Canvas无限滚动映射对象位置

Question

试图让无限循环滚动在 KonvaJS 中工作，所以会有一个包含 24 个项目的网格，它只会不断滚动。

感谢@lavrton，基本网格可以正常工作，但添加项目意味着它们不会在重绘时留在原地。我猜它与：

 fill: grid[indexX][indexY],

关于如何将文本映射到块的任何想法？

 const stage = new Konva.Stage({
        container: 'container',
        width: window.innerWidth,
        height: window.innerHeight,
        draggable: true
    });

    const layer = new Konva.Layer();
    stage.add(layer);


    const WIDTH = 100;
    const HEIGHT = 100;

    const grid = [
        ['red', 'yellow'],
        ['green', 'blue']
    ];

    const blocks = [
        { w: 150, h: 150 , background: "white" , image: "/img/test2.png" , fullImage: false, title: "" , text: "" },
        { w: 150, h: 150 , background: "white" , image: "/img/person-icon.png" ,  fullImage: false ,title: "" , text: "" },
        { w: 150, h: 150 , background: "#575756" , image: "" ,  fullImage: false, title: "Title" , text: "" },
        { w: 300, h: 300 , background: "white" , image: "/img/test.png", fullImage: true, title: "" , text: "" }

    ];

        function checkShapes() {
        const startX = Math.floor((-stage.x() - stage.width()) / WIDTH) * WIDTH;
        const endX = Math.floor((-stage.x() + stage.width() * 2) / WIDTH) * WIDTH;

        const startY = Math.floor((-stage.y() - stage.height()) / HEIGHT) * HEIGHT;
        const endY = Math.floor((-stage.y() + stage.height() * 2) / HEIGHT) * HEIGHT;



        var i = 0;
        for(var x = startX; x < endX; x += WIDTH) {
            for(var y = startY; y < endY; y += HEIGHT) {

                if(i === 4)
                {
                    i = 0;
                }

                const indexX = Math.abs(x / WIDTH) % grid.length;
                const indexY = Math.abs(y / HEIGHT) % grid[0].length;

                layer.add(new Konva.Rect({
                    x,
                    y,
                    width: WIDTH,
                    height: HEIGHT,
                    fill: grid[indexX][indexY],
                    stroke: 'black',
                    strokeWidth: 4
                }))

                if(blocks[i].title != ""){

                    var complexText = new Konva.Text({
                        x,
                        y,
                        text: "TEST TEXT",
                        fontSize: 14,
                        fontFamily: 'Calibri',
                        fill: 'white',
                        width: WIDTH,
                        height: HEIGHT,
                        verticalAlign: 'middle',
                        align : "center"
                    });

                    layer.add(complexText);

                }



            }
            i++
        }

    }

    checkShapes();
    layer.draw();

    stage.on('dragend', () => {
        layer.destroyChildren();
        checkShapes();
        layer.draw();
    })

https://jsfiddle.net/kiksy/jqo2h3dx/2/

Answer 1

解释：

问题是 i 的计算。它需要基于 indexX 和 indexY

的值

像这样：

//maps from 0 to 3
const i = indexX * 2 + indexY;

当观察你的 blocks 数组时，只有一个有标题，它位于 2 的索引处，它（取决于你的视角）对应于绿色。

const i = 1 * 2 + 0; //index 2

为什么 * 2？它只是硬编码，但对应于内部网格数组长度为 2。

(Ex: grid[0].length)

完整解决方案：

const stage = new Konva.Stage({
  container: 'container',
  width: window.innerWidth,
  height: window.innerHeight,
  draggable: true
});

const layer = new Konva.Layer();
stage.add(layer);


const WIDTH = 100;
const HEIGHT = 100;

const grid = [
  ['red', 'yellow'],
  ['green', 'blue']
];

const blocks = [{
    w: 150,
    h: 150,
    background: "white",
    image: "/img/test2.png",
    fullImage: false,
    title: "",
    text: ""
  },
  {
    w: 150,
    h: 150,
    background: "white",
    image: "/img/person-icon.png",
    fullImage: false,
    title: "",
    text: ""
  },
  {
    w: 150,
    h: 150,
    background: "#575756",
    image: "",
    fullImage: false,
    title: "Title",
    text: ""
  },
  {
    w: 300,
    h: 300,
    background: "white",
    image: "/img/test.png",
    fullImage: true,
    title: "",
    text: ""
  }

];

function checkShapes() {
  const startX = Math.floor((-stage.x() - stage.width()) / WIDTH) * WIDTH;
  const endX = Math.floor((-stage.x() + stage.width() * 2) / WIDTH) * WIDTH;

  const startY = Math.floor((-stage.y() - stage.height()) / HEIGHT) * HEIGHT;
  const endY = Math.floor((-stage.y() + stage.height() * 2) / HEIGHT) * HEIGHT;



  for (var x = startX; x < endX; x += WIDTH) {
    for (var y = startY; y < endY; y += HEIGHT) {


      const indexX = ((x / WIDTH) + grid.length * WIDTH) % grid.length;
      const indexY = ((y / HEIGHT) + grid[0].length * HEIGHT) % grid[0].length;

      //maps from 0 to 3
      const i = indexX * 2 + indexY;

      layer.add(new Konva.Rect({
        x,
        y,
        width: WIDTH,
        height: HEIGHT,
        fill: grid[indexX][indexY],
        stroke: 'black',
        strokeWidth: 4
      }))

      if (blocks[i].title != "") {

        var complexText = new Konva.Text({
          x,
          y,
          text: "TEST TEXT",
          fontSize: 14,
          fontFamily: 'Calibri',
          fill: 'white',
          width: WIDTH,
          height: HEIGHT,
          verticalAlign: 'middle',
          align: "center"
        });

        layer.add(complexText);

      }
    }
  }

}

checkShapes();
layer.draw();

stage.on('dragend', () => {
  layer.destroyChildren();
  checkShapes();
  layer.draw();
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/konva/2.6.0/konva.min.js"></script>
<div id="container"></div>

带有红色和蓝色标题的完整解决方案：

const stage = new Konva.Stage({
  container: 'container',
  width: window.innerWidth,
  height: window.innerHeight,
  draggable: true
});

const layer = new Konva.Layer();
stage.add(layer);


const WIDTH = 100;
const HEIGHT = 100;

const grid = [
  ['red', 'yellow'],
  ['green', 'blue']
];

const blocks = [{
    w: 150,
    h: 150,
    background: "white",
    image: "/img/test2.png",
    fullImage: false,
    title: "Title",
    text: ""
  },
  {
    w: 150,
    h: 150,
    background: "white",
    image: "/img/person-icon.png",
    fullImage: false,
    title: "",
    text: ""
  },
  {
    w: 150,
    h: 150,
    background: "#575756",
    image: "",
    fullImage: false,
    title: "",
    text: ""
  },
  {
    w: 300,
    h: 300,
    background: "white",
    image: "/img/test.png",
    fullImage: true,
    title: "Title",
    text: ""
  }

];

function checkShapes() {
  const startX = Math.floor((-stage.x() - stage.width()) / WIDTH) * WIDTH;
  const endX = Math.floor((-stage.x() + stage.width() * 2) / WIDTH) * WIDTH;

  const startY = Math.floor((-stage.y() - stage.height()) / HEIGHT) * HEIGHT;
  const endY = Math.floor((-stage.y() + stage.height() * 2) / HEIGHT) * HEIGHT;



  for (var x = startX; x < endX; x += WIDTH) {
    for (var y = startY; y < endY; y += HEIGHT) {


      const indexX = ((x / WIDTH) + grid.length * WIDTH) % grid.length;
      const indexY = ((y / HEIGHT) + grid[0].length * HEIGHT) % grid[0].length;
      //maps from 0 to 3
      const i = indexX * 2 + indexY;

      layer.add(new Konva.Rect({
        x,
        y,
        width: WIDTH,
        height: HEIGHT,
        fill: grid[indexX][indexY],
        stroke: 'black',
        strokeWidth: 4
      }))

      if (blocks[i].title != "") {

        var complexText = new Konva.Text({
          x,
          y,
          text: "TEST TEXT",
          fontSize: 14,
          fontFamily: 'Calibri',
          fill: 'white',
          width: WIDTH,
          height: HEIGHT,
          verticalAlign: 'middle',
          align: "center"
        });

        layer.add(complexText);

      }
    }
  }

}

checkShapes();
layer.draw();

stage.on('dragend', () => {
  layer.destroyChildren();
  checkShapes();
  layer.draw();
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/konva/2.6.0/konva.min.js"></script>
<div id="container"></div>

镜像问题解决方案：

这是由于以下计算直接导致的：

const indexX = Math.abs(x / WIDTH) % grid.length;
const indexY = Math.abs(y / HEIGHT) % grid[0].length;

并解决了：

const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;
const indexY = ((y/HEIGHT) + grid.length * HEIGHT) % grid[0].length;

当您计算颜色时，您将其基于您的网格阵列：

  ['red', 'yellow', 'pink' ]
  ['green', 'blue' , 'gray' ]
  ['orange', 'blue' , 'black']

当你逻辑上向下或向右移动（正值）时没有问题，当你向上或向左移动（负值）时一切都变得疯狂，因为你用 Math.abs 计算 indexX 和 indexY。

例如，位于 [-1,-1] 的红色框与网格中的任何颜色都不匹配。根据您的公式，它会简单地选择 'blue' 颜色，而实际上它应该是 'black' 颜色。

Canvas无限滚动映射对象位置

Canvas Infinite Scroll mapping object location

html

javascript

canvas

html5-canvas

konvajs

解释：

完整解决方案：

带有红色和蓝色标题的完整解决方案：

镜像问题解决方案：