderUnit>} */
    this.shaders = [vertexShader, fragmentShader];
    /** @member {Map<string, WebGLUniformLocation>} */
    this.uniforms = uniforms;
    /** @member {Map<string, number>} */
    this.attribs = attribs;
    /** @member {number} */
    this.attribsCount = 0;

    gl.attachShader(id, vertexShader.webglResource);
    gl.attachShader(id, fragmentShader.webglResource);
    gl.linkProgram(id);

    if (gl.getProgramParameter(id, gl.LINK_STATUS)) {
      for (let i = 0, l = gl.getProgramParameter(id, gl.ACTIVE_UNIFORMS); i < l; i++) {
        let object = gl.getActiveUniform(id, i);

        if (object.size === 1) {
          uniforms[object.name] = gl.getUniformLocation(id, object.name);
        } else {
          let base = object.name.substr(0, object.name.length - 3);

          for (let index = 0; index < object.size; index++) {
            let name = base + '[' + index + ']';

            uniforms[name] = gl.getUniformLocation(id, name);
          }
        }
      }

      for (let i = 0, l = gl.getProgramParameter(id, gl.ACTIVE_ATTRIBUTES); i < l; i++) {
        let object = gl.getActiveAttrib(id, i);

        this.attribsCount += object.size;

        if (object.size === 1) {
          attribs[object.name] = gl.getAttribLocation(id, object.name);
        } else {
          let base = object.name.substr(0, object.name.length - 3);

          for (let index = 0; index < object.size; index++) {
            let name = base + '[' + index + ']';

            attribs[name] = gl.getAttribLocation(id, name);
          }
        }
      }

      this.ok = true;
    } else {
      console.error('Shader program failed to link!');
      console.error(gl.getProgramInfoLog(id));
    }
  }
}