04-27-2025, 10:51 PM
Hi
Maybe the path is NOT _clearcolor
in the meanwhile I had 2 study with _Clearcolor and _SetAlpha
I took the third example from the wiki and going on I develop this first snippet...
BUT I brought with me a conceptual error that is in that example....
as result of running the code we must get that the foreground parts of the image copied over the screen always overwrite the background image of the screen, while increasing the alpha channel from 0 to 255, we must see the presence of the background of the image copied over the screen covering the background image of the screen. This doesn't happen because in the code it has been used _Setalpha without a specific color OR range of colors so all the colors of the image copied over the screen (including its background color that before by _Clearcolor made transparent) change their degree of transparency. So all the image changes from transparent to opaque with no blending between image of the screen and the background of image pasted over it.
I must say that wiki says clearly that _Setalpha changes the alpha channel of all the colors of the image, also those that have been treated with _clearcolor before .
here the code
So going on in the wiki I found the right information in page _SetAlpha and I keep informations from the example about the specific :
how to give the range of colors to treat with _setalpha without affecting all the colors of the image
here the code in which finally the background of the image copied on the screen goes ranging from transparent to opaque
I have found no day for _Clearcolor and _Setalpha keywords also if it seems a recurrent issue dealing with them
making mask or use _clearcolor
setting _cleacolor
printing to image handle
[/url][url=https://qb64phoenix.com/forum/showthread.php?tid=3606&highlight=_clearcolor]setalpha and clearcolor
I think that it is useful to have more example about how to specify the range of colors to treat with _Setalpha.
the range from Color1& TO Color2& must be continue?
(i.e. from _RGB32(255,0,0) TO _RGB32(0,255,0) means that all colors with values between full Red and full Green are treated by _Setalpha?)
for different colors must I use an array with handles of colors and apply _setalpha on each one at a time? (i.e. simulating the action of Palette Using and _SetPalette of legacy graphic screens?)
in the example taken from the wiki why topcolor = _RGBA(0,0,0,0)- _RGBA(1,1,1,0) and not only _RGBA(1,1,1,0) that is the next one after black transparent?
Is it possible to claim a day for _Clearcolor and _Setalpha in the keyword of day?
a good day like this _Putimage day
Quote:This would need to be fast, like for animation.can you be more specific with an example?
Maybe the path is NOT _clearcolor
in the meanwhile I had 2 study with _Clearcolor and _SetAlpha
I took the third example from the wiki and going on I develop this first snippet...
BUT I brought with me a conceptual error that is in that example....
as result of running the code we must get that the foreground parts of the image copied over the screen always overwrite the background image of the screen, while increasing the alpha channel from 0 to 255, we must see the presence of the background of the image copied over the screen covering the background image of the screen. This doesn't happen because in the code it has been used _Setalpha without a specific color OR range of colors so all the colors of the image copied over the screen (including its background color that before by _Clearcolor made transparent) change their degree of transparency. So all the image changes from transparent to opaque with no blending between image of the screen and the background of image pasted over it.
I must say that wiki says clearly that _Setalpha changes the alpha channel of all the colors of the image, also those that have been treated with _clearcolor before .
here the code
Code: (Select All)
Dim Shared As Long mainScreen, Image1, NewImage1, a
mainScreen = _NewImage(1200, 800, 32) ' Main Screen (viewable)
Screen mainScreen
_Title "Clearcolor study 1"
_ScreenMove 1, 1
Image1 = _NewImage(1200, 800, 32)
init
a = 0
d = 5
Do
_Limit 10 'regulate speed of fades
_PutImage , Image1
a = a + d
If a >= 255 Or a <= 0 Then d = -d: a = a + d: Sleep 2 'reverse fade
_SetAlpha a, , NewImage1 'sets alpha level of all colors to fade image page in/out
_PutImage (0, 342), NewImage1
Locate 1, 1: Print "Alpha: "; a: Locate 1, 12: Print " Press a key to pause, r to restart, a to change alpha step, spacebar to quit "
_Display
Kp$ = InKey$
Select Case Kp$
Case " ":
System
Case "r", "R":
init
a = 0
Case "a", "A":
Select Case d
Case 1
d = 5
Case 5
d = 10
Case 10
d = 15
Case 15
d = 1
End Select
Case Else
If Kp$ <> "" Then Sleep
End Select
Loop
End
Sub init
If Image1& < -1 Then 'check loaded image handle value before using!
_Dest Image1&
Cls , _RGB32(Rnd * 255, Rnd * 255, Rnd * 255)
For I = 1 To 10
x = Rnd * 800
y = Rnd * 400
k = _RGB32(Rnd * 255, Rnd * 255, Rnd * 255)
Circle (x, y), Rnd * 100, k
Paint Step(0, 0), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), k
Next I
_Source Image1
clr~& = Point(0, 0) 'get background color from image source
_ClearColor clr~&, Image1 'clear background color of image
NewImage1 = _NewImage(_Width(Image1), _Height(Image1), 32) 'new image page
_PutImage , Image1, NewImage1 'put image without background color on new page
_FreeImage Image1 'free loaded image from memory
End If
_Dest mainScreen:
Cls , _RGB32(0, 0, 0, 255) 'the background of mainscreen is opaque black
For I = 1 To 10
Line (Rnd * 1200, Rnd * 800)-(Rnd * 1200, Rnd * 800), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), BF
Next I
Image1 = _CopyImage(mainScreen)
End Sub
So going on in the wiki I found the right information in page _SetAlpha and I keep informations from the example about the specific :
how to give the range of colors to treat with _setalpha without affecting all the colors of the image
here the code in which finally the background of the image copied on the screen goes ranging from transparent to opaque
Code: (Select All)
Dim Shared As Long mainScreen, Image1, NewImage1, a, topcolor
mainScreen = _NewImage(1200, 800, 32) ' Main Screen (viewable)
Screen mainScreen
_Title "Clearcolor study 2"
_ScreenMove 1, 1
Image1 = _NewImage(1200, 800, 32)
init
a = 0
d = 5
Do
_Limit 10 'regulate speed of fades
_PutImage , Image1
a = a + d
If a >= 255 Or a <= 0 Then d = -d: a = a + d: Sleep 2 'reverse fade
_SetAlpha a, 0 To topcolor, NewImage1 'sets alpha level of all colors to fade image page in/out
_PutImage (0, 342), NewImage1
Locate 1, 1: Print "Alpha: "; a: Locate 1, 12: Print " Press a key to pause, r to restart, a to change alpha step, spacebar to quit "
_Display
Kp$ = InKey$
Select Case Kp$
Case " ":
System
Case "r", "R":
init
a = 0
Case "a", "A":
Select Case d
Case 1
d = 5
Case 5
d = 10
Case 10
d = 15
Case 15
d = 1
End Select
Case Else
If Kp$ <> "" Then Sleep
End Select
Loop
End
Sub init
If Image1 < -1 Then 'check loaded image handle value before using!
_Dest Image1
Cls , _RGB32(Rnd * 255, Rnd * 255, Rnd * 255)
For I = 1 To 10
x = Rnd * 800
y = Rnd * 400
k = _RGB32(Rnd * 255, Rnd * 255, Rnd * 255)
Circle (x, y), Rnd * 100, k
Paint Step(0, 0), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), k
Next I
_Source Image1
clr~& = Point(0, 0) 'get background color from image source
_ClearColor clr~&, Image1 'clear background color of image
topcolor = clr~& - _RGBA(1, 1, 1, 0)
NewImage1 = _NewImage(_Width(Image1), _Height(Image1), 32) 'new image page
_PutImage , Image1, NewImage1 'put image without background color on new page
_FreeImage Image1 'free loaded image from memory
End If
_Dest mainScreen:
Cls , _RGB32(0, 0, 0, 255) 'the background of mainscreen is opaque black
For I = 1 To 10
Line (Rnd * 1200, Rnd * 800)-(Rnd * 1200, Rnd * 800), _RGB32(Rnd * 255, Rnd * 255, Rnd * 255), BF
Next I
Image1 = _CopyImage(mainScreen)
End Sub
I have found no day for _Clearcolor and _Setalpha keywords also if it seems a recurrent issue dealing with them
making mask or use _clearcolor
setting _cleacolor
printing to image handle
[/url][url=https://qb64phoenix.com/forum/showthread.php?tid=3606&highlight=_clearcolor]setalpha and clearcolor
I think that it is useful to have more example about how to specify the range of colors to treat with _Setalpha.
the range from Color1& TO Color2& must be continue?
(i.e. from _RGB32(255,0,0) TO _RGB32(0,255,0) means that all colors with values between full Red and full Green are treated by _Setalpha?)
for different colors must I use an array with handles of colors and apply _setalpha on each one at a time? (i.e. simulating the action of Palette Using and _SetPalette of legacy graphic screens?)
in the example taken from the wiki why topcolor = _RGBA(0,0,0,0)- _RGBA(1,1,1,0) and not only _RGBA(1,1,1,0) that is the next one after black transparent?
Is it possible to claim a day for _Clearcolor and _Setalpha in the keyword of day?
a good day like this _Putimage day