Revolution Hypercard cellophane color

J. Landman Gay jacque at
Sun Jan 30 11:32:29 EST 2005

On 1/29/05 3:58 PM, Cubist at wrote:

> sez FMoyer at
>>...when I set the ink
>>of the graphic to blend, the colors underneath blend with the color of the 
> graphic.
>>That's not what happens in Hypercard. In Hypercard, the color of the top
>>object trumps everything underneath unless what is underneath is black.
>>Any other color is completely obliterated. There is no blending. So blue 
> over a white
>>background remains blue. With "blend" in Revolution, I believe blue over
>>a white background becomes light blue. 
>>Perhaps there is something that I don't understand about blend.
>    The thing you're missing may well be a property called "blendLevel", which 
> basically defines how opaque the top graphic is. 

Fred and I talked about this in email a while back. I don't think 
Revolution can do what he wants. The reason is that AddColor was an 
add-on, an overlay of which HC itself was completely unaware. AddColor 
has special color effects that no other graphics program allows -- 
specifially, it allows various blends or opacity to operate with its own 
graphics, but it *always* allowed black pixels on the card layer to show 
through no matter what graphics effect it used for itself.

Thus, when using two "opaque" addColor objects, the top object would 
cover the lower one and there would be no color blending between the 
two. However, when laid over the card, all of HyperCard's text or native 
paint images *do* show through. It was possible to have an opaque 
addColor object overlapping both another addColor object as well as a 
field, for example, and the opaque object would cover the other addColor 
object while still allowing the field text to show through.

When color is implemented natively, as it is in Revolution, the 
blendlevel or opacity applies to the entire card with no exceptions. 
There is no way to make color objects opaque to each other but not 
opaque to black text or graphics. And that's what Fred wants to do.

Jacqueline Landman Gay         |     jacque at
HyperActive Software           |

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