For X=1 To 60
Pixel X,60-(60^2-X^2)^-2
Next X

' Routine to draw an arc segment of a circle
' - based on segment code from Peter Mather.
' test parameters and test code
x% =400
y% =200
outsize% = 100
startradial% = 225
endradial% = 135
col% = 65534
insize% = 50
cls
for outsize% = 100 to 102
insize% = outsize%
arc x%,y%,outsize%,startradial%,endradial%,col%,insize%
next outsize%
end
' End of test code

' Routine to draw an arc segment of a circle
' Parameters are:
' x-coordinate of centre of arc circle
' y-coordinate of centre of arc circle
' outsize or radius of circle
' start radial of arc to be drawn (0-360 degrees)
' NB: 0 degrees is at North (top)
' end radial of arc to be drawn (0-360 degrees)
' colour to draw arc
' inner radius for drawing radial lines (thickness or arc), leave blank or set to zero if not required
' NB arc is composed of radial lines so if insize is more than about
' 5 different from outsize, the arc will not be smooth. If a thick, smooth arc
' is required, draw multiple arcs with differing radii
Sub arc(x%, y%, outsize%, startradial%, endradial%, col%, insize%)
Local integer i%, x1%, x2%, y1%, y2%, sr%, er%
Local stepsize% = 1
If startradial% < endradial% Then
sr%=startradial%
er%=endradial%
' now draw arc
For i%=sr% To er% Step stepsize%
x2%=Sin(Rad(i%))*outsize% + x%
y2%=-Cos(Rad(i%))*outsize% + y%
x1%=Sin(Rad(i%-stepsize%))*insize% + x%
y1%=-Cos(Rad(i%-stepsize%))*insize% + y%
Line x1%,y1%,x2%,y2%,,col%
Next i%
Else ' draw 2 part arc via zero
er%=360
sr%=startradial%
' now draw arc from sr to 0
For i%=sr% To er% Step stepsize%
x2%=Sin(Rad(i%))*outsize% + x%
y2%=-Cos(Rad(i%))*outsize% + y%
x1%=Sin(Rad(i%-stepsize%))*insize% + x%
y1%=-Cos(Rad(i%-stepsize%))*insize% + y%
Line x1%,y1%,x2%,y2%,,col%
Next i%
er%=endradial%
sr%=0
' now draw arc from 0 to er
For i%=sr% To er% Step stepsize%
x2%=Sin(Rad(i%))*outsize% + x%
y2%=-Cos(Rad(i%))*outsize% + y%
x1%=Sin(Rad(i%-stepsize%))*insize% + x%
y1%=-Cos(Rad(i%-stepsize%))*insize% + y%
Line x1%,y1%,x2%,y2%,,col%
Next i%
EndIf
End Sub

DIM i%, j%, w%, lc%
' This test code is designed to run on a 800x480 LCD panel

CLS RGB(144,144,144)

For j% = 0 To 2
w% = j% + 1 'to test wider line widths, replace the 1 by a larger number

For i% = 0 To 7
select Case i%
case 0
lc% = RGB(White)
case 1
lc% = RGB(Yellow)
case 2
lc% = RGB(Green)
case 3
lc% = RGB(Blue)
case 4
lc% = RGB(Black)
case 5
lc% = RGB(Magenta)
case 6
lc% = RGB(Red)
case 7
lc% = RGB(Cyan)
End Select

Arc((i% * 100),((j% * 150) + 100),80,w%,0,135,lc%)
Next i%
Next j%

END 'of test code

' Routine to draw an arc segment of a circle
' based on segment code from Peter Mather.
'
' Parameters are:
' x-coordinate of centre of arc circle
' y-coordinate of centre of arc circle
' inradius - inner radius of arc circle
' lw - line width (thickness of arc)
' NB: line widths > 1 are achieved by drawing arcs of concentric circles
' with the arc radius increased by 1 pixel each time.
' start radial of arc to be drawn (0-360 degrees)
' NB: 0 degrees is at North (top)
' end radial of arc to be drawn (0-360 degrees)
' colour of arc line
Sub Arc(x%, y%, inradius%, lw%, startradial%, endradial%, col%)
If startradial% < endradial% Then
' draw arc
DrawArc(x%, y%, inradius%, lw%, startradial%, endradial%, col%)

Else ' draw 2 part arc via zero
' draw arc from startradial to 360
DrawArc(x%, y%, inradius%, lw%, startradial%, 360, col%)
' draw arc from 0 to endradial
DrawArc(x%, y%, inradius%, lw%, 0, endradial%, col%)
EndIf
End Sub

Sub DrawArc(x%, y%, inrad%, lw%, sr%, er%, col%)
Local c%, i%, r%
For c% = 0 To (lw%-1) Step 1
r% = inrad% + c%
For i%=sr% To er% Step 1
x1%=Sin(Rad(i%-1))*r% + x%
y1%=-Cos(Rad(i%-1))*r% + y%
Pixel x1%,y1%,col%
Next i%
Next c%
End Sub

For X=1 To 60
Pixel X,60-SQR(60^2-X^2)
Next X

void drawcircle(int x0, int y0, int radius)
{
int x = radius-1;
int y = 0;
int dx = 1;
int dy = 1;
int err = dx - (radius << 1);

while (x >= y)
{
putpixel(x0 + x, y0 + y);
putpixel(x0 + y, y0 + x);
putpixel(x0 - y, y0 + x);
putpixel(x0 - x, y0 + y);
putpixel(x0 - x, y0 - y);
putpixel(x0 - y, y0 - x);
putpixel(x0 + y, y0 - x);
putpixel(x0 + x, y0 - y);

if (err <= 0)
{
y++;
err += dy;
dy += 2;
}

if (err > 0)
{
x--;
dx += 2;
err += dx - (radius << 1);
}
}
}

CLS
bezier 10,10,106,80,212,80,309,10,rgb(yellow)
bezier 10,230,106,150,212,150,309,230,rgb(yellow)
bezier 10,10,80,80,80,160,10,230,rgb(green)
bezier 309,10,239,80,239,160,309,230,rgb(green)
text 85,110,"Cubic Bezier Curves"
pause 5000
CLS
timer=0
for i=0 to 99 step 4
Arc mm.hres/2,mm.vres/2,20+i,,325+2*i,5+5*i,rgb(yellow)
next i
print timer 'takes 30mSec on Armmite H7
pause 5000
CLS
timer=0
arc mm.hres\2,mm.vres\2,100,110,315,45,rgb(red)
arc mm.hres\2,mm.vres\2,100,110,45,315,rgb(green)
print timer ' takes 12mSec on Armmite H7

void bezier(float x0, float y0, float x1, float y1, float x2, float y2, float x3, float y3, int c){
float tmp,tmp1,tmp2,tmp3,tmp4,tmp5,tmp6,tmp7,tmp8,t=0.0,xt=x0,yt=y0;
int i, xti,yti,xtlast=-1, ytlast=-1;
for (i=0; i<1000; i++)
{
tmp = 1.0 - t;
tmp3 = t * t;
tmp4 = tmp * tmp;
tmp1 = tmp3 * t;
tmp2 = tmp4 * tmp;
tmp5 = 3.0 * t;
tmp6 = 3.0 * tmp3;
tmp7 = tmp5 * tmp4;
tmp8 = tmp6 * tmp;
xti=(int)xt;
yti=(int)yt;
xt = ((((tmp2 * x0) + (tmp7 * x1)) + (tmp8 * x2)) + (tmp1 * x3));
yt = ((((tmp2 * y0) + (tmp7 * y1)) + (tmp8 * y2)) +(tmp1 * y3));
if((xti!=xtlast) || (yti!=ytlast)) {
DrawPixel(xti, yti, c);
xtlast=xti;
ytlast=yti;
}
t+=0.001;
}
}
void SmallArc(float x, float y, float r, float a1i, float a2i, int col){
// First compute all four points for an arc that subtends the same total angle
// but is centered on the X-axis
float a1,a2,a,x1,y1,x2,y2,x3,y3,x4,y4,f,ar,cos_ar,sin_ar ;
float x2i,x3i,y2i,y3i ;
float pidiv2=PI_VALUE/2.0, k = 0.5522847498 ;
a1=Rad(a1i)- pidiv2 ;
a2=Rad(a2i)- pidiv2 ;
a = (a2-a1) / 2.0 ;
x4 = r * cos(a) ;
y4 = r * sin(a) ;
x1= x4 ;
y1= -y4 ;
f = k * tan(a) ;
x2 = x1 + f * y4 ;
y2 = y1 + f * x4 ;
x3 = x2 ;
y3= -y2 ;
// Now find the arc points actual locations by computing x1,y1 and x4,y4
// and rotating the control points by a + a1
ar = a + a1 ;
cos_ar = cos(ar) ;
sin_ar = sin(ar) ;
x1 = r * cos(a1) + x ;
y1 = r * sin(a1) + y ;
x2i = x2 * cos_ar - y2 * sin_ar + x ;
y2i = x2 * sin_ar + y2 * cos_ar + y ;
x3i = x3 * cos_ar - y3 * sin_ar + x ;
y3i = x3 * sin_ar + y3 * cos_ar + y ;
x4 = r * cos(a2) + x ;
y4 = r * sin(a2) + y ;
bezier(x1,y1,x2i,y2i,x3i,y3i,x4,y4,col) ;
}
void cmd_arc(void){
// Parameters are:
// X coordinate of centre of arc
// Y coordinate of centre of arc
// inner radius of arc
// outer radius of arc - omit it 1 pixel wide
// start radial of arc in degrees
// end radial of arc in degrees
// Colour of arc
int x, y, r1, r2, c;
float f, rad1, rad2, rstart;
getargs(&cmdline, 13,",");
if(Option.DISPLAY_TYPE == 0) error("Display not configured");
if(!(argc == 11 || argc == 13)) error("Argument count");
x = getinteger(argv[0]);
y = getinteger(argv[2]);
r1 = getinteger(argv[4]);
if(*argv[6])r2 = getinteger(argv[6]);
else r2=r1;
if(r2 < r1)error("Inner radius < outer");
rad1 = getnumber(argv[8]);
rad2 = getnumber(argv[10]);
if(argc == 13)
c = getint(argv[12], 0, WHITE);
else
c = gui_fcolour;
while(rad2<rad1)rad2+=360;
for(f = r1 ; f<= r2; f+=1.0){
rstart=rad1;
while(rad2 - rstart > 90){
SmallArc(x , y , f , rstart, rstart+90 , c);
rstart+=90;
}
SmallArc(x , y , f , rstart, rad2 , c);
}
}
void cmd_bezier(void) {
// X coordinate of start point
// Y coordinate of start point
// X coordinate of first control point
// Y coordinate of first control point
// X coordinate of second control point
// Y coordinate of second control point
// X coordinate of end point
// Y coordinate of end point
// Colour of curve
int xx0, yy0, xx1, yy1, xx2, yy2, xx3, yy3, c;
getargs(&cmdline, 17,",");
if(!(argc==15 || argc==17))error("Argument count");
if(Option.DISPLAY_TYPE == 0) error("Display not configured");
xx0 = getint(argv[0],0,HRes-1);
yy0 = getint(argv[2],0,VRes-1);
xx1 = getinteger(argv[4]);
yy1 = getinteger(argv[6]);
xx2 = getinteger(argv[8]);
yy2 = getinteger(argv[10]);
xx3 = getint(argv[12],0,HRes-1);
yy3 = getint(argv[14],0,VRes-1);
c = gui_fcolour; // setup the defaults
if(argc > 15 && *argv[16]) c = getint(argv[16], 0, WHITE);
bezier(xx0, yy0, xx1, yy1, xx2, yy2, xx3, yy3, c);
}