%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2003-2009. All Rights Reserved.
%%
%% 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 online 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.
%%
%% %CopyrightEnd%
%%
-module(otp_4790).
-export([?MODULE/0]).
?MODULE() ->
pan_test().
% --------------------------- OTP Ticket --------------------------------
% *Id: OTP-4790
% *Notes: In the code below, the compiler incorrectly assumes
% wings_pref:get_value(pan_speed) returns a float,
% causing a crash at run-time.
% The same error could cause tuple tests to be removed,
% but that would propbably only cause a crash if the
% Erlang code was incorrect or if it depended on a catch
% to catch exceptions. Therefore, I consider it unlikely
% that Erlang programs that don't use floating point
% arithmetic are likely to be bitten by this bug.
% -----------------------------------------------------------------------
-record(view, {pan_x,pan_y,distance}).
pan_test() ->
pan(13, 3).
pan(Dx0, Dy0) ->
#view{pan_x=PanX0,pan_y=PanY0,distance=D} = View = current(),
S = D*(1/8)/(51-pref_get_value(pan_speed)),
Dx = Dx0*S,
Dy = Dy0*S,
PanX = PanX0 + Dx,
PanY = PanY0 - Dy,
set_current(View#view{pan_x=PanX,pan_y=PanY}).
current() ->
#view{pan_x=2.0,pan_y=9.75,distance=25.3}.
set_current(#view{pan_x=X,pan_y=Y,distance=D})
when is_float(X), is_float(Y), is_float(D) ->
io:format("X=~p Y=~p D=~p\n", [X,Y,D]).
pref_get_value(pan_speed) ->
32.
