Thus, in , it was separated into two "profiles". Core and compatibility. Core profile breaks BC in favor of performance improvements and some of the new features. It even completely removes some legacy features. Compatibility profile maintains BC with all versions down to 1.
It is only to be used for old, legacy systems, all new applications should use the core profile. Because of that, there is a problem with our basic setup - it only provides the context that is backwards compatible with OpenGL 1. The pixel format is limited too. There is a better approach, using extensions. Any addition to the original functionality of OpenGL are called extensions. Generally, they can either make some things legal that weren't before, extend parameter value range, extend GLSL, and even add completely new functionality.
EXT extensions are made by several vendors working together. After some time, they may become ARB extensions, which are all the officially supported ones and ones approved by ARB. To acquire function pointer types and function prototypes of all the extensions and as mentioned before, all the function pointer types from OpenGL 1. For example, the function for getting the list of all supported extensions is actually an extension itself, the wglGetExtensionsStringARB it returns a big string with a space-separated list of all the supported extensions.
Getting extensions is handled via wglGetProcAddress too, so we can just use our wrapper like before. Unlike before, we don't use a struct.
Instead, we pass the list of wanted attributes. Why didn't we just start off with them? Well, that's because the extensions allow us to do this, and to get extensions we need wglGetProcAddress , but that only works with an active valid context. So in essence, before we are able to create the context we want, we need to have some context active already, and it's usually referred to as a dummy context. However, Windows doesn't allow setting the pixel format of a window more than once.
In the first line, navigate to the unzipped folder. If unsure, choose the folder that contains the CMakeLists. Notice that it can be anywhere, not necessarily in the same folder. In the Build menu, click Build All. Every tutorial and dependency will be compiled. Hopefuly no error occurs. You can also launch any tutorial from inside Visual Studio. You can now debug the code by pressing F5. In particular, this one has built-in support for CMake, and it will provide a much nicer experience when debugging.
Here are the instructions for QtCreator :. You should run the tutorials directly from the right directory : simply double-click on the executable. If you like command line best, cd to the right directory.
However, you will never modify these projects : they are for reference only. Torture it in any way you like. We will provide snippets of code all along the tutorials. OpenGL code! Well, not really. It will prove very useful soon. Build this and run. A window should appear, and be closed right away.
Of course! All the threads within a process share access to the same memory, whereas processes do not by default share any memory. Within your games you can have multiple threads running that can perform multiple calculations at once and thus provide your game with multitasking within itself. Going even further, each thread in your process has the ability to house multiple fibers , which can perform multiple operations at once within a single thread.
Event-driven programming Windows is what is known as an event-driven operating system. What this means is that each process is executed based on the events they receive from the operating system.
For instance, an application may sit at idle and wait for the user to press a key. When that key is pressed Windows will register an event to the application that the key is down.
Windows programming is not difficult at all in most cases, and to start we'll use the most basic program ever created.
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