please! help me about antialiasing!!!

Shiwan Sung

I am under developing graphic programing. I already completed main parts. But there is problem. I used gdi implementing graphics, and so there is aliasing. It looks all figures nasty. I searched all the articles here, but I could not find any articles about antialiasing. Is there any good argorithm to apply antialiasing to my graphics without using gdi+. I also used gdi+, but the performance is not good for my graphics. please help me. thanks in advance.:((

YoSilver

The link: http://alglib.manual.ru/translate.php?location=/graphics/wuline&target=cpp[^] It is a Russian resource, I guess you don't speak Russian. So, here you are:

#include "ap.h"

/*-----------------------------------------------
User-defined routine

void setpixel(int x, int y, double c);
-----------------------------------------------*/

void drawwuline(double x1, double y1, double x2, double y2);
double myfrac(double x);

/*************************************************************************

Wu Xiaolin algorithm with fractional coordinates (a-la DX90)

*************************************************************************/
void drawwuline(double x1, double y1, double x2, double y2)
{
double grad;
double xd;
double yd;
double length;
double xm;
double ym;
double xgap;
double ygap;
double xend;
double yend;
double xf;
double yf;
double brightness1;
double brightness2;
int x;
int y;
int ix1;
int ix2;
int iy1;
int iy2;
bool wasexchange;
int tmpint;
double tmpreal;

xd = x2-x1;
yd = y2-y1;
if( xd==0&&yd==0 )
{
    return;
}
if( fabs(xd)>fabs(yd) )
{
    wasexchange = false;
}
else
{
    wasexchange = true;
    tmpreal = x1;
    x1 = y1;
    y1 = tmpreal;
    tmpreal = x2;
    x2 = y2;
    y2 = tmpreal;
    tmpreal = xd;
    xd = yd;
    yd = tmpreal;
}
if( x1>x2 )
{
    tmpreal = x1;
    x1 = x2;
    x2 = tmpreal;
    tmpreal = y1;
    y1 = y2;
    y2 = tmpreal;
    xd = x2-x1;
    yd = y2-y1;
}
grad = yd/xd;
xend = floor(x1+0.5);
yend = y1+grad\*(xend-x1);
xgap = 1-myfrac(x1+0.5);
ix1 = floor(x1+0.5);
iy1 = floor(yend);
brightness1 = (1-myfrac(yend))\*xgap;
brightness2 = myfrac(yend)\*xgap;
if( wasexchange )
{
    setpixel(iy1, ix1, brightness1);
    setpixel(iy1+1, ix1, brightness2);
}
else
{
    setpixel(ix1, iy1, brightness1);
    setpixel(ix1, iy1+1, brightness2);
}
yf = yend+grad;
xend = floor(x2+0.5);
yend = y2+grad\*(xend-x2);
xgap = 1-myfrac(x2-0.5);
ix2 = floor(x2+0.5)

Shiwan Sung

thanks a lot. I'll try...:)