Windows2003-3790/windows/advcore/gdiplus/test/cycloid/cycloid.cpp
2020-09-30 16:53:55 +02:00

83 lines
1.9 KiB
C++

/**************************************************************************
*
* Copyright (c) 2000 Microsoft Corporation
*
* Module Name:
*
* Main cycloid canvas paint procedure
*
* Created:
*
* 06/11/2000 asecchia
* Created it.
*
**************************************************************************/
#include "cycloid.hpp"
#include "wndstuff.h"
void HypoCycloid::Draw(Graphics *g, int x, int y, int width, int height)
{
#define _2PI 2*3.141592653689
// Compute the center point for the cycle.
float fXo=static_cast<float>(width)/2.0f;
float fYo=static_cast<float>(height)/2.0f;
float ScaleX = fXo/( (a>b)?a:a+b );
float ScaleY = fYo/( (a>b)?a:a+b );
int cycle=b/gcf(a,b); //number of times round the outer circle
int Num = cycle*30;
PointF *points = new PointF[Num];
// Compute the points tracking the cycloid path.
for(int i=0; i<Num; i++)
{
float t = (float)(cycle*_2PI*i/Num);
points[i].X = x+(float)(fXo+ScaleX*((a-b)*cos(t)+b*cos((a-b)*t/b)));
points[i].Y = y+(float)(fYo+ScaleY*((a-b)*sin(t)-b*sin((a-b)*t/b)));
}
Color PenColor(0xffff0000);
Pen myPen(PenColor, 2.0f);
myPen.SetLineJoin(LineJoinBevel);
g->DrawPolygon(&myPen, points, Num);
#undef _2PI
}
VOID
PaintWindow(
HDC hdc
)
{
// Clear the window
HGDIOBJ hbrush = GetStockObject(WHITE_BRUSH);
HGDIOBJ holdBrush = SelectObject(hdc, hbrush);
PatBlt(hdc, -10000, -10000, 20000, 20000, PATCOPY);
SelectObject(hdc, holdBrush);
DeleteObject(hbrush);
Graphics *g = new Graphics(hdc);
g->SetCompositingQuality(CompositingQualityGammaCorrected);
g->SetSmoothingMode(SmoothingModeAntiAlias);
// Do some stuff
HypoCycloid *h = new HypoCycloid(52, 16);
h->Draw(g, 10, 10, 400, 100);
delete h;
delete g;
}