Canvas Infinite Scroll mapping object location












1















Trying to get infinite looping scrolling to work in KonvaJS, so there would be a grid of say 24 items, which would just keep scrolling over and over.



Thanks to @lavrton the basic grid is working, but adding items means that they don't stay in place on the redraw. Im guessing it relates to:



 fill: grid[indexX][indexY],


Any ideas how I can map the text to the blocks? 



 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/






javascript html5 canvas html5-canvas konvajs







share|improve this question

























  • You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

    – Oen44
    Jan 2 at 15:55
















1















Trying to get infinite looping scrolling to work in KonvaJS, so there would be a grid of say 24 items, which would just keep scrolling over and over.



Thanks to @lavrton the basic grid is working, but adding items means that they don't stay in place on the redraw. Im guessing it relates to:



 fill: grid[indexX][indexY],


Any ideas how I can map the text to the blocks? 



 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/






javascript html5 canvas html5-canvas konvajs







share|improve this question

























  • You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

    – Oen44
    Jan 2 at 15:55














1












1








1








Trying to get infinite looping scrolling to work in KonvaJS, so there would be a grid of say 24 items, which would just keep scrolling over and over.



Thanks to @lavrton the basic grid is working, but adding items means that they don't stay in place on the redraw. Im guessing it relates to:



 fill: grid[indexX][indexY],


Any ideas how I can map the text to the blocks? 



 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/






javascript html5 canvas html5-canvas konvajs







share|improve this question
















Trying to get infinite looping scrolling to work in KonvaJS, so there would be a grid of say 24 items, which would just keep scrolling over and over.



Thanks to @lavrton the basic grid is working, but adding items means that they don't stay in place on the redraw. Im guessing it relates to:



 fill: grid[indexX][indexY],


Any ideas how I can map the text to the blocks? 



 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/






javascript html5 canvas html5-canvas konvajs




javascript html5 canvas html5-canvas konvajs






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Dec 19 '18 at 17:49









chazsolo

5,4001234




5,4001234










asked Dec 19 '18 at 17:31









KiksyKiksy

31821433




31821433













  • You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

    – Oen44
    Jan 2 at 15:55



















  • You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

    – Oen44
    Jan 2 at 15:55

















You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

– Oen44
Jan 2 at 15:55





You are making illusion of infinite scroll. You need world and camera to make it work. Right know you are showing stuff at coordination that depends on the size of canvas so whatever is outside won't work. It's easier to use something else than KonvaJS in this situation.

– Oen44
Jan 2 at 15:55












1 Answer
1






active

oldest

votes


















2





+200









Explanation:



The issue is the calculation of i. It needs to be based on the values of indexX and indexY



Something like this:



//maps from 0 to 3

const i = indexX * 2 + indexY;


When observing your blocks array, only one has title and it is at the index of 2 which (depending on your perspective) corresponds to the green color.



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


Why * 2 ? It's just hard coded, but corresponds to the inner grid array length which is 2. 



(Ex: grid[0].length)


Full solution:






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>





Full Solution with Red and Blue having titles:






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>





Mirror Issue Solution:



This is directly caused because of the following calculations:



const indexX = Math.abs(x / WIDTH) % grid.length;

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


and solved with:



const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;

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


When you calculate colors you base it off of your grid array:



  ['red', 'yellow', 'pink' ]

  ['green', 'blue' , 'gray' ]

  ['orange', 'blue' , 'black']


And when you advance logically down or right (positive values) there are no issues, when you move up or left (negative values) everything goes nuts because you calculate indexX and indexY with Math.abs.



So for example, a red box located [-1,-1] doesn't match any color in the grid. Based on your formula, it'll simply choose the 'blue' color when in fact it should be the 'black' color.






share|improve this answer


























  • Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

    – Kiksy
    Jan 3 at 15:57











  • I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

    – Kiksy
    Jan 3 at 16:18













  • ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

    – Kiksy
    Jan 3 at 16:59












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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









2





+200









Explanation:



The issue is the calculation of i. It needs to be based on the values of indexX and indexY



Something like this:



//maps from 0 to 3

const i = indexX * 2 + indexY;


When observing your blocks array, only one has title and it is at the index of 2 which (depending on your perspective) corresponds to the green color.



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


Why * 2 ? It's just hard coded, but corresponds to the inner grid array length which is 2. 



(Ex: grid[0].length)


Full solution:






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>





Full Solution with Red and Blue having titles:






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>





Mirror Issue Solution:



This is directly caused because of the following calculations:



const indexX = Math.abs(x / WIDTH) % grid.length;

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


and solved with:



const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;

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


When you calculate colors you base it off of your grid array:



  ['red', 'yellow', 'pink' ]

  ['green', 'blue' , 'gray' ]

  ['orange', 'blue' , 'black']


And when you advance logically down or right (positive values) there are no issues, when you move up or left (negative values) everything goes nuts because you calculate indexX and indexY with Math.abs.



So for example, a red box located [-1,-1] doesn't match any color in the grid. Based on your formula, it'll simply choose the 'blue' color when in fact it should be the 'black' color.






share|improve this answer


























  • Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

    – Kiksy
    Jan 3 at 15:57











  • I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

    – Kiksy
    Jan 3 at 16:18













  • ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

    – Kiksy
    Jan 3 at 16:59
















2





+200









Explanation:



The issue is the calculation of i. It needs to be based on the values of indexX and indexY



Something like this:



//maps from 0 to 3

const i = indexX * 2 + indexY;


When observing your blocks array, only one has title and it is at the index of 2 which (depending on your perspective) corresponds to the green color.



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


Why * 2 ? It's just hard coded, but corresponds to the inner grid array length which is 2. 



(Ex: grid[0].length)


Full solution:






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>





Full Solution with Red and Blue having titles:






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>





Mirror Issue Solution:



This is directly caused because of the following calculations:



const indexX = Math.abs(x / WIDTH) % grid.length;

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


and solved with:



const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;

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


When you calculate colors you base it off of your grid array:



  ['red', 'yellow', 'pink' ]

  ['green', 'blue' , 'gray' ]

  ['orange', 'blue' , 'black']


And when you advance logically down or right (positive values) there are no issues, when you move up or left (negative values) everything goes nuts because you calculate indexX and indexY with Math.abs.



So for example, a red box located [-1,-1] doesn't match any color in the grid. Based on your formula, it'll simply choose the 'blue' color when in fact it should be the 'black' color.






share|improve this answer


























  • Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

    – Kiksy
    Jan 3 at 15:57











  • I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

    – Kiksy
    Jan 3 at 16:18













  • ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

    – Kiksy
    Jan 3 at 16:59














2





+200







2





+200



2




+200





Explanation:



The issue is the calculation of i. It needs to be based on the values of indexX and indexY



Something like this:



//maps from 0 to 3

const i = indexX * 2 + indexY;


When observing your blocks array, only one has title and it is at the index of 2 which (depending on your perspective) corresponds to the green color.



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


Why * 2 ? It's just hard coded, but corresponds to the inner grid array length which is 2. 



(Ex: grid[0].length)


Full solution:






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>





Full Solution with Red and Blue having titles:






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>





Mirror Issue Solution:



This is directly caused because of the following calculations:



const indexX = Math.abs(x / WIDTH) % grid.length;

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


and solved with:



const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;

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


When you calculate colors you base it off of your grid array:



  ['red', 'yellow', 'pink' ]

  ['green', 'blue' , 'gray' ]

  ['orange', 'blue' , 'black']


And when you advance logically down or right (positive values) there are no issues, when you move up or left (negative values) everything goes nuts because you calculate indexX and indexY with Math.abs.



So for example, a red box located [-1,-1] doesn't match any color in the grid. Based on your formula, it'll simply choose the 'blue' color when in fact it should be the 'black' color.






share|improve this answer















Explanation:



The issue is the calculation of i. It needs to be based on the values of indexX and indexY



Something like this:



//maps from 0 to 3

const i = indexX * 2 + indexY;


When observing your blocks array, only one has title and it is at the index of 2 which (depending on your perspective) corresponds to the green color.



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


Why * 2 ? It's just hard coded, but corresponds to the inner grid array length which is 2. 



(Ex: grid[0].length)


Full solution:






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>





Full Solution with Red and Blue having titles:






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>





Mirror Issue Solution:



This is directly caused because of the following calculations:



const indexX = Math.abs(x / WIDTH) % grid.length;

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


and solved with:



const indexX = ((x/WIDTH) + grid.length * WIDTH )  % grid.length;

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


When you calculate colors you base it off of your grid array:



  ['red', 'yellow', 'pink' ]

  ['green', 'blue' , 'gray' ]

  ['orange', 'blue' , 'black']


And when you advance logically down or right (positive values) there are no issues, when you move up or left (negative values) everything goes nuts because you calculate indexX and indexY with Math.abs.



So for example, a red box located [-1,-1] doesn't match any color in the grid. Based on your formula, it'll simply choose the 'blue' color when in fact it should be the 'black' color.






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>





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>





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>





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>






share|improve this answer














share|improve this answer



share|improve this answer








edited Jan 3 at 18:27

























answered Jan 2 at 17:12









kemicofakemicofa

10.7k44083




10.7k44083













  • Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

    – Kiksy
    Jan 3 at 15:57











  • I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

    – Kiksy
    Jan 3 at 16:18













  • ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

    – Kiksy
    Jan 3 at 16:59



















  • Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

    – Kiksy
    Jan 3 at 15:57











  • I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

    – Kiksy
    Jan 3 at 16:18













  • ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

    – Kiksy
    Jan 3 at 16:59

















Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

– Kiksy
Jan 3 at 15:57





Wow thanks! That answers my question. I've expanded on it here: jsfiddle.net/kiksy/hpduwr09/3 you can see that the 2 titled blocks stay in the correct order when dragging down or left, but draggin up or right means they go out of order. I assume becuase it needs to draw in reverse for a negative x/y drag?

– Kiksy
Jan 3 at 15:57













I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

– Kiksy
Jan 3 at 16:18







I think I understood that part, the issue is the redraw on a up or left drag (so a minus) seems to redraw in the wrong order, even with the updated * 2 .see jsfiddle.net/kiksy/hpduwr09/10 . Notice the 4 numbered blocks go out of order. Thanks for your help with this. Its been melting my brain for so long now.

– Kiksy
Jan 3 at 16:18















ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

– Kiksy
Jan 3 at 16:59





ah yes! I've just been playing around with trying to adjust those values based on the drag direction! Your solution is much simpler! Thanks so much.

– Kiksy
Jan 3 at 16:59




















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