1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
Program Bezier;
{
This program draws Bezier curves using the degree elevation
method. For large numbers of points (more than 10, for
example) this is faster than the recursive way.
}
{
History:
Changed the source to use 2.0+.
Looks a lot better.
Added CloseWindowSafely.
Made the window dynamic, it will
adjust the size after the screen size.
9 May 1998.
Translated the source to fpc.
20 Aug 1998.
Changed to use TAGS and pas2c.
31 Oct 1998.
Removed Opening of graphics.library,
handled by graphics.pas.
21 Mar 2001.
Uses systemvartags and
OpenScreenTags
OpenWindowTags
Text to GText.
09 Nov 2002.
nils.sjoholm@mailbox.swipnet.se
}
uses exec, intuition, graphics, utility,pastoc, systemvartags;
type
PointRec = packed Record
X, Y : Real;
end;
Const
w : pWindow = Nil;
s : pScreen = Nil;
{
This will make the new look for screen.
SA_Pens, Integer(pens)
}
pens : array [0..0] of integer = (not 0);
Var
rp : pRastPort;
PointCount : Word;
Points : Array [1..200] of PointRec;
LastX, LastY : Word;
Procedure CleanUpAndDie;
begin
if assigned(w) then CloseWindow(w);
if assigned(s) then CloseScreen(s);
Halt(0);
end;
Procedure DrawLine;
begin
Move(rp, Trunc(Points[PointCount].X), Trunc(Points[PointCount].Y));
Draw(rp, LastX, LastY);
end;
Procedure GetPoints;
var
LastSeconds,
LastMicros : Longint;
IM : pIntuiMessage;
StoreMsg : tIntuiMessage;
Leave : Boolean;
OutOfBounds : Boolean;
BorderLeft, BorderRight,
BorderTop, BorderBottom : Word;
dummy : Boolean;
Procedure AddPoint;
begin
Inc(PointCount);
with Points[PointCount] do begin
X := Real(StoreMsg.MouseX);
Y := Real(StoreMsg.MouseY);
end;
with StoreMsg do begin
LastX := MouseX;
LastY := MouseY;
LastSeconds := Seconds;
LastMicros := Micros;
end;
SetAPen(rp, 2);
SetDrMd(rp, JAM1);
DrawEllipse(rp, LastX, LastY, 5, 3);
SetAPen(rp, 3);
SetDrMd(rp, COMPLEMENT);
DrawLine;
end;
Function CheckForExit : Boolean;
{ This function determines whether the user wanted to stop
entering points. I added the position tests because my
doubleclick time is too long, and I was too lazy to dig
out Preferences to change it. }
begin
with StoreMsg do
CheckForExit := DoubleClick(LastSeconds, LastMicros,
Seconds, Micros) and
(Abs(MouseX - Trunc(Points[PointCount].X)) < 5) and
(Abs(MouseY - TRunc(Points[PointCount].Y)) < 3);
end;
Procedure ClearIt;
{ This just clears the screen when you enter your first point }
begin
SetDrMd(rp, JAM1);
SetAPen(rp, 0);
RectFill(rp, BorderLeft, BorderTop,
BorderRight, BorderBottom);
SetDrMd(rp, COMPLEMENT);
SetAPen(rp, 3);
end;
begin
dummy := ModifyIDCMP(w, IDCMP_CLOSEWINDOW or IDCMP_MOUSEBUTTONS or
IDCMP_MOUSEMOVE);
SetDrMd(rp, COMPLEMENT);
PointCount := 0;
Leave := False;
OutOfBounds := False;
BorderLeft := w^.BorderLeft;
BorderRight := (w^.Width - w^.BorderRight) -1;
BorderTop := w^.BorderTop;
BorderBottom := (w^.Height - w^.BorderBottom) -1;
repeat
IM := pIntuiMessage(WaitPort(w^.UserPort));
IM := pIntuiMessage(GetMsg(w^.UserPort));
StoreMsg := IM^;
ReplyMsg(pMessage(IM));
case StoreMsg.IClass of
IDCMP_MOUSEMOVE : if PointCount > 0 then begin
if not OutOfBounds then
DrawLine;
LastX := StoreMsg.MouseX;
LastY := StoreMsg.MouseY;
if (LastX > BorderLeft) and
(LastX < BorderRight) and
(LastY > BorderTop) and
(LastY < BorderBottom) then begin
DrawLine;
OutOfBounds := False;
end else
OutOfBounds := True;
end;
IDCMP_MOUSEBUTTONS : if StoreMsg.Code = SELECTUP then begin
if PointCount > 0 then
Leave := CheckForExit
else
ClearIt;
if (not Leave) and (not OutOfBounds) then
AddPoint;
end;
IDCMP_CLOSEWINDOW : CleanUpAndDie;
end;
until Leave or (PointCount > 50);
if not Leave then
DrawLine;
dummy := ModifyIDCMP(w, IDCMP_CLOSEWINDOW);
SetDrMd(rp, JAM1);
SetAPen(rp, 1);
end;
Procedure Elevate;
var
t, tprime,
RealPoints : Real;
i : Integer;
begin
Inc(PointCount);
RealPoints := Real(PointCount);
Points[PointCount] := Points[Pred(PointCount)];
for i := Pred(PointCount) downto 2 do
with Points[i] do begin
t := Real(i) / RealPoints;
tprime := 1.0 - t;
X := t * Points[Pred(i)].X + tprime * X;
Y := t * Points[Pred(i)].Y + tprime * Y;
end;
end;
Procedure DrawCurve;
var
i : Integer;
begin
Move(rp, Trunc(Points[1].X), Trunc(Points[1].Y));
for i := 2 to PointCount do
Draw(rp, Round(Points[i].X), Round(Points[i].Y));
end;
Procedure DrawBezier;
begin
SetAPen(rp, 2);
while PointCount < 100 do begin
Elevate;
DrawCurve;
if GetMsg(w^.UserPort) <> Nil then
CleanUpAndDie;
end;
SetAPen(rp, 1);
DrawCurve;
end;
begin
s := OpenScreenTags(nil,[SA_Pens,@pens,
SA_Depth, 2,
SA_DisplayID, HIRES_KEY,
SA_Title, 'Simple Bezier Curves',
TAG_END]);
if s = NIL then CleanUpAndDie;
w := OpenWindowTags(nil,[
WA_IDCMP, IDCMP_CLOSEWINDOW,
WA_Left, 0,
WA_Top, s^.BarHeight +1,
WA_Width, s^.Width,
WA_Height, s^.Height - (s^.BarHeight + 1),
WA_DepthGadget, ltrue,
WA_DragBar, ltrue,
WA_CloseGadget, ltrue,
WA_ReportMouse, ltrue,
WA_SmartRefresh, ltrue,
WA_Activate, ltrue,
WA_Title, 'Close the Window to Quit',
WA_CustomScreen, s,
TAG_END]);
IF w=NIL THEN CleanUpAndDie;
rp := w^.RPort;
Move(rp, 252, 30);
GText(rp, pas2c('Enter points by pressing the left mouse button'), 46);
Move(rp, 252, 40);
GText(rp, pas2c('Double click on the last point to begin drawing'), 47);
repeat
GetPoints; { Both these routines will quit if }
DrawBezier; { the window is closed. }
until False;
CleanUpAndDie;
end.
|
