[UniXoiD]

Привет программисты!
Помогите Рисую график, но нужно вводить функцию. Т.е. она не должна быть задана в коде, а юзер должен сам её вводить. Покажите как?! И ещё.. посмотрите чуть чуть на код проги, подправьте, а то я ньюби совсем. Вот смотрел на прогу http://midp.dev.juga.ru/ и облизывался

 
program graph;
var 
x1,x2:real;     
y1,y2:real; 
ff:real;
okCommand:command;
nameField,nameField2,d:integer; 
userName,a:string;
m:real; 
label_id:integer;
choiceGroupID: integer; 
repa: integer; 
choiceGroupID2: integer;
par, lin, sin, gep, sq, par2: integer; 
igrat, about, vyhod, help, hist : integer; 
exit, exit1, play, clicked : command;
function f(x:real): real;
begin  
if choiceIsSelected 
(choiceGroupID, par) then 
begin
f:=x*x;
end;
if choiceIsSelected 
(choiceGroupID, par2) then 
begin
f:=x*x*x;
end;
if choiceIsSelected 
(choiceGroupID, sq) then 
begin
f:=sqrt(x);
end;
if choiceIsSelected  
(choiceGroupID, gep) then 
begin
f:=2/x;
end;
if choiceIsSelected  
(choiceGroupID, lin) then 
begin
f:=2*x+5;
end;                             
if choiceIsSelected   
(choiceGroupID, sin) then 
begin
f:=x;
end; 
end;
procedure GrOfFunc;
var                  
x:real;             
y:real;            
dx:real;
l,b:real;          
w,h:real;          
x0,y0:real;        
i:integer;   
cm:command;           
begin
l:=getWidth div 2;    
b:=getHeight div 2;     
h:=getHeight div 2;    
w:=getWidth; 
if choiceIsSelected 
(choiceGroupID, sq) then 
x1:=0;
else
x1:=-9; 
x2:=9;
dx:=0.1;
setcolor(0,0,0);
x0:=getWidth div 2;   
y0:=b;               
DrawLine(trunc(x0-w), trunc(y0), trunc(x0+w), trunc(y0)); 
DrawLine(trunc(l), trunc(b-h), trunc(l), trunc(b+h));     
setColor(255, 0, 0);    
x:=x1;          
if m=0 then m:=1;     
repeat
y:=f(x);
DrawLine(trunc(x0+x*m), trunc(y0-y*m), trunc(x0+(x+dx)*m), trunc(y0-f(x+dx)*m));
setColor(255, 255, 255);
fillRect(0, 0, 50, 23); 
setColor(255, 0, 0);
drawtext(IntegerToString(trunc(x*m)),1,0);
drawtext(IntegerToString(trunc(y*m)),1,11);
//delay(d*1000);
x:=x+dx; 
repaint;
until (x>=x2); 

end;
procedure form;forward;
Procedure paint;
begin
if not choiceIsSelected      
(choiceGroupID2, repa) then 
begin
setColor(255, 255, 255);
fillRect(0, 0, 200, 200); 
end;
if formGetText(nameField)='' then m:=1 else
begin
m:=stringToReal(formGetText(nameField), 10);
d:=StringToInteger(formGetText(nameField2));
end;
ShowCanvas; 
GrOfFunc;
while 
getKeyClicked = KE_NONE do 
begin 
setColor(255, 0, 0);
drawtext('Press any',3,getHeight-20);
repaint;
end; 
form;
end;
 
procedure menu; forward;
procedure form;
begin
ClearForm;
showForm;
choiceGroupID := formAddChoice('Выберите функцию', CH_EXCLUSIVE); 
par := choiceAppendString(choiceGroupID, 'Y=X^2'); 
par2 := choiceAppendString(choiceGroupID, 'Y=X^3');
lin := choiceAppendString(choiceGroupID, 'Y=2*X+5'); 
sin := choiceAppendString(choiceGroupID, 'Y=X'); 
gep := choiceAppendString(choiceGroupID, 'Y=2/X'); 
sq := choiceAppendString(choiceGroupID, 'Y=sqrt(X)'); 
nameField := formAddTextField('Масштаб(X,Y*)', '', 2, TF_NUMERIC);
nameField2 := formAddTextField('Задержка(sec)', '', 1, TF_NUMERIC);
choiceGroupID2 := formAddChoice('Накладка', CH_MULTIPLE); 
repa := choiceAppendString(choiceGroupID2, 'Да'); 
okCommand := createCommand('OK', CM_OK, 1); 
addCommand(okCommand);
play := CreateCommand('Назад', CM_BACK, 1); 
AddCommand(play);
clicked := getClickedCommand;  
repeat  
//delay(100);  
clicked := getClickedCommand;  
until (clicked = play) or (clicked = okCommand);
if clicked = play then menu;
paint; 
end;
procedure ab;
begin
clearform;
showform;
{!}
play := CreateCommand('Назад', CM_BACK, 2); 
AddCommand(play); 
repeat 
//delay(100); 
until GetClickedCommand <> EmptyCommand; 
end;
procedure pomosh;
begin
clearform;
showForm;
{!}
play := CreateCommand('Назад', CM_BACK, 2); 
AddCommand(play); 
repeat 
//delay(100); 
until GetClickedCommand <> EmptyCommand; 
end;

procedure vers;
begin
clearform;
showForm;
{!}
play := CreateCommand('Назад', CM_BACK, 2); 
AddCommand(play); 
repeat 
//delay(100); 
until GetClickedCommand <> EmptyCommand; 
end;

procedure menu; 
begin 
ShowMenu('График функции.', CH_IMPLICIT); 
igrat := MenuAppendString('График'); 
about := MenuAppendString('Аффтар'); 
help := MenuAppendString('Помощь'); 
hist := MenuAppendString('История'); 
vyhod := MenuAppendString('Выход'); 
play := CreateCommand('OK', CM_SCREEN  , 1); 
AddCommand(play);
exit := CreateCommand('Выход', CM_EXIT, 2); 
AddCommand(exit);
repeat  
//delay(100);  
clicked := getClickedCommand;  
until (clicked = play) or (clicked = exit);
if clicked = exit then halt;
showCanvas;
if menuGetSelectedIndex = igrat then form; 
if menuGetSelectedIndex = about then ab; 
if menuGetSelectedIndex = vyhod then halt; 
if menuGetSelectedIndex = hist then vers;
if menuGetSelectedIndex = help then pomosh;
menu;
end;
begin  
menu;
while (getClickedCommand <> okCommand) do
begin
while 
getKeyClicked = KE_NONE do 
begin end;
end;
end.