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Fading error
Posted: Thu May 08, 2014 9:02 pm
by TheOddByte
Hello, I'm not so familiar with Löve and I'm not sure what I'm doing wrong here..
I'll explain what's wrong, when I try fading an image it fades as it should, but for example when it's completly faded out it reappears for about a millisecond or something and then disappears, it's the same when fading it in but it disappears instead and then reappears..
Here's the code I'm using
Code: Select all
function love.load()
--# Fading variables
fade = false;
fade_mode = nil;
fade_time = 5
fade_timer = 5
--# Load test image
image = love.graphics.newImage("logo.png")
end
function love.update(dt)
--# Handle fading
if fade then
--# Fade out
if fade_mode == "out" then
if fade_timer > 0 then
fade_timer = fade_timer - dt
else
if fade_timer < 0 then
fade_timer = 0
end
fade = false;
end
else
--# Fade in
if fade_timer < fade_time then
fade_timer = fade_timer + dt
else
if fade_timer > fade_time then
fade_timer = fade_time
end
fade = false;
end
end
end
end
function fadeOut( rate )
fade = true;
fade_mode = "out";
fade_timer = rate;
fade_time = rate;
end
function fadeIn( rate )
fade = true;
fade_mode = "in";
fade_time = rate;
end
function love.draw()
love.graphics.setColor(255, 255, 255, fade_timer*(255/fade_time))
love.graphics.draw(image, 100, 100)
end
function love.keypressed(key, unicode)
if key == "left" then
if fade_mode == "out" then
fadeIn(2)
else
fadeOut(2)
end
end
end
Note: My indenting of the code may get screwed up when pasting it here
Re: Fading error
Posted: Thu May 08, 2014 9:29 pm
by DaedalusYoung
Try clamping the alpha value before calling
setColor, fade_timer*(255/fade_time) might create odd rounding results.
Code: Select all
local alpha = math.min(255, math.max(0, fade_timer*(255/fade_time)))
love.graphics.setColor(255, 255, 255, alpha)
Re: Fading error
Posted: Thu May 08, 2014 9:33 pm
by TheOddByte
DaedalusYoung wrote:
-Snip-
Thanks! It worked as a charm!
I'm very grateful, Here's a virtual cookie for you
* hands over cookie *
Re: Fading error
Posted: Fri May 09, 2014 2:28 pm
by DaedalusYoung
Thank you and you're very welcome, I'm glad you got it working
Another question
Posted: Fri May 09, 2014 7:36 pm
by TheOddByte
Even though this problem have been solved I have another question, But I don't want to start another topic for it since it's probably something simple. I'm wondering how I can invert a picture like this
Code: Select all
--# This is a "picture"
+--------+
| :-) |
| |
+--------+
--# That I want to become like this
+--------+
| (-: |
| |
+--------+
Re: Fading error
Posted: Fri May 09, 2014 8:37 pm
by micha
The
love.graphics.draw function takes a whole lot of input parameters:
Code: Select all
love.graphics.draw( drawable, x, y, r, sx, sy, ox, oy, kx, ky )
sx and sy are scale factors in x- and y-direction. To flip an image left to right, set sx to -1:
Code: Select all
love.graphics.draw( image, x, y, 0, -1, 1)
(you don't need to hand over all of the parameters. If you omit some, they use some default values.
Re: Fading error
Posted: Fri May 09, 2014 8:58 pm
by TheOddByte
Oh thanks!
Where exactly is stuff like this documented? I viewed the wiki and didn't find out that you could do -1.
Re: Fading error
Posted: Fri May 09, 2014 9:56 pm
by micha
I am not aware of one specific location, where stuff like this is documented. The wiki is very good in answer the question "What can a specific function do". However, to answer the question "What function do I need to achieve a certain thing", the wiki cannot help you directly. The usual approach here is to
- Learn more and more over time and get a feeling for this
- Ask people from the community, like you just did
- Browse the wiki and read stuff, even if you are not looking for something specific. That way you more and more get an overview of what is possible. This is not the first thing you would do, when you learn LÖVE, because at that time you have no clue, what you really need.
- In the beginning of course, it is most convenient to read tutorials and try to learn from code others write.
Re: Fading error
Posted: Sat May 10, 2014 9:41 am
by TheOddByte
micha wrote:I am not aware of one specific location, where stuff like this is documented. The wiki is very good in answer the question "What can a specific function do". However, to answer the question "What function do I need to achieve a certain thing", the wiki cannot help you directly. The usual approach here is to
- Learn more and more over time and get a feeling for this
- Ask people from the community, like you just did
- Browse the wiki and read stuff, even if you are not looking for something specific. That way you more and more get an overview of what is possible. This is not the first thing you would do, when you learn LÖVE, because at that time you have no clue, what you really need.
- In the beginning of course, it is most convenient to read tutorials and try to learn from code others write.
Well I will mess around with LÖVE until I'm used to it, I feel like I've browsed the wiki one million times, but I might as well do it one million times more xP
Thanks for the help everyone!