void drawCubicBezier(HDC hdc,ALPoint b, ALPoint e, ALPoint c1, ALPoint c2) {
GdiPlusIniter ginit;
Graphics *graphics = Graphics::FromHDC(hdc);
graphics->SetSmoothingMode(SmoothingModeHighQuality);
Point p1(b.x, -b.y);
Point p2(c1.x, -c1.y);
Point p3(c2.x, -c2.y);
Point p4(e.x, -e.y);
Pen pen(Color::Red);
pen.SetLineJoin(LineJoinRound);
pen.SetStartCap(LineCapRound);
pen.SetEndCap(LineCapRound);
graphics->DrawBezier(&pen, p1,p2,p3,p4);
/*
AlPointsArray points(50,5);
float t = 0;
while(t <= 1) {
ALPoint alp = calcuBezierPoint(b,e,c1,c2,t);
alp.y = (negative?-1:1)*alp.y;
points.append(alp);
t += 0.02;
}
drawPoly(hdc,points);
*/
}
// #define DrawPolygonMacro
void drawBezierSmoothPoly(HDC hdc, AlpointsList &points, float f, COLORREF color) {
if(points.count()<3) return;
GdiPlusIniter ginit;
Graphics *graphics = Graphics::FromHDC(hdc);
graphics->SetSmoothingMode(SmoothingModeHighQuality);
graphics->SetCompositingMode(CompositingModeSourceOver);
Pen pen(Color::Red);
pen.SetLineJoin(LineJoinRound);
pen.SetLineCap(LineCapRound,LineCapRound, DashCapRound);
// 绘制多边形
#if defined(DrawPolygonMacro)
pen.SetColor(Color::Blue);
pen.SetDashStyle(DashStyleDash);
for(int i=0; i<points.count() - 1; i++){
Point p1(points[i+0].x, -points[i+0].y);
Point p2(points[i+1].x, -points[i+1].y);
graphics->DrawLine(&pen, p1, p2 );
}
#endif
#if defined(ThroghtEveryPoint)
ALPoint b, e, n, c1, c2, c3;
int last = 0;
for(int i=0; i<points.count()-1; i++){
if( distance(points[last], points[i+1])<4 ){
continue;
}
b = points[last];
e = points[i+1];
n = points[i+2];
c1 = last==0? points[0]:c3;
c2 = cubicBezierControlPoint(b, e, n, &c3, f);
{
// 绘制控制点!!!
#if 0
pen.SetDashStyle(DashStyleDot);
pen.SetColor(Color::Green);
Point p1(c2.x, -c2.y);
Point p2(c3.x, -c3.y);
graphics->DrawEllipse(&pen, p1.X-1, p1.Y-1,2,2);
graphics->DrawEllipse(&pen, p2.X-1, p2.Y-1,2,2);
graphics->DrawLine(&pen, p1, p2);
#endif
}
pen.SetDashStyle(DashStyleSolid);
pen.SetColor(Color::Red);
Point p1(b.x, -b.y);
Point p2(c1.x, -c1.y);
Point p3(c2.x, -c2.y);
Point p4(e.x, -e.y);
graphics->DrawBezier(&pen, p1,p2,p3,p4);
last = i+1;
}
#else // 使用顶点作为控制点!!!!!
pen.SetColor(Color::Red);
pen.SetDashStyle(DashStyleSolid);
int last = 0;
float bx,by,cx,cy,ex,ey;
for(int i=0; i<points.count(); i++){
bx = i==0?points[0].x:ex;
by = i==0?points[0].y:ey;
ex = (points[i+1].x + points[i+2].x)/2;
ey = (points[i+1].y + points[i+2].y)/2;
cx = points[i+1].x; cy = points[i+1].y;
// b(t) = (1-t)^2*p0 + 2t(1-t)*p1 + t^2*p2
float x0 = bx, y0 = -by;
for(float t=0.02; t<=1.0; t+=0.02){
float x1 = square(1-t)*bx + 2*t*(1-t)*cx + square(t)*ex;
float y1 = square(1-t)*by + 2*t*(1-t)*cy + square(t)*ey;
y1 = -y1;
graphics->DrawLine(&pen,x0, y0,x1,y1);
x0 = x1; y0 = y1;
}
}
#endif
}