Отрисовка на Canvas "гладкой" наклонной линии

    ::Graphics::TBitmap *bmp=new ::Graphics::TBitmap();
 
    bmp->Width=300;
    bmp->Height=300;
 
    Gdiplus::Graphics g(bmp->Canvas->Handle);
 
    Gdiplus::REAL dots[2] = {1, 1};
    Gdiplus::Pen blackPen(Gdiplus::Color(255, 0, 0, 0), 1);
    Gdiplus::Pen greenPen(Gdiplus::Color(255, 0, 255, 0), 10);
    blackPen.SetDashPattern(dots, 2);
 
    for (int i=0; i<30; i++)
    {
        g.DrawLine(&blackPen, i*10, 0, i*10, 300);
        g.DrawLine(&blackPen, 0, i*10, 300, i*10);
    }
 
    Gdiplus::REAL dashValues[4] = {4, 2, 2, 2};
    Gdiplus::Pen pen2(Gdiplus::Color(255, 175, 0, 0), 2);
    Gdiplus::Pen pen3(Gdiplus::Color(255, 0, 175, 0), 2);
 
    pen2.SetDashPattern(dashValues, 4);
    pen3.SetDashPattern(dashValues, 4);
    g.SetSmoothingMode(Gdiplus::SmoothingModeAntiAlias);
    for (int i=0; i<10; i++)
    {
        g.DrawLine(&pen2, 5+i*10, 5, i*25, i*35);
    }
    for (int i=0; i<10; i++)
    {
        g.DrawLine(&pen3, 5, 5+i*10, i*35, i*15);
    }
    Img->Picture->Bitmap->Assign(bmp);
    delete bmp;

#define STRICT
#pragma option -w-hid
#include <windows.h>
#include <GdiPlus.h>
#pragma comment(lib, "GdiPlus.lib") // для статик линковки
#pragma option -whid

Canvas->MoveTo()
Canvas->LineTo()

g.DrawLine();