John Horn (Home) <[EMAIL PROTECTED]> wrote:
> I am unfamilar with imaging lingo, could you help to point me in
> the right direction, a few commands to look up or something.
Hi John,
Here is a chunk of unfinished code that I originally wrote for one of
the Paintbox behaviors in D8's Library Palette. Its purpose was to make
a bitmap sprite appear transparent by copying all the image data from
the sprites behind it. The sprites behind may have a variety of inks
(though you will see that I did not complete the treatment of "mask"
ink): to get a transparent effect you could use transparent,
background transparent or matte inks.
I realise that you may not be working directly from sprites but rather
from a set of members. You could modify the handler so that, instead of
working through sprites 1 to (thisSprite - 1), it works through a list
with the format:
[[#member: < >, #rect: < >, #ink: < >, #blendLevel: < >, #color: < >,
#bgColor: < >, ... ], ...]
"thatSprite" could take the value of each of the nested property lists
in turn (it might be worthwhile renaming the variable so that it makes
better sense).
Note that the handler uses mapStageToMember() which would be
inappropriate if you are not using sprites: you would have to rework
this section. Note also that some member types do not have an "image"
property, and so cannot be dealt with in this way. Shape members
(rects, lines, ovals, ...) can be faked using the draw() command. Field
members need to be converted to text.
(This code was never used, since the Paintbox behaviors were already
sufficiently complex without dealing with painting on a "transparent"
canvas. It has thus not been fully tested: I cannot guarantee its
usefulness).
Cheers,
James
------------------------------------------------------------------------
-
on getImageBehind(thisSprite)
case ilk(thisSprite)of
#sprite: spriteNumber = thisSprite.spriteNum
#integer:
if thisSprite <> the lastChannel then
spriteNumber = thisSprite
thisSprite = sprite(thisSprite)
else
return #notASprite
end if
otherwise
return #notASprite
end case
thisRect = thisSprite.rect
--Create a blank image the same color as the Stage
imageData = image(thisRect.width, thisRect.height, the colordepth)
colorOfStage = paletteIndex(the stageColor)
colorOfStage.colorType = #rgb
imageData.fill(imageData.rect, colorOfStage)
hAdjust = -thisRect.left
vAdjust = -thisRect.top
previousSprite = spriteNumber - 1
repeat with i = 1 to previousSprite
-- Copy the appropriate part of the sprite into the blank image
if sprite i intersects spriteNumber then
thatSprite = sprite(i)
thatMember = thatSprite.member
case thatMember.type of
#bitmap, #text: -- continue
otherwise
-- * Other member types don't (yet) have an #image property
next repeat
end case
-- Find which part of thatSprite overlaps our blank image
thatRect = thatSprite.rect
overlap = intersect(thisRect, thatRect)
-- Modify thatRect so that it represents the rect of the
-- member concerned by this overlap. (* This only works
-- correctly with unstretched, unrotated and unquadded sprites)
topLeft = point(overlap.left, overlap.top)
topLeft = mapStageToMember(thatSprite, topLeft)
bottomRight = point(overlap.right, overlap.bottom) - 1 -- * ??
bottomRight = mapStageToMember(thatSprite, bottomRight) + 1 -- *
thatRect = rect(topLeft, bottomRight)
-- Determine which options to use for the copyPixels command
optionsList = [ \
#ink: thatSprite.ink, \
#blendLevel: thatSprite.blendLevel, \
#color: thatSprite.color, \
#bgColor: thatSprite.bgColor \
]
-- Prepare the image of thatSprite
if thatSprite.ink = #mask then
thatImage = getMaskedImage(thatSprite.member)
optionsList.deleteProp(#ink)
else
thatImage = thatSprite.member.image
end if
-- Determine which part of imageData thatSprite covers
destRect = offset(overlap, hAdjust, vAdjust)
imageData.copyPixels(thatImage, destRect, thatRect, optionsList)
end if
end repeat
return imageData
end getImageBehind
on getMaskedImage(maskedMember)
-- This handler was never finished
maskedImage = maskedMember.image
return maskedImage
end getMaskedImage
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