EZwin 资源 C++

#include <math.h> #include <assert.h> #include "ray.h" RaySegment::RaySegment(SimpleWindow &w, const Position &Start, const Position &End, const color &c, float t, bool a) : WindowObject(w, Start), EndPoint(End), Color(c), Thickness(t), Arrow(a) { // No body needed } RaySegment::RaySegment(SimpleWindow &w, float StartX, float StartY, float EndX, float EndY, const color &c, float t, bool a) : WindowObject(w, Position(StartX, StartY)), EndPoint(Position(EndX, EndY)), Color(c), Thickness(t), Arrow(a) { // No body needed } Position RaySegment::GetStartPoint() const { return (GetPosition()); } void RaySegment::GetStartPoint(float &x, float &y) const { GetPosition(x, y); return; } Position RaySegment::GetEndPoint() const { return EndPoint; } void RaySegment::GetEndPoint(float &x, float &y) const { x = EndPoint.GetXDistance(); y = EndPoint.GetYDistance(); return; } void RaySegment::GetPoints(Position &Start, Position &End) const { Start = GetPosition(); End = EndPoint; } color RaySegment::GetColor() const { return Color; } float RaySegment::GetThickness() const { return Thickness; } float RaySegment::GetLength() const { float x, y; GetPosition(x, y); x -= EndPoint.GetXDistance(); y -= EndPoint.GetYDistance(); return sqrt(x*x + y*y); } bool RaySegment::HasArrow() const { return Arrow; } void RaySegment::SetStartPoint(const Position &p) { SetPosition(p); return; } void RaySegment::SetStartPoint(float x, float y) { SetPosition(x, y); return; } void RaySegment::SetEndPoint(const Position &p) { EndPoint = p; return; } void RaySegment::SetEndPoint(float x, float y) { EndPoint = Position(x, y); return; } void RaySegment::SetPoints(const Position &Start, const Position &End) { SetPosition(Start); EndPoint = End; return; } void RaySegment::SetColor(const color &c) { assert(c >= 0 && c < MaxColors); Color = c; return; } void RaySegment::SetThickness(float t) { Thickness = t; return; } void RaySegment::SetArrowhead() { Arrow = true; return; } void RaySegment::ClearArrowhead() { Arrow = false; return; } void RaySegment::Draw() { Position NewStartVector, NewStartPoint; Position NewEndVector, NewEndPoint; Position Start = GetPosition(); Position End = GetEndPoint(); const float t = GetThickness(); const float length = GetLength(); Position RayVector = EndPoint - Start; bool TooShortToDraw; bool TooShortForArrow = false; if (length == 0) return; // Line cannot be drawn properly if its length // is less than its width TooShortToDraw = length < t; // Line should not be drawn with arrow if it is // shorter than the arrow if (length < (4 * t)) TooShortForArrow = true; // Compute new start point (to offset the extra bit that LineTo includes) float CutOff = Thickness / 2.0; if (TooShortToDraw) { NewStartVector = Position(RayVector.GetXDistance() / 2.0, RayVector.GetYDistance() / 2.0); NewStartPoint = Start + NewStartVector; } else { // If not too short, then move the start point such that the line // will appear to begin at the proper point. NewStartVector = Position(RayVector.GetXDistance() * CutOff / length, RayVector.GetYDistance() * CutOff / length); NewStartPoint = Start + NewStartVector; } if (Arrow) End = DrawArrow(Color); else if (!TooShortToDraw) { // If we don't have an arrow and the line length isn't too short, // then move the end point such that the line will appear to end // at the proper position. float NewLength = length - Thickness / 2.0; Position NewEndVector(RayVector.GetXDistance() * NewLength / length, RayVector.GetYDistance() * NewLength / length); Position NewEndPoint = GetPosition() + NewEndVector; End = NewEndPoint; } else { End = NewStartPoint; } Start = NewStartPoint; // Don't want to draw anything if the line // is too short and there is an arrow if (!Arrow || !TooShortForArrow) GetWindow().RenderLine(Start, End, GetColor(), t); return; } Position RaySegment::DrawArrow(const color &ArrowColor) { const float length = GetLength(); const float ArrowWidth = 2.0 * Thickness; const float ArrowLength = 2.0 * ArrowWidth; Position FirstVertex, SecondVertex, ThirdVertex; // In the following code, *Vector refer to vector objects that have // an endpoint at the origin (like most vectors). const Position StartPoint = GetPosition(); // Find new endpoint of line by finding the vector from // the start point to the endpoint, rescaling the vector, // and then adding it to the start point Position RayVector = EndPoint - StartPoint; float NewLength = length - ArrowLength; float scalefactor = NewLength / length; Position NewRayVector(RayVector.GetXDistance() * scalefactor, RayVector.GetYDistance() * scalefactor); Position NewEndPoint = StartPoint + NewRayVector; FirstVertex = EndPoint; // Find other vertices. if (EndPoint.GetXDistance() == StartPoint.GetXDistance()) { SecondVertex = NewEndPoint + Position(ArrowWidth, 0); ThirdVertex = NewEndPoint - Position(ArrowWidth, 0); } else { float Slope = (EndPoint.GetYDistance() - StartPoint.GetYDistance()) / (EndPoint.GetXDistance() - StartPoint.GetXDistance()); if (Slope == 0) { SecondVertex = NewEndPoint + Position(0, ArrowWidth); ThirdVertex = NewEndPoint - Position(0, ArrowWidth); } else { float PerpSlope = - 1 / Slope; Position TempPosition(1.0, PerpSlope); float TempLength = sqrt(1 + PerpSlope * PerpSlope); SecondVertex = NewEndPoint + Position( TempPosition.GetXDistance() * ArrowWidth / TempLength, TempPosition.GetYDistance() * ArrowWidth / TempLength); ThirdVertex = NewEndPoint - Position( TempPosition.GetXDistance() * ArrowWidth / TempLength, TempPosition.GetYDistance() * ArrowWidth / TempLength); } } // Create an array containing the positions of the // vertices of the triangle vector<Position> TrianglePoints(3); TrianglePoints[0] = FirstVertex; TrianglePoints[1] = SecondVertex; TrianglePoints[2] = ThirdVertex; // Draw the triangle GetWindow().RenderPolygon(TrianglePoints, 3, ArrowColor, false); return NewEndPoint; } void RaySegment::Erase() { Position Start = GetPosition(); Position End = GetEndPoint(); const float t = GetThickness(); const float length = GetLength(); Position RayVector = EndPoint - Start; float NewLength = Thickness / 2.0; Position NewStartVector(RayVector.GetXDistance() * NewLength / length, RayVector.GetYDistance() * NewLength / length); Position NewStartPoint = Start + NewStartVector; Start = NewStartPoint; if (Arrow) End = DrawArrow(White); else { NewLength = length - Thickness / 2.0; Position NewEndVector(RayVector.GetXDistance() * NewLength / length, RayVector.GetYDistance() * NewLength / length); Position NewEndPoint = GetPosition() + NewEndVector; End = NewEndPoint; } GetWindow().RenderLine(Start, End, White, t); return; }