Can you use SFML to create OpenGL contexts?
On OS X, SFML supports creating OpenGL 3.2+ contexts using the core profile only. If you want to use the graphics module on OS X, you are limited to using a legacy context which implies OpenGL version 2.1. A typical OpenGL-with-SFML program Here is what a complete OpenGL program would look like with SFML:
How to draw a pointed star in OpenGL?
The issue is in this line: For numPoints = 5, for each step i will be incremented with 360/ (2*5) = 36. For numPoints = 7, for each step i will be incremented with 360/ (2*7) = 25 (integer division, truncating 25.714… to 25 ). So, at each step there is a 0.714.. degrees loss.
What happens when you call OpenGL draw function?
Calling OpenGL draw functions while a context without a visible framebuffer is active will result in those draw commands not producing any visible output. Splitting OpenGL operations among multiple contexts will also result in the state changes being spread across the contexts.
Do you need to deactivate a window in OpenGL?
Only one context (window) can be active in a thread, so you don’t need to deactivate a window before activating another one, it is deactivated automatically. This is how OpenGL works. Another thing to know is that all the OpenGL contexts created by SFML share their resources.
Do you need to manage multiple OpenGL Windows?
Managing multiple OpenGL windows is not more complicated than managing one, there are just a few things to keep in mind. OpenGL calls are made on the active context (thus the active window). Therefore if you want to draw to two different windows within the same program, you have to select which window is active before drawing something.
Is the OpenGL header the same on every OS?
OpenGL headers are not the same on every OS. Therefore, SFML provides an “abstract” header that takes care of including the right file for you. This header includes OpenGL functions, and nothing else.
Do you need a window to use OpenGL?
As you know, one of the most important features of OpenGL is portability. But OpenGL alone won’t be enough to create complete programs: you need a window, a rendering context, user input, etc. You would have no choice but to write OS-specific code to handle this stuff on your own. That’s where the sfml-window module comes into play.
Why does SFML create 3.2 + contexts?
By default, SFML creates 3.2+ contexts using the compatibility profile because the graphics module makes use of legacy OpenGL functionality. If you intend on using the graphics module, make sure to create your context without the core profile setting or the graphics module will not function correctly.