|
| 1 | +/** |
| 2 | + * |
| 3 | + * layer pick utils |
| 4 | + * can use by PointLayer,LineStringLayer,PolygonLayer,VectorTileLayer,Geo3DTilesLayer,GLTFLayer etc |
| 5 | + * |
| 6 | + * @returns |
| 7 | + */ |
| 8 | +import Canvas from '../Canvas'; |
| 9 | + |
| 10 | +export function isGLRenderLayer(layer) { |
| 11 | + if (!layer) { |
| 12 | + return false; |
| 13 | + } |
| 14 | + const renderer = layer.getRenderer && layer.getRenderer(); |
| 15 | + return !!(renderer && renderer.gl); |
| 16 | +} |
| 17 | + |
| 18 | +export function checkCanvasSize(targetCanvas, sourceCanvas) { |
| 19 | + if (!targetCanvas || !sourceCanvas) { |
| 20 | + return null; |
| 21 | + } |
| 22 | + const { width, height, style } = sourceCanvas; |
| 23 | + if (targetCanvas.width !== width || targetCanvas.height !== height) { |
| 24 | + targetCanvas.width = width; |
| 25 | + targetCanvas.height = height; |
| 26 | + } |
| 27 | + if (targetCanvas.style.width !== style.width || targetCanvas.style.height !== style.height) { |
| 28 | + targetCanvas.style.width = style.width; |
| 29 | + targetCanvas.style.height = style.height; |
| 30 | + } |
| 31 | + return targetCanvas; |
| 32 | +} |
| 33 | + |
| 34 | +export function clearCanvas(canvas) { |
| 35 | + if (!canvas) { |
| 36 | + return null; |
| 37 | + } |
| 38 | + const ctx = Canvas.getCanvas2DContext(canvas); |
| 39 | + Canvas.clearRect(ctx, 0, 0, canvas.width, canvas.height); |
| 40 | + return ctx; |
| 41 | +} |
| 42 | + |
| 43 | +let tempCanvas; |
| 44 | +export function layerIsBlankInPoint(layer, containerPoint, tolerance = 1) { |
| 45 | + if (!layer || !containerPoint) { |
| 46 | + return true; |
| 47 | + } |
| 48 | + const renderer = layer.getRenderer && layer.getRenderer(); |
| 49 | + if (!renderer || !renderer.canvas) { |
| 50 | + return true; |
| 51 | + } |
| 52 | + const map = layer.getMap(); |
| 53 | + if (!map) { |
| 54 | + return true; |
| 55 | + } |
| 56 | + if (!tempCanvas) { |
| 57 | + tempCanvas = Canvas.createCanvas(1, 1); |
| 58 | + // document.body.appendChild(tempCanvas); |
| 59 | + } |
| 60 | + tempCanvas = checkCanvasSize(tempCanvas, renderer.canvas); |
| 61 | + if (!tempCanvas) { |
| 62 | + return true; |
| 63 | + } |
| 64 | + const ctx = clearCanvas(tempCanvas); |
| 65 | + if (!ctx) { |
| 66 | + return true; |
| 67 | + } |
| 68 | + tolerance = Math.max(layer.options.geometryEventTolerance || 1, tolerance); |
| 69 | + tolerance = Math.abs(Math.round(tolerance)); |
| 70 | + tolerance = Math.max(1, tolerance); |
| 71 | + const r = map.getDevicePixelRatio(); |
| 72 | + const { x, y } = containerPoint; |
| 73 | + let left = x - tolerance, top = y - tolerance; |
| 74 | + left = Math.round(left * r); |
| 75 | + top = Math.round(top * r); |
| 76 | + left = Math.max(0, left); |
| 77 | + top = Math.max(0, top); |
| 78 | + const size = tolerance * 2; |
| 79 | + let imageData; |
| 80 | + try { |
| 81 | + ctx.drawImage(renderer.canvas, 0, 0); |
| 82 | + imageData = ctx.getImageData(left, top, size, size); |
| 83 | + } catch (error) { |
| 84 | + console.warn('hit detect failed with tainted canvas, some geometries have external resources in another domain:\n', error); |
| 85 | + } |
| 86 | + if (!imageData) { |
| 87 | + return false; |
| 88 | + } |
| 89 | + const data = imageData.data; |
| 90 | + for (let i = 0, len = data.length; i < len; i += 4) { |
| 91 | + const A = data[i + 3]; |
| 92 | + if (A > 0) { |
| 93 | + return false; |
| 94 | + } |
| 95 | + } |
| 96 | + return true; |
| 97 | + |
| 98 | +} |
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