Path2D

Path2D allows you to describe a path through an existing path. This path can be drawn through the stroke API of Canvas.

addPath

addPath(path: Object): void

Adds a path to this path.

  • Parameters
Name Type Description
path Object Path to be added to this path.
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 500px; height: 500px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path1 = ctx.createPath2D("M250 150 L150 350 L350 350 Z");
        var path2 = ctx.createPath2D();
        path2.addPath(path1);
        ctx.stroke(path2);
      }
    }
    

    img

setTransform

setTransform(scaleX: number, skewX: number, skewY: number, scaleY: number, translateX: number, translateY: number): void

Sets the path transformation matrix.

  • Parameters
Name Type Description
scaleX number Scale ratio of the x-axis
skewX number Skew angle of the x-axis
skewY number Skew angle of the y-axis
scaleY number Scale ratio of the y-axis
translateX number Translation distance of the x-axis
translateY number Translation distance of the y-axis
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D("M250 150 L150 350 L350 350 Z");
        path.setTransform(0.8, 0, 0, 0.4, 0, 0);
        ctx.stroke(path);
      }
    }
    

    img

closePath

closePath(): void

Moves the current point of the path back to the start point of the path, and draws a straight line between the current point and the start point. If the shape is closed or has only one point, this method does not perform any action.

  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.moveTo(200, 100);
        path.lineTo(300, 100);
        path.lineTo(200, 200);
        path.closePath();
        ctx.stroke(path);
      }
    }
    

    img

moveTo

moveTo(x: number, y: number): void

Moves the current coordinate point of the path to the target point, without drawing a line during the movement.

  • Parameters
Parameter Type Description
x number X-coordinate of the target point
y number Y-coordinate of the target point
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 300px; height: 250px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.moveTo(50, 100);
        path.lineTo(250, 100);
        path.lineTo(150, 200);
        path.closePath();
        ctx.stroke(path);
      }
    }
    

    img

lineTo

lineTo(x: number, y: number): void

Draws a straight line from the current point to the target point.

  • Parameters
Parameter Type Description
x number X-coordinate of the target point
y number Y-coordinate of the target point
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 400px; height: 450px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.moveTo(100, 100);
        path.lineTo(100, 200);
        path.lineTo(200, 200);
        path.lineTo(200, 100);
        path.closePath();
        ctx.stroke(path);
      }
    }
    

    img

bezierCurveTo

bezierCurveTo(cp1x: number, cp1y: number, cp2x: number, cp2y: number, x: number, y: number): void

Draws a cubic bezier curve on the canvas.

  • Parameters
Parameter Type Description
cp1x number X-coordinate of the first parameter of the bezier curve
cp1y number Y-coordinate of the first parameter of the bezier curve
cp2x number X-coordinate of the second parameter of the bezier curve
cp2y number Y-coordinate of the second parameter of the bezier curve
x number X-coordinate of the end point on the bezier curve
y number Y-coordinate of the end point on the bezier curve
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.moveTo(10, 10);
        path.bezierCurveTo(20, 100, 200, 100, 200, 20);
        ctx.stroke(path);
      }
    }
    

    img

quadraticCurveTo

quadraticCurveTo(cpx: number, cpy: number, x: number, y: number): void

Draws a quadratic curve on the canvas.

  • Parameters
Parameter Type Description
cpx number X-coordinate of the bezier curve parameter
cpy number Y-coordinate of the bezier curve parameter
x number X-coordinate of the end point on the bezier curve
y number Y-coordinate of the end point on the bezier curve
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.moveTo(10, 10);
        path.quadraticCurveTo(100, 100, 200, 20);
        ctx.stroke(path);
      }
    }
    

    img

arc

arc(x: number, y: number, radius: number, startAngle: number, endAngle: number, anticlockwise: number): void

Draws an arc on the canvas.

  • Parameters
Parameter Type Description
x number X-coordinate of the center point of the arc
y number Y-coordinate of the center point of the arc
radius number Radius of the arc
startAngle number Start radian of the arc
endAngle number End radian of the arc
anticlockwise boolean Whether to draw the arc counterclockwise
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.arc(100, 75, 50, 0, 6.28);
        ctx.stroke(path);
      }
    }
    

    img

arcTo

arcTo(x1: number, y1: number, x2: number, y2: number, radius: number): void

Draws an arc based on the radius and points on the arc.

  • Parameters
Parameter Type Description
x1 number X-coordinate of the first point on the arc
y1 number Y-coordinate of the first point on the arc
x2 number X-coordinate of the second point on the arc
y2 number Y-coordinate of the second point on the arc
radius number Radius of the arc
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 200px; height: 150px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.arcTo(150, 20, 150, 70, 50);
        ctx.stroke(path);
      }
    }
    

    img

ellipse

ellipse(x: number, y: number, radiusX: number, radiusY: number, rotation: number, startAngle: number, endAngle: number, anticlockwise: number): void

Draws an ellipse in the specified rectangular region.

  • Parameters
Parameter Type Description
x number X-coordinate of the ellipse center
y number Y-coordinate of the ellipse center
radiusX number Ellipse radius on the x-axis.
radiusY number Ellipse radius on the y-axis.
rotation number Rotation angle of the ellipse. The unit is radian.
startAngle number Angle of the start point for drawing the ellipse. The unit is radian.
endAngle number Angle of the end point for drawing the ellipse. The angle is represented by radians.
anticlockwise number Whether to draw the ellipse in the anticlockwise direction. The value 0 indicates clockwise and the value 1 indicates anticlockwise. This parameter is optional. The default value is 0.
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 500px; height: 450px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx =el.getContext('2d');
        var path = ctx.createPath2D();
        path.ellipse(200, 200, 50, 100, Math.PI * 0.25, Math.PI * 0.5, Math.PI, 1);
        ctx.stroke(path);
      }
    }
    

    img

rect

rect(x: number, y: number, width: number, height: number): void

Creates a rectangle.

  • Parameters
Parameter Type Description
x number X-coordinate of the upper left corner of the rectangle.
y number Y-coordinate of the upper left corner of the rectangle.
width number Width of the rectangle.
height number Height of the rectangle.
  • Example

    <!-- xxx.hml -->
    <div>
      <canvas ref="canvas" style="width: 500px; height: 450px; background-color: #ffff00;"></canvas>
    </div>
    
    //xxx.js
    export default {
      onShow() {
        const el =this.$refs.canvas;
        const ctx = el.getContext('2d');
        var path = ctx.createPath2D();
        path.rect(20, 20, 100, 100);
        ctx.stroke(path);
      }
    }
    

    img