I'm doing a platformer game using gtkmm and cairo, and i can't find a way to set an image as a background, so i don't have to redraw it on every draw event. I'm managing images as pixbufs.
Is it actually possible, or am i thinking it wrong?
Redraw events are always necessary. The difference is about who has to take care of them. Lower level libraries such as Cairo require you to do that.
Maybe you should look into Goocanvas. Particularly for games where you have to move things around easily and capture events, a higher level library than Cairo is handy. GooCanvas also handles screen redraws.
You can just put in the image with GooCanvasImage, and forget about it.
If you're not bound to C++, then have a look at PyGame for Python - it not only handles those events, but provides loads of other tools for game programming.
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So im currently coding a snake game , and i need to draw the first pixel that indicates the head of the snake (positioned in the middle of the software). But i can't seem to find any function that does drawing on the screen . I've tried using DrawRectang and DrawPixel.
Any help ples?
wxWidgets has capabilities to custom draw a widget/window (or a small invalidated part of one) through it's own drawing API.
This is usually used for customized buttons or other controls, graphs, etc. You can handle EVT_PAINT (wxPaintEvent) where you can create a DC ("Device Context"). As well as on creation or size changes, you can force a redraw with wxWindow::Refresh or wxWindow::RefreshRect (for a small part). You might do so using a timer.
Note that the performance and capability is fairly limited. You can use OpenGL or Direct3D , or various high level libraries with wxWidgets, the native platform window handle is obtainable through wxWindow::GetHandle.
I'm Using the SDL library in C to learn some game dev , however i'm quite confused as to what SDL_RenderClear does and when do we use it. I did check the SDL documentation about the same , however i still wasn't able to understand where exactly we would use it and what is its use.
It's like rendering background color to color you have set via another API namely SDL_SetRenderDrawColor as you already found on documentation online.
Imagine you have rendered several things on screen. To begin again, you need to clear it to start over. Underlying of SDL_RenderClear wraps specific native platform your application runs on top, it can be OpenGL, DirectX, etc. It helps in communicating with such specific function that platform provides in order for you to flexibly clear your screen without a need to know low level functions, and use SDL2 for other things else like windowing, inputs from keyboard/mouse/joysticks, sound, and even utility functions related to rendering to aid your own rendering implementation.
To add a few more, SDL2 provides minimal but optimized rendering capability. SDL_RenderClear is one of those several functions you can use in rendering category. Anyway, you can decide to go on integrating with what you prefer i.e. OpenGL, DirectX, Vulkan etc. yourself.
I'm developing an application with C++ and GTK3 but I'm stucked. I've created a visual application with glade which has three columns and one of them, the middle one, is a DrawingArea. In that DrawingArea I want to draw some circles at the point I want to after pressing a button and have different mouse events on that circles (like drag and drop, double click, right click...). I've made the first thing (draw a circle after pressing a button) following the official documentation, but the problem is that I don't know how to do the mouse events, but I thought about it and I have some different solutions (I don't know if they are the bests solutions or maybe there are better):
I think the best way is to create a signal to the cairomm context, but I didn't see anything to do that. Maybe the way would be to create a cairo surface or something like that.
Every time I click to create a circle, I would have to create a gtk widget in which I can handle mouse events. The problem here is that the widget needs to have circular shape and need to be drawable. Is it possible to create a circular DrawingArea? It could be the best. I saw the way to create custom widgets here.
Use goocanvasmm. The problem here is that goocanvasmm has a little documentation (I'm sorry I can not post more than two links because of my reputation) and I think this is not the best solution, I prefer to use cairomm.
This application was written in C using GTK2, and the circles were drawn using gnomecanvas, adding signals in an easy way to each circle; and now I'm moving this application to C++ and GTK3 to renew it.
I'm very new to GTK (and graphical interfaces in general), but I looked for solutions for hours and I don't know what is the best way in order to continue my work.
Thank you for your help :)
It's best to use a canvas library for this such as GooCanvas. Doing it with cairo alone would require you to listen to mouse events on the whole drawing area, and keep track of where the circles were in order to decide which circle the mouse event belongs to - exactly the problem which the canvas library has already solved for you.
If you are having trouble with goocanvasmm documentation, a look at the documentation for GooCanvas' C API combined with knowledge of how the C API translates into C++ will usually suffice. Although the GooCanvasmm documentation seems fairly extensive to me.
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.
I have an application that I want add some cool animations to show state changes. However, wxwidgets would be difficult because I'd have to program these animations in straight gdi. What's the best way to add these effect windows? Should I open a flash window and run a flash sequence or is maybe some other technology? Does .net have something I could code into a dll and run from my wxwidgets binary? I need something that is super easy to draw and set up the animation.
It's hard to say what the best approach would be to achieve "cool effects", but in most cases you would want a double-buffered drawing surface. That's what I've used in similar-sounding situations.
In wxWidgets, you would want wxBufferedDC.
You could prepare animation as a bunch of images (wxImage loaded from PNG, GIF, JPG or whatever files), and then use a timer and paint them on a control. Maybe it sounds like too much, you I believe you could do it in 50-70 lines of code.
Perhaps you just could make a single widget that has a custom paint-event that hand-draws the various widgets inside it? Then you could draw them at the appropriate locations/sizes without having to involve wxwidgets at all, it would just be a bunch of line-draw/rectangle-draw/text-draw commands to update the display for each frame of animation.