问题描述
我正在尝试搭建和。
是一个简单的项目，它有一个在拖动滑块时旋转的齿轮。这很棒，但我想用鼠标进行交互。
Here is a simple project that has the gears that spin when a slider is dragged. This is great but I would like to do the interaction with the mouse instead.
这是svg齿轮的一个例子：
This is an example of the gears as svg:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="240" height="200" xml:space="preserve" id="gears">
<!-- Generated by PaintCode - http://www.paintcodeapp.com -->
<path id="gears-largeGear" stroke="none" fill="rgb(69, 131, 212)" d="M 2.78,-67.94 C 3.71,-63.88 4.74,-59.43 5.59,-55.72 7.73,-55.51 9.84,-55.18 11.9,-54.73 13.87,-58 16.21,-61.91 18.36,-65.49 20.15,-64.99 21.91,-64.42 23.64,-63.78 23.27,-59.62 22.87,-55.08 22.54,-51.28 24.5,-50.42 26.4,-49.45 28.23,-48.37 31.11,-50.87 34.55,-53.87 37.69,-56.6 39.24,-55.58 40.73,-54.49 42.18,-53.34 40.55,-49.5 38.77,-45.3 37.28,-41.79 38.87,-40.37 40.37,-38.87 41.79,-37.28 45.3,-38.77 49.5,-40.55 53.34,-42.18 54.49,-40.73 55.58,-39.24 56.6,-37.69 53.87,-34.55 50.87,-31.11 48.37,-28.23 49.45,-26.4 50.42,-24.5 51.28,-22.54 55.08,-22.87 59.62,-23.27 63.78,-23.64 64.42,-21.91 64.99,-20.15 65.49,-18.36 61.91,-16.21 58,-13.87 54.73,-11.9 55.18,-9.84 55.51,-7.73 55.72,-5.59 59.43,-4.74 63.88,-3.71 67.94,-2.78 67.98,-1.86 68,-0.93 68,0 68,0.93 67.98,1.86 67.94,2.78 63.88,3.71 59.43,4.74 55.72,5.59 55.51,7.73 55.18,9.84 54.73,11.9 58,13.87 61.91,16.21 65.49,18.36 64.99,20.15 64.42,21.91 63.78,23.64 59.62,23.27 55.08,22.87 51.28,22.54 50.42,24.5 49.45,26.4 48.37,28.23 50.87,31.11 53.87,34.55 56.6,37.69 55.58,39.24 54.49,40.73 53.34,42.18 49.5,40.55 45.3,38.77 41.79,37.28 40.37,38.87 38.87,40.37 37.28,41.79 38.77,45.3 40.55,49.5 42.18,53.34 40.73,54.49 39.24,55.58 37.69,56.6 34.55,53.87 31.11,50.87 28.23,48.37 26.4,49.45 24.5,50.42 22.54,51.28 22.87,55.08 23.27,59.62 23.64,63.78 21.91,64.42 20.15,64.99 18.36,65.49 16.21,61.91 13.87,58 11.9,54.73 9.84,55.18 7.73,55.51 5.59,55.72 4.74,59.43 3.71,63.88 2.78,67.94 1.86,67.98 0.93,68 -0,68 -0.93,68 -1.86,67.98 -2.78,67.94 -3.71,63.88 -4.74,59.43 -5.59,55.72 -7.73,55.51 -9.84,55.18 -11.9,54.73 -13.87,58 -16.21,61.91 -18.36,65.49 -20.15,64.99 -21.91,64.42 -23.64,63.78 -23.27,59.62 -22.87,55.08 -22.54,51.28 -24.5,50.42 -26.4,49.45 -28.23,48.37 -31.11,50.87 -34.55,53.87 -37.69,56.6 -39.24,55.58 -40.73,54.49 -42.18,53.34 -40.55,49.5 -38.77,45.3 -37.28,41.79 -38.87,40.37 -40.37,38.87 -41.79,37.28 -45.3,38.77 -49.5,40.55 -53.34,42.18 -54.49,40.73 -55.58,39.24 -56.6,37.69 -53.87,34.55 -50.87,31.11 -48.37,28.23 -49.45,26.4 -50.42,24.5 -51.28,22.54 -55.08,22.87 -59.62,23.27 -63.78,23.64 -64.42,21.91 -64.99,20.15 -65.49,18.36 -61.91,16.21 -58,13.87 -54.73,11.9 -55.18,9.84 -55.51,7.73 -55.72,5.59 -59.43,4.74 -63.88,3.71 -67.94,2.78 -67.98,1.86 -68,0.93 -68,-0 -68,-0.93 -67.98,-1.86 -67.94,-2.78 -63.88,-3.71 -59.43,-4.74 -55.72,-5.59 -55.51,-7.73 -55.18,-9.84 -54.73,-11.9 -58,-13.87 -61.91,-16.21 -65.49,-18.36 -64.99,-20.15 -64.42,-21.91 -63.78,-23.64 -59.62,-23.27 -55.08,-22.87 -51.28,-22.54 -50.42,-24.5 -49.45,-26.4 -48.37,-28.23 -50.87,-31.11 -53.87,-34.55 -56.6,-37.69 -55.58,-39.24 -54.49,-40.73 -53.34,-42.18 -49.5,-40.55 -45.3,-38.77 -41.79,-37.28 -40.37,-38.87 -38.87,-40.37 -37.28,-41.79 -38.77,-45.3 -40.55,-49.5 -42.18,-53.34 -41.55,-53.84 -40.91,-54.33 -40.26,-54.81 -39.42,-55.43 -38.56,-56.03 -37.69,-56.6 -34.55,-53.87 -31.11,-50.87 -28.23,-48.37 -26.4,-49.45 -24.5,-50.42 -22.54,-51.28 -22.87,-55.08 -23.27,-59.62 -23.64,-63.78 -21.91,-64.42 -20.15,-64.99 -18.36,-65.49 -16.21,-61.91 -13.87,-58 -11.9,-54.73 -9.84,-55.18 -7.73,-55.51 -5.59,-55.72 -4.74,-59.43 -3.71,-63.88 -2.78,-67.94 -1.93,-67.98 -1.08,-68 -0.23,-68 L 0,-68 C 0.93,-68 1.86,-67.98 2.78,-67.94 Z M 0,-36 C -6.22,-36 -12.07,-34.42 -17.18,-31.65 -28.39,-25.55 -36,-13.66 -36,-0 -36,19.88 -19.88,36 0,36 19.88,36 36,19.88 36,-0 36,-19.88 19.88,-36 0,-36 Z M 0,-36" transform="translate(150, 96) rotate(-0.5)" />
<path id="gears-smallGear" stroke="none" fill="rgb(115, 152, 218)" d="M 2.12,-37.94 L 2.45,-37.92 C 3.29,-34.48 4.2,-30.71 4.97,-27.56 6.23,-27.34 7.46,-27.03 8.65,-26.64 9.87,-26.24 11.04,-25.77 12.18,-25.22 14.65,-27.32 17.61,-29.83 20.31,-32.12 21.69,-31.25 23.02,-30.28 24.27,-29.24 22.92,-25.96 21.45,-22.37 20.22,-19.37 21.97,-17.55 23.47,-15.49 24.68,-13.24 27.91,-13.49 31.78,-13.78 35.32,-14.05 35.92,-12.54 36.42,-10.99 36.83,-9.39 33.81,-7.53 30.5,-5.49 27.75,-3.79 27.91,-2.55 28,-1.29 28,-0 28,1.29 27.91,2.55 27.75,3.79 30.51,5.49 33.81,7.53 36.83,9.39 36.42,10.99 35.92,12.54 35.32,14.05 31.78,13.78 27.91,13.49 24.68,13.24 23.47,15.49 21.97,17.55 20.22,19.37 21.45,22.37 22.92,25.96 24.27,29.24 23.02,30.28 21.69,31.25 20.31,32.12 17.61,29.83 14.65,27.32 12.18,25.22 9.93,26.31 7.51,27.11 4.97,27.56 4.2,30.71 3.29,34.48 2.45,37.92 1.64,37.97 0.82,38 -0,38 -0.82,38 -1.64,37.97 -2.45,37.92 -3.29,34.48 -4.2,30.71 -4.97,27.56 -7.51,27.11 -9.93,26.31 -12.18,25.22 -14.65,27.32 -17.61,29.83 -20.31,32.12 -21.69,31.25 -23.02,30.28 -24.27,29.24 -22.92,25.96 -21.45,22.37 -20.22,19.37 -21.97,17.55 -23.47,15.49 -24.68,13.24 -27.91,13.49 -31.78,13.78 -35.32,14.05 -35.92,12.54 -36.42,10.99 -36.83,9.39 -33.81,7.53 -30.5,5.49 -27.75,3.79 -27.91,2.55 -28,1.29 -28,-0 -28,-1.29 -27.91,-2.55 -27.75,-3.79 -30.51,-5.49 -33.81,-7.53 -36.83,-9.39 -36.42,-10.99 -35.92,-12.54 -35.32,-14.05 -31.78,-13.78 -27.91,-13.49 -24.68,-13.24 -23.47,-15.49 -21.97,-17.55 -20.22,-19.37 -21.45,-22.37 -22.92,-25.96 -24.27,-29.24 -23.02,-30.28 -21.69,-31.25 -20.31,-32.12 -17.61,-29.83 -14.65,-27.32 -12.18,-25.22 -9.93,-26.31 -7.51,-27.11 -4.97,-27.56 -4.2,-30.71 -3.29,-34.48 -2.45,-37.92 -1.64,-37.97 -0.82,-38 0,-38 0.71,-38 1.42,-37.98 2.12,-37.94 Z M 0,-14 C -7.73,-14 -14,-7.73 -14,-0 -14,7.73 -7.73,14 0,14 7.73,14 14,7.73 14,-0 14,-5.48 10.85,-10.22 6.27,-12.52 4.38,-13.47 2.25,-14 0,-14 Z M 0,-14" transform="translate(62, 137) rotate(1)" />
</svg>
我想要解决的是如何点击齿轮 - largeGear 或 gears-smallGear 一个或另一个齿轮并拖动鼠标使其旋转，类似于滑块的工作方式。
What I am trying to sort out is how to click inside either gears-largeGear or gears-smallGear one or the other gear and drag the mouse to cause them to rotate similar to how the slider works.
搜索它看起来像Snap SVG是一个很好的方法，但我一直在努力将SVG和Snap文档连接在一起。在Snap我看到如何加载SVG但我不太明白如何获得路径或组到设置交互和轮换。
Searching around it seems like Snap SVG is a good way to do this but I've struggled to bridge the SVG and the Snap documentation together. In Snap I see how to load the SVG but I don't quite see how to get the path or group to setup the interaction and rotation.
如果我使用这样的组 gears-largeGroup 和 gears-smallGroup 它会是同一种代码，就好像它只是动画路径一样吗？
If I used groups like this gears-largeGroup and gears-smallGroup would it be the same sort of code as if it were just paths being animated?
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="240" height="200" xml:space="preserve" id="gears">
<!-- Generated by PaintCode - http://www.paintcodeapp.com -->
<g id="gears-largeGroup" transform="translate(149.59, 96.41)" >
<path id="gears-largeGear" stroke="none" fill="rgb(69, 131, 212)" d="M 2.78,-67.94 C 3.71,-63.88 4.74,-59.43 5.59,-55.72 7.73,-55.51 9.84,-55.18 11.9,-54.73 13.87,-58 16.21,-61.91 18.36,-65.49 20.15,-64.99 21.91,-64.42 23.64,-63.78 23.27,-59.62 22.87,-55.08 22.54,-51.28 24.5,-50.42 26.4,-49.45 28.23,-48.37 31.11,-50.87 34.55,-53.87 37.69,-56.6 39.24,-55.58 40.73,-54.49 42.18,-53.34 40.55,-49.5 38.77,-45.3 37.28,-41.79 38.87,-40.37 40.37,-38.87 41.79,-37.28 45.3,-38.77 49.5,-40.55 53.34,-42.18 54.49,-40.73 55.58,-39.24 56.6,-37.69 53.87,-34.55 50.87,-31.11 48.37,-28.23 49.45,-26.4 50.42,-24.5 51.28,-22.54 55.08,-22.87 59.62,-23.27 63.78,-23.64 64.42,-21.91 64.99,-20.15 65.49,-18.36 61.91,-16.21 58,-13.87 54.73,-11.9 55.18,-9.84 55.51,-7.73 55.72,-5.59 59.43,-4.74 63.88,-3.71 67.94,-2.78 67.98,-1.86 68,-0.93 68,0 68,0.93 67.98,1.86 67.94,2.78 63.88,3.71 59.43,4.74 55.72,5.59 55.51,7.73 55.18,9.84 54.73,11.9 58,13.87 61.91,16.21 65.49,18.36 64.99,20.15 64.42,21.91 63.78,23.64 59.62,23.27 55.08,22.87 51.28,22.54 50.42,24.5 49.45,26.4 48.37,28.23 50.87,31.11 53.87,34.55 56.6,37.69 55.58,39.24 54.49,40.73 53.34,42.18 49.5,40.55 45.3,38.77 41.79,37.28 40.37,38.87 38.87,40.37 37.28,41.79 38.77,45.3 40.55,49.5 42.18,53.34 40.73,54.49 39.24,55.58 37.69,56.6 34.55,53.87 31.11,50.87 28.23,48.37 26.4,49.45 24.5,50.42 22.54,51.28 22.87,55.08 23.27,59.62 23.64,63.78 21.91,64.42 20.15,64.99 18.36,65.49 16.21,61.91 13.87,58 11.9,54.73 9.84,55.18 7.73,55.51 5.59,55.72 4.74,59.43 3.71,63.88 2.78,67.94 1.86,67.98 0.93,68 -0,68 -0.93,68 -1.86,67.98 -2.78,67.94 -3.71,63.88 -4.74,59.43 -5.59,55.72 -7.73,55.51 -9.84,55.18 -11.9,54.73 -13.87,58 -16.21,61.91 -18.36,65.49 -20.15,64.99 -21.91,64.42 -23.64,63.78 -23.27,59.62 -22.87,55.08 -22.54,51.28 -24.5,50.42 -26.4,49.45 -28.23,48.37 -31.11,50.87 -34.55,53.87 -37.69,56.6 -39.24,55.58 -40.73,54.49 -42.18,53.34 -40.55,49.5 -38.77,45.3 -37.28,41.79 -38.87,40.37 -40.37,38.87 -41.79,37.28 -45.3,38.77 -49.5,40.55 -53.34,42.18 -54.49,40.73 -55.58,39.24 -56.6,37.69 -53.87,34.55 -50.87,31.11 -48.37,28.23 -49.45,26.4 -50.42,24.5 -51.28,22.54 -55.08,22.87 -59.62,23.27 -63.78,23.64 -64.42,21.91 -64.99,20.15 -65.49,18.36 -61.91,16.21 -58,13.87 -54.73,11.9 -55.18,9.84 -55.51,7.73 -55.72,5.59 -59.43,4.74 -63.88,3.71 -67.94,2.78 -67.98,1.86 -68,0.93 -68,-0 -68,-0.93 -67.98,-1.86 -67.94,-2.78 -63.88,-3.71 -59.43,-4.74 -55.72,-5.59 -55.51,-7.73 -55.18,-9.84 -54.73,-11.9 -58,-13.87 -61.91,-16.21 -65.49,-18.36 -64.99,-20.15 -64.42,-21.91 -63.78,-23.64 -59.62,-23.27 -55.08,-22.87 -51.28,-22.54 -50.42,-24.5 -49.45,-26.4 -48.37,-28.23 -50.87,-31.11 -53.87,-34.55 -56.6,-37.69 -55.58,-39.24 -54.49,-40.73 -53.34,-42.18 -49.5,-40.55 -45.3,-38.77 -41.79,-37.28 -40.37,-38.87 -38.87,-40.37 -37.28,-41.79 -38.77,-45.3 -40.55,-49.5 -42.18,-53.34 -41.55,-53.84 -40.91,-54.33 -40.26,-54.81 -39.42,-55.43 -38.56,-56.03 -37.69,-56.6 -34.55,-53.87 -31.11,-50.87 -28.23,-48.37 -26.4,-49.45 -24.5,-50.42 -22.54,-51.28 -22.87,-55.08 -23.27,-59.62 -23.64,-63.78 -21.91,-64.42 -20.15,-64.99 -18.36,-65.49 -16.21,-61.91 -13.87,-58 -11.9,-54.73 -9.84,-55.18 -7.73,-55.51 -5.59,-55.72 -4.74,-59.43 -3.71,-63.88 -2.78,-67.94 -1.93,-67.98 -1.08,-68 -0.23,-68 L 0,-68 C 0.93,-68 1.86,-67.98 2.78,-67.94 Z M 0,-36 C -6.22,-36 -12.07,-34.42 -17.18,-31.65 -28.39,-25.55 -36,-13.66 -36,-0 -36,19.88 -19.88,36 0,36 19.88,36 36,19.88 36,-0 36,-19.88 19.88,-36 0,-36 Z M 0,-36" transform="rotate(-38)" />
</g>
<g id="gears-smallGroup" transform="translate(62, 137)" >
<path id="gears-smallGear" stroke="none" fill="rgb(115, 152, 218)" d="M 2.12,-37.94 L 2.45,-37.92 C 3.29,-34.48 4.2,-30.71 4.97,-27.56 6.23,-27.34 7.46,-27.03 8.65,-26.64 9.87,-26.24 11.04,-25.77 12.18,-25.22 14.65,-27.32 17.61,-29.83 20.31,-32.12 21.69,-31.25 23.02,-30.28 24.27,-29.24 22.92,-25.96 21.45,-22.37 20.22,-19.37 21.97,-17.55 23.47,-15.49 24.68,-13.24 27.91,-13.49 31.78,-13.78 35.32,-14.05 35.92,-12.54 36.42,-10.99 36.83,-9.39 33.81,-7.53 30.5,-5.49 27.75,-3.79 27.91,-2.55 28,-1.29 28,-0 28,1.29 27.91,2.55 27.75,3.79 30.51,5.49 33.81,7.53 36.83,9.39 36.42,10.99 35.92,12.54 35.32,14.05 31.78,13.78 27.91,13.49 24.68,13.24 23.47,15.49 21.97,17.55 20.22,19.37 21.45,22.37 22.92,25.96 24.27,29.24 23.02,30.28 21.69,31.25 20.31,32.12 17.61,29.83 14.65,27.32 12.18,25.22 9.93,26.31 7.51,27.11 4.97,27.56 4.2,30.71 3.29,34.48 2.45,37.92 1.64,37.97 0.82,38 -0,38 -0.82,38 -1.64,37.97 -2.45,37.92 -3.29,34.48 -4.2,30.71 -4.97,27.56 -7.51,27.11 -9.93,26.31 -12.18,25.22 -14.65,27.32 -17.61,29.83 -20.31,32.12 -21.69,31.25 -23.02,30.28 -24.27,29.24 -22.92,25.96 -21.45,22.37 -20.22,19.37 -21.97,17.55 -23.47,15.49 -24.68,13.24 -27.91,13.49 -31.78,13.78 -35.32,14.05 -35.92,12.54 -36.42,10.99 -36.83,9.39 -33.81,7.53 -30.5,5.49 -27.75,3.79 -27.91,2.55 -28,1.29 -28,-0 -28,-1.29 -27.91,-2.55 -27.75,-3.79 -30.51,-5.49 -33.81,-7.53 -36.83,-9.39 -36.42,-10.99 -35.92,-12.54 -35.32,-14.05 -31.78,-13.78 -27.91,-13.49 -24.68,-13.24 -23.47,-15.49 -21.97,-17.55 -20.22,-19.37 -21.45,-22.37 -22.92,-25.96 -24.27,-29.24 -23.02,-30.28 -21.69,-31.25 -20.31,-32.12 -17.61,-29.83 -14.65,-27.32 -12.18,-25.22 -9.93,-26.31 -7.51,-27.11 -4.97,-27.56 -4.2,-30.71 -3.29,-34.48 -2.45,-37.92 -1.64,-37.97 -0.82,-38 0,-38 0.71,-38 1.42,-37.98 2.12,-37.94 Z M 0,-14 C -7.73,-14 -14,-7.73 -14,-0 -14,7.73 -7.73,14 0,14 7.73,14 14,7.73 14,-0 14,-5.48 10.85,-10.22 6.27,-12.52 4.38,-13.47 2.25,-14 0,-14 Z M 0,-14" transform="rotate(-3)" />
</g>
</svg>
使用Javascript而不是使用Snap进行鼠标命中测试和交互会更容易吗？ / p>
Would it be easier to do the mouse hit-test and interaction in Javascript instead of using Snap?
推荐答案
编辑：为了改进方法而向下看
首先，将变换从第二个示例中的组移动到路径可能更容易。然后，您可以将任何旋转变换添加到组中，而不会太乱。例如。
Firstly, it may be easier to move the transform from the group in the 2nd example to the path. Then you can add any rotation transforms to the group without getting too messy. Eg.
<g id="gears-largeGroup" >
<path transform="translate(149.59, 96.41)" id="gears-largeGear".....
获得SVG后，可以使用Snap.select（）方法在Snap中选择它。这需要一个css选择器。
Once you have your SVG, you can select it in Snap with the Snap.select() method. This takes a css selector.
所以我们可以找到一个
Snap.select('#gears-smallGroup')
现在我们有装备，我们可以添加它的拖动处理程序。
Now we have our gear, we can add a drag handler to it.
Snap.select('#gears-smallGroup').drag( dragRotate, dragStart )
所以我们只需编写处理程序。首先，我们要存储拖动的开始（请参阅最后的更新解决方案，这是更好的），因此我们可以编写startRotate函数。这只是在元素旁边存储一个x，y对象。
So we just need to write our handler. Firstly we want to store the start of the drag (see updated solution at end, which is better), so we can write our startRotate function. This just stores an x,y object alongside the element.
function dragRotateStart( x, y ) {
this.data('oxy', { x: x, y: y })
}
然后我们可以编写主拖动旋转处理程序。
这将获取上面存储的原始起始位置oxy，并将其添加到经过的drags delta增量。
Then we can write the main drag rotation handler.This takes the original start position oxy stored above, and adds it to the drags delta increments that is passes over.
然后我们使用Snaps angle（）方法计算两点之间的角度。一个是我们刚刚拥有的x，y，另一个是元素的中心。
Then we uses Snaps angle() method to calculate the angle between two points. One the x,y we just had, and the other the center of the element.
现在我们有角度，我们可以做一个旋转变换。 Snap可以使用shortform进行变换（r = rotation，t = translate，s = scale和r& s，Snap将从它们的中心转换，除非指定）。
Now we have the angle, we can just do a rotation transform. Snap can use a shortform for a transform (r=rotation, t=translate, s=scale and r&s with Snap will transform from their centers unless specified).
所以这变成了
function dragRotate( dx, dy, x, y ) {
this.transform('r' + Snap.angle( this.getBBox().cx, this.getBBox().cy, dx + this.data('oxy').x, dy + this.data('oxy').y ) );
}
所以整个代码......
So whole code...
Snap.select('#gears-smallGroup').drag( dragRotate, dragRotateStart )
Snap.select('#gears-largeGroup').drag( dragRotate, dragRotateStart )
function dragRotate( dx, dy, x, y ) {
this.transform('r' + Snap.angle( this.getBBox().cx, this.getBBox().cy, dx + this.data('oxy').x, dy + this.data('oxy').y ) );
}
function dragRotateStart( x, y ) {
this.data('oxy', { x: x, y: y })
}
现在你有了它，你可以摆弄它，这样一个人可以旋转另一个。您可能还需要检查重新划分后的起点，具体取决于新拖动的起始位置。
Now you have this, you can fiddle with it, so that one will rotate the other. You may also have to check the starting points after a redrag depending on where your new drag starts from.
（快速刺入使较小的齿轮旋转较大）
(quick stab at making smaller gear rotate bigger one jsfiddle)
更新和改进版本：
进一步扩展这一点，您需要对其进行调整，以考虑起始旋转（如果它是预先旋转的）和起始角度在拖动中，我们只想要角度的差异，所以它不会重置。
Extending this further, you will need to adapt it, to take into account both the starting rotation (also if it's pre-rotated) and the starting angle in the drag, we only want the difference in angles, so it doesn't reset.
所以我们可以存储起始位。拖动的开始是什么角度（我将默认值设置为10，因为图像点偏移了大约10度）。元素的旧旋转是什么。
So we can store out starting bits. What angle was the start of the drag at (I've set default to 10 as the image dot was offset by about 10deg). What was the old rotation of the element.
function dragRotateStart(x, y) {
this.data('startingAngle', Snap.angle(this.getBBox().cx, this.getBBox().cy, x, y));
this.data('startingRotation', this.data('rotation')||10)
}
然后从起始旋转计算正确的旋转，加上角度差，在我们去的时候存储它（所以如果我们稍后再拖动，我们知道它的最后一次旋转是什么）...
And then calculate the correct rotation from the starting rotation, plus the angle difference, storing it as we go (so if we drag again later, we know what its last rotation was)...
function dragRotate(dx, dy, x, y) {
var angleDiff = Snap.angle(this.getBBox().cx, this.getBBox().cy, x, y) - this.data('startingAngle')
var newRotation = angleDiff + +this.data('startingRotation');
this.data('rotation', newRotation)
this.transform('r' + newRotation);
}
这篇关于Paintcode和Snap SVG的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！