Spiro

[Charles Pegge]

Code: OxygenBasic

1. include "win64.h"
2.  
3. Window "Spiro", 800, 800, 2
4. Font 12,24,0,"courier"
5. sys_mode=4
6.  
7.  
8. 'VELOCITIES
9. '
10. 'alter these to create different shapes
11. '
12. '------------------------------
13. ti1=0.666  'x angle
14. ti2=0.999  'y angle
15. ti3=0.3315 'both x and y angles
16. '==============================
17.  
18. x1=0      'start of line x
19. y1=0      'start of line y
20. x2=0      'end of line x
21. y2=0      'end of line y
22. xc=400    'centre x
23. yc=400    'centre y
24. xa=370.0  'size x
25. ya=370.0  'size y
26. an1=0.0   'angle for x
27. an2=pi/3  'angle for y
28. an3=0.0   'angle for both x and y
29. st=0.1    'line step size
30. cr=32     'line color red
31. cg=32     'line color green
32. cb=96     'line color blue
33. e=5000    'nuber of steps
34. da=.9999  'decay of amplitude
35.  
36. 'backgound color r g b
37.  
38. ClsColor 200,200,248
39.  
40.  
41. 'calculating point position
42.  
43. macro pos(x,y)
44.   x=cos(an1)*xa*cos(an3)+xc
45.   y=sin(an2)*ya*sin(an3)+yc
46. end macro
47. '
48. 'draw shape
49. '
50. pos(x1,y1)
51. for i=1 to e
52.   pos(x2,y2)
53.   Line x1, y1, x2, y2, 1, cr,cg,cb
54.   an1+=st*ti1
55.   an2+=st*ti2
56.   an3+=st*ti3
57.   xa*=da
58.   ya*=da
59.   x1=x2
60.   y1=y2
61. next
62.  
63. 'Esc to exit
64.  
65. WaitKey(27)
66. WinEnd
67.  

Charles

[Charles Pegge]

Hi Peter,

When the macro is invoked then x and y are replaced by x1,y1 and then in the iteration, x2 and y2. Gives better performance than a function at the expense of extra binary.

Macros have to be used with caution, I agree, but they can replace small functions to good effect.

Charles

[efgee]

Peter you can think a macro (as Charles implemented it) as the following:

Code: [Select]

inline function pos(x,y)  
  x=cos(an1)*xa*cos(an3)+xc  
  y=sin(an2)*ya*sin(an3)+yc  
end function

The "inline function" will substitute this:

Code: [Select]

pos(x1,y1)  

for i=1 to e  
  pos(x2,y2)  
  Line x1, y1, x2, y2, 1, cr,cg,cb  
  an1+=st*ti1  
  an2+=st*ti2  
  an3+=st*ti3  
  xa*=da  
  ya*=da  
  x1=x2  
  y1=y2  
next

with that:

Code: [Select]

x1=cos(an1)*xa*cos(an3)+xc  
y1=sin(an2)*ya*sin(an3)+yc

for i=1 to e  
  pos(x2,y2)  
  Line x1, y1, x2, y2, 1, cr,cg,cb  
  an1+=st*ti1  
  an2+=st*ti2  
  an3+=st*ti3  
  xa*=da  
  ya*=da  
  x1=x2  
  y1=y2  
next

at compile time; which makes the app faster as there is one less function call to do...

[Aurel]

Because i don't have 64bit computer i try Peter example translate to ABasic and resulting
image you can see in attachment.Is this right drawing ?

[Charles Pegge]

Yes that looks okay, Aurel. Only the colors are different.

Peter's Win64 is somewhat misnamed. It actually works in all modes of Oxygen.

[Charles Pegge]

Thanks Peter.

And a manual too!

I created an alternative sky, to save using a background BMP

Code: OxygenBasic

1.   'SetBmp s1,0,0,320,240,0
2.  'sky
3.   for y=0 to 239
4.      line 0,y,320,y,25,10,10,240-y
5.    next
6.   'stars
7.   sys_seed=0x35353535
8.    for i=0 to 100
9.       poke rand(0,319),rand(0,239),rand(128,200),rand(128,200),rand(128,200)
10.    next
11.  

Charles