I'm researching about 2D game for Android to implement an Android Game Project. My project looks nearly like PaperToss. Instance of throwing a page, my game will throw a coin. Suppose that I have a coin put in three-dimensional that have coordinates at A(x,y,z). I throw that point ahead, after 1/100 second, that coin move from A(x,y,z) to A'(x',y',z'). By this way, I have two problems need to solve.
Determine the formulas can be used to compute the coordinates of the coin at time t.
This problem is under-researching. I have no idea to solve this problem.
Mapping three-dimensional points to a two-dimensional and use those new coordinates (a two-dimensional coordinates) to draw our coin on screen. I have found two solutions for this problem: Orthographic projection & Perspective projection
However, my old friend said that OpenGL supports to solve problems like my problems. Any body have experiences about my problems?
Help me please :)
Thank for reading my question.
My personal opinion is to use a 3D engine since I don't like doing hacky stuff trying to fake 3D with 2D. However, 2D is much more beginner friendly, so if you're not planning to do anything fancy like actually emulating how coin actually rotates in air then I think it's doable in 2D.
My approach to do this would be to use a framework like libgdx instead of dealing with OpenGL ES directly. They have built in support for view projection (PerspectiveCamera), high level 2D/3D rendering support and even a wrapper for OpenGL ES if you really want to go low level. I'm not so sure about how you would approach the physics part right now.
Good luck....
Related
I have done some reading on OpenGl ES for Android. I know that I could make a game with the canvas API, but I would like to experiment with OpenGl ES first.
From here I can see two options: Use a game engine or develop my OpenGl ES from the ground up.
The coder/math person that I am is pushing me to the harder option(second option). The way I want to start on this journey is by creating a mesh and manipulating it with various transformations. I will worry about the textures later on. I've learned that I could develop my mesh using outside software such as Blender or LibGdx. However, I would like to learn to develop it with the android API. Do you think this is possible? Will it be very taxing for the android system to process many meshes and transform them? I think It will.
Should I just stick to the game engine way, and forget the "from the ground up mindset".
I also just found out about the replica island source code. Perhaps, I should start reading it and tweaking it on my own.
One more thing, from what I see, I have several options when developing graphics on android using OpenGl ES. Create the 3D model meshes or use sprites(such as replica island). Are there any other ways of doing this?
It all depends on the complexity of the game.
If it's on the simpler side, you could very well 'start from scratch'. I'm pretty sure, you'll end up creating something similar to replica island. For a complex game, you'll be near (as we're from moon) unity on the other extreme. We're talking about hundreds of thousands of man-hours.
As far as creating the meshes is concerned, OpenGL(ES) can only render the meshes.
Unless it's a very primitive mesh or one which can be modelled mathematically with a few equations (less likely for a game), you'll have to create them in blender, maya etc.
For a first timer, I suggest reusing an existing game/engine.
The transition from rendering meshes, then applying textures, then using lighting and shadows etc has a decent learning curve.
Trust me, even with this approach the coder/Math person will have enough on his plate.
I've been having fun with Android and OpenGL in a little side project meant to learn about it, but now I want to implement some animations and I'm having trouble getting information on how to proceed.
Let's say I have a square with a texture on it. Let's say I want to create it very small, and then gradually stretch it to its normal size. Only that square can be subjected to the effect and nothing else around it. I have this assumption that building a new vertex buffer every time is expensive, and for the animation to be fluid, this would need to happen very frequently. Is that the norm or is there a better way of doing this?
To stretch/scale objects you should use matrices, not recreating vertices.
You can read a tutorial here http://www.learnopengles.com/understanding-opengls-matrices/ or google for another one, there are lots of educational materials on OpenGL ES 2.0.
I am planning to make an android game. The game doesn't include a lot of movement. It will be like custom maps that user can switch between, maybe zoom in and out, select parts of the land, draw some objects on the map. User should also have a dashboard to manage his game . It will NOT include objects moving like cars/people.
I am new to both Canvas and OpenGL-ES developing but i feel that OpenGL-ES includes a lot more that what i need.. but just little skeptic if Canvas would be good enough to fulfill my requirements.
So, what would you advise me to do?
Thanks in advance.
Adel
I would say it's a difficult one to answer as it's virtually impossible for anyone but yourself (as the game designer) to know which one your particular game would require.
However, I would say, personally, I would go with openGL ES 2.0. I spent months designing a game (and even longer writing it) only to find that canvas wasn't powerful enough. Granted it did have 'moving objects' but not a huge amount of them - and it ended up with a lot of jerky movement that I just couldn't eliminate, so I am in the process of re-coding it with openGL ES 2.0.
I would say, look at some examples of games written with Canvas / Surfaceview and judge to the best of your ability which one you think you should go with.
Bear in mind while making this decision, that if you think Canvas / Surfaceview would be good enough, then go for it, however even if it is, are you going to be creating more demanding games later down the line? If so, then like I said above, I would just jump straight into openGL ES 2.0.
Canvas = simpler coding, worse performance
Open GL ES 2.0 = more demanding coding, but potential for much better performance.
Just my opinion!
This is a big issue for me I'm trying to figure out for a long time already.
I'm working on an application that should include a 2D vector indoor map in it.
The map will be drawn out from an .svg file that will specify all the data of the lines, curved lines (path) and rectangles that should be drawn.
My main requirement from the map are
Support touch events to detect where exactly the finger is touching.
Great image quality especially when considering the drawings of curved and diagonal lines (anti-aliasing)
Optional but very nice to have - Built in ability to zoom, pan and rotate.
So far I tried AndEngine and Android's canvas.
With AndEngine I had troubles with implementing anti-aliasing for rendering smooth diagonal lines or drawing curved lines, and as far as I understand, this is not an easy thing to implement in AndEngine.
Though I have to mention that AndEngine's ability to zoom in and pan with the camera instead of modifying the objects on the screen was really nice to have.
I also had some little experience with the built in Android's Canvas, mainly with viewing simple bitmaps, but I'm not sure if it supports all of these things, and especially if it would provide smooth results.
Last but no least, there's the option of just plain OpenGLES 1 or 2, that as far as I understand, with enough work should be able to support all the features I require. However it seems like something that would be hard to implement. And I've never programmed in OpenGL or anything like it, but I'm willing very much to learn.
To sum it all up, I need a platform that would provide me with the ability to do the 3 things I mentioned before, but also very important - To allow me to implement this feature as fast as possible.
Any kind of answer or suggestion would be very much welcomed as I'm very eager to solve this problem!
Thanks!
Is there a way to decide up front based on the expected complexity of a game/app in the planning phase whether to use regular Canvas drawing in a SurfaceView or to go with OpenGL?
I've been playing around with a Canvas and only need 2D movement, and on a fairly new phone I'm getting pretty decent performance with a bunch of primitive objects and a few bitmaps running around the screen on a solid background.
Is it fair to say that if I'm going to be drawing background images and increasing the number of objects being moved and drawn on top of them that I should go straight to OpenGL?
All I can say is that it depends on how many sprites you're gonna use. Chris Pruett from Google has also documented this part very well.
Google I/O 2009 and Google I/O 2010.
Below is a picture from one of his slides that are related to your topic:
With that knowledge, you should go with OpenGL using the draw_texture extension. Remember to query out the string and check if draw_texture is supported on the actual device.
For further information that are related to game development in general, see this.
SurfaceView
A GLSurfaceView is a SurfaceView that you can render into with OpenGL.
Choosing between them is simple:
If you're familiar with OpenGL and need what it provides, use a
GLSurfaceView. Otherwise, use a SurfaceView. OpenGL is low-level. If
you're not already familiar with it, it's an undertaking to learn. If
you only need 2D drawing, SurfaceView uses the high-level, reasonably
high-performance Canvas. It's very easy to work with.
Unless you have a strong reason to use a GLSurfaceView, you should use
a regular SurfaceView. I would suggest that if you don't already know
that you need GL, then you probably don't.
OpenGL
OpenGL would be able to handle the rotations and scaling easily.
Honestly, you would probably need to learn a lot of OpenGL to do this,
specifically related to the topics of:
Geometry Lighting (or just disabling it) Picking (selecting geometry
to draw on it) Pixel Maps Texture Mapping Mipmapping Also, learning
OpenGL for this might be overkill, and you would have to be pretty
good at it to make it efficient.
Instead, I would recommend using the graphic components of a game
library built on top of openGL, such as:
Cocos2d
libgdx
Any of the engines listed here
Source
Difference between SurfaceView and GLSurfaceView in Android
Android: Canvas vs OpenGL