int main (int argc, char *argv[])
{
int arc_type;
if (argc != 2)
{
printf ("USAGE: WHICHARC arcfile\n");
return 100;
}
arc_type = WhichArc (argv[1]);
if (arc_type == -1)
printf ("File %s not found!\n", argv[1]);
else
{
printf ("%s:\tArchive type is %s\t(return value = %d)\n",
argv[1],
Arctypes[arc_type],
arc_type
);
}
return arc_type;
}
int main(int argc,char *argv[])
{
char *arc_types[]={"UNKNOWN", "ARC", "ZOO", "ARJ", "LHARC", "LHA",
"ZIP", "PAK", "PAK", "ARC7", "SFXARC", "SFXARJ",
"SFXLHARC", "SFXLHA", "SFXZIP", "SFXARC7", "SFXPAK",
"EXE"};
while (--argc)
{
enum ArcType which;
if (ArcERR == (which = WhichArc(*++argv)))
printf("File error accessing %s\n", *argv);
else printf("%s archive type is %s\n", *argv, arc_types[which]);
}
return(0);
}
//---------------------------------------------------------------------------
void EllipseArc2D (int xc, int yc, int a, int b, float fx0, float fy0,
float fx1, float fy1, void (*callback)(int,int))
{
// Assert (within floating point roundoff errors):
// (fx0-xc)^2/a^2 + (fy0-yc)^2/b^2 = 1
// (fx1-xc)^2/a^2 + (fy1-yc)^2/b^2 = 1
// Assume if (fx0,fy0) == (fx1,fy1), then entire ellipse should be drawn.
//
// Integer points on arc are guaranteed to be traversed clockwise.
const int a2 = a*a, b2 = b*b;
// get integer end points for arc
int x0, y0, x1, y1;
SelectEllipsePoint(a2,b2,fx0-xc,fy0-yc,x0,y0);
SelectEllipsePoint(a2,b2,fx1-xc,fy1-yc,x1,y1);
int dx = x0 - x1;
int dy = y0 - y1;
int sqrlen = dx*dx+dy*dy;
if ( sqrlen == 1 || ( sqrlen == 2 && abs(dx) == 1 ) )
{
callback(xc+x0,yc+y0);
callback(xc+x1,yc+y1);
return;
}
// determine initial case for arc drawing
int arc = WhichArc(a2,b2,x0,y0);
while ( 1 )
{
// process the pixel
callback(xc+x0,yc+y0);
// Determine next pixel to process. Notation <(x,y),dy/dx>
// indicates point on ellipse and slope at that point.
int sigma;
switch ( arc )
{
case 0: // <(0,b),0> to <(u0,v0),-1>
x0++;
dx++;
sigma = b2*x0*x0+a2*(y0-1)*(y0-1)-a2*b2;
if ( sigma >= 0 )
{
y0--;
dy--;
}
if ( b2*x0 >= a2*y0 )
arc = 1;
break;
case 1: // <(u0,v0),-1> to <(a,0),infinity>
y0--;
dy--;
sigma = b2*x0*x0+a2*y0*y0-a2*b2;
if ( sigma < 0 )
{
x0++;
dx++;
}
if ( y0 == 0 )
arc = 2;
break;
case 2: // <(a,0),infinity> to <(u1,v1),+1>
y0--;
dy--;
sigma = b2*(x0-1)*(x0-1)+a2*y0*y0-a2*b2;
if ( sigma >= 0 )
{
x0--;
dx--;
}
if ( b2*x0 <= -a2*y0 )
arc = 3;
break;
case 3: // <(u1,v1),+1> to <(0,-b),0>
x0--;
dx--;
sigma = b2*x0*x0+a2*y0*y0-a2*b2;
if ( sigma < 0 )
{
y0--;
dy--;
}
if ( x0 == 0 )
arc = 4;
break;
case 4: // <(0,-b),0> to <(u2,v2,-1)>
x0--;
dx--;
sigma = b2*x0*x0+a2*(y0+1)*(y0+1)-a2*b2;
if ( sigma >= 0 )
{
y0++;
dy++;
}
if ( a2*y0 >= b2*x0 )
arc = 5;
break;
case 5: // <(u2,v2,-1)> to <(-a,0),infinity>
y0++;
dy++;
sigma = b2*x0*x0+a2*y0*y0-a2*b2;
if ( sigma < 0 )
{
x0--;
dx--;
}
if ( y0 == 0 )
arc = 6;
break;
case 6: // <(-a,0),infinity> to <(u3,v3),+1>
y0++;
dy++;
sigma = b2*(x0+1)*(x0+1)+a2*y0*y0-a2*b2;
if ( sigma >= 0 )
{
x0++;
dx++;
}
if ( a2*y0 >= -b2*x0 )
arc = 7;
break;
case 7: // <(u3,v3),+1> to <(0,b),0>
x0++;
dx++;
sigma = b2*x0*x0+a2*y0*y0-a2*b2;
if ( sigma < 0 )
{
y0++;
dy++;
}
if ( x0 == 0 )
arc = 0;
break;
}
sqrlen = dx*dx+dy*dy;
if ( sqrlen <= 1 )
break;
}
}
