A simple color transition function for corona

Audio and Graphics
#1

Hi guys,

While working on my project, I found I needed to be able to animate display objects’ colors.

Corona doesn’t seem to support this functionality.

A google search seems to make references to someone who made a library for this, but I couldn’t find it at all since the links google has are old.

So, I made my own.

Here you go.

https://code.coronalabs.com/code/display-object-color-transition

code.coronalabs doesn’t have a comment system, so use this topic as a way to communicate with me and provide feedback/ideas/abuse.

Ideas:

  • start/complete callbacks

  • pause/resume

  • easing options for non-linear interpolation

#2

Hello again.

Decided I needed to implement corona’s easing library.

See the revised gist.

For those who are wondering how corona’s easing library works:

See this implementation https://github.com/EmmanuelOga/easing/blob/master/lib/easing.lua

Corona’s is almost exactly the same, except I’ve figured out that corona has swapped the variable positions around in the function parameters

For example, you can call robert penners easing.linear(time, begin, change, duration)

Corona’s swapped them around to easing.linear(time, duration, begin, change)

Which does make a lot more sense.

Anyway, if you update with my gist, you will have the option of using corona’s easing library like so:

TransitionColor(displayObj, { startColor = {0,0,0,0}, endColor = {1,1,1,1}, transition = easing.outCubic })

And if you decide to omit the transition parameter, it will default to easing.linear, just like corona does.

#3

your solution is clever, though there is an easier way:

local rect = display.newRect(50,50,100,100) rect:setFillColor(0,0,0,0) transition.to( rect.fill, { r=1, g=1, b=1, a=1, time=500, transition=easing.inCubic })
#4

You have to be kidding me hahaha. Well, that was fun while it lasted.

#5

Hello again.

Decided I needed to implement corona’s easing library.

See the revised gist.

For those who are wondering how corona’s easing library works:

See this implementation https://github.com/EmmanuelOga/easing/blob/master/lib/easing.lua

Corona’s is almost exactly the same, except I’ve figured out that corona has swapped the variable positions around in the function parameters

For example, you can call robert penners easing.linear(time, begin, change, duration)

Corona’s swapped them around to easing.linear(time, duration, begin, change)

Which does make a lot more sense.

Anyway, if you update with my gist, you will have the option of using corona’s easing library like so:

TransitionColor(displayObj, { startColor = {0,0,0,0}, endColor = {1,1,1,1}, transition = easing.outCubic })

And if you decide to omit the transition parameter, it will default to easing.linear, just like corona does.

#6

your solution is clever, though there is an easier way:

local rect = display.newRect(50,50,100,100) rect:setFillColor(0,0,0,0) transition.to( rect.fill, { r=1, g=1, b=1, a=1, time=500, transition=easing.inCubic })
#7

You have to be kidding me hahaha. Well, that was fun while it lasted.