[bb] Rounding Numbers by rolow [ 1+ years ago ]

[BlitzBot]

Title : Rounding Numbers
Author : rolow
Posted : 1+ years ago

Description : I have modified the code example provided with Blitz Basic 3D to show a true X,Y coordinate system demonstrating the use of the CEIL, FLOOR and INT commands.

Code :

Code: BlitzBasic

1. ; This example modified by RoLoW in September 2009
2. ; is based upon the original Ceil / Floor / Int
3. ; example from Blitz3D for three kinds of rounding.
4. ;
5. ; Resolutions and Divisor:
6. ;      640 x 480 use with 32
7. ;      800 x 600 use with 40
8. ;     1024 x 768 use with 51
9. ;
10. Global ScreenWide = 800
11. Global ScreenHigh = 600
12. Global Divisor = 40
13. ;
14. Global Origin_X = ScreenWide/2
15. Global Origin_Y = ScreenHigh/2
16. ;
17. Graphics ScreenWide, ScreenHigh
18. ;
19. SetBuffer BackBuffer()
20. Origin Origin_X,Origin_Y
21. ;
22. MoveMouse Origin_X,Origin_Y : HidePointer
23. ;
24. While Not GetKey();press any key
25.     ;
26.     Cls
27.     ;
28.     Color 255,255,255
29.     Text -Origin_X,-Origin_Y,   "         Blitz3D ROUNDING Example"
30.     Text -Origin_X,-Origin_Y+20,"Demonstrates Functions CEIL, FLOOR and INT"
31.     ;
32.     Text -Origin_X,-Origin_Y+60, " CEIL rounds up to the next whole number"
33.     Text -Origin_X,-Origin_Y+80, "FLOOR rounds down to the next whole number"
34.     Text -Origin_X,-Origin_Y+100,"  INT rounds to the closest whole number"
35.     ;
36.     Text -Origin_X,-Origin_Y+150,"Move mouse around to check different values"
37.     Text -Origin_X,-Origin_Y+170,"of X and Y on the coordinate system."
38.     Text -Origin_X,-Origin_Y+210,"Press any key to exit."
39.     ;
40.     DrawNumberLineX
41.     DrawNumberLineY
42.     ;
43.     my = MouseY() - Origin_Y
44.     mx = MouseX() - Origin_X
45.     ;
46.     Color 255,100,100
47.     Line -Origin_X, my, Origin_X-1, my
48.     Line mx,-Origin_Y,mx,Origin_Y
49.     ;
50.     x# = Float( mx ) / Divisor
51.     Color 100,100,0
52.     Text -225, Divisor*2, " X = " + x
53.     Text -225, Divisor*2+20, " Ceil( x ) = " + Ceil( x )
54.     Text -225, Divisor*2+40, " Floor( x ) = " + Floor( x )
55.     Text -225, Divisor*2+60, " Int( x ) = " + Int( x )
56.     ;
57.     y# = Float( -my ) / Divisor
58.     Color 100,100,0
59.     Text Divisor*2, Divisor*2,    " Y = " + y
60.     Text Divisor*2, Divisor*2+20, " Ceil( y ) = " + Ceil( y )
61.     Text Divisor*2, Divisor*2+40, " Floor( y ) = " + Floor( y )
62.     Text Divisor*2, Divisor*2+60, " Int( y ) = " + Int( y )
63.     ;
64.     Flip
65.     ;
66. Wend
67. ;
68. End
69. ;
70. Function DrawNumberLineX( ) ; horizontal line with numeric labels
71.     ;
72.     Color 200,200,200
73.     Line  -Origin_X, -1, Origin_X-1 , -1
74.     Line  -Origin_X,  0, Origin_X-1 ,  0
75.     Line  -Origin_X,  1, Origin_X-1 ,  1
76.     ;
77.     For n = -9 To 9
78.         xn = -Divisor * n
79.         Line xn, -4, xn, 4
80.         Color 255,255,255
81.         If n <> 0 Then Text xn-10, -20, RSet( -n, 2 )
82.         If Abs(n) = 9 Then Text xn, 20, "X"
83.     Next
84.     ;
85. End Function
86. ;
87. Function DrawNumberLineY( ) ; vertical line with numeric labels
88.     ;
89.     Color 200,200,200
90.     Line -1, -Origin_Y, -1, Origin_Y-1
91.     Line  0, -Origin_Y,  0, Origin_Y-1
92.     Line  1, -Origin_Y,  1, Origin_Y-1
93.     ;
94.     For n = -7 To 7
95.         yn = -Divisor * n
96.         Line -4, yn, 4, yn
97.         Color 255,255,255
98.         If n <> 0 Then Text -30, yn - 6, RSet( n, 2 )
99.         If Abs(n) = 7 Then Text 20, yn-6, "Y"
100.     Next
101.     ;
102. End Function

Comments :


_PJ_(Posted 1+ years ago)

 A nicely done example.There's a small bug in there somewhere though (I'll try to narrow it down) but if you move the crosshair beyond the scale of the graph axes, it messes up the recorded values. This could cause problems in rare cases. . . Just as a warning