How to make a hole in a pygame surface? [duplicate] - pygame

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how to make circular surface in pygame
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Closed 1 year ago.
I have 2 different images A and B, B is blit on top of A. I'd like to have (blit I guess) a hole in B that lets me see A through it.
Can anyone help me with that? Thanks in advance.

You can set make a hole in B before blitting it above A, using a color key (see https://www.pygame.org/docs/ref/surface.html#pygame.Surface.set_colorkey)
pick a color K not used in B
fill the "hole" in B with this color
set the color key of B to K
blit A
blit B
Instead of a color key you also can use alpha transparency.

Related

How to let the cross part of elements be opaque in HTML? [duplicate]

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CSS overlapping elements & opacity issue
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Closed last month.
This post was edited and submitted for review last month and failed to reopen the post:
Original close reason(s) were not resolved
I tried to write a HTML that enables the user to create a element with angle and color(rgba). I want the cross part to be opaque that each element has transparency
However, I can not use the simple way to do this because the cross area is still not opaque(0.5*0.5=0.75)
I want to ask for a solution to make the cross part of two element be opaque by using CSS or JavaScript.
It must be completely filled into the area. However, the element will have angle so simple JavaScript to calculate it is not working.
I wonder if someone can give me a solution.
opacity doesn't add like that..
it is like discount of 50% + 50%.. if original price is 100 . you get first discount your price is 50 but with second discount, it is 25 more so final price will be 25
for case of opacity... you have one layer which lets 50% of light through it .. and 2nd layer also 50% so basically 50% of the 50% of the lowermost layer.
easy way to think is that both of them have some transparency so together they can't be fully opaque
Imagine that are two glasses, red glass, and green glass. When you put the red glass on top of green glass, it is an overlay, not an addition. You can try it in real life

Colouring a TD based on its value [duplicate]

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I have a table and I am trying to give the cells a background colour based on its value. The only issue is that if there is the same part of the word in the td they become the same colour. i.e. - Intensive and Lion Intensive become the same colour. Is there any way to make this distinct to the word?
$('td:contains("M/S Select Farm")').css('background','yellow');
$('td:contains("Lion Free Range")').css('background','Blue');
$('td:contains("Barn")').css('background','Orange');
$('td:contains("Free Range")').css('background','green');
$('td:contains("Lion Intensive")').css('background','Red');
$('td:contains("Intensive")').css('background','White');

Change Title with Octave imshow() [duplicate]

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How to change the window title of a MATLAB plotting figure?
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Closed 3 years ago.
Octave imshow() will display the image but the title of the image as "Figure 1", How can I change the title.
You can add your own title to a figure window's title bar by setting the Name property to the desired title and you can turn off the figure number by setting the NumberTitle property to 'off' as follows:
title ("imshow with random 100x100 matrix");
see document for more

Why there are so many color values for HTML like (RGB, HEX, HSL, RGBA, HSLA)? [duplicate]

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CSS - hsl or rgb(a) colors
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Closed 4 years ago.
I am a beginner at HTML and CSS. Why are there are so many color values if each of them can be used for a particular color?
It's very simple, all of them use different properties, so you have the power to choose whatever is convenient to you.
RGB = Red, Green and Blue amount from 0 to 255;
HEX = A shorter version of the RGBs amount, you can see how it works here: How does hexadecimal color work?;
HSL = Hue (0 to 360), Saturation and Lightness (both 0 to 100), example: https://www.w3schools.com/colors/colors_hsl.asp (I don't like to quote w3schools but you'll get the point there as well) - basically the first it's the color, second how strong it is, third how light or dark it is;
RGBA = Same of RGB but it'll include and extra value for Alpha, which is the transparency;
Same = Same of HSL but with the Alpha channel mentioned on RGBA as well.

AS3 alpha of multiple objects adds up [duplicate]

This question already has an answer here:
As3: Draw overlapping rectangles to a sprite and apply alpha
(1 answer)
Closed 7 years ago.
It seems that when I set alpha on a DisplayObjectContainer, then it works on each individual child separately and not on the container as a whole. Consequently I start seeing overlap regions which are normally not visible.
My question is - How do I fade a container as a whole?
Set the blendMode property on your DisplayObjectContainer to BlendMode.LAYER