Gradient Bob

[Hotshot]

Code: [Select]

' GRADIENT - FEB 08 2007
; this was from zawran on BlitzMax a
; And I have convert to freebasic with Bob and gradients =)

Const ScreenX=106
Const ScreenY=106
Const ESCAPE =1

' PLAY AROUND WITH THESE ON SIZE AND DEGREE( 0 TO 360 )
Const SIZE  =140
Const DEGREE=100

'' set screen mode
   SCREEN 18
   
   '' allocate and draw to an image buffer
   DIM image_buffer AS ANY PTR
   image_buffer = ImageCreate( 256, 256, RGBA( 64, 160, 0, 255 ) )
   
   'CIRCLE  ( 32, 32 ), 28, RGBA( 255, 0, 0, 128 ),,,,F
For X=1 To ScreenX
          For Y=1 To ScreenY
              ' Play around with X,Y by swap around for different COLORS!
          Color (X,Y)
          ' Draw the Line
        Line image_buffer,(X,Y)-(X,Y)
    Next X
Next Y
     
' bob effect !
Dim  bobx(DEGREE)
Dim  boby(DEGREE)

For i = 0 To 63
    bobx( i ) = i * SIZE Mod DEGREE
    boby( i ) = i * SIZE Mod DEGREE
Next

bobXadd = 1 ' this is the values we add To move the bobs
bobYadd = 2 ' change these For different patterns

While INKEY$ = ""   
  Cls
  For i = 0 To 63
          ' blit image buffer to screen
          PUT( 300 + Sin( bobx(i) ) * 300, 300 + Sin( boby(i) ) * 224 ), image_buffer, PSET
          'PUT( 180, 140 ), image_buffer, ALPHA        
  Next i
     
      For i = 0 To 63
          bobx(i) = bobx(i) + bobXadd Mod DEGREE
          boby(i) = boby(i) + bobYadd Mod DEGREE
      Next i
Wend

I got a problem with this and could anyone sort out for me please

cheers

[Clyde]

It's to do with your sin and cosine calculations and it working differently from Blitz
In FB it deals with Radians and not degrees in the argument, which BB automatically converts for you.

Code: [Select]

PUT( 300 + Sin( bobx(i) *(PI/180) ) * 300, 300 + Sin( boby(i)*(PI/180) ) * 224 ), image_buffer, PSET

you'll need to change your *300 & 224 speeds.
Also you'll need to set up a variable for Pie;

eg:

Code: [Select]

Const PI = 3.14151693

Cheers and this helps,
Clyde.

[Jim]

Const PI = 3.14151693

That's not quite right
Const PI = 3.14159265
not that one ten-thousandth of a circle is going to make that much difference

Like Clyde says, Blitz uses degrees, FB uses radians.
degrees = radians * 180 / pi
radians = degrees * pi / 180

Jim

[Shockwave]

3.1415926535897932 Maybe we should have a comp to see how many decimal places we can calculate Pi to? 

[Jim]

Or a memory competition.  I can remember it to 3.141592653589 but seem to have got stuck there even though I've tried.  I think it was written round the wall of some class I was bored in so I just sat there and memorised some digits

Jim

[taj]

http://3.141592653589793238462643383279502884197169399375105820974944592.com/index1.html


lalalala....

[Clyde]

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