littlejsengine
Version:
LittleJS - Tiny and Fast HTML5 Game Engine
719 lines (643 loc) • 26.2 kB
JavaScript
/**
* LittleJS Debug System
* - Press Esc to show debug overlay with mouse pick
* - Number keys toggle debug functions
* - +/- apply time scale
* - Debug primitive rendering
* - Save a 2d canvas as a png image
* @namespace Debug
*/
;
/** True if debug is enabled
* @type {boolean}
* @default
* @memberof Debug */
const debug = true;
/** Size to render debug points by default
* @type {number}
* @default
* @memberof Debug */
const debugPointSize = .5;
/** True if watermark with FPS should be shown, false in release builds
* @type {boolean}
* @default
* @memberof Debug */
let showWatermark = true;
/** Key code used to toggle debug mode, Esc by default
* @type {string}
* @default
* @memberof Debug */
let debugKey = 'Escape';
/** True if the debug overlay is active, always false in release builds
* @type {boolean}
* @default
* @memberof Debug */
let debugOverlay = false;
// Engine internal variables not exposed to documentation
let debugPrimitives = [], debugPhysics = false, debugRaycast = false, debugParticles = false, debugGamepads = false, debugMedals = false, debugTakeScreenshot, downloadLink, debugCanvas;
///////////////////////////////////////////////////////////////////////////////
// Debug helper functions
/** Asserts if the expression is false, does nothing in release builds
* Halts execution if the assert fails and throws an error
* @param {boolean} assert
* @param {...Object} [output] - error message output
* @memberof Debug */
function ASSERT(assert, ...output)
{
if (assert) return;
console.assert(assert, ...output)
throw new Error('Assert failed!'); // halt execution
}
/** Log to console if debug is enabled, does nothing in release builds
* @param {...Object} [output] - message output
* @memberof Debug */
function LOG(...output) { console.log(...output); }
/** Draw a debug rectangle in world space
* @param {Vector2} pos
* @param {Vector2} [size=Vector2()]
* @param {Color|string} [color]
* @param {number} [time]
* @param {number} [angle]
* @param {boolean} [fill]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugRect(pos, size=vec2(), color=WHITE, time=0, angle=0, fill=false, screenSpace=false)
{
ASSERT(isVector2(pos), 'pos must be a vec2');
ASSERT(isVector2(size), 'size must be a vec2');
ASSERT(isString(color) || isColor(color), 'color is invalid');
ASSERT(isNumber(time), 'time must be a number');
ASSERT(isNumber(angle), 'angle must be a number');
if (typeof size === 'number')
size = vec2(size); // allow passing in floats
if (isColor(color))
color = color.toString();
pos = pos.copy();
size = size.copy();
const timer = new Timer(time);
debugPrimitives.push({pos:pos.copy(), size:size.copy(), color, timer, angle, fill, screenSpace});
}
/** Draw a debug poly in world space
* @param {Vector2} pos
* @param {Array<Vector2>} points
* @param {Color|string} [color]
* @param {number} [time]
* @param {number} [angle]
* @param {boolean} [fill]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugPoly(pos, points, color=WHITE, time=0, angle=0, fill=false, screenSpace=false)
{
ASSERT(isVector2(pos), 'pos must be a vec2');
ASSERT(isArray(points), 'points must be an array');
ASSERT(isString(color) || isColor(color), 'color is invalid');
ASSERT(isNumber(time), 'time must be a number');
ASSERT(isNumber(angle), 'angle must be a number');
if (isColor(color))
color = color.toString();
pos = pos.copy();
points = points.map(p=>p.copy());
const timer = new Timer(time);
debugPrimitives.push({pos, points, color, timer, angle, fill, screenSpace});
}
/** Draw a debug circle in world space
* @param {Vector2} pos
* @param {number} [size] - diameter
* @param {Color|string} [color]
* @param {number} [time]
* @param {boolean} [fill]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugCircle(pos, size=0, color=WHITE, time=0, fill=false, screenSpace=false)
{
ASSERT(isVector2(pos), 'pos must be a vec2');
ASSERT(isNumber(size), 'size must be a number');
ASSERT(isString(color) || isColor(color), 'color is invalid');
ASSERT(isNumber(time), 'time must be a number');
if (isColor(color))
color = color.toString();
pos = pos.copy();
const timer = new Timer(time);
debugPrimitives.push({pos, size, color, timer, angle:0, fill, screenSpace});
}
/** Draw a debug point in world space
* @param {Vector2} pos
* @param {Color|string} [color]
* @param {number} [time]
* @param {number} [angle]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugPoint(pos, color, time, angle, screenSpace=false)
{ debugRect(pos, undefined, color, time, angle, false, screenSpace); }
/** Draw a debug line in world space
* @param {Vector2} posA
* @param {Vector2} posB
* @param {Color|string} [color]
* @param {number} [width]
* @param {number} [time]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugLine(posA, posB, color, width=.1, time, screenSpace=false)
{
ASSERT(isVector2(posA), 'posA must be a vec2');
ASSERT(isVector2(posB), 'posB must be sa vec2');
ASSERT(isNumber(width), 'width must be a number');
const halfDelta = vec2((posB.x - posA.x)/2, (posB.y - posA.y)/2);
const size = vec2(width, halfDelta.length()*2);
debugRect(posA.add(halfDelta), size, color, time, halfDelta.angle(), true, screenSpace);
}
/** Draw a debug combined axis aligned bounding box in world space
* @param {Vector2} posA
* @param {Vector2} sizeA
* @param {Vector2} posB
* @param {Vector2} sizeB
* @param {Color|string} [color]
* @param {number} [time]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugOverlap(posA, sizeA, posB, sizeB, color, time, screenSpace=false)
{
ASSERT(isVector2(posA), 'posA must be a vec2');
ASSERT(isVector2(posB), 'posB must be a vec2');
ASSERT(isVector2(sizeA), 'sizeA must be a vec2');
ASSERT(isVector2(sizeB), 'sizeB must be a vec2');
const minPos = vec2(
min(posA.x - sizeA.x/2, posB.x - sizeB.x/2),
min(posA.y - sizeA.y/2, posB.y - sizeB.y/2)
);
const maxPos = vec2(
max(posA.x + sizeA.x/2, posB.x + sizeB.x/2),
max(posA.y + sizeA.y/2, posB.y + sizeB.y/2)
);
debugRect(minPos.lerp(maxPos,.5), maxPos.subtract(minPos), color, time, 0, false, screenSpace);
}
/** Draw a debug axis aligned bounding box in world space
* @param {string|number} text
* @param {Vector2} pos
* @param {number} [size]
* @param {Color|string} [color]
* @param {number} [time]
* @param {number} [angle]
* @param {string} [font]
* @param {boolean} [screenSpace]
* @memberof Debug */
function debugText(text, pos, size=1, color=WHITE, time=0, angle=0, font='monospace', screenSpace=false)
{
ASSERT(isString(text), 'text must be a string');
ASSERT(isVector2(pos), 'pos must be a vec2');
ASSERT(isNumber(size), 'size must be a number');
ASSERT(isString(color) || isColor(color), 'color is invalid');
ASSERT(isNumber(time), 'time must be a number');
ASSERT(isNumber(angle), 'angle must be a number');
ASSERT(isString(font), 'font must be a string');
if (isColor(color))
color = color.toString();
pos = pos.copy();
const timer = new Timer(time);
debugPrimitives.push({text, pos, size, color, timer, angle, font, screenSpace});
}
/** Clear all debug primitives in the list
* @memberof Debug */
function debugClear() { debugPrimitives = []; }
/** Trigger debug system to take a screenshot
* @memberof Debug */
function debugScreenshot() { debugTakeScreenshot = 1; }
/** Save a canvas to disk
* @param {HTMLCanvasElement|OffscreenCanvas} canvas
* @param {string} [filename]
* @param {string} [type]
* @memberof Debug */
function debugSaveCanvas(canvas, filename='screenshot', type='image/png')
{
if (canvas instanceof OffscreenCanvas)
{
// copy to temporary canvas and save
if (!debugCanvas)
debugCanvas = document.createElement('canvas');
debugCanvas.width = canvas.width;
debugCanvas.height = canvas.height;
debugCanvas.getContext('2d').drawImage(canvas, 0, 0);
debugSaveDataURL(debugCanvas.toDataURL(type), filename);
}
else
debugSaveDataURL(canvas.toDataURL(type), filename);
}
/** Save a text file to disk
* @param {string} text
* @param {string} [filename]
* @param {string} [type]
* @memberof Debug */
function debugSaveText(text, filename='text', type='text/plain')
{ debugSaveDataURL(URL.createObjectURL(new Blob([text], {'type':type})), filename); }
/** Save a data url to disk
* @param {string} dataURL
* @param {string} filename
* @memberof Debug */
function debugSaveDataURL(dataURL, filename)
{
downloadLink.download = filename;
downloadLink.href = dataURL;
downloadLink.click();
}
/** Breaks on all asserts/errors, hides the canvas, and shows message in plain text
* This is a good function to call at the start of your game to catch all errors
* In release builds this function has no effect
* @memberof Debug */
function debugShowErrors()
{
const showError = (message)=>
{
// replace entire page with error message
document.body.style = 'background-color:#111;margin:8px';
document.body.innerHTML = `<pre style=color:#f00;font-size:28px;white-space:pre-wrap>` + message;
}
const originalAssert = console.assert;
console.assert = (assertion, ...output)=>
{
originalAssert(assertion, ...output);
if (!assertion)
{
const message = output.join(' ');
const stack = new Error().stack;
throw 'Assertion failed!\n' + message + '\n' + stack;
}
};
onunhandledrejection = (event)=>
showError(event.reason.stack || event.reason);
onerror = (message, source, lineno, colno)=>
showError(`${message}\n${source}\nLn ${lineno}, Col ${colno}`);
}
///////////////////////////////////////////////////////////////////////////////
// Engine debug functions (called automatically)
function debugInit()
{
// create link for saving screenshots
downloadLink = document.createElement('a');
}
function debugUpdate()
{
if (!debug)
return;
if (keyWasPressed(debugKey)) // Esc
debugOverlay = !debugOverlay;
if (debugOverlay)
{
if (keyWasPressed('Digit0'))
showWatermark = !showWatermark;
if (keyWasPressed('Digit1'))
debugPhysics = !debugPhysics, debugParticles = false;
if (keyWasPressed('Digit2'))
debugParticles = !debugParticles, debugPhysics = false;
if (keyWasPressed('Digit3'))
debugGamepads = !debugGamepads;
if (keyWasPressed('Digit4'))
debugRaycast = !debugRaycast;
if (keyWasPressed('Digit5'))
debugScreenshot();
if (keyWasPressed('Digit6'))
debugVideoCaptureIsActive() ? debugVideoCaptureStop() : debugVideoCaptureStart();
}
}
function debugRender()
{
if (debugVideoCaptureIsActive())
return; // don't show debug info when capturing video
// flush any gl sprites before drawing debug info
glFlush();
if (debugTakeScreenshot)
{
// combine canvases, remove alpha and save
combineCanvases();
const w = mainCanvas.width, h = mainCanvas.height;
overlayContext.fillRect(0,0,w,h);
overlayContext.drawImage(mainCanvas, 0, 0);
debugSaveCanvas(overlayCanvas);
debugTakeScreenshot = 0;
}
if (debugGamepads && gamepadsEnable)
{
// draw gamepads
const maxGamepads = 8;
let gamepadConnectedCount = 0;
for (let i = 0; i < maxGamepads; i++)
gamepadConnected(i) && gamepadConnectedCount++;
for (let i = 0; i < maxGamepads; i++)
{
if (!gamepadConnected(i))
continue;
const stickScale = 1;
const buttonScale = .2;
const cornerPos = cameraPos.add(vec2(-stickScale*2, ((gamepadConnectedCount-1)/2-i)*stickScale*3));
debugText(i, cornerPos.add(vec2(-stickScale, stickScale)), 1);
if (i === gamepadPrimary)
debugText('Main', cornerPos.add(vec2(-stickScale*2, 0)),1, '#0f0');
// read analog sticks
const stickCount = gamepadStickData[i].length;
for (let j = 0; j < stickCount; j++)
{
const stick = gamepadStick(j, i);
const drawPos = cornerPos.add(vec2(j*stickScale*2, 0));
const stickPos = drawPos.add(stick.scale(stickScale));
debugCircle(drawPos, stickScale*2, '#fff7',0,true);
debugLine(drawPos, stickPos, '#f00');
debugText(j, drawPos, .3);
debugPoint(stickPos, '#f00');
}
const buttonCount = inputData[i+1].length;
for (let j = 0; j < buttonCount; j++)
{
const drawPos = cornerPos.add(vec2(j*buttonScale*2, -stickScale-buttonScale*2));
const pressed = gamepadIsDown(j, i);
debugCircle(drawPos, buttonScale*2, pressed ? '#f00' : '#fff7', 0, true);
debugText(j, drawPos, .3);
}
}
}
let debugObject;
if (debugOverlay)
{
const saveContext = mainContext;
mainContext = overlayContext;
// draw red rectangle around screen
const cameraSize = getCameraSize();
debugRect(cameraPos, cameraSize.subtract(vec2(.1)), '#f008');
// mouse pick
let bestDistance = Infinity;
for (const o of engineObjects)
{
if (o.destroyed)
continue;
if (o instanceof TileLayer)
continue; // prevent tile layers from being picked
o.renderDebugInfo();
if (!o.size.x || !o.size.y)
continue;
const distance = mousePos.distanceSquared(o.pos);
if (distance < bestDistance)
{
bestDistance = distance;
debugObject = o;
}
}
if (tileCollisionTest(mousePos))
{
// show floored tile pick for tile collision
drawRect(mousePos.floor().add(vec2(.5)), vec2(1), rgb(1,1,0,.5));
}
mainContext = saveContext;
}
{
// draw debug primitives
overlayContext.lineWidth = 2;
debugPrimitives.forEach(p=>
{
overlayContext.save();
// create canvas transform from world space to screen space
// without scaling because we want consistent pixel sizes
let pos = p.pos, scale = 1, angle = p.angle;
if (!p.screenSpace)
{
pos = worldToScreen(p.pos);
scale = cameraScale;
angle -= cameraAngle;
}
overlayContext.translate(pos.x|0, pos.y|0);
overlayContext.rotate(angle);
overlayContext.scale(1, p.text ? 1 : -1);
overlayContext.fillStyle = overlayContext.strokeStyle = p.color;
if (p.text !== undefined)
{
overlayContext.font = p.size*scale + 'px '+ p.font;
overlayContext.textAlign = 'center';
overlayContext.textBaseline = 'middle';
overlayContext.fillText(p.text, 0, 0);
}
else if (p.points !== undefined)
{
// poly
overlayContext.beginPath();
for (const point of p.points)
{
const p2 = point.scale(scale).floor();
overlayContext.lineTo(p2.x, p2.y);
}
overlayContext.closePath();
p.fill && overlayContext.fill();
overlayContext.stroke();
}
else if (p.size === 0 || (p.size.x === 0 && p.size.y === 0))
{
// point
const pointSize = debugPointSize * scale;
overlayContext.fillRect(-pointSize/2, -1, pointSize, 3);
overlayContext.fillRect(-1, -pointSize/2, 3, pointSize);
}
else if (p.size.x !== undefined)
{
// rect
const s = p.size.scale(scale).floor();
const w = s.x, h = s.y;
p.fill && overlayContext.fillRect(-w/2|0, -h/2|0, w, h);
overlayContext.strokeRect(-w/2|0, -h/2|0, w, h);
}
else
{
// circle
overlayContext.beginPath();
overlayContext.arc(0, 0, p.size*scale/2, 0, 9);
p.fill && overlayContext.fill();
overlayContext.stroke();
}
overlayContext.restore();
});
// remove expired primitives
debugPrimitives = debugPrimitives.filter(r=>r.timer<0);
}
if (debugObject)
{
const saveContext = mainContext;
mainContext = overlayContext;
const raycastHitPos = tileCollisionRaycast(debugObject.pos, mousePos);
raycastHitPos && drawRect(raycastHitPos.floor().add(vec2(.5)), vec2(1), rgb(0,1,1,.3));
drawLine(mousePos, debugObject.pos, .1, raycastHitPos ? rgb(1,0,0,.5) : rgb(0,1,0,.5));
const debugText = 'mouse pos = ' + mousePos +
'\nmouse collision = ' + tileCollisionGetData(mousePos) +
'\n\n--- object info ---\n' +
debugObject.toString();
drawTextScreen(debugText, mousePosScreen, 24, rgb(), .05, undefined, 'center', 'monospace');
mainContext = saveContext;
}
{
// draw debug overlay
const fontSize = 20;
const lineHeight = fontSize * 1.2 | 0;
overlayContext.save();
overlayContext.fillStyle = '#fff';
overlayContext.textAlign = 'left';
overlayContext.textBaseline = 'top';
overlayContext.font = fontSize + 'px monospace';
overlayContext.shadowColor = '#000';
overlayContext.shadowBlur = 9;
let x = 9, y = 0, h = lineHeight;
if (debugOverlay)
{
overlayContext.fillText(`${engineName} v${engineVersion}`, x, y += h/2 );
overlayContext.fillText('Time: ' + formatTime(time), x, y += h);
overlayContext.fillText('FPS: ' + averageFPS.toFixed(1) + (glEnable?' WebGL':' Canvas2D'),
x, y += h);
overlayContext.fillText('Objects: ' + engineObjects.length, x, y += h);
overlayContext.fillText('Draw Count: ' + drawCount, x, y += h);
overlayContext.fillText('---------', x, y += h);
overlayContext.fillStyle = '#f00';
overlayContext.fillText('ESC: Debug Overlay', x, y += h);
overlayContext.fillStyle = debugPhysics ? '#f00' : '#fff';
overlayContext.fillText('1: Debug Physics', x, y += h);
overlayContext.fillStyle = debugParticles ? '#f00' : '#fff';
overlayContext.fillText('2: Debug Particles', x, y += h);
overlayContext.fillStyle = debugGamepads ? '#f00' : '#fff';
overlayContext.fillText('3: Debug Gamepads', x, y += h);
overlayContext.fillStyle = debugRaycast ? '#f00' : '#fff';
overlayContext.fillText('4: Debug Raycasts', x, y += h);
overlayContext.fillStyle = '#fff';
overlayContext.fillText('5: Save Screenshot', x, y += h);
overlayContext.fillText('6: Toggle Video Capture', x, y += h);
let keysPressed = '';
let mousePressed = '';
for (const i in inputData[0])
{
if (!keyIsDown(i, 0))
continue;
if (parseInt(i) < 3)
mousePressed += i + ' ' ;
else if (keyIsDown(i, 0))
keysPressed += i + ' ' ;
}
mousePressed && overlayContext.fillText('Mouse: ' + mousePressed, x, y += h);
keysPressed && overlayContext.fillText('Keys: ' + keysPressed, x, y += h);
// show gamepad buttons
for (let i = 1; i < inputData.length; i++)
{
let buttonsPressed = '';
if (inputData[i])
for (const j in inputData[i])
{
if (keyIsDown(j, i))
buttonsPressed += j + ' ' ;
}
buttonsPressed && overlayContext.fillText(`Gamepad ${i-1}: ` + buttonsPressed, x, y += h);
}
}
else
{
overlayContext.fillText(debugPhysics ? 'Debug Physics' : '', x, y += h);
overlayContext.fillText(debugParticles ? 'Debug Particles' : '', x, y += h);
overlayContext.fillText(debugRaycast ? 'Debug Raycasts' : '', x, y += h);
overlayContext.fillText(debugGamepads ? 'Debug Gamepads' : '', x, y += h);
}
overlayContext.restore();
}
}
///////////////////////////////////////////////////////////////////////////////
// video capture - records video and audio at 60 fps using MediaRecorder API
// internal variables used to capture video
let debugVideoCapture, debugVideoCaptureTrack, debugVideoCaptureIcon, debugVideoCaptureTimer;
/** Check if video capture is active
* @memberof Debug */
function debugVideoCaptureIsActive() { return !!debugVideoCapture; }
/** Start capturing video
* @memberof Debug */
function debugVideoCaptureStart()
{
if (debugVideoCaptureIsActive())
return; // already recording
// captureStream passing in 0 to only capture when requestFrame() is called
const stream = mainCanvas.captureStream(0);
const chunks = [];
debugVideoCaptureTrack = stream.getVideoTracks()[0];
if (debugVideoCaptureTrack.applyConstraints)
debugVideoCaptureTrack.applyConstraints({frameRate:60}); // force 60 fps
debugVideoCapture = new MediaRecorder(stream, {mimeType:'video/webm;codecs=vp8'});
debugVideoCapture.ondataavailable = (e)=> chunks.push(e.data);
debugVideoCapture.onstop = ()=>
{
const blob = new Blob(chunks, {type: 'video/webm'});
const url = URL.createObjectURL(blob);
downloadLink.download = 'capture.webm';
downloadLink.href = url;
downloadLink.click();
URL.revokeObjectURL(url);
};
if (audioMasterGain)
{
// connect to audio master gain node
const audioStreamDestination = audioContext.createMediaStreamDestination();
audioMasterGain.connect(audioStreamDestination);
for (const track of audioStreamDestination.stream.getAudioTracks())
stream.addTrack(track); // add audio tracks to capture stream
}
// start recording
LOG('Video capture started.');
debugVideoCapture.start();
debugVideoCaptureTimer = new Timer(0);
if (!debugVideoCaptureIcon)
{
// create recording icon to show it is capturing video
debugVideoCaptureIcon = document.createElement('div');
debugVideoCaptureIcon.style.position = 'absolute';
debugVideoCaptureIcon.style.padding = '9px';
debugVideoCaptureIcon.style.color = '#f00';
debugVideoCaptureIcon.style.font = '50px monospace';
document.body.appendChild(debugVideoCaptureIcon);
}
// show recording icon
debugVideoCaptureIcon.textContent = '';
debugVideoCaptureIcon.style.display = '';
}
/** Stop capturing video and save to disk
* @memberof Debug */
function debugVideoCaptureStop()
{
if (!debugVideoCaptureIsActive())
return; // not recording
// stop recording
LOG(`Video capture ended. ${debugVideoCaptureTimer.get().toFixed(2)} seconds recorded.`);
debugVideoCapture.stop();
debugVideoCapture = 0;
debugVideoCaptureIcon.style.display = 'none';
}
// update video capture, called automatically by engine
function debugVideoCaptureUpdate()
{
if (!debugVideoCaptureIsActive())
return; // not recording
// save the video frame
combineCanvases();
debugVideoCaptureTrack.requestFrame();
debugVideoCaptureIcon.textContent = '● REC ' + formatTime(debugVideoCaptureTimer);
}
///////////////////////////////////////////////////////////////////////////////
// debug utility functions
// make color constants immutable with debug assertions
function debugProtectConstant(obj)
{
if (debug)
{
// get properties and store original values
const props = Object.keys(obj), values = {};
props.forEach(prop => values[prop] = obj[prop]);
// replace with getters/setters that assert
props.forEach(prop =>
{
Object.defineProperty(obj, prop, {
get: () => values[prop],
set: (value) =>
{
ASSERT(false, `Cannot modify engine constant. Attempted to set constant (${obj}) property '${prop}' to '${value}'.`);
},
enumerable: true
});
});
}
// freeze the object to prevent adding new properties
return Object.freeze(obj);
}