Cesium-Prequel/Specs/pick.js

import { BoundingRectangle } from "../Source/Cesium.js";
import { Color } from "../Source/Cesium.js";
import { defined } from "../Source/Cesium.js";
import { ClearCommand } from "../Source/Cesium.js";
import { Pass } from "../Source/Cesium.js";
import { CreditDisplay } from "../Source/Cesium.js";
import { FrameState } from "../Source/Cesium.js";
import { JobScheduler } from "../Source/Cesium.js";
import { PickFramebuffer } from "../Source/Cesium.js";

function executeCommands(context, passState, commands) {
  var length = commands.length;
  for (var i = 0; i < length; ++i) {
    commands[i].execute(context, passState);
  }
}

function pick(frameState, primitives, x, y) {
  frameState.commandList.length = 0;

  var context = frameState.context;

  var rectangle = new BoundingRectangle(x, y, 1, 1);
  var pickFramebuffer = new PickFramebuffer(context);
  var passState = pickFramebuffer.begin(rectangle);

  var oldPasses = frameState.passes;
  frameState.passes = new FrameState(
    new CreditDisplay(
      document.createElement("div"),
      undefined,
      document.createElement("div")
    ),
    new JobScheduler()
  ).passes;
  frameState.passes.pick = true;

  primitives.update(frameState);

  var clear = new ClearCommand({
    color: new Color(0.0, 0.0, 0.0, 0.0),
    depth: 1.0,
    stencil: 1.0,
  });
  clear.execute(context, passState);

  var i;
  var renderCommands = new Array(Pass.NUMBER_OF_PASSES);
  for (i = 0; i < Pass.NUMBER_OF_PASSES; ++i) {
    renderCommands[i] = [];
  }

  var commands = frameState.commandList;
  var length = commands.length;
  for (i = 0; i < length; i++) {
    var command = commands[i];
    var pass = defined(command.pass) ? command.pass : Pass.OPAQUE;
    renderCommands[pass].push(command);
  }

  for (i = 0; i < Pass.NUMBER_OF_PASSES; ++i) {
    executeCommands(context, passState, renderCommands[i]);
  }

  frameState.passes = oldPasses;

  var p = pickFramebuffer.end(rectangle);
  pickFramebuffer.destroy();

  return p;
}
export default pick;