1. circle.e
I have created a circle routine that uses
center, radius, and ratio.
It is here for the pickings.
--circle is similiar to ellipse.
--ellipse's use is stated below.
--circle's use follow ellipse's use.
--ellipse uses box like corners.
--circle uses a center, a radius, and a ratio.
-----------------------------------<ellipse>------------------------------------
--Syntax: include graphics.e
-- ellipse(i1, i2, s1, s2)
--Description: Draw an ellipse with color i1 on a pixel-graphics screen.
The
-- ellipse will neatly fit inside the rectangle defined by
diagonal
-- points s1 {x1, y1} and s2 {x2, y2}. If the rectangle is a
square
-- then the ellipse will be a circle. Fill the ellipse when
i2 is 1.
-- Don't fill when i2 is 0.
--
--Example: ellipse(MAGENTA, 0, {10, 10}, {20, 20})
-- This would make a magenta colored circle just fitting inside the
-- square: {10, 10}, {10, 20}, {20, 20}, {20, 10}.
--Example Program: demo\sb.ex
-----------------------------------<circle>-------------------------------------
--Syntax: include circle.e
-- circle(i, s1, a, s2)
--Description: Draw an ellipse or circle at center point of s1 {x, y}
with
-- color i and radius of a using a ratio of x to y {x, y}.
--Example: circle(MAGENTA, {160, 100}, 50, {1, 1})
-- This would make a magenta colored circle with at the center point
-- of {160, 100} with a radius of 50 with ratio of 1 to 1 {1, 1}.
-- no filling created (supported) yet.
-----------------------------------<circle>-------------------------------------
procedure circle(integer c, sequence p, atom r, sequence ratio)
atom r1, r2
integer t
r1 = ratio[1]
r2 = ratio[2]
if r1 != r2 then
if r1 > r2 then
r1 = r2 / r1
r2 = 1
else
r2 = r1 / r2
r1 = 1
end if
end if
ratio = {r1, r2}
for a = -r to r do
t = floor(sqrt(r * r - a * a) + .5)
pixel(c, {a, t} * ratio + p)
pixel(c, {t, a} * ratio + p)
pixel(c, {a, -t} * ratio + p)
pixel(c, {-t, a} * ratio + p)
end for
end procedure
--Lucius Lamar Hilley III
-- E-mail at luciuslhilleyiii at juno.com
-- JUNO JUNO JUNO. I use JUNO and
-- I support transferring of files less than 60K.
-- I can Decode both UU and Base64 format.
