Constrain

[Peter]

Deleted

[Charles Pegge]

Hi Peter,

We need your latest window.h for bmpw() and bmph()

Charles

[Charles Pegge]

Hi Peter,

I've been working on the idea of a constraining box and point transforms

Code: OxygenBasic

1.  
2.  
3. indexbase 0
4. include "window.h"
5.  
6. SetWindow "Spinning squares",800,600,w_2
7. SetFont 12,24,100,"courier"
8.  
9.    Long seed=0x12345678
10.  
11.   '------------------------
12.  Function RndF() as Single
13.   '========================
14.  '
15.  Static As Single f, d=1/0x7fffffff
16.   mov eax,seed
17.   rol eax,7
18.   imul eax,eax,13
19.   mov seed,eax
20.   push eax
21.   fild dWord [esp]
22.   add esp,4
23.   fmul dWord d
24.   fstp dWord f
25.   Function=f
26.   End Function
27.  
28.  
29.   'TYPES
30.  '=====
31.  
32.   type boxF        single xb,yb,zb, xt,yt,zt
33.   type pointF      single x,y,z, sys c
34.   type projectionF single xa,ya,za, xs,ys,zs, xo,yo,zo
35.  
36.  
37.   function LimitWithinBox(pointF*p, boxF*b)
38.   '========================================
39.  if p.x<b.xb then p.x=b.xb
40.   if p.y<b.xb then p.y=b.yb
41.   if p.z<b.xt then p.z=b.zb
42.   if p.x>b.xt then p.x=b.xt
43.   if p.y>b.xt then p.y=b.yt
44.   if p.z>b.xt then p.z=b.zt
45.   end function
46.  
47.  
48.   sub projectPoint(pointF*p,projectionF*pr)
49.   '========================================
50.  single r,a
51.   r=hypot(p.x,p.y)
52.   a=atan(p.y,p.x)+pr.za
53.   pixel r*cos(a)*pr.xs+pr.xo, r*sin(a)*pr.ys+pr.yo,p.c
54.   end sub
55.  
56.  
57.   single      pi2 = pi()*2
58.  
59.  
60.   sub RotaClamp(single*a)
61.   '======================
62.  if a < pi2 then
63.     a+=pi2
64.   elseif a > pi2 then
65.     a-=pi2
66.   end if
67.   end sub
68.  
69.  
70.   'MAIN
71.  '====
72.  
73.   boxF        b1
74.   pointF      p1
75.   projectionF pr1,pr2,pr3
76.  
77.   'BOX DATA
78.  b1<= -.5, -.5, -.5, .5, .5, .5
79.  
80.   'PROJECTION DATA
81.  pr1<= 0,0,.2,  200,200,200,  400,250,0
82.   pr2<= 0,0,.3,  150,150,150,  400,300,0
83.   pr3<= 0,0,.4,  100,100,100,  600,200,0
84.   '
85.  
86. While WinExit=0
87.  
88.   cls 0x551111
89.   pr1.za+=.0025
90.   pr2.za+=.005
91.   pr3.za-=.007
92.   RotaClamp pr1.za 'clamp angle range
93.  RotaClamp pr2.za 'clamp angle range
94.  '
95.  seed=0x12345678 'reset random seed
96.  for i=1 to 4000
97.     p1<=rndf(),rndf(),rndf(),0xaaaaaa
98.     ProjectPoint p1,pr1
99.     ProjectPoint p1,pr2
100.     LimitWithinBox p1,b1
101.     ProjectPoint p1,pr3
102.   next
103.  
104.   DoEvents
105.   SwapBuffers
106.   FrameRate 60
107.   'pause
108. Wend
109. WinEnd
110.  

Charles

[Charles Pegge]

Thanks Peter.

Simple types like that are needed everywhere in geometry so why not make them as easy as creating variables. It has taken me thirty years to get this far, but I'm a slow learner

How do you make a bitmap spin?

This article looks promising:

http://www.codeguru.com/cpp/g-m/gdi/article.php/c3693

Charles