Hue Shift (like photoshop) Effect

Hey Sswift, thanks for jumping in!

I'm afraid I'd already tried that approach and found that it didn't work either (though I suspect it's <more> right than the one that i posted). In fact, it looks identical to the HSL version that I posted based on jfk's suggestion.

I still don't understand what I can do to eliminate the intermediate stages where the colors add together to be too bright. Please let me know if you have any other ideas!

thanks again,
roland

here's a version of it based on that approach. It adds to the next color while the previous color is at 255, then decrements the previous color, etc. A 6-step approach instead of 3.

Graphics3D 640,480,0,2

pivot = CreatePivot()
cam = CreateCamera(pivot)
PositionEntity cam,0,0,30
PointEntity cam,pivot

Type col
	Field image
	Field red
	Field green
	Field blue
	Field state
End Type

Function makecol(file$,red,green,blue,state)
	c.col = New col
	c\image = LoadSprite(file)
	ScaleSprite c\image,20,20
	EntityFX c\image,1
	EntityBlend c\image,3

	c\red = red
	c\green = green
	c\blue = blue
	c\state = state
	
	EntityColor c\image,c\red,c\green,c\blue
	
End Function


makecol("red.jpg",255,0,0,1)
makecol("green.jpg",0,255,0,3)
makecol("blue.jpg",0,0,255,5)

speed = 10

While Not KeyHit(1)

	For c.col= Each col
	
		Select c\state
		
			Case 1
			c\green = c\green+speed
			If c\green>255 Then c\state = 2
			
			Case 2
			c\red = c\red-speed
			If c\red < 0  Then c\state = 3
			
			Case 3
			c\blue = c\blue+speed
			If c\blue > 255 Then c\state = 4
			
			Case 4
			c\green = c\green-speed
			If c\green < 0 Then c\state = 5	
			
			Case 5
			c\red = c\red+speed
			If c\red > 255 Then c\state = 6				

			Case 6
			c\blue = c\blue -speed
			If c\blue < 0 Then c\state = 1	
				
		
		End Select	
	
		EntityColor c\image,c\red,c\green,c\blue
	
		If c\red < 0 Then c\red = 0
		If c\green < 0 Then c\green = 0
		If c\blue < 0 Then c\blue = 0
	
	
	Next

RenderWorld()

c.col = First col

Text 0,0,c\red
Text 0,14,c\green
Text 0,28,c\blue

Text 0,50,c\red+c\green+c\blue

Flip

Wend