wrong alpha color

[toto971]

hello all,
see this code

Code: Select all

#include "fbgfx.bi"

dim as any ptr imags

using fb
screenres 1280,800,32,,GFX_SHAPED_WINDOW
    Color RGBA(255,0,255,255),RGBA(255,0,255,255)
    cls
imags= ImageCreate( 1280, 600 )      
circle imags,(100,100),25,rgba(243,50,133,65),,,,f
circle imags,(100,120),25,rgba(123,150,233,65),,,,f

put(0,0),imags,alpha,255          ' normal color
put step(120,120),imags,alpha,21 ' with alpha 
sleep

why i can't get good transparency color ?
thanks

[Merick]

I did a quick edit:

Code: Select all

#include "fbgfx.bi"

dim as any ptr imags

using fb
screenres 1280,800,32,,GFX_SHAPED_WINDOW
Color RGBA(255,0,255,255),RGBA(255,0,255,255)
cls
imags= ImageCreate( 1280, 600 )
circle imags,(100,100),25,rgba(243,50,133,65),,,,f
circle imags,(100,120),25,rgba(123,150,233,65),,,,f

dim as ubyte i
dim as string k
while k = ""
	k = inkey
   i += 1
	put(0,0),imags,alpha,255          ' normal color
	put (120,120),imags,alpha, i ' with alpha
	sleep 5
	cls
wend
sleep

From the results of this, I think the problem is that the colors of the circles are getting blended with the pink color that is used to set the transparent areas of the window. As the alpha value goes up, less of the pink color shows through the circles return to the original color.