Point startPoint = new Point(width/2, height-50)
时间: 2024-01-03 17:05:10 浏览: 34
This line of code creates a new object of the Point class and assigns it to the variable startPoint. The Point object is initialized with the x-coordinate as the center of the canvas (width/2) and the y-coordinate as 50 pixels from the bottom of the canvas (height-50).
In other words, this code sets the starting point for some kind of graphical element to be drawn near the bottom center of the canvas.
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import QtQuick 2.4 import QtQuick.Controls 1.4 import QtQuick.Window 2.3 ApplicationWindow { visible: true width: 800 height: 600 title: "Drawing Board Example" Rectangle { width: 600 height: 400 MouseArea { id: mouseArea anchors.fill: parent hoverEnabled: true property bool isDragging: false property var startPoint: Qt.point(0,0) property var rect: { x: 0, y: 0, width: 100, height: 100, angle: 0 } // 绘制矩形 function drawRect() { canvas.getContext("2d").clearRect(0, 0, width, height); canvas.getContext("2d").save(); canvas.getContext("2d").translate(rect.x, rect.y); canvas.getContext("2d").rotate(rect.angle); canvas.getContext("2d").fillRect(-rect.width / 2, -rect.height / 2, rect.width, rect.height); canvas.getContext("2d").restore(); } // 鼠标事件处理 onPressed: { const x = mouse.x - width / 2; const y = mouse.y - height / 2; if (x > rect.x - rect.width / 2 && x < rect.x + rect.width / 2 && y > rect.y - rect.height / 2 && y < rect.y + rect.height / 2) { isDragging = true; startPoint = Qt.point(mouse.x, mouse.y); } } onPositionChanged:: { if (isDragging) { const dx = mouse.x - startPoint.x; const dy = mouse.y - startPoint.y; rect.x += dx; rect.y += dy; startPoint = Qt.point(mouse.x, mouse.y); drawRect(); } } onReleased: { isDragging = false; } onWheel: { const zoom = angleDelta.y > 0 ? 0.9 : 1.1; rect.width *= zoom; rect.height *= zoom; drawRect(); } // 画布 Canvas { id: canvas anchors.fill: parent contextType: "2d" // 设置画布初始位置和网格线样式 onPaint: { canvas.getContext("2d").translate(width / 2, height / 2); canvas.getContext("2d").lineWidth = 0.5; canvas.getContext("2d").strokeStyle = '#ddd'; // 绘制网格线 for (let i = -width / 2; i <= width / 2; i += 10) { canvas.getContext("2d").beginPath(); canvas.getContext("2d").moveTo(i, -height / 2); canvas.getContext("2d").lineTo(i, height / 2); canvas.getContext("2d").stroke(); } for (let i = -height / 2; i <= height / 2; i += 10) { canvas.getContext("2d").beginPath(); canvas.getContext("2d").moveTo(-width / 2, i); canvas.getContext("2d").lineTo(width / 2, i); canvas.getContext("2d").stroke(); } drawRect(); } } } } }这段代码中的property var rect: { x: 0, y: 0, width: 100, height: 100, angle: 0 }这一行发生报错,请基于qt的qml语言做出修改
根据Qt QML语言的语法,正确的写法应该是:
```qml
property var rect: QtObject {
property int x: 0
property int y: 0
property int width: 100
property int height: 100
property int angle: 0
}
```
将原先的 rect 变量类型修改为 QtObject ,然后在其内部定义各个属性,即可避免报错。
registerEvent () { let endPoint = cc.v2(0,0) let startPoint = cc.v2(0,0) this.node.on(cc.Node.EventType.TOUCH_MOVE, (e) => { startPoint = e.getStartLocation(); endPoint = e.getLocation(); const distance = startPoint.sub(endPoint).mag(); if (distance <= 300) { this.draw.clear(); this.draw.moveTo(startPoint.x, startPoint.y); this.draw.lineTo(e.getLocationX(), e.getLocationY()); this.draw.stroke(); } }, this); this.node.on(cc.Node.EventType.TOUCH_END, (e) => { this.draw.clear(); let lineStart = startPoint.clone(); // 保存 300 线段的起点 let lineEnd = endPoint.clone(); // 保存 300 线段的终点 this.cut(lineStart, lineEnd); // 在 cut() 方法中处理 300 线段 }, this); } cut(pOne,pTwo){ let ropeJoints: cc.RopeJoint[] = [] if(this.chapterOne.active === true){ //ropeJoints = cc.director.getScene().getComponentsInChildren(cc.RopeJoint); ropeJoints =this.chapterOne.getComponentsInChildren(cc.RopeJoint); } else if(this.chapterTwo.active === true) { //ropeJoints = cc.director.getScene().getComponentsInChildren(cc.RopeJoint); ropeJoints =this.chapterTwo.getComponentsInChildren(cc.RopeJoint); } ropeJoints.forEach((item) => { if(item.node.width ==10&&item.node.height==10){ let lineP1 = pOne; // 线段起点 let lineP2 = pTwo; // 线段终点 let rectPoint = cc.v2(item.node.x-5, item.node.y-5) let rectWorldPoint = item.node.convertToWorldSpaceAR(rectPoint) let rect = cc.rect(rectWorldPoint.x,rectWorldPoint.y, 20, 20); // 矩形,左下角坐标为(5,5),宽高为10 let isIntersect = cc.Intersection.lineRect(lineP1, lineP2, rect); console.log(isIntersect); // 输出 true 或 false if(isIntersect== true){ item.node.parent.active = false } } }); }
这段代码实现了一个简单的画线和切割功能。当手指在屏幕上滑动时,会在画布上绘制一条直线;当手指离开屏幕时,会根据画线的起点和终点计算出一条线段,并将该线段和所有的 `cc.RopeJoint` 组件进行碰撞检测,如果检测到碰撞则将相应的节点隐藏。
其中,`registerEvent()` 方法用于注册触摸事件,`cut()` 方法用于进行碰撞检测。
需要注意的是,这段代码仅适用于场景中只有 `cc.RopeJoint` 组件的情况,如果场景中还有其他类型的组件,需要修改代码以区分不同类型的组件。另外,代码中的一些变量和方法没有给出定义,需要根据具体情况进行修改。