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%% ``The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved via the world wide web at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% The Initial Developer of the Original Code is Ericsson Utvecklings AB.
%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
%% AB. All Rights Reserved.''
%%
%% $Id$
%%
%% ------------------------------------------------------------
%% A simple demo showing a line
%% bouncing within a window.
%% ------------------------------------------------------------
-module(line_demo).
-export([start/0,init/0,line/3]).
start() ->
spawn(line_demo,init,[]).
init() ->
I= gs:start(),
W= gs:window(I,[{title,"Line Demo"},{width,300},{height,300},{map,true}]),
C= gs:canvas(W,[{width,300},{height,300},{bg,blue}]),
gs:button(W,[{label,{text,"Quit"}},{width,40},{bg,yellow}]),
Line2 = gs:line(C,[{coords,[{0,0},{50,50}]},{fg,white},{width,3}]),
line(Line2,{100,100,9.5,5},{0,0,-6,-8.4}).
line(Line,{X1,Y1,DX1,DY1},{X2,Y2,DX2,DY2}) ->
{NX1,NDX1} = cc(X1,DX1),
{NY1,NDY1} = cc(Y1,DY1),
{NX2,NDX2} = cc(X2,DX2),
{NY2,NDY2} = cc(Y2,DY2),
gs:config(Line,{coords,[{NX1,NY1},{NX2,NY2}]}),
receive
{gs,_,click,_,_} -> exit(normal);
{gs,_,destroy,_,_} -> exit(normal)
after 50 ->
true
end,
line(Line,{NX1,NY1,NDX1,NDY1},{NX2,NY2,NDX2,NDY2}).
cc(X,DX) ->
if
DX>0 ->
if
X<300 ->
{X+DX,DX};
x>=300 ->
{X-DX,-DX}
end;
DX<0 ->
if
X>0 ->
{X+DX,DX};
X=<0 ->
{X-DX,-DX}
end
end.
%% ------------------------------------------------------------
|
