Binary color separation trick [RESOLVED]

Blitz3D Forums/Blitz3D Beginners Area/Binary color separation trick [RESOLVED]

Mikorians

(Posted 2015) [#1]

I'm darned if I can remember the old
'And' trick to obtain red, green, blue, alpha values
In that rapid way with the logical AND trick...
Red=Col AND $something bla bla...
Erm, anybody remember it?
Should be an easy one to solve.
The REAL FAST one?
I need it for another programming language also.

Matty

(Posted 2015) [#2]

Yep....

Rgb = red shl 16 or green shl 8 or blue

And to get components

Red =( rgb shr 16) and 255
etc....

GfK	(Posted 2015) [#3]

BlitzMax code but you get the idea:

Local col:Int = $FF0AC216

Local Alpha:Int = (col Shr 24) & $FF
Local RED:Int = (col Shr 16) & $FF
Local GREEN:Int = (col Shr 8) & $FF
Local BLUE:Int = col & $FF

Mikorians

(Posted 2015) [#4]

Yep.
And for those who need the Visual Basic 6 version (Yeesh):
B=(Col And &HFF0000)/&H10000
G=(Col And &HFF00)/&H100
R=(Col And &HFF&)
If Col<0 Then A=((Col And &H7F000000)/&H1000000) Or &H80& Else A=Col/&H1000000

If I've made an error with the alpha, let me know...

Floyd

(Posted 2015) [#5]

Silly trick which I occasionally use:

Print DottedIP( $01020304 )

WaitKey

I know that doesn't answer the original question of getting A,R,G,B. But it is a handy way to see the four bytes in an integer.

Guy Fawkes

(Posted 2015) [#6]

O for god sake, GFK! HELP the man.

Here, @Mikorians:

Graphics3D(800, 600, 0, 2)
SetBuffer BackBuffer()
SeedRnd MilliSecs()

	Global col = $FF0AC216
	Global clr_max = 255

	Dim My_Color(clr_max)

	Global My_Alpha = Validate_Color_Alpha(0, $FF)
	Global My_Red = Validate_Color_Alpha(1, 256)
	Global My_Green = Validate_Color_Alpha(2, 5.12)
	Global My_Blue = Validate_Color_Alpha(3, -10.24)
	
	Global test1
	Global test2
	Global ending

	While Not KeyDown(1) Or ending

		If KeyHit(57) Then test1 = 1

		If test1 = 0
			
			Text GraphicsWidth()/2, GraphicsHeight()/2, "Press Space to start test 1!", 1, 1

		Else
			
			Cls
			
				Text GraphicsWidth()/2, GraphicsHeight()/2, "col: "+col, 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+20, "My_Alpha: "+My_Alpha, 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+40, "My_Red: "+My_Red, 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+60, "My_Green: "+My_Green, 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+80, "My_Blue: "+My_Blue, 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+100, "", 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+120, "TEST 1 DONE!", 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+140, "", 1, 1
				Text GraphicsWidth()/2, GraphicsHeight()/2+160, "Press Space to start test 2!", 1, 1

			Flip

		EndIf
			
		If ( KeyHit(57) And test1 = 1 ) Then test2 = 1 : test1 = 0 : Cls

			If test2
				
				Repeat

						For x = 0 To 255
	
							;Generate random colors 0 - 255
	
							;Note :: 256 is put in as a maximum random value
							;on PURPOSE!
	
							My_Color(x) = Validate_Color_Alpha( Rnd(0, 3), Rnd(0, 256) )
										
							Locate 0, x*10
										
							Print "My_Color"+"("+x+"): "+My_Color(x)
		
						Next
						
						Print
						
						Print "TEST 2 DONE!"
						
						FlushKeys()
						
						WaitKey()
						
						test2 = 0

					Flip
						
				Until test2 = 0
				
				If test2 = 0 Then ending = 1

				If ending
				
					FlushKeys()
				
					Repeat
					
						Cls
						
							Text GraphicsWidth()/2, GraphicsHeight()/2, "Press any key to exit!", 1, 1
					
						Flip
					
					Until GetKey()
					
				EndIf
	
			EndIf

		RenderWorld
		
		Flip
		
	Wend

End

Function Validate_Color_Alpha(colour=0, val=25)

	Local ALPHA
	Local RED
	Local GREEN
	Local BLUE

		If colour < 0 Then colour = 0
		If colour > 3 Then colour = 3

		val = Int(val)
		If val < 0 Then val = 0
		If val > 255 Then val = 255
	
		ALPHA = ( Abs ( (col Shr 24) And val ) )
		RED = ( Abs ( (col Shr 16) And val ) )
		GREEN = ( Abs ( (col Shr 8) And val ) )
		BLUE = ( Abs ( col And val ) )
	
		If colour = 0 Then Return ALPHA
		If colour = 1 Then Return RED
		If colour = 2 Then Return GREEN
		If colour = 3 Then Return BLUE

	Return False

End Function

I hope you like this. It took an hour & a half to make! :)

And yes, I'm aware that if you go above 255 for some reason, even though I TOLD it NOT to, the "Red" value will be set to "10" for some reason. Other than that, I think it's pretty straight forward!

Anyways, good luck with your project! I hope this helps! :)

Sincerely,

~GF