canvaseyeDropper
我需要实现一个吸管工具。 我想要它,所以你点击吸管按钮使其激活,然后使用onmove它将改变我的颜色选择器的颜色,当你点击使用onclick它将使用以下颜色选择颜色选择器:
$('#colorpickerHolder').ColorPickerSetColor(eyeDropperColour);
变量eyeDropperColour将根据您所使用的颜色像素使用onlick设置。 我想知道我必须根据我拥有的图层来做它:canvas和canvasCursor。
我一直在看这个指南,但我不能让它适用于我的项目? http://palebluepixel.org/2011/11/16/html5-canvas-eyedropper/
这是我的项目: http : //www.taffatech.com/Paint.html
我有:
var eyeDropperActive = false; var eyeDropperColour;
和:
$("#brushEyeDropper").click(function() { if ( eyeDropperActive == true) { eyeDropperActive = false; } else if ( eyeDropperActive == false) { eyeDropperActive = true; } });
创建canvas“吸管”工具
这是如何读取canvas上任何X / Y处的像素颜色:
function getPixelColor(x, y) { var pxData = ctx.getImageData(x,y,1,1); return("rgb("+pxData.data[0]+","+pxData.data[1]+","+pxData.data[2]+")"); }
其余的只是通过点击canvas来控制何时接受颜色。
var eyedropperIsActive=false; // Activate reading pixel colors when a #startDropper button is clicked $("#startDropper").click(function(e){eyedropperIsActive=true;}); // if the tool is active, report the color under the mouse $("#canvas").mousemove(function(e){handleMouseMove(e);}); // when the user clicks on the canvas, turn off the tool // (the last color will remain selected) $("#canvas").click(function(e){eyedropperIsActive=false;});
这里是mousemove事件处理程序,它调用getPixelColor并报告该颜色
// if the tool is active, report any color under the mouse function handleMouseMove(e){ if(!eyedropperIsActive){return;} mouseX=parseInt(e.clientX-offsetX); mouseY=parseInt(e.clientY-offsetY); // Put your mousemove stuff here var eyedropColor=getPixelColor(mouseX,mouseY); $("#results").css("backgroundColor",getPixelColor(mouseX,mouseY)); }
这是代码和小提琴: http : //jsfiddle.net/m1erickson/zpfdv/
Click "Activate Eyedropper" to read pixel color under the mouse
Click canvas to set the color and de-active the eyedropper