I've recently been working on a java awt application, it started out as a very simple render testing demo but has sort of cascaded and so to make my life easier I have decided to switch to imgui (with an lwjgl backend). I have never used lwjgl but I have used imgui with c++.
In it's current format the gui of the application is incredibly simplistic as I tweak most variables for the algorithms i'm demoing with it from within code which is precisely why I want to start switching over to imgui.
Currently it mostly consists of a pair of images, one which is a per pixel visualisation of my 2d algorithms and one which uses awts graphics features to draw some rectangles to represent other data. essentially producing 2 dynamic images every frame.
my question is then, how would I do this per pixel rendering (and possibly some of the rectangle drawing) inside of lwjgl and get these displaying as part of an imgui gui.
that or getting imgui and my existing awt renderer to coexist within the same window.
EDIT:
Thought I'd add a summary here:
Littereally all I wanna know is how I can get ImGui to render an image that I can modify from within java every frame with some sort of SetPixelAt function.
Related
In a game I have a GridPane displaying the Tiles of the world in square cells. The player can, using the keyboard, move what is displayed by a column\row. The approaches I've thought of are:
Having the GridPane change programmatically the displayed tiles by moving everything by x steps on player input.
Wrapping the GridPane in a ScrollPane and tying the ScrollPane's scroll to Keyboard input.
My question is, assuming that things that are off-sight but on the same map are always loaded, what are the pros and cons of each approach efficiency-wise? Most specifically, I'm wondering if wrapping the GridPane in a ScrollPane would keep the Images loaded even if they are off-screen, thus impacting performance and if in that case it would be better to just reload them when needed. I'm also wondering if there's a third, more efficient way I haven't thought about.
I'm using JavaFX8
General approach
The most efficient approach for providing a limited viewport onto a very large world is to use a tile based model for the world and to only load the graphics resources and display the tiles that are required for the current viewport.
Sample canvas based implementation
A nice overview of how to accomplish this is the eppleton JavaFX tile engine which is described in an eppleton blog post. That particular implementation uses a Canvas direct draw based approach rather than a scene graph node oriented approach.
Sample scene graph node based implementation
A scene graph based approach relies on what is termed a virtual control; where the control provides cells which are windows on to the underlying data model. The JavaFX ListView and TableView are examples of virtualized controls. These virtual controls can be backed my data structures which contain thousands of items but only visual items for the currently visible tens of items are actually shown on the screen. As the control is scrolled or its underlying data structure is modified, callbacks are invoked to refresh the graphical nodes for each displayed cell.
An example of a scene graph based virtual control for a grid is the ControlsFX GridView. Note that, unlike the canvas based eppleton Tile Engine, the ControlsFX GridView is not specifically built for and optimized to be the core tile based renderer for a game engine, so if you would use GridView in such a way, you would need to add significantly more features to a fork or extension of the GridView to bring it functionally on par with a full gameplay tile engine.
Existing specifications and toolsets
Note that there are existing specifications for Tile map formats such as TMX and existing editors to create files which conform to such formats. Usage of a tilemap is appropriate for both realtime and turn based games and may even be useful outside the gaming genre, though it's traditional usage is in the creation of video games.
Answers to additional questions
would you mind elaborating, even if just slightly about what you mean with GridView is not optimized?
Your primary application seems to be writing tile based game engine. Such an engine usually provides support for reading tile map data, tile image data, overlaying animated sprites on to the tiles, etc. Those kind of features aren't in a ControlsFX GridView because that has a different focus (e.g. displaying a viewport of thumbnail images for a file directory). The point is not that GridView is not optimized performance wise (because it is), the point is that GridView won't provide you with the optimal set of out of the box features which you might need for your particular application (a tile based game).
I forgot to mention in my case the Entities move Tile by Tile and not Pixel by Pixel
That makes implementation simpler as you only have to worry about tiles at discrete co-ordinates and the entity can be an exact tile co-ordinate without an offset for current location and rendering between tiles. However it doesn't really change the whole approach of using a virtualized viewport of only onto the world which only renders what you can currently see rather than rendering the entire world all the time.
Had I know all this a year ago I would had taken a very different route in my delevopment.
Sometimes it pays to do research and sometimes you learn by mistakes :-) I'm sure John Carmack would have written the original Doom differently if he knew then what he knows now. I wouldn't let such things worry you too much. Just assess where you are now and go from there.
I am conducting a learning experiment with Java. I am attempting to create a simple "Megaman" style game using Java and the 3rd party API "LibGDX". I have obtained a rather solid understanding of the relationship between the OrthographicCamera object from LibGDX and the World object from LibGDX's implementation of "JBox2d".
However, when I resize the window the objects inside World stretch. I have made use of the resize(int width, int height) method of the Screen interface. Inside of which i reset the OrthographicCamera's width and height. This does not seem to have any effect of the way the images looks or behaves in the physics simulation.
So my question is this: How do i properly resize a LibGDX/JBox2d application's window without distorting the objects being simulated?
here is the code (in the form of a git repo because i find GitHub faster, easier, and kinder to the SO server...)
EXTERNAL LINK
https://gist.github.com/konnerdroid/8113302
EXTERNAL LINK
AHA!!!! i wasnt updating my camera...
For any changes made to the camera to be visible and their effect to be felt you need to call camera.update() either in your loop or after any changes are made
well... at least i learned how to use github =)
I'm beginning to write a special use graphing program and I'm leaning towards using OpenGL to generate the graphics. The ultimate goal is an architecture that accommodates both 2D and 3D graphs with the basic framework.
Exporting the generated graphs as images is a critical feature, and eventually I'm going to write the code to generate vector images of the graphs' 2D projections. However, in the mean time, I want to be able to export the graphs as high resolution images--images significantly larger than the application window.
I'm writing this application in Java and using the LWJGL OpenGL wrapper. I've figured out how to take screenshots of the display window, but I haven't been successful creating larger images. I've tried to make invisible Canvases, but I can't make it work.
The documentation says here that the Canvas's isDisplayable() method must return true, and to that end I've overridden the isDisplayable() method to always return true, so that it shouldn't care whether or not it's in a Frame, but this doesn't work. Instead, it throws the following error:
java.lang.RuntimeException: No OpenGL context found in the current thread.
at org.lwjgl.opengl.GLContext.getCapabilities(GLContext.java:124)
at org.lwjgl.opengl.GL20.glDeleteProgram(GL20.java:311)
The problem seems to be that it also needs some properties from the top-level window, but even when I make a dummy Frame class I get the same error as before, until I call setVisible(true) on the frame.
Does anyone know how to fake these graphics properties into thinking it has a visible top-level window? Does anyone know an easier way?
As an alternative, you could use a framebuffer object (FBO) to render into a texture.
Have a look at this render to texture example.
Finally decided to learn 2d (for now) java game programming. Am working on a game that has a central object that the user will guide with the directional keys. I have that working perfectly, cobbled together from examples and tutorials I've found.
I'm using this method of generating colored background tiles but I'd like to scroll (move) the background as the primary object the user is moving reaches the window edges. I'm fairly sure I can make that work, I have the basics in place, but I can't find a good tutorial or actual demonstration of a way to continue to generate additional tiles to fill in the space the user is moving too.
At this point, this is purely background and I have no need to save the exact tiles generated - but eventually I would like this ability. I'm sure I'll have to find a way to divide the areas into "chunks" like minecraft does.
But for now - how can I continually fill in the area with the same pattern? Or is there a better way to create the tiles that's better for this?
Instead of a solid color you can use a TexturePaint, as shown here. Let your model contain a reference to the desired texture for each grid cell. Let your view use a flyweight pattern for rendering, as illustrated here.
I am having a problem with manipulating images in java 7. I have researched the problem I am having for three weeks and have failed to find a solution,
I am trying to set an image over an area, basically setting the corner posistions.
I am using a BufferedImage.
This is for a 3D game where I am writing the 3D conversion code. I have managed to create a 3d world, and populate it with cubes, filling in the sides with graphics.fillPolygon():
What I would like to do is draw an image that fills a polygon's shape.
Any help I will be grateful for (even if it is formating this post better).
You can use transformations on your graphics. Here is a little tutorial on it. With that you can transform already drawn stuff. If you want to transform multiple images in different ways, you can draw them on different canvases and transform then separately. Then you can merge the images together...
But I would recommend using a 3D engine (JOGL, jMonkeyEngine, or others) for that (unless you want to learn about the geometric calculations with this task). It is also much faster to use OpenGL than drawing the stuff by yourself and doing the calculations in code (most probably meaning: on the CPU and not the GPU).
Have you tried using the drawImage? instead of .fillPolygon?