Merge pull request #8602 from DrWenz/feature/drmoutput-performance

Improve DRM startup time

src/Linux/Avalonia.LinuxFramebuffer/DrmOutputOptions.cs

@@ -0,0 +1,27 @@
+using Avalonia.LinuxFramebuffer.Output;
+using Avalonia.Media;
+using JetBrains.Annotations;
+
+namespace Avalonia.LinuxFramebuffer
+{
+    public class DrmOutputOptions
+    {
+        /// <summary>
+        /// Scaling factor.
+        /// Default: 1.0
+        /// </summary>
+        public double Scaling { get; set; } = 1.0;
+        
+        /// <summary>
+        /// If true an two cycle buffer swapping is processed at init.
+        /// Default: True
+        /// </summary>
+        public bool EnableInitialBufferSwapping { get; set; } = true;
+        
+        /// <summary>
+        /// Color for <see cref="EnableInitialBufferSwapping"/>
+        /// Default: R0 G0 B0 A0
+        /// </summary>
+        public Color InitialBufferSwappingColor { get; set; } = new Color(0, 0, 0, 0);
+    }
+}

src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs

@@ -140,6 +140,8 @@ public static class LinuxFramebufferPlatformExtensions
 
     public static int StartLinuxDrm<T>(this T builder, string[] args, string card = null, double scaling = 1)
         where T : AppBuilderBase<T>, new() => StartLinuxDirect(builder, args, new DrmOutput(card) {Scaling = scaling});
+    public static int StartLinuxDrm<T>(this T builder, string[] args, string card = null, bool connectorsForceProbe = false, [CanBeNull] DrmOutputOptions options = null)
+        where T : AppBuilderBase<T>, new() => StartLinuxDirect(builder, args, new DrmOutput(card, connectorsForceProbe, options));
     
     public static int StartLinuxDirect<T>(this T builder, string[] args, IOutputBackend backend)
         where T : AppBuilderBase<T>, new()

src/Linux/Avalonia.LinuxFramebuffer/Output/Drm.cs

@@ -162,6 +162,8 @@ namespace Avalonia.LinuxFramebuffer.Output
         [DllImport(libdrm, SetLastError = true)]
         public static extern drmModeConnector* drmModeGetConnector(int fd, uint connector);
         [DllImport(libdrm, SetLastError = true)]
+        public static extern drmModeConnector* drmModeGetConnectorCurrent(int fd, uint connector);
+        [DllImport(libdrm, SetLastError = true)]
         public static extern void drmModeFreeConnector(drmModeConnector* res);
         
         [DllImport(libdrm, SetLastError = true)]

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmBindings.cs

@@ -84,7 +84,7 @@ namespace Avalonia.LinuxFramebuffer.Output
     {
         public List<DrmConnector> Connectors { get; }= new List<DrmConnector>();
         internal Dictionary<uint, DrmEncoder> Encoders { get; } = new Dictionary<uint, DrmEncoder>();
-        public DrmResources(int fd)
+        public DrmResources(int fd, bool connectorsForceProbe = false)
         {
             var res = drmModeGetResources(fd);
             if (res == null)
@@ -107,7 +107,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             
             for (var c = 0; c < res->count_connectors; c++)
             {
-                var conn = drmModeGetConnector(fd, res->connectors[c]);
+                var conn = connectorsForceProbe ? drmModeGetConnector(fd, res->connectors[c]) : drmModeGetConnectorCurrent(fd, res->connectors[c]);
                 Connectors.Add(new DrmConnector(conn));
                 drmModeFreeConnector(conn);
             }
@@ -168,7 +168,7 @@ namespace Avalonia.LinuxFramebuffer.Output
             }
         }
 
-        public DrmResources GetResources() => new DrmResources(Fd);
+        public DrmResources GetResources(bool connectorsForceProbe = false) => new DrmResources(Fd, connectorsForceProbe);
         public void Dispose()
         {
             close(Fd);

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs

@@ -7,6 +7,7 @@ using Avalonia.OpenGL;
 using Avalonia.OpenGL.Egl;
 using Avalonia.OpenGL.Surfaces;
 using Avalonia.Platform.Interop;
+using JetBrains.Annotations;
 using static Avalonia.LinuxFramebuffer.NativeUnsafeMethods;
 using static Avalonia.LinuxFramebuffer.Output.LibDrm;
 using static Avalonia.LinuxFramebuffer.Output.LibDrm.GbmColorFormats;
@@ -15,20 +16,35 @@ namespace Avalonia.LinuxFramebuffer.Output
 {
     public unsafe class DrmOutput : IGlOutputBackend, IGlPlatformSurface
     {
+        private DrmOutputOptions _outputOptions = new();
         private DrmCard _card;
         public PixelSize PixelSize => _mode.Resolution;
-        public double Scaling { get; set; }
+
+        public double Scaling
+        {
+            get => _outputOptions.Scaling;
+            set => _outputOptions.Scaling = value;
+        }
         public IGlContext PrimaryContext => _deferredContext;
 
         private EglPlatformOpenGlInterface _platformGl;
         public IPlatformOpenGlInterface PlatformOpenGlInterface => _platformGl;
 
-        public DrmOutput(string path = null)
+        public DrmOutput(DrmCard card, DrmResources resources, DrmConnector connector, DrmModeInfo modeInfo,
+            DrmOutputOptions? options = null)
         {
+            if(options != null) 
+                _outputOptions = options;
+            Init(card, resources, connector, modeInfo);
+        }
+        public DrmOutput(string path = null, bool connectorsForceProbe = false, [CanBeNull] DrmOutputOptions options = null)
+        {
+            if(options != null) 
+                _outputOptions = options;
+            
             var card = new DrmCard(path);
 
-            var resources = card.GetResources();
-
+            var resources = card.GetResources(connectorsForceProbe);
 
             var connector =
                 resources.Connectors.FirstOrDefault(x => x.Connection == DrmModeConnection.DRM_MODE_CONNECTED);
@@ -142,9 +158,14 @@ namespace Avalonia.LinuxFramebuffer.Output
 
             _deferredContext = _platformGl.PrimaryEglContext;
 
+            var initialBufferSwappingColorR = _outputOptions.InitialBufferSwappingColor.R / 255.0f;
+            var initialBufferSwappingColorG = _outputOptions.InitialBufferSwappingColor.G / 255.0f;
+            var initialBufferSwappingColorB = _outputOptions.InitialBufferSwappingColor.B / 255.0f;
+            var initialBufferSwappingColorA = _outputOptions.InitialBufferSwappingColor.A / 255.0f;
             using (_deferredContext.MakeCurrent(_eglSurface))
             {
-                _deferredContext.GlInterface.ClearColor(0, 0, 0, 0);
+                _deferredContext.GlInterface.ClearColor(initialBufferSwappingColorR, initialBufferSwappingColorG, 
+                    initialBufferSwappingColorB, initialBufferSwappingColorA);
                 _deferredContext.GlInterface.Clear(GlConsts.GL_COLOR_BUFFER_BIT | GlConsts.GL_STENCIL_BUFFER_BIT);
                 _eglSurface.SwapBuffers();
             }
@@ -162,13 +183,17 @@ namespace Avalonia.LinuxFramebuffer.Output
             _mode = mode;
             _currentBo = bo;
             
-            // Go trough two cycles of buffer swapping (there are render artifacts otherwise)
-            for(var c=0;c<2;c++)
-                using (CreateGlRenderTarget().BeginDraw())
-                {
-                    _deferredContext.GlInterface.ClearColor(0, 0, 0, 0);
-                    _deferredContext.GlInterface.Clear(GlConsts.GL_COLOR_BUFFER_BIT | GlConsts.GL_STENCIL_BUFFER_BIT);
-                }
+            if (_outputOptions.EnableInitialBufferSwapping)
+            {
+                //Go trough two cycles of buffer swapping (there are render artifacts otherwise)
+                for(var c=0;c<2;c++)
+                    using (CreateGlRenderTarget().BeginDraw())
+                    {
+                        _deferredContext.GlInterface.ClearColor(initialBufferSwappingColorR, initialBufferSwappingColorG, 
+                            initialBufferSwappingColorB, initialBufferSwappingColorA);
+                        _deferredContext.GlInterface.Clear(GlConsts.GL_COLOR_BUFFER_BIT | GlConsts.GL_STENCIL_BUFFER_BIT);
+                    }
+            }
             
         }