What is the best way to edit singular pixels of an texture multiple times per frame? I have tried using a couple ways to no avail. What is the most optimal way to do this? I have tried using Intermediate mode and drawing each quad, thought, this is really slow.
Edit:
I forgot to mention that I am doing an unusual "fog of war" system. This system doesn't let you see around walls but instead acts like a 2D ray traced shadow. I want these shadows to be pixelated as this is part of the style of the game. I am trying to find the best way to do a form of a shadow map that I can overlay over the world to show what you can see.
I recommend using a Pixel Buffer Object.
Related
For reference the effect I'm going for is this:
I'm working in Processing 3, NOT p5.js.
I've looked around processing forums, but i can't find anything that works in the current version or doesn't use PGraphics and a mask which from what I've read can be expensive to use.
My current ideas and implementations have resulted to drawing shapes around the player and filling the gaps in with a circles with no fill that has a large stroke weight.
Does anyone know of any methods to easily and inexpensively draw a black background over everything except a small circular area?
If this is the wrong place to ask this question just send me on my way I guess, but please be nice. Thank you:)
You could create an image (or PGraphics) that consists of mostly black, with a transparent circle in it. This is called image masking or alpha compositing. Doing a Google image search for "alpha composite" returns a bunch of the images I'm talking about.
Anyway, after you have the image, it's just a matter of drawing it on top of your scene wherever the player is. You might also use the PImage#mask() function. More info can be found in the reference.
In LibGDX, I am currently trying to achieve the effect of a pixellated GUI, meaning the buttons are pixellated, like an 8-bit theme.
When I make my GUI elements, such as a TextButton, I am using images that are small, say 34x16 pixels, but I am rendering them on a large resolution like 1920x1080. What is the best way to render such a small image at a high resolution?
My thoughts were to use stage.setViewport(WIDTH,HEIGHT), and set the width and height to a scaled down resolution, so the gui elements wouldn't be so big. This works, however when adding elements things go wrong.
This my stage/table currently, using a scaled down resolution. I am adding widgets using to the table like this:
table.add(playButton);
table.row();
table.add(title);
but as you can see, the table.row() makes a row that is much too large, perhaps a row fit for a larger resolution. Is there any way to change the gap that is made by the row? I would have thought that the gap would be zero, and by using table.add().pad() you could change the gap, but I am not doing any of that.
Any help would be greatly appreciated.
Ninepatch
This is a common issue in all apps. To overcome this, images which can be safely resized in parts are used. they are called ninepatches.
Here is a nice Tutorial about using them in libgdx.
Distance Field Fonts
Although you haven't mentioned it here, you'd also find font sizing (pixellated fonts) as an issue. For that Distance Field Fonts are used.
Hope this helps.
I would say don't worry about scaling them up and making the virtual resolution bigger. If you want to see picture still pixelated when you scale it use Texture filter. For your case you want to use Nearest filter. use it like this:
yourTexture.setFilter(TextureFilter.Nearest, TextureFilter.Nearest);
where yourTexture is the texture that you have all your bitmaps and skin elements on. If you are using texturePacker than you can specify the filter before packing too. Or just open the .pack file and on the top you will see filtering options, and edit those to Nearest.
Lets say I use a black key jpg image as my layout in Java Code. Is there an easy way to get the region out of an image so I can use region.Contains() for my onTouchListener?
I've looked for them and there isn't any. I ask this because Im making a piano app and would like to get the regions of the images I use for the black/white keys.
Rather than use an image, try rendering the piano keys yourself, and check if input is in the black key regions you render, rather than using an image.
If you really want to use the image, define the black regions within the image by hand.
Detecting regions in an image is a difficult problem, one you probably don't want to get into for such a simple purpose. If you had many images, or had to do this frequently it might be worth the headache but as you presumably don't... don't worry about it.
So basically this is my problem:
I am creating a game that needs a texture for each object. Now I would use a sprite sheet but the textures are different sizes. I am using VBOs and I need to some how bind the correct textures when calling drawElements. Now I don't know what to do because I don't want to separate each class to its own VBO because that will just make it like 100+ VBO per level which isn't so efficient (or maybe it is?)
Note this is a 2D game but I still want to make it efficient.
Maybe there is some thing I can do with shaders? I am using shaders...
So that is my question:
What Do I Do?
Things I came up with:
Separate the classes to different VBOs (Easy but I am not sure if very efficient)
Use sprite sheets but have a really really big cellsize then just draw big quads with transparent backgrounds.. (Seems like a stupid idea :P)
Thats it.. So I hope you have ideas!
EDIT: I read some where its possible to have an attribute of which texture to use, pass it in as an element and then the fragment shaders use it.. If this is true I'd love if some one could describe it in more detail and add some examples.. (Also if you need to customize the fragment shader please tell me how because I dont know how to write shaders)
Solved by just separating the classes to different VBOs..
I have my image with a transparent background. I want to find the edges of the image and form a polygon from the outline. There are multiple methods/ways I could do this. I want to do it in Java (its for my game, which is using JBox2d Polygons for collision detection).
I have had some thought about this and am thinking how this would work. I could try detecting all transparent pixels, then invert the selection and only select the pixels that have 1 adjacent transparent pixel. This is all very complicated and I would like some guidence.
There are two aspects to your question.
Edge-detection. If your image has an alpha-channel, then you should be able to choose a suitable threshold and perform edge-detection to find the 'edges' of the transparent/opaque pixels. If it's just a GIF with a 'transparent' color, then it should a bit easier since you're effectively working with a black & white image.
Vectorization. This is where it gets (really) tricky. The field of raster to vector conversion is fertile ground. I would look at how solutions such as Potrace (GPL) are implemented then maybe attempt to build my own off that.
However, for a game, personally, I wouldn't even try real-time edge/collision detection this way. Since I'm working with sprites, I would use bounding boxes and other raster-based techniques.
If I really want polygon-based edge/collision detection, then I would probably opt to manually trace edges beforehand and just store them along with each raster image, then perform computations on those (trade space for time). I presume that the images you work with aren't dynamically generated at run-time making pre-computation possible.
This isn't really an answer to your question to make pixel-perfect collision, but I want to say that it is a bad idea to make the fixtures depending on the images.
Box2D doesn't support concave fixtures.
Box2D (the original version in C++, I don't know how this works in JBox2D) has a limit to 8 vertices per polygon.
Because of these two reason, you might think to create one square fixture per pixel, but that is going to be very expensive in processing time.
In my almost finished game, I'm defining my fixtures with a level editor.
Here is an excerpt of one of my levels (xml):
<body id="STONE" depth="13" angle="0.000000" type="static" x="7.939437" y="0.750494" tags="" >
<image id="stone_img" img="IMG_STONE" depth="0" x="-0.362081" y="0.526663" w="1.400000" h="1.600000" angle="0.000000" colorize="ffffffff"/>
<fixture id="" density="1.000000" friction="0.300000" restitution="0.300000" sensor="false" shape="rect" x="-0.188671" y="0.806253" w="1.000000" h="2.200000" angle="0.545597" tags="" />
<fixture id="" density="1.000000" friction="0.300000" restitution="0.300000" sensor="false" shape="rect" x="0.412080" y="-0.097607" w="1.000000" h="2.200000" angle="0.000000" tags="" />
</body>
I think this is the best way of working with Box2D.
Hopefully this inspires you :D