window handlers for opengl - c++

I've been programming opengl using glut as my window handler, lately i've been thinking if there are any advantages to switching to an alternate window handler such as wxWidgets or qt.
Are there any major differences at all or is it just a matter of taste? Since glut provides some additional functions for opengl-programming beyond the window handling features, would there be a point in combining an additional toolkit with glut?

I can only speak from experiential of using QT:
Once you have the basic structure set up then it is a simple case of doing what you have always done: for example, the project I am working on at the moment has an open gl widget embedded in the window.
This widget has functions such as initializeGL, resize...paintGL etc. Advantages include the ability to pass variables to an from the other windows / widgets etc. QT also has additional functions for handelling mouse clicks and stuff (great for 2d stuff, 32d stuff requires some more complex maths)

You need to move from glut as soon as you want more complex controls and dialogs etc.
QT has an excellent openGL widget there is also an interesting article in the newsletter about drawing controls ontop of GL to give cool WPF style effects.
wxWidgets also comes with an opengl example but I don't have much experience of it.

Well - glut is okay to get a prototype going.
It depends on the OS, but later on you may want to prevent the screen-saver from starting, you may want to disable the task switch (only the bad guys do this though), You may want to react to power down events. You may find out that glut can't deal with dead-keys on one or another operation system, or, or, or... There are thousand reasons why you may want to get rid of it.
It's a framework designed to make the start easy and do 90% of the usual stuff you need, but it can never do 100%. You can always hack yourself into glut or lift the init-code, but one day you will find out that it's easier to redesign the init-code from scratch and adjust it to your task.
Opening a window and initializing OpenGL is not rocket-science . Use glut as long as it works for you, but as soon as it makes problems get rid of it. It'll take you just a hand full of hours, so you won't loose much.
For a toy project glut is the way to go though.

SDL, while not just a window handler, will make it easier to use OpenGL than raw Win32 code. However, my experience with Qt, GTK and wxWidgets has not been too bad... certainly not that much better than Win32, its probably a matter of taste in those cases.
I'd recommend avoiding widgets and wrappers like GLUT if you want a fine level of control over the window and resources, but if you are just looking for speed of development then these tools are ideal.

Related

OpenGL/GLUT view contained in WinAPI window

What I'm trying to achieve is something like this - that is, an OpenGL view contained in a standard window, alongside some buttons, menus, etc.
However, I'm trying to use non-managed C++ and WinAPI to accomplish that (project requirements), and, if possible, (free)GLUT.
However, it seems to me that the only thing possible using GLUT is to create a separate window. Am I right, or is there actually a way to pass a window handle to GLUT for rendering? Or am I completely off the track?
Yeah, as far as I am aware GLUT only lets you do full-blown windows and will not let you paint into an arbitrary rectangle. There are a number of tutorials on setting up a render context in Windows using nothing but the Win32 and WGL APIs. Once you get your context setup, you can effectively do everything the same way you would with GLUT, but use the appropriate WGL function for swapping buffers.
Here's a high-level overview of what would be involved, though it's really text-heavy and related to MFC it outlines the whole process. You should be able to lookup the appropriate WGL API reference to implement this.
There's really no point in using GLUT if you've already decided to use the Win32 API to be honest, it is going to try to hide everything from you including the message pump that you'll need to handle dialog initialization and button events. If your requirements weren't limited to Win32 API, I would suggest something a little more portable like Qt for a framework that's dialog-friendly and supports OpenGL.

Qt library for 2D/3D game development

As a hobby, I've been working on remaking an old video game, and I want to avoid reinventing the wheel where possible. The game is heavily GUI-based, but the GUI needs to be customized in terms of look-and-feel, and also needs to work with 3D OpenGL rendering for a few game screens.
To give you an idea, here's a screenshot from the initial prototype:
There's a lot of animation used, and 3D also, but the GUI widgets behave much the same as in a standard desktop application.
Thus far, I've been using my own GUI library (it's not robust or complete, and I've been running into some problems).
I've been considering migrating to Qt given it's reputation and impressive features, and some of the nice screenshots on the Qt website. But I've never used Qt before, so I don't really have an idea of what it's capable of, or what kind of time investment would be required to learn it. (Note I've used FLTK).
My question is: would it be possible / practical to use Qt in this situation?
UPDATE: After mocking up some game screens in Qt, I've decided not to use it. While it supports many of the features I need out-of-the-box (particularly through Style Sheets), I need to support custom bitmap-based pre-rendered fonts (I can't convert/replace them). And I can't subclass QFont, or reimplement it without it breaking in future Qt releases. That said, I was extremely impressed with Qt (both in its ease of use, and good documentation). I will be borrowing some of its features for my own engine. Thank you to all who provided input.
It's hard to know everything your game needs to do based on a screenshot; however, I will echo the sentiments of other posters here and provide a couple of avenues for you to look at.
One, is that you might want to consider QtQuick over the GraphicsView Framework, but this REALLY depends on what you need to do. I just want to throw it out there as an alternative so you don't miss it. This tutorial uses QtQuick to put together a really slick looking connect four style game. This may be more simplistic than what you want to go for, but then again, maybe it isn't, it depends on what you need to do.
Second, before writing custom paint events for all of your buttons, I would consider using Qt Style Sheets and style your widgets in a CSS like syntax. This will allow you to change the look and feel of your GUI in a very flexible way really quickly. Based on your screenshot, I think you can get what you want out of style sheets much faster than subclassing and rolling your own setup. But once again, it's hard to know based on one screenshot. Here's an example of a dark and orange GUI that was implemented using only Qt Style Sheets. The border-radius property of QPushButton's style sheet would give you the rounded buttons (ref).
The simple answer has been given above but to throw some more thoughts in: yes it's possible, you probably won't need to fight against Qt too much. For the most part the recommended advice for going to heavily customised widgets like that is subclass and implemented the paint event yourself.
You can then use a load of basic drawing primitives to get the basic shapes for the elements and expand from there. There's actually a couple of questions on here with really good resources about how to do it.

How to create custom skin like WinAmp

I guess this question has been ask before, but I have not found sufficient answer to even start poking around. Most answer refers to catching WM_PAINT method directly and do custom rendering, or use a onwer draw object. However, I did not see a centralized place that has the info. to start researching. Hence, the question.
My goal is to create a very simple GUI program with custom look into it. I prefer the way winamp does their custom look that is customizable through "skins". However, I am not interested in using some cross-platform library like GTK+, QT or wxWidget.
I have some experience in system programming, but not much for GUI. I spent most of my time developing console applications, and I just started doing some QT development. If you can point me in the right direction, I'd be very appreciated.
PS: I am interested in both windows and linux environment.
Everybody,
Sorry for the late reply. I had a chance to have a quick talk with the original developer for winamp, and this is the quick answers I have:
Using skins: Artists create skins, developer will render the skins
To the OS (Windows), winamp is just one pretty box, nothing else. There is a container windows, and that's about it
All controls (button, label, list, etc) are implemented by winamp team themselves. All messages and stuffs are passed as relative position to the container window. WinAmp and the GUI engine has to decide if a button is clicked or if the label next to it is the target, etc.
Rendering artists skins created in XML
I do not have the details on if they use any libraries to do all that, but I am suspecting they do hook a window call directly, and do custom rendering themselves.
GUI skin usually using plug-in mechanism
I guess this is exactly what you are looking for:
https://www.linux.com/learn/tutorials/428800:weekend-project-creating-qt-interfaces-with-gimp?utm_medium=twitter&utm_source=twitterfeed
I also interested in creating custom look of window and widgets.
Speaking about widgets it's not hard, just need to create subclass (if you are using C++) or some widget and implement some methods like draw, handle etc. But this solution is good only if you use some high-level library like GTK, QT, etc. If you want to implement all controls by your own, you may get any graphics library, which can create window and do any graphics inside. For example, SDL2 + Cairo. SDL2 for creating window, Cairo for vector rendering controls/widgets. Both of this libraries are for win and linux. Another option is take opengl/vulkan + some lib for rendering window. It could be SDL2, SFML, GLFW.
If you really interested how it works on low level, then search Windows API for Windows and XLib or XCB for Linux/X.Org.
Speaking about window, I still investigate it. However I have one thought: you may create an empty window and then draw whatever you want. Then you need to add handlers for resizing window on the borders. But I am not sure if it's good solution, and if it won't freezes.

Common game controls/ User interface libraries or source code?

Sorry for the ackward title, but i don't know what to call it exactly. I'm looking for code or libraries that allow easy creation of commonly used user input devices, and code/libs that make gaming controls easy to set up (i'm using SFML and Box2D at the moment)
I don't want to re-invent things like buttons, arrows being placed wherever the mouse is located, and more game specific items such as "controls settings" or even being able to drag objects around with the mouse.
More specifically i want source code for interfaces that....
Makes Buttons and Textboxes easy to create
allows mouse input to press buttons or drag objects in games
has "Focuses" (like a textbox being able to gain focus and be typed in)
Is compatable with SFML/Box2D
and code for common game mechanics/controls that....
Allows easy setup of controls for a game
Makes events like clicking and holding on an object easy to setup, as so objects can be dragged around afterward
Are there any simple libraries or resources out there that i can use to avoid spending much of my time coding these now standard input devices/tecniques?
I think CEGUI is the type of thing you are looking for:
http://www.cegui.org.uk/wiki/index.php/Main_Page
It is a GUI framework to work with OpenGL. Some others can be found in this list.
Still, if I were you, I would just use a major toolkit, such as GTK, Qt, or wxWidgets combined with SFML instead of dealing with CEGUI.
SFML has guides for Qt and wxWidgets with the rest of them at http://www.sfml-dev.org/tutorials/1.6/.
I have created my own little guide for GTK here: http://lalaland.github.com/gtkGuide.html

Gui library for game

I'm making a game with OpenGL render api. Now I need in level editor. It should consist of lots of widgets parents/children etc, so it's hard to write need widgets by hands.
Any ideas about good gui-system which can be easilly connected with opengl? The most important part is gui editing. I really need some editing-tool for it.
Thanks
You should have a look to http://qt.nokia.com/ .
It is very easy to inject the OpenGL rendering into Qt widgets.
To easily edit your GUI, you can use Qt Creator ( http://qt.nokia.com/products/developer-tools ).
You have several options (and this has been answered before, but probably not exactly like this):
SDL: very good abstraction layer for audio, graphics and anything related. It will force you to write your widget stuff by hand.
Qt: has an OpenGL module that makes it easy to set up an OpenGL context. It will make widgets and everything very easy.
wxWidgets: same as Qt, but has slightly worse documentation and tools (if I might be so blunt)
I'd go with number two: it has a beautiful Designer tool to create Widgets with all the fancyness you'll need. OpenGL is also built right in.
If you're running Windows (can't confirm Mono will do it), another option would be to use C# and WinForms to make your life significantly easier.
Check out CEGUI:
http://www.cegui.org.uk/wiki/index.php/Main_Page
It defines its GUIs in XML and has editors for it.