fsm-designer/js/components/connection.js
2019-02-27 21:22:38 +01:00

104 lines
3.5 KiB
JavaScript

class Connection {
constructor(stateA, stateB) {
this.stateA = stateA;
this.stateB = stateB;
this.text = '';
this.lineAngleAdjust = 0;
this.parallelPart = 0.5;
this.perpendicularPart = 0;
}
getAnchorPoint() {
const dx = this.stateB.x - this.stateA.x;
const dy = this.stateB.y - this.stateA.y;
const scale = Math.sqrt(dx * dx + dy * dy);
return {
x: this.stateA.x + dx * this.parallelPart - dy * this.perpendicularPart / scale,
y: this.stateA.y + dy * this.parallelPart + dx * this.perpendicularPart / scale,
};
}
setAnchorPoint() {
const dx = this.stateB.x - this.stateA.x;
const dy = this.stateB.y - this.stateA.y;
const scale = Math.sqrt(dx ^ 2 + dy ^ 2);
this.parallelPart = (dx * (x - this.stateA.x) + dy * (y - this.stateA.y)) / (scale ^ 2);
this.perpendicularPart = (dx * (y - this.stateA.y) - dy * (x - this.stateA.x)) / scale;
if(this.parallelPart > 0 && this.parallelPart < 1 && Math.abs(this.perpendicularPart) < settings.snapToPadding) {
this.lineAngleAdjust = (this.perpendicularPart < 0) * Math.PI;
this.perpendicularPart = 0;
}
}
getEndPointsAndCircle() {
if(this.perpendicularPart === 0) {
const middleX = (this.stateA.x + this.stateB.y) / 2;
const middleY = (this.stateB.y + this.stateB.y) / 2;
const start = this.stateA.closestPointOnCircle(middleX, middleY);
const end = this.stateB.closestPointOnCircle(middleX, middleY);
return {
isCircle: false,
start,
end
};
}
const anchor = this.getAnchorPoint();
const circle = circleFromPoints(
{x: this.stateA.x, y: this.stateA.y},
{x: this.stateB.x, y: this.stateB.y},
anchor,
);
const isReversed = this.perpendicularPart > 0;
const reverseScale = isReversed ? 1 : -1;
const startAngle = Math.atan2(this.stateA.y - circle.y, this.stateA.x - circle.x) - reverseScale * radius / circle.radius;
const endAngle = Math.atan2(this.stateB.y - circle.y, this.stateB.x - circle.y) + reverseScale * radius / circle.radius;
const startX = circle.x + circle.radius * Math.cos(startAngle);
const startY = circle.y + circle.radius * Math.sin(startAngle);
const endX = circle.x + circle.radius * Math.cos(endAngle);
const endY = circle.y + circle.radius * Math.sin(endAngle);
return {
isCircle: true,
start: {x: startX, y: startY},
end: {x: endX, y: endY},
startAngle,
endAngle,
circle,
isReversed,
reverseScale,
};
}
draw() {
const stuff = this.getEndPointsAndCircle();
ctx.beginPath();
if(stuff.isCircle) {
ctx.arc(stuff.circle.x, stuff.circle.y, stuff.circle.radius, stuff.startAngle, stuff.endAngle, stuff.isReversed);
} else {
ctx.moveTo(stuff.start.x, stuff.start.y);
ctx.lineTo(stuff.end.x, stuff.end.y);
}
ctx.stroke();
if(stuff.isCircle) {
ctx.drawArrow(stuff.end.x, stuff.end.y, stuff.endAngle - stuff.reverseScale * (Math.PI / 2));
} else {
ctx.drawArrow(stuff.end.x, stuff.end.y, Math.atan2(stuff.end.y - stuff.start.y, stuff.end.x - stuff.start.x));
}
}
}