Javascript布尔“切换”

Question

我有一个函数，查看游标（x，y），看它是否落在几个矩形之一（a<x<b, c<y<d）。但是，我需要根据光标是否曾经落入而设置一个布尔值，使其成为一个特定的矩形，并且只有在光标落入其他矩形时才能将其重置。换句话说

1. A为真，如果光标下降矩形X

2. A内是假，如果光标落在矩形1，2，3内或4

3. A保留如果其前值它的任何地方，但Y或Z

麻烦的是，无论我做什么布尔返回false，如果我离开第一个矩形，我是否前往其他2 rectan无论是否。我试图做布尔全球但这没有帮助。

代码;

var r 
var s 
var l 
var inCenter = false 

function makeRects(a,b) 


{  
    r = a-b 
    s = (a/2) - (b/2) 
    l = (a/2) + (b/2) 

    lSide = new Array(4) 
    lSide[0] = 0 
    lSide[1] = 0 
    lSide[2] = a 
    lSide[3] = b 

    tSide = new Array(4) 
    tSide[0] = 0 
    tSide[1] = 0 
    tSide[2] = b 
    tSide[3] = a 

    rSide = new Array(4) 
    rSide[0] = r 
    rSide[1] = 0 
    rSide[2] = b 
    rSide[3] = b 

    bSide = new Array(4) 
    bSide[0] = 0 
    bSide[1] = r 
    bSide[2] = b 
    bSide[3] = b 

    aSquare = new Array(4) 
    aSquare[0] = 0 
    aSquare[1] = 0 
    aSquare[2] = s 
    aSquare[3] = s 

    bSquare = new Array(4) 
    bSquare[0] = l 
    bSquare[1] = 0 
    bSquare[2] = b 
    bSquare[3] = s 

    cSquare = new Array(4) 
    cSquare[0] = 0 
    cSquare[1] = l 
    cSquare[2] = s 
    cSquare[3] = r 

    dSquare = new Array(4) 
    dSquare[0] = l 
    dSquare[1] = l 
    dSquare[2] = r 
    dSquare[3] = r 

    lCenter = new Array(4) 
    lCenter[0] = 0 
    lCenter[1] = s 
    lCenter[2] = b 
    lCenter[3] = l 

    tCenter = new Array(4) 
    tCenter[0] = s 
    tCenter[1] = 0 
    tCenter[2] = l 
    tCenter[3] = b 

    rCenter = new Array(4) 
    rCenter[0] = r 
    rCenter[1] = s 
    rCenter[2] = a 
    rCenter[3] = l 

    bCenter = new Array(4) 
    bCenter[0] = s 
    bCenter[1] = r 
    bCenter[2] = l 
    bCenter[3] = a 

    mCenter = new Array(4) 
    mCenter[0] = s 
    mCenter[1] = s 
    mCenter[2] = l 
    mCenter[3] = l 
} 

function cursor(a,b) 

{ 
    var inaSquare = false 
    var inbSquare = false 
    var incSquare = false 
    var indSquare = false 
    var inCenter = false 

    if ((a>aSquare[0] && a<aSquare[2])&&(b>aSquare[1] && b<aSquare[3])) 
    { 
    inaSquare = true 
    post("aSquare"); 
    post(); 
    } 

    if ((a>bSquare[0] && a<bSquare[2])&&(b>bSquare[1] && b<bSquare[3])) 
    { 
    inbSquare = true 
    post("bSquare"); 
    post(); 
    } 

    if ((a>cSquare[0] && a<cSquare[2])&&(b>cSquare[1] && b<cSquare[3])) 
    { 
    inbSquare = true 
    post("cSquare"); 
    post(); 
    } 

    if ((a>dSquare[0] && a<dSquare[2])&&(b>dSquare[1] && b<dSquare[3])) 
    { 
    indSquare = true 
    post("dSquare"); 
    post(); 
    } 

    if (inaSquare||inbSquare||incSquare||indSquare) 
    { 
    inCenter = false 
    } 

    if ((a>mCenter[0] && a<mCenter[2])&&(b>mCenter[1] && b<mCenter[3])) 
    { 
    inCenter = true 
    inaSquare = false 
    inbSquare = false 
    incSquare = false 
    indSquare = false 
    } 

    if (((inCenter && a>s) && a<l) && b<lCenter[3]) 

    { 
    outlet (1, 1) 
    } 

    else if (((inCenter && a>s) && a<l) && b>rCenter[0]) 

    { 
    outlet (1, 2) 
    } 

    else if (((inCenter && b>s) && b<l) && a<tCenter[3]) 

    { 
    outlet (1, 3) 
    } 


    else if (((inCenter && b>s) && b<l) && b>bCenter[1]) 

    { 
    outlet (1, 4) 
    } 

    else 

    { 
    outlet (1, 0) 
    } 
    post("inCenter"); 
    post(inCenter); 
    post(); 
    post("inaSquare"); 
    post(inaSquare); 
    post(); 
    post("inbSquare"); 
    post(inbSquare); 
    post(); 
    post("incSquare"); 
    post(incSquare); 
    post(); 
    post("indSquare"); 
    post(indSquare); 
    post(); 

} 

Answer 1

好吧，我修改了原来的演示基于我认为你所要完成的，但它仍然不是很清楚，所以你需要更好地描述你所要完成的，而不是如何根据切换布尔什么在矩形坐标点击测试。您可能会以简单的方式完成您尝试完成的任务，而无需使用基于坐标的命中测试。

演示：

http://jsfiddle.net/DaveAlger/cVPpU/5/

HTML：

<p id="toggle-state">false: center not hit</p> 
<p id="mouse-xy"></p> 

<canvas id="top" class="box" x="200" y="50" width="100" height="100" c="#933" b="#faa"></canvas> 
<canvas id="left" class="box" x="50" y="200" width="100" height="100" c="#993" b="#ffa"></canvas> 
<canvas id="right" class="box" x="350" y="200" width="100" height="100" c="#696" b="#dfd"></canvas> 
<canvas id="bottom" class="box" x="200" y="350" width="100" height="100" c="#369" b="#adf"></canvas> 
<canvas id="center" class="box" x="200" y="200" width="100" height="100" c="#999" b="#ddd"></canvas> 

CSS：

.box{position: absolute;} 
#mouse-xy{float:right;padding:30px;color:#999;font-family:sans-serif;} 

JS：

var isCenterHit = false; 
var checkCenterHit = true; 

// draw canvas rectangles 
$('.box').each(function(i) { 
    //alert(i); 
    var id = $(this).attr('id') 
    var w = $(this).width(); 
    var h = $(this).height(); 
    var c = $(this).attr('c'); 
    var x = $(this).attr('x'); 
    var y = $(this).attr('y'); 

    drawRect(document.getElementById(id).getContext('2d'), w, h, c, id); 
    $(this).offset({top: y, left: x}); 
}); 

function drawRect(ctx, width, height, color, text) { 
    ctx.fillStyle = color; 
    ctx.fillRect(0, 0, width, height); 
    ctx.fillStyle = '#fff'; 
    ctx.font = '30px sans-serif'; 
    ctx.textBaseline = 'top'; 
    ctx.fillText(text, 0, 0); 
} 

// listen for mouse over 
$(document).mousemove(function(e){ 
    var x = e.pageX; 
    var y = e.pageY; 

    var tX = $(e.target).attr('x'); 
    var tY = $(e.target).attr('y'); 
    var tW = $(e.target).width(); 
    var tH = $(e.target).height(); 

    // update mouse location 
    $('#mouse-xy').html("center hit: " + isCenterHit + " | X: " + x + " Y: " + y); 

    // rectangle coordinate hit test (this can be done other ways too) 
    if (x > tX && x < tX + tW && y > tY && y < tY + tH) { 

     // toggle the boolean 
     if (checkCenterHit && $(e.target).attr('id') === 'center') { 
      isCenterHit = !isCenterHit; 
      checkCenterHit = false; 
     } 

     if (isCenterHit) { 
      // do this when center hit state is 'on' 
      $('body').css('background-color',$(e.target).attr('b')); 
      $('canvas').css('cursor','pointer'); 
     } else { 
      // do this when center hit state is 'off' 
      $('body').css('background-color',''); 
      $('canvas').css('cursor',''); 
     } 
    } 
    else { 
     $('body').css('background-color','#ffffff'); 
     checkCenterHit = true; 
    } 
}); 

Answer 2

对不起，这不是一个真正的答案，但我编辑了代码以使用循环和数组/地图。这样你可以得到更多的帮助。希望您能够从中学到一些东西，以及:)

所以，你的代码也可能是这样的：

var r 
var s 
var l 

function makeRects(a,b) 
{ 
    r = a-b 
    s = (a/2) - (b/2) 
    l = (a/2) + (b/2) 

    // Place all arrays inside maps, so that we can loop through them later. 
    side = { 
     l: [0, 0, a, b], 
     t: [0, 0, b, a], 
     r: [r, 0, b, b], 
     b: [0, r, b, b], 
    } 

    square = { 
     a: [0, 0, s, s], 
     b: [l, 0, b, s], 
     c: [0, l, s, r], 
     d: [l, l, r, r] 
    } 

    center = { 
     l: [0, s, b, l], 
     t: [s, 0, l, b], 
     r: [r, s, a, l], 
     b: [s, r, l, a], 
     m: [s, s, l, l] 
    } 
} 

function cursor(a,b) 
{ 
    var inside = { 
     a: false, 
     b: false, 
     c: false, 
     d: false, 
     center: true 
    } 

    // This loop will run through every key of the map, and x will hold the key 
    for (var x in square) { 
     if ((a>square[a][x] && a<square[x][2])&&(b>square[x][1] && b<square[x][3])) 
     { 
      inside[x] = true; 
      // Instead of checking if the cursor is inside the center, we assume it 
      // is by default, and if it is found inside a square, inside['center'] is set to false 
      inside['center'] = false; 
      post(x + "Square"); 
      post(); 
     } 
    } 

    // Not sure what you want to do here... 
    if (((inside['center'] && a>s) && a<l) && b<center['l'][3]) 
    { 
    outlet (1, 1) 
    } 

    else if (((inside['center'] && a>s) && a<l) && b>center['r'][0]) 
    { 
    outlet (1, 2) 
    } 

    else if (((inside['center'] && b>s) && b<l) && a<center['t'][3]) 
    { 
    outlet (1, 3) 
    } 


    else if (((inside['center'] && b>s) && b<l) && b>center['b'][1]) 
    { 
    outlet (1, 4) 
    } 

    else 
    { 
    outlet (1, 0) 
    } 


} 

Answer 3

可能是你的命中测试功能需要呼吁一个标志doTest设置为true最初，然后设置为false，一旦中心矩形打

那么你可以一次不同的矩形打