using System; using System.Collections.Generic; namespace Assistance { public class AssistantVanishingPoint: Assistant { public ActivePoint center; public ActivePoint a0; public ActivePoint a1; public ActivePoint b0; public ActivePoint b1; public ActivePoint step; public AssistantVanishingPoint(Document document, Point center): base(document) { this.center = new ActivePoint(this, ActivePoint.Type.CircleCross, center); a0 = new ActivePoint(this, ActivePoint.Type.CircleFill, center + new Point(-100.0, 0.0)); a1 = new ActivePoint(this, ActivePoint.Type.Circle, center + new Point(-200.0, 0.0)); b0 = new ActivePoint(this, ActivePoint.Type.CircleFill, center + new Point(100.0, 0.0)); b1 = new ActivePoint(this, ActivePoint.Type.Circle, center + new Point(200.0, 0.0)); step = new ActivePoint(this, ActivePoint.Type.Circle, (a0.position + a1.position)/2); } private void fixCenter() { if (!a0.position.isEqual(a1.position) && !b0.position.isEqual(b1.position)) { Point a = a0.position; Point b = b0.position; Point da = a1.position - a; Point db = b1.position - b; Point ab = b - a; double k = db.x*da.y - db.y*da.x; if (Math.Abs(k) > 0.00001) { double lb = (da.x*ab.y - da.y*ab.x)/k; center.position.x = lb*db.x + b.x; center.position.y = lb*db.y + b.y; } } } private void fixSidePoint(ActivePoint p0, ActivePoint p1, Point previousP0) { if (!p0.position.isEqual(center.position)) { Point dp0 = p0.position - center.position; Point dp1 = p1.position - previousP0; p1.position = center.position + dp0*(dp0.len() + dp1.len())/dp0.len(); } } private void fixSidePoint(ActivePoint p0, ActivePoint p1) { fixSidePoint(p0, p1, p0.position); } public void fixPoints() { fixSidePoint(a0, a1); fixSidePoint(a0, step); fixSidePoint(b0, b1); fixCenter(); } public override void onMovePoint(ActivePoint point, Point position) { Point previous = point.position; point.position = position; if (point == center) { a0.position += point.position - previous; a1.position += point.position - previous; step.position += point.position - previous; b0.position += point.position - previous; b1.position += point.position - previous; } else if (point == a0) { fixSidePoint(a0, a1, previous); fixSidePoint(a0, step, previous); fixSidePoint(b0, b1); } else if (point == b0) { fixSidePoint(a0, a1); fixSidePoint(a0, step); fixSidePoint(b0, b1, previous); } else { fixCenter(); fixSidePoint(a0, a1); fixSidePoint(a0, step); fixSidePoint(b0, b1); } } /* public override Point[] getGridPoints(Point target, bool truncate) { double k = (a0.position - center.position).len(); if (k < 0.00001) return new Point[0]; k = (step.position - center.position).len()/k; //if (Math.Abs(k - 1.0) < 0.1) return new Point[0]; Point[] points = new Point[truncate ? gridPointsCount + 1 : gridPointsCount*2 + 1]; Point a = target - center.position; Point b = a; points[gridPointsCount] = a + center.position; for(int i = 1; i <= gridPointsCount; ++i) { a /= k; b *= k; points[gridPointsCount - i] = a + center.position; if (!truncate) points[gridPointsCount + i] = b + center.position; } return points; } */ public override void draw(Cairo.Context context) { context.Save(); pen.apply(context); context.MoveTo(center.position.x, center.position.y); context.LineTo(a0.position.x, a0.position.y); context.MoveTo(center.position.x, center.position.y); context.LineTo(a1.position.x, a1.position.y); context.MoveTo(center.position.x, center.position.y); context.LineTo(b0.position.x, b0.position.y); context.MoveTo(center.position.x, center.position.y); context.LineTo(b1.position.x, b1.position.y); context.Stroke(); context.Restore(); } public override void getGuidelines(List outGuidelines, Point target) { if (!target.isEqual(center.position)) outGuidelines.Add(new GuidelineLine(target, center.position)); } } }