public override void Update(float time) { if (m_pTarget != null) { float xa = 0; float xb = m_sConfig.ControlPoint1.X; float xc = m_sConfig.ControlPoint2.X; float xd = m_sConfig.EndPosition.X; float ya = 0; float yb = m_sConfig.ControlPoint1.Y; float yc = m_sConfig.ControlPoint2.Y; float yd = m_sConfig.EndPosition.Y; float x = CCSplineMath.CubicBezier(xa, xb, xc, xd, time); float y = CCSplineMath.CubicBezier(ya, yb, yc, yd, time); CCPoint currentPos = m_pTarget.Position; CCPoint diff = currentPos - m_previousPosition; m_startPosition = m_startPosition + diff; CCPoint newPos = m_startPosition + new CCPoint(x, y); m_pTarget.Position = newPos; m_previousPosition = newPos; } }
/// <summary> /// draws a cubic bezier path /// @since v0.8 /// </summary> public static void DrawCubicBezier(CCPoint origin, CCPoint control1, CCPoint control2, CCPoint destination, int segments, CCColor4B color) { var vertices = new VertexPositionColor[segments + 1]; float t = 0; for (int i = 0; i < segments; ++i) { float x = CCSplineMath.CubicBezier(origin.X, control1.X, control2.X, destination.X, t); float y = CCSplineMath.CubicBezier(origin.Y, control1.Y, control2.Y, destination.Y, t); vertices[i] = new VertexPositionColor(); vertices[i].Position = new Vector3(x, y, 0); vertices[i].Color = new Color(color.R, color.G, color.B, color.A); t += 1.0f / segments; } vertices[segments] = new VertexPositionColor { Color = new Color(color.R, color.G, color.B, color.A), Position = new Vector3(destination.X, destination.Y, 0) }; BasicEffect basicEffect = CCDrawManager.PrimitiveEffect; basicEffect.Projection = CCDrawManager.ProjectionMatrix; basicEffect.View = CCDrawManager.ViewMatrix; basicEffect.World = CCDrawManager.WorldMatrix; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); basicEffect.GraphicsDevice.DrawUserPrimitives(PrimitiveType.LineStrip, vertices, 0, segments); } }