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Transparency or opacity

For those not familiar with the concepts surrounding screen color and transparency, the value of alphaspecifies a transparency or opacity level. When an attempt is made to draw a pixel in the same screen location as an existing pixel, the colorof the last pixel drawn will be completely opaque and will dominate if it has an alpha value of 1.0. In that case, the first pixel drawn will no longer bevisible.

If the last pixel drawn has an alpha value of 0, it will be totally transparent and the first pixel drawn will continue to be totally visible.

For values between 0.0 and 1.0, the first pixel drawn will show through to some extent and the final color of the pixel will be a mix of the original colorand the new color.

Four runs with different alpha values

For this example, the Flex 3 application was modified, compiled, and run four times in succession by substituting four different values of backgroundAlpha into the code in Listing 2. The results are shown in Figure 3.

Application window background for alpha values of 0.0, 0.33, 0.66, and 1.0.

Missing image.
Application window background for alpha values of 0.0, 0.33, 0.66, and 1.0.

Four output images

The four images shown in Figure 3, going from left to right, top to bottom, represent alpha values of 0.0, 0.33, 0.66, and 1.0 respectively.

An alpha value of 0.0

For an alpha value of 0.0, the output color is pure red as shown by the top-left image in Figure 3. In this case, the gradient color scheme istotally transparent.

An alpha value of 1.0

For an alpha value of 1.0, the output colors range from pure green at the top to pure blue at the bottom as shown in the bottom-right image in Figure 3.In this case, the gradient color scheme is totally opaque and the red background color doesn't show through at all.

Alpha values of 0.33 and 0.66

For alpha values of 0.33 and 0.66, the output is a mix of the red background and the green/blue gradient as shown by the top-right and bottom-left images inFigure 3.

(The image in the bottom-left corner of Figure 3 corresponds to what you should see if you run the online version of this application.)

Conclusion regarding the Flex 3 version

These results suggest that the alpha value specified by backgroundAlpha in Flex 3 applies to the colors specified by backgroundGradientColors and does not apply to the color specified by backgroundColor . .

In other words, the gradient colors can be made more or less transparent by changing the value of backgroundAlpha allowing the red backgroundColor to show through the gradient colors. However, the value of alpha doesn't appear to affect the background color.

If you modify the code in Listing 2 by removing the backgroundColor attribute, and then compile and run it for different values of alpha, you willsee a similar result. In that case, however, the resulting colors will be a mixture of the default gray background color shown in Figure 1 and thegreen/blue gradient shown in the bottom right corner of Figure 3.

The Flex 4 version

The Flex 4 program named AppBackground03 replicates the behavior of the Flex 3 version named AppBackground01 . By necessity, this version of the program is significantly more complicated thanthe Flex 3 version.

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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