Dose sdl.SetHint(Sdl.HintWindowsDpiAwareness, "system"); not work?

[Cn-mjt44]

I create a sdl opengl window in 1280x720, but it scale by system hdpi.
So I try to use sdl.SetHint(Sdl.HintWindowsDpiAwareness, "system") to disable that function, but is looks not work.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using Silk.NET.Assimp;
using Silk.NET.Input;
using Silk.NET.Maths;
using Silk.NET.OpenGL;
using Silk.NET.SDL;
using Silk.NET.Windowing;

namespace SpaceFlight
{
    public class Game
    {

        private static GL? _gl = null;
        private static IWindow? _window = null;
        private static IInputContext? _input = null;
        internal static readonly HashSet<GameObject> allGameObjects = new HashSet<GameObject>();



        public static GL? gl => _gl;
        public static Sdl sdl => SdlProvider.SDL.Value;
        public static IWindow? window => _window;
        public static IInputContext? input => _input;

        public Game(string name)
        {
            if (_window != null) throw new Exception("Game arrady start");
            sdl.SetHint(Sdl.HintWindowsDpiAwareness, "system");
            Silk.NET.Windowing.Window.PrioritizeSdl();
            //Silk.NET.Windowing.Window.PrioritizeGlfw();
            WindowOptions options = new WindowOptions(true, new Vector2D<int>(Sdl.WindowposUndefined, Sdl.WindowposUndefined), new Vector2D<int>(1280, 720), 0.0, 0.0, GraphicsAPI.Default, name, WindowState.Normal, WindowBorder.Resizable, isVSync: false, shouldSwapAutomatically: true, VideoMode.Default);
            _window = Silk.NET.Windowing.Window.Create(options);
            _window.Load += Loaded;
            _window.Update += Update;
            _window.Render += Render;
            _window.Run();
        }

        private void Loaded()
        {
            _gl = _window?.CreateOpenGL();
            _input = _window?.CreateInput();
            // gl?.DepthFunc(DepthFunction.Gequal);
            gl?.ClearColor(0,0,0,1);
            gl?.ClearDepth(0);
            gl?.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit | ClearBufferMask.StencilBufferBit);
        }

        private void Update(double delta)
        {
            List<GameObject> cache = new List<GameObject>(from x in allGameObjects where !x.Destoryed select x);
            foreach(GameObject gameObject in cache) gameObject.Update(delta);
        }

        private void Render(double delta)
        {
            gl?.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit | ClearBufferMask.StencilBufferBit);
            gl?.Viewport(0,0,(uint)_window.Size.X,(uint)_window.Size.Y);
            List<GameObject> cache = new List<GameObject>(from x in allGameObjects where !x.Destoryed select x);
            Dictionary<uint,HashSet<GameObject>> objectAndSignal = new Dictionary<uint, HashSet<GameObject>>();
            foreach(GameObject gameObject in cache)
            {
                foreach(uint signal in gameObject.RenderSignal())
                {
                    if(!objectAndSignal.TryGetValue(signal,out HashSet<GameObject>? list))
                    {
                        list = new HashSet<GameObject>();
                        objectAndSignal.Add(signal,list);
                    }
                    list.Add(gameObject);
                }
            }

            List<KeyValuePair<uint,HashSet<GameObject>>> values = new List<KeyValuePair<uint, HashSet<GameObject>>>(objectAndSignal);
            for (int i = 0; i < values.Count; i++)
            {
                var a = values[i];
                for (int j = i + 1; j < values.Count; j++)
                {
                    var b = values[j];
                    if (a.Key > b.Key)
                    {
                        values[j] = a;
                        values[i] = b;
                        a = b;
                    }
                }
            }

            for (int i = 0; i < values.Count; i++)
            {
                uint signal = values[i].Key;
                foreach(GameObject gameObject in values[i].Value)
                {
                    gameObject.Render(delta,signal);
                }
            }
        }

        public void Destory()
        {
            _window?.Close();
            _window = null;
            _gl = null;
            _input = null;
        }
    }
}

• Scale by system
  
• Not scale by system
  

[qian-o]

Create an application manifest file in the project to configure DPI awareness so that developers can control scaling through code. Reference documentation: Please refer to Setting the default DPI awareness for a process.

[Cn-mjt44]

Not work, but I found sloution.

[Cn-mjt44]

By checking SDL2 c code and make few test, I found the sloution.

sdl.SetHint(Sdl.HintWindowsDpiAwareness, "permonitor");
sdl.VideoInit(null as string);

Just invoke SDL_VideoInit() before create window. it looks like some kind of bug on SDL2 that SDL_Init() and SDL_InitSubSystem() not invoke SDL_VideoInit(). It probably came from SDL2 compiltion issues.