Function drawParticlesProgram

src/lib/programs/drawParticlesProgram.js:14–122

(ctx)

 * @param {Object} ctx rendering context. Holds WebGL state
 */
export default function drawParticlesProgram(ctx) {
  var gl = ctx.gl;

  var particleStateResolution, particleIndexBuffer;
  var numParticles;

  var currentVectorField = '';
  var updatePositionProgram = makeUpdatePositionProgram(ctx);
  var audioProgram;

  var drawProgram;
  initPrograms();

  return {
    updateParticlesCount,
    updateParticlesPositions,
    drawParticles,
    updateCode,
    updateColorMode
  }

  function initPrograms() {
    // need to update the draw graph because color mode shader has changed.
    initDrawProgram();

    if (config.isAudioEnabled) {
      if (audioProgram) audioProgram.dispose();
      audioProgram = createAudioProgram(ctx);
    }
  }

  function initDrawProgram() {
    if (drawProgram) drawProgram.unload();

    const drawGraph = new DrawParticleGraph(ctx);
    const vertexShaderCode = drawGraph.getVertexShader(currentVectorField);
    drawProgram = util.createProgram(gl, vertexShaderCode, drawGraph.getFragmentShader());
  }

  function updateParticlesPositions() {
    if (!currentVectorField) return;

    ctx.frame += 1
    ctx.frameSeed = Math.random();

    // TODO: Remove this.
    if (audioProgram) audioProgram.updateTextures();

    updatePositionProgram.updateParticlesPositions();
  }

  function updateColorMode() {
    initDrawProgram();
  }

  function updateCode(vfCode) {
    ctx.frame = 0;
    currentVectorField = vfCode;