ofPolylinefile

ofPolyLine allows you to combine multiple points into a single vector data object that can be drawn to the screen, manipulated point by point, and combined with other ofPolyline instances. It is less complex than the ofPath and generally represents a single line or vector shape rather than multiple lines or shapes.

You can add points to an ofPolyline by adding vertices:

float i = 0;
while (i < TWO_PI) { // make a heart
    float r = (2-2*sin(i) + sin(i)*sqrt(abs(cos(i))) / (sin(i)+1.4)) * -80;
    float x = ofGetWidth()/2 + cos(i) * r;
    float y = ofGetHeight()/2 + sin(i) * r;
    line.addVertex(ofVec2f(x,y));
    i+=0.005*HALF_PI*0.5;
}
line.close(); // close the shape

Or you can draw lines or curves:

float angle = 0;
while (angle < TWO_PI ) {
    b.curveTo(100*cos(angle), 0, 100*sin(angle));
    b.curveTo(300*cos(angle), 300, 300*sin(angle));
    angle += TWO_PI / 30;
}

ofPolyline also includes methods to get the closest point, determine whether a point is inside shape, and resample shapes. Along with the ofPath class, it's the best way to draw and manipulate 2D and 3D vector graphics that you'll need to update and manipulate frequently.

If you use the lineTo() or curveTo() or bezierTo() functions, you move the drawing point, so that drawing a line to 100,100 means a line from 0,0 to 100, 100. The next line would be a line from 100,100 to wherever you go next. Storing this position means that you can easily create continuous drawings without difficulty.

ofPolylineclass

Constructors

ofPolyline ()

fromRectangle ()

Add and Remove Vertices

clear ()

addVertex ()

addVertices ()

insertVertex ()

resize ()

Access Vertices

size ()

operator[] ()

getVertices ()

begin ()

rbegin ()

end ()

rend ()

Lines and Curves

lineTo ()

arc ()

void arc(const ofPoint ¢er, float radiusX, float radiusY, float angleBegin, float angleEnd, bool clockwise, int circleResolution=20)

Adds an arc around the ofPoint center with the width of radiusX and the height of radiusY to the polyline.

The angleBegin and angleEnd indicate the start and end angles of the arc in degrees measured clockwise from the x-axis.

The clockwise boolean sets the drawing direction. Passing 'false' to it will draw the arc counter-clockwise.

Optionally, you can specify circleResolution, which is the number of line segments a circle would be drawn with.

If the arc doesn't start at the same point the last vertex finished a straight line will be created to join both

void arc(const ofPoint ¢er, float radiusX, float radiusY, float angleBegin, float angleEnd, int circleResolution=20)

Adds an arc around the ofPoint center with the width of radiusX and the height of radiusY.

The angleBegin and angleEnd indicate the start and end angles of the arc in degrees measured clockwise from the x-axis.

Optionally, you can specify circleResolution, which is the number of line segments a circle would be drawn with. A partial arc will be drawn with the same resolution: if circleResolution == 20, a half- circle will be drawn with 10 segments.

If there are already vertexes in the ofPolyline the arc will extend them; a line will be created from the endmost point on the ofPolyline to the beginning point of the arc.

ofPolyline polyline1, polyline2;
// draw an line, then an semi-circle in red
polyline2.lineTo(300, 50);
ofPoint point2(450,120);
polyline2.arc(point2,100,100,0,180);
ofSetColor(ofColor::red);
polyline2.draw();

void arc(float x, float y, float radiusX, float radiusY, float angleBegin, float angleEnd, int circleResolution=20)

Adds an arc around the coordinates (x,y) with the width of radiusX and the height of radiusY.

The angleBegin and angleEnd indicate the start and end angles of the arc in degrees measured clockwise from the x-axis.

Optionally, you can specify circleResolution, which is the number of line segments a circle would be drawn with.

void arc(float x, float y, float z, float radiusX, float radiusY, float angleBegin, float angleEnd, int circleResolution=20)

Adds an arc around the coordinates (x,y,z) with the width of radiusX and the height of radiusY.

The angleBegin and angleEnd indicate the start and end angles of the arc in degrees measured clockwise from the x-axis.

Optionally, you can specify circleResolution, which is the number of line segments a circle would be drawn with.

arcNegative ()

curveTo ()

bezierTo ()

quadBezierTo ()

Smoothing and Resampling

getSmoothed ()

getResampledBySpacing ()

getResampledByCount ()

simplify ()

Polyline State

close ()

setClosed ()

isClosed ()

hasChanged ()

flagHasChanged ()

Geometric Functions

inside ()

getBoundingBox ()

getPerimeter ()

getArea ()

getCentroid2D ()

getClosestPoint ()

inside ()

Other Functions

getIndexAtLength ()

getIndexAtPercent ()

getLengthAtIndex ()

getLengthAtIndexInterpolated ()

getPointAtLength ()

getPointAtPercent ()

getPointAtIndexInterpolated ()

getAngleAtIndex ()

getAngleAtIndexInterpolated ()

getRotationAtIndex ()

getRotationAtIndexInterpolated ()

getTangentAtIndex ()

getTangentAtIndexInterpolated ()

getNormalAtIndex ()

getNormalAtIndexInterpolated ()

getWrappedIndex ()

setRightVector ()

getRightVector ()

Drawing

draw ()