carInsightSystem_wxapp/components/word-cloud/word-cloud.js

function WordCloud(wdata, laySize) {

    var cloudRadians = Math.PI / 180,
        cw = 1 << 11 >> 5,
        ch = 1 << 11;
    let data = wdata
    let words = wdata
    let canvas = cloudCanvas
    let random = Math.random
    let size = laySize
    let spiral = archimedeanSpiral


    step()

    function zeroArray(n) {
        var a = [],
            i = -1;
        while (++i < n) a[i] = 0;
        return a;
    }

    function step() {
        var contextAndRatio = getContext(canvas()),
            board = zeroArray((size[0] >> 5) * size[1]),
            bounds = null,
            n = words.length,
            i = 0,
            tags = []
        for (i; i < n; i++) {
            var d = data[i];
            d.x = (size[0] * (random() + .5)) >> 1;
            d.y = (size[1] * (random() + .5)) >> 1;
            cloudSprite(contextAndRatio, d, data, i);
            if (d.hasText && place(board, d, bounds)) {
                tags.push(d);

                if (bounds) cloudBounds(bounds, d);
                else bounds = [{ x: d.x + d.x0, y: d.y + d.y0 }, { x: d.x + d.x1, y: d.y + d.y1 }];
                // Temporary hack
                d.x -= size[0] >> 1;
                d.y -= size[1] >> 1;
            }
        }
    }

    function cloudCanvas() {
        return document.createElement("canvas");
    }

    function getContext(canvas) {
        canvas.width = canvas.height = 1;
        var ratio = Math.sqrt(canvas.getContext("2d").getImageData(0, 0, 1, 1).data.length >> 2);
        canvas.width = (cw << 5) / ratio;
        canvas.height = ch / ratio;

        var context = canvas.getContext("2d");
        context.fillStyle = context.strokeStyle = "red";
        context.textAlign = "center";

        return { context: context, ratio: ratio };
    }


    function cloudSprite(contextAndRatio, d, data, di) {
        if (d.sprite) return;
        var c = contextAndRatio.context,
            ratio = contextAndRatio.ratio;

        c.clearRect(0, 0, (cw << 5) / ratio, ch / ratio);
        var x = 0,
            y = 0,
            maxh = 0,
            n = data.length;
        --di;
        while (++di < n) {
            d = data[di];
            c.save();

            // c.font = ~~((d.size + 1) / ratio) + "px " + (d.font || "Arial");
            c.font = `${(((d.size) / ratio))}px  ${(d.font || "Arial")}`
            var w = c.measureText(d.text + "m").width * ratio,
                h = d.size << 1;
            if (d.rotate) {
                var sr = Math.sin(d.rotate * cloudRadians),
                    cr = Math.cos(d.rotate * cloudRadians),
                    wcr = w * cr,
                    wsr = w * sr,
                    hcr = h * cr,
                    hsr = h * sr;
                w = (Math.max(Math.abs(wcr + hsr), Math.abs(wcr - hsr)) + 0x1f) >> 5 << 5;
                h = ~~Math.max(Math.abs(wsr + hcr), Math.abs(wsr - hcr));
            } else {
                w = (w + 0x1f) >> 5 << 5;
            }
            if (h > maxh) maxh = h;
            if (x + w >= (cw << 5)) {
                x = 0;
                y += maxh;
                maxh = 0;
            }
            if (y + h >= ch) break;
            c.translate((x + (w >> 1)) / ratio, (y + (h >> 1)) / ratio);
            if (d.rotate) c.rotate(d.rotate * cloudRadians);
            c.fillText(d.text, 0, 0);
            if (d.padding) c.lineWidth = 2 * d.padding, c.strokeText(d.text, 0, 0);
            c.restore();
            d.width = w;
            d.height = h;
            d.xoff = x;
            d.yoff = y;
            d.x1 = w >> 1;
            d.y1 = h >> 1;
            d.x0 = -d.x1;
            d.y0 = -d.y1;
            d.hasText = true;
            x += w;
        }
        var pixels = c.getImageData(0, 0, (cw << 5) / ratio, ch / ratio).data,
            sprite = [];
        while (--di >= 0) {
            d = data[di];
            if (!d.hasText) continue;
            var w = d.width,
                w32 = w >> 5,
                h = d.y1 - d.y0;
            // Zero the buffer
            for (var i = 0; i < h * w32; i++) sprite[i] = 0;
            x = d.xoff;
            if (x == null) return;
            y = d.yoff;
            var seen = 0,
                seenRow = -1;
            for (var j = 0; j < h; j++) {
                for (var i = 0; i < w; i++) {
                    var k = w32 * j + (i >> 5),
                        m = pixels[((y + j) * (cw << 5) + (x + i)) << 2] ? 1 << (31 - (i % 32)) : 0;
                    sprite[k] |= m;
                    seen |= m;
                }
                if (seen) seenRow = j;
                else {
                    d.y0++;
                    h--;
                    j--;
                    y++;
                }
            }
            d.y1 = d.y0 + seenRow;
            d.sprite = sprite.slice(0, (d.y1 - d.y0) * w32);
        }
    }

    function place(board, tag, bounds) {
        var perimeter = [{ x: 0, y: 0 }, { x: size[0], y: size[1] }],
            startX = tag.x,
            startY = tag.y,
            maxDelta = Math.sqrt(size[0] * size[0] + size[1] * size[1]),
            s = spiral(size),
            dt = random() < .5 ? 1 : -1,
            t = -dt,
            dxdy,
            dx,
            dy;

        while (dxdy = s(t += dt)) {
            dx = ~~dxdy[0];
            dy = ~~dxdy[1];

            if (Math.min(Math.abs(dx), Math.abs(dy)) >= maxDelta) break;

            tag.x = startX + dx;
            tag.y = startY + dy;

            if (tag.x + tag.x0 < 0 || tag.y + tag.y0 < 0 ||
                tag.x + tag.x1 > size[0] || tag.y + tag.y1 > size[1]) continue;
            // TODO only check for collisions within current bounds.
            if (!bounds || !cloudCollide(tag, board, size[0])) {
                if (!bounds || collideRects(tag, bounds)) {
                    var sprite = tag.sprite,
                        w = tag.width >> 5,
                        sw = size[0] >> 5,
                        lx = tag.x - (w << 4),
                        sx = lx & 0x7f,
                        msx = 32 - sx,
                        h = tag.y1 - tag.y0,
                        x = (tag.y + tag.y0) * sw + (lx >> 5),
                        last;
                    for (var j = 0; j < h; j++) {
                        last = 0;
                        for (var i = 0; i <= w; i++) {
                            board[x + i] |= (last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0);
                        }
                        x += sw;
                    }
                    delete tag.sprite;
                    return true;
                }
            }
        }
        return false;
    }

    function cloudCollide(tag, board, sw) {
        sw >>= 5;
        var sprite = tag.sprite,
            w = tag.width >> 5,
            lx = tag.x - (w << 4),
            sx = lx & 0x7f,
            msx = 32 - sx,
            h = tag.y1 - tag.y0,
            x = (tag.y + tag.y0) * sw + (lx >> 5),
            last;
        for (var j = 0; j < h; j++) {
            last = 0;
            for (var i = 0; i <= w; i++) {
                if (((last << msx) | (i < w ? (last = sprite[j * w + i]) >>> sx : 0))
                    & board[x + i]) return true;
            }
            x += sw;
        }
        return false;
    }

    function collideRects(a, b) {
        return a.x + a.x1 > b[0].x && a.x + a.x0 < b[1].x && a.y + a.y1 > b[0].y && a.y + a.y0 < b[1].y;
    }

    function cloudBounds(bounds, d) {
        var b0 = bounds[0],
            b1 = bounds[1];
        if (d.x + d.x0 < b0.x) b0.x = d.x + d.x0;
        if (d.y + d.y0 < b0.y) b0.y = d.y + d.y0;
        if (d.x + d.x1 > b1.x) b1.x = d.x + d.x1;
        if (d.y + d.y1 > b1.y) b1.y = d.y + d.y1;
    }

    function archimedeanSpiral(size) {
        var e = size[0] / size[1];
        return function (t) {
            return [e * (t *= .1) * Math.cos(t), t * Math.sin(t)];
        };
    }

}