window.attachDebugScreen = function (screen) { const debugCanvas = mk('canvas') const ctx = debugCanvas.getContext('2d') debugCanvas.style.position = 'absolute' // hackity hack should probably set this in CSS debugCanvas.style.top = '6px' debugCanvas.style.left = '6px' debugCanvas.style.pointerEvents = 'none' let addCanvas = function () { if (!debugCanvas.parentNode) screen.canvas.parentNode.appendChild(debugCanvas) } let removeCanvas = function () { if (debugCanvas.parentNode) debugCanvas.parentNode.removeChild(debugCanvas) } let updateCanvasSize = function () { let { width, height, devicePixelRatio } = screen.window let cellSize = screen.getCellSize() debugCanvas.width = width * cellSize.width * devicePixelRatio debugCanvas.height = height * cellSize.height * devicePixelRatio debugCanvas.style.width = `${width * cellSize.width}px` debugCanvas.style.height = `${height * cellSize.height}px` } let startTime, endTime, lastReason let cells = new Map() let clippedRects = [] let startDrawing screen._debug = { drawStart (reason) { lastReason = reason startTime = Date.now() clippedRects = [] }, drawEnd () { endTime = Date.now() console.log(`Draw: ${lastReason} (${(endTime - startTime)} ms) with fancy graphics: ${screen.window.graphics}`) startDrawing() }, setCell (cell, flags) { cells.set(cell, [flags, Date.now()]) }, clipRect (...args) { clippedRects.push(args) } } let clipPattern { let patternCanvas = document.createElement('canvas') patternCanvas.width = patternCanvas.height = 12 let pctx = patternCanvas.getContext('2d') pctx.lineWidth = 1 pctx.strokeStyle = '#00f' pctx.beginPath() pctx.moveTo(0, 0) pctx.lineTo(0 - 4, 12) pctx.moveTo(4, 0) pctx.lineTo(4 - 4, 12) pctx.moveTo(8, 0) pctx.lineTo(8 - 4, 12) pctx.moveTo(12, 0) pctx.lineTo(12 - 4, 12) pctx.moveTo(16, 0) pctx.lineTo(16 - 4, 12) pctx.stroke() clipPattern = ctx.createPattern(patternCanvas, 'repeat') } let isDrawing = false let drawLoop = function () { if (isDrawing) requestAnimationFrame(drawLoop) let { devicePixelRatio, width, height } = screen.window let { width: cellWidth, height: cellHeight } = screen.getCellSize() let screenLength = width * height let now = Date.now() ctx.setTransform(devicePixelRatio, 0, 0, devicePixelRatio, 0, 0) ctx.clearRect(0, 0, width * cellWidth, height * cellHeight) let activeCells = 0 for (let cell = 0; cell < screenLength; cell++) { if (!cells.has(cell) || cells.get(cell)[0] === 0) continue let [flags, timestamp] = cells.get(cell) let elapsedTime = (now - timestamp) / 1000 if (elapsedTime > 1) continue activeCells++ ctx.globalAlpha = 0.5 * Math.max(0, 1 - elapsedTime) let x = cell % width let y = Math.floor(cell / width) if (flags & 1) { // redrawn ctx.fillStyle = '#f0f' } if (flags & 2) { // updated ctx.fillStyle = '#0f0' } ctx.fillRect(x * cellWidth, y * cellHeight, cellWidth, cellHeight) if (flags & 4) { // wide cell ctx.lineWidth = 2 ctx.strokeStyle = '#f00' ctx.strokeRect(x * cellWidth, y * cellHeight, cellWidth, cellHeight) } } if (clippedRects.length) { ctx.globalAlpha = 0.5 ctx.beginPath() for (let rect of clippedRects) { ctx.rect(...rect) } ctx.fillStyle = clipPattern ctx.fill() } if (activeCells === 0) { isDrawing = false removeCanvas() } } startDrawing = function () { if (isDrawing) return addCanvas() updateCanvasSize() isDrawing = true drawLoop() } }