wasmboy/lib/debug/debug.js

Gameboy / Gameboy Color Emulator written for Web Assembly using AssemblyScript. Shell/Debugger in Preact

import { WasmBoyLib } from '../wasmboy/wasmboy';
import { WasmBoyGraphics } from '../graphics/graphics';

import { waitForLibWorkerMessageType } from '../wasmboy/onmessage';
import { WORKER_MESSAGE_TYPE } from '../worker/constants';
import { getEventData } from '../worker/util';

// requestAnimationFrame() for headless mode
import raf from 'raf';

// https://www.npmjs.com/package/big-integer
import bigInt from 'big-integer';

let currentRaf = undefined;
const forceOutputFrame = () => {
  WasmBoyLib.worker.postMessage({
    type: WORKER_MESSAGE_TYPE.FORCE_OUTPUT_FRAME
  });
  WasmBoyGraphics.renderFrame();
};

export const runNumberOfFrames = async frames => {
  await WasmBoyLib.pause();

  // Set up a raf function to continually update the canvas
  const rafUpdateCanvas = () => {
    currentRaf = raf(() => {
      if (currentRaf) {
        forceOutputFrame();
        rafUpdateCanvas();
      }
    });
  };
  rafUpdateCanvas();

  for (let i = 0; i < frames; i++) {
    await runWasmExport('executeFrame', []);
  }

  currentRaf = undefined;
  forceOutputFrame();
};

export const runWasmExport = async (exportKey, parameters, timeout) => {
  if (!WasmBoyLib.worker) {
    return;
  }

  const event = await WasmBoyLib.worker.postMessage(
    {
      type: WORKER_MESSAGE_TYPE.RUN_WASM_EXPORT,
      export: exportKey,
      parameters
    },
    undefined,
    timeout
  );

  const eventData = getEventData(event);
  return eventData.message.response;
};

export const getWasmMemorySection = async (start, end) => {
  if (!WasmBoyLib.worker) {
    return;
  }

  const event = await WasmBoyLib.worker.postMessage({
    type: WORKER_MESSAGE_TYPE.GET_WASM_MEMORY_SECTION,
    start,
    end
  });

  const eventData = getEventData(event);
  return new Uint8Array(eventData.message.response);
};

export const getWasmConstant = async constantKey => {
  if (!WasmBoyLib.worker) {
    return;
  }

  const event = await WasmBoyLib.worker.postMessage({
    type: WORKER_MESSAGE_TYPE.GET_WASM_CONSTANT,
    constant: constantKey
  });

  const eventData = getEventData(event);
  return eventData.message.response;
};

export const getStepsAsString = async radix => {
  const stepsPerStepSet = await runWasmExport('getStepsPerStepSet');
  const stepSets = await runWasmExport('getStepSets');
  const steps = await runWasmExport('getSteps');

  const bigSteps = bigInt(stepsPerStepSet)
    .multiply(stepSets)
    .add(steps);

  if (radix) {
    return bigSteps.toString(radix);
  }
  return bigSteps.toString(10);
};

export const getCyclesAsString = async radix => {
  const cyclesPerCycleSet = await runWasmExport('getCyclesPerCycleSet');
  const cycleSets = await runWasmExport('getCycleSets');
  const cycles = await runWasmExport('getCycles');

  const bigCycles = bigInt(cyclesPerCycleSet)
    .multiply(cycleSets)
    .add(cycles);

  if (radix) {
    return bigCycles.toString(radix);
  }
  return bigCycles.toString(10);
};