Added MSDF to Font and FontRenderer

GlitchyEngine/BeefProj.toml

@@ -1,5 +1,5 @@
 FileVersion = 1
-Dependencies = {GlitchLog = "*", corlib = "*", DirectX = "*", ImGui = "*", ImGuiImplWin32 = "*", ImGuiImplDX11 = "*", DirectXTK = "*", FreeType = "*", cgltf-beef = "*"}
+Dependencies = {GlitchLog = "*", corlib = "*", DirectX = "*", ImGui = "*", ImGuiImplWin32 = "*", ImGuiImplDX11 = "*", DirectXTK = "*", FreeType = "*", cgltf-beef = "*", msdfgen-beef = "*"}
 
 [Project]
 Name = "GlitchyEngine"

GlitchyEngine/src/Renderer/Text/Font.bf

@@ -2,6 +2,7 @@ using System;
 using FreeType;
 using GlitchyEngine.Math;
 using System.Collections;
+using msdfgen;
 
 using internal GlitchyEngine.Renderer.Text;
 
@@ -44,6 +45,11 @@ namespace GlitchyEngine.Renderer.Text
 		GlyphDescriptor _missingGlyph;
 		
 		private SamplerState _sampler ~ _.ReleaseRef();
+		
+		/// How much we have to scale the geometry to fit it into our desired pixels
+		private double _geometryScaler;
+
+		private double _range = 4.0;
 
 		/**
 		 * Gets or sets the fallback Font for this Font.
@@ -84,6 +90,12 @@ namespace GlitchyEngine.Renderer.Text
 			}
 		}
 
+		[Inline]
+		double F26Dot6ToDouble(int32 value)
+		{
+			return (double(value) / 64.0);
+		}
+
 		public this(GraphicsContext context, String fontPath, uint32 fontSize, bool hasColor = true, char32 firstChar = '\0', uint32 charCount = 128, int32 faceIndex = 0)
 		{
 			_context = context..AddRef();
@@ -105,6 +117,11 @@ namespace GlitchyEngine.Renderer.Text
 			res = FreeType.Set_Pixel_Sizes(_face, 0, _fontSize);
 			Log.EngineLogger.Assert(res.Success, scope $"Set_Pixel_Sizes failed({(int)res}): {res}");
 
+			double unitsPerEm = F26Dot6ToDouble(_face.units_per_EM);
+			_geometryScaler = _fontSize / unitsPerEm;
+
+			_range = 4.0 / _geometryScaler;
+
 			LoadGlyphs(firstChar, charCount);
 		}
 
@@ -171,6 +188,21 @@ namespace GlitchyEngine.Renderer.Text
 			DrawAtlas();
 		}
 
+		/// Debug only
+		public void RedrawAtlas()
+		{
+			for(let (char, desc) in _glyphs)
+			{
+				desc?.IsCalculated = false;
+				desc?.IsRendered = false;
+			}
+
+			_penPos = .Zero;
+			_lastRowHeight = 0;
+
+			UpdateAtlas();
+		}
+
 		Int32_3 PrepareAtlas()
 		{
 			const uint32 maxRes = 16384; // D3D11_REQ_TEXTURE2D_U_OR_V_DIMENSION
@@ -201,13 +233,20 @@ namespace GlitchyEngine.Renderer.Text
 
 				desc.Metrics = _face.glyph.metrics;
 
-				int32 glyphWidth = (desc.Metrics.width / 64) + 1;
+				int32 border = 2;
-				int32 glyphHeight = (desc.Metrics.height / 64) + 1;
+
+				// TODO: adjust size to glyph
+				int32 glyphWidth = (.)_fontSize + border;
+				//int32 glyphWidth = (desc.Metrics.width / 64) + 1;
+				int32 glyphHeight = (.)_fontSize + border;
+				//int32 glyphHeight = (desc.Metrics.height / 64) + 1;
 
 				// when size is 0 (1 because we added 1) the glyph has no image
-				if(glyphWidth != 1 || glyphHeight != 1)
+				if(glyphWidth != border || glyphHeight != border)
 				{
-					int32 glyphRight = penLeft + glyphWidth;
+					//int32 glyphRight = penLeft + glyphWidth;
+
+					int32 glyphRight = penLeft + glyphWidth + border;
 
 					if(glyphRight > maxRes)
 					{
@@ -216,7 +255,7 @@ namespace GlitchyEngine.Renderer.Text
 						rowHeight = 0;
 					}
 
-					int32 glyphBottom = penTop + glyphHeight;
+					int32 glyphBottom = penTop + glyphHeight + border;
 
 					if(glyphBottom > maxRes)
 					{
@@ -234,8 +273,10 @@ namespace GlitchyEngine.Renderer.Text
 				}
 
 				desc.MapCoord = pen;
-				desc.SizeX = glyphWidth - 1;
+				//desc.SizeX = glyphWidth - 1;
-				desc.SizeY = glyphHeight - 1;
+				//desc.SizeY = glyphHeight - 1;
+				desc.SizeX = (.)_fontSize;
+				desc.SizeY = (.)_fontSize;
 
 				if(desc.GlyphIndex == 0 && _missingGlyph == null)
 				{
@@ -262,6 +303,8 @@ namespace GlitchyEngine.Renderer.Text
 			return .(atlasWidth, atlasHeight, atlasArray);
 		}
 
+		public bool secondTime = false;
+
 		void DrawAtlas()
 		{
 			Int32_3 oldAtlasSize = _atlasSize;
@@ -272,7 +315,7 @@ namespace GlitchyEngine.Renderer.Text
 				var oldAtlas = _atlas;
 
 				Texture2DDesc desc;
-				desc.Format = .B8G8R8A8_UNorm;
+				desc.Format = .R8G8B8A8_SNorm;
 				desc.MipLevels = 1;
 				desc.Width = (.)_atlasSize.X;
 				desc.Height = (.)_atlasSize.Y;
@@ -302,50 +345,129 @@ namespace GlitchyEngine.Renderer.Text
 					continue;
 				}
 
-				var loadResult = FreeType.Load_Glyph(_face, glyphIndex, .Color | .Render | .TargetNormal);
+				DoTheThing(desc);
-				if(loadResult.Error)
-				{
-					Log.EngineLogger.Error($"Failed to render glyph for '{char}'(Char Code:{(uint32)char} | Error {(int)loadResult}): {loadResult}");
-				}
-				
-				FT_GlyphSlot glyphSlot = _face.glyph;
-				FT_Bitmap bitmap = glyphSlot.bitmap;
-
-				//ResourceBox glyphBox = .((.)desc.MapCoord.X, (.)desc.MapCoord.X, 0,
-				//	(.)desc.MapCoord.X + (.)desc.SizeX, (.)desc.MapCoord.Y + (.)desc.SizeY, 1);
-
-				if(_face.glyph.format == .Bitmap)
-				{
-					if(bitmap.pixel_mode == .Gray)
-					{
-						Color[] pixels = new Color[bitmap.width * bitmap.rows];
-						defer delete pixels;
-
-						for(int i < pixels.Count)
-						{
-							uint8 gray = bitmap.buffer[i];
-
-							pixels[i] = .(gray, gray, gray, gray);
-						}
-
-						_atlas.SetData(pixels.Ptr, (.)desc.MapCoord.X, (.)desc.MapCoord.Y,
-							(.)desc.SizeX, (.)desc.SizeY, (.)desc.MapCoord.Z);
-					}
-					else if(bitmap.pixel_mode == .Bgra)
-					{
-						_atlas.SetData<Color>((.)bitmap.buffer, (.)desc.MapCoord.X, (.)desc.MapCoord.Y,
-							(.)desc.SizeX, (.)desc.SizeY, (.)desc.MapCoord.Z);
-
-						desc.IsBitmap = true;
-					}
-				}
-				else
-				{
-					Runtime.NotImplemented();
-				}
 
 				desc.IsRendered = true;
 			}
 		}
+
+		void DoTheThing(GlyphDescriptor desc)
+		{
+			// prepare shape
+			
+			double advance = 0;
+
+			Shape shape;
+			msdfgen.LoadGlyph(out shape, ref _face, desc.GlyphIndex, out advance);
+
+			shape.Normalize();
+
+			var bounds = shape.GetBounds();
+			
+			msdfgen.EdgeColoringSimple(shape, 3.0);
+
+			// prepare projection
+
+			int width;
+			int height;
+			
+			double translationX;
+			double translationY;
+
+			if(bounds.Left < bounds.Right && bounds.Bottom < bounds.Top)
+			{
+				double l = bounds.Left;
+				double r = bounds.Right;
+				double b = bounds.Bottom;
+				double t = bounds.Top;
+
+				l -= 0.5 * _range;
+				b -= 0.5 * _range;
+				r += 0.5 * _range;
+				t += 0.5 * _range;
+
+				// TODO: miter?!
+
+				double w = _geometryScaler * (r - l);
+				double h = _geometryScaler * (t - b);
+
+				width = (int)Math.Ceiling(w) + 1;
+				height = (int)Math.Ceiling(h) + 1;
+
+				translationX = -l + 0.5 * (width - w) / _geometryScaler;
+				translationY = -b + 0.5 * (height - h) / _geometryScaler;
+			}
+			else
+			{
+				width = 0;
+				height = 0;
+				translationX = 0;
+				translationY = 0;
+			}
+
+			msdfgen.Projection projection = .();
+			projection.ScaleX = _geometryScaler;
+			projection.ScaleY = _geometryScaler;
+
+			projection.TranslationX = translationX;
+			projection.TranslationY = translationY;
+
+			/*
+
+			void GlyphGeometry::wrapBox(double scale, double range, double miterLimit) {
+			    scale *= geometryScale;
+			    range /= geometryScale;
+			    box.range = range;
+			    box.scale = scale;
+			    if (bounds.l < bounds.r && bounds.b < bounds.t) {
+			        double l = bounds.l, b = bounds.b, r = bounds.r, t = bounds.t;
+			        l -= .5*range, b -= .5*range;
+			        r += .5*range, t += .5*range;
+			        if (miterLimit > 0)
+			            shape.boundMiters(l, b, r, t, .5*range, miterLimit, 1);
+			        double w = scale*(r-l);
+			        double h = scale*(t-b);
+			        box.rect.w = (int) ceil(w)+1;
+			        box.rect.h = (int) ceil(h)+1;
+			        box.translate.x = -l+.5*(box.rect.w-w)/scale;
+			        box.translate.y = -b+.5*(box.rect.h-h)/scale;
+			    } else {
+			        box.rect.w = 0, box.rect.h = 0;
+			        box.translate = msdfgen::Vector2();
+			    }
+			}
+
+			*/
+
+			int x = _fontSize;
+			int y = _fontSize;
+
+			Bitmap<ColorRGB, const 1> bitmap = .((.)x, (.)y);
+
+			MSDFGeneratorConfig config = .();
+
+			msdfgen.GenerateMSDF(*(Bitmap<float, const 3>*)&bitmap, shape, projection, _range, config);
+			
+			int8[] pixels = new int8[x * y * 4];
+			
+			int8 ToInt8(float f) => (.)Math.Clamp(127f * f, int8.MinValue, int8.MaxValue);
+
+			for(int iy = 0; iy < y; iy++)
+			for(int ix = 0; ix < x; ix++)
+			{
+				ColorRGB pixel = bitmap.Pixels[iy * x + ix];
+
+				int index = ((y - iy - 1) * x + ix) * 4;
+
+				pixels[index + 0] = ToInt8(pixel.Red);
+				pixels[index + 1] = ToInt8(pixel.Green);
+				pixels[index + 2] = ToInt8(pixel.Blue);
+
+				pixels[index + 3] = Int8.MaxValue;
+			}
+
+			_atlas.SetData<Color>((Color*)pixels.Ptr, (.)desc.MapCoord.X, (.)desc.MapCoord.Y,
+				(.)desc.SizeX, (.)desc.SizeY, (.)desc.MapCoord.Z);
+		}
 	}
 }

GlitchyEngine/src/Renderer/Text/FontRenderer.bf

@@ -61,6 +61,15 @@ namespace GlitchyEngine.Renderer.Text
 
 			List<Texture2D> atlasses = scope .();
 
+			// We render every char with a slightly greater depth, so that the chars don't cull each other.
+			// In order to do that we increment an integer for each glyph and use it as the depth for the next one.
+			// Whenn passing the depth to the renderer we treat the integer as the binary representation of a float.
+			// Therefore every increment will increment the mantissa of the float and is therefore equivalent to the
+			// smallest possible increase a float can represent.
+			// Note: This might do funky stuff when objects are very close to each other. But realistically whe have to do
+			// about 8 million (2^23) increments to reach a depth of 1 so I think it's safe enough.
+			int32 depthInt = 0;
+
 			// enumerate through the unicode codepoints
 			for(char32 char in text.DecodedChars)
 			{
@@ -99,10 +108,21 @@ namespace GlitchyEngine.Renderer.Text
 
 				Vector2 atlasSize = .(atlas.Width, atlas.Height);
 
+				float geoToTex = (float)glyphDesc.Font.[Friend]_geometryScaler;
+
+				float adjustToPenX = - 4.0f / geoToTex + (glyphDesc.Metrics.horiBearingX / 64);
+				adjustToPenX *= (float)fontSize / glyphDesc.Font._fontSize;
+
+				float adjustToBaseline = glyphDesc.Font._fontSize - 4.0f / geoToTex -
+					(glyphDesc.Metrics.height / 64) * geoToTex +
+					(glyphDesc.Metrics.horiBearingY / 64) * geoToTex;
+
+				adjustToBaseline *= (float)fontSize / glyphDesc.Font._fontSize;
+				
 				// Rectangle on the screen
 				Vector4 viewportRect = .(
-					penPosition + (glyphDesc.Metrics.horiBearingX / 64) * scale,
+					penPosition + adjustToPenX,
-					baseline - (glyphDesc.Metrics.horiBearingY / 64) * scale,
+					baseline - adjustToBaseline,
 					glyphDesc.SizeX * scale,
 					glyphDesc.SizeY * scale);
 
@@ -113,9 +133,12 @@ namespace GlitchyEngine.Renderer.Text
 
 				texRect /= Vector4(atlasSize, atlasSize);
 
-				renderer.Draw(atlas, viewportRect.X, viewportRect.Y, viewportRect.Z, viewportRect.W, glyphColor, 0.0f, texRect);
+				renderer.Draw(atlas, viewportRect.X, viewportRect.Y, viewportRect.Z, viewportRect.W, glyphColor, *(float*)(&depthInt), texRect);
 
 				penPosition += (glyphDesc.Metrics.horiAdvance / 64) * scale;
+
+				// Increase depth for the next glyph
+				depthInt++;
 			}
 
 			renderer.End();

Sandbox/content/Shaders/msdfShader.hlsl

@@ -43,9 +43,7 @@ float4 PS(PS_Input input) : SV_Target0
     float screenPxDistance = screenPixelRange * (sd - 0.5);
     float opacity = clamp(screenPxDistance + 0.5, 0.0, 1.0);
     //color = mix(bgColor, fgColor, opacity);
-
     //float4 color = lerp(float4(0, 0, 0, 0), input.Color, opacity);
-
     //return color;
 
     return float4(input.Color.rgb, opacity * input.Color.a);

Sandbox/src/SandboxApp2D.bf

@@ -135,186 +135,13 @@ namespace Sandbox
 			emojis.Fallback = mathstuff..ReleaseRefNoDelete();
 
 			// Load test text
-			var result = File.ReadAllText("test.txt", testText = new String(), true);
+			File.ReadAllText("test.txt", testText = new String(), true);
-			//Log.EngineLogger.Assert(result)
 
 			_msdfEffect = _effectLibrary.Load("content\\Shaders\\msdfShader.hlsl");
 
 			_textureViewer = new TextureViewer(_context, Renderer2D, _effectLibrary);
 		}
 
-		double F26Dot6ToDouble(uint16 value)
-		{
-			return (double(value) / 64.0);
-		}
-
-		void DoTheThing(FreeType.FT_Face fontFace, double pixelSizeY)
-		{
-			double unitsPerEm = F26Dot6ToDouble(fontFace.units_per_EM);
-
-			// How much we have to scale the geometry to fit it into our desired pixels
-			double geometryScaler = pixelSizeY / unitsPerEm;
-
-			// prepare shape
-			
-			double advance = 0;
-
-			var glyphIndex = FreeType.FreeType.Get_Char_Index(fonty.[Friend]_face, 'ß');
-
-			Shape shape;
-			msdfgen.LoadGlyph(out shape, &fonty.[Friend]_face, glyphIndex, out advance);
-
-			shape.Normalize();
-
-			var bounds = shape.GetBounds();
-			
-			msdfgen.EdgeColoringSimple(shape, 3.0);
-
-			// prepare projection
-
-			double scale = geometryScaler;
-			double range = 4.0 / geometryScaler;
-
-			int width;
-			int height;
-			
-			double translationX;
-			double translationY;
-
-			if(bounds.Left < bounds.Right && bounds.Bottom < bounds.Top)
-			{
-				double l = bounds.Left;
-				double r = bounds.Right;
-				double b = bounds.Bottom;
-				double t = bounds.Top;
-
-				l -= 0.5 * range;
-				b -= 0.5 * range;
-				r += 0.5 * range;
-				t += 0.5 * range;
-
-				// TODO: miter?!
-
-				double w = scale * (r - l);
-				double h = scale * (t - b);
-
-				width = (int)Math.Ceiling(w) + 1;
-				height = (int)Math.Ceiling(h) + 1;
-
-				translationX = -l + 0.5 * (width - w) / scale;
-				translationY = -b + 0.5 * (height - h) / scale;
-			}
-			else
-			{
-				width = 0;
-				height = 0;
-				translationX = 0;
-				translationY = 0;
-			}
-
-			msdfgen.Projection projection = .();
-			projection.ScaleX = scale;
-			projection.ScaleY = scale;
-
-			projection.TranslationX = translationX;
-			projection.TranslationY = translationY;
-
-			/*
-
-			void GlyphGeometry::wrapBox(double scale, double range, double miterLimit) {
-			    scale *= geometryScale;
-			    range /= geometryScale;
-			    box.range = range;
-			    box.scale = scale;
-			    if (bounds.l < bounds.r && bounds.b < bounds.t) {
-			        double l = bounds.l, b = bounds.b, r = bounds.r, t = bounds.t;
-			        l -= .5*range, b -= .5*range;
-			        r += .5*range, t += .5*range;
-			        if (miterLimit > 0)
-			            shape.boundMiters(l, b, r, t, .5*range, miterLimit, 1);
-			        double w = scale*(r-l);
-			        double h = scale*(t-b);
-			        box.rect.w = (int) ceil(w)+1;
-			        box.rect.h = (int) ceil(h)+1;
-			        box.translate.x = -l+.5*(box.rect.w-w)/scale;
-			        box.translate.y = -b+.5*(box.rect.h-h)/scale;
-			    } else {
-			        box.rect.w = 0, box.rect.h = 0;
-			        box.translate = msdfgen::Vector2();
-			    }
-			}
-
-			*/
-
-			int x = (int)pixelSizeY;
-			int y = (int)pixelSizeY;
-
-			Bitmap<ColorRGB, const 1> bitmap = .((.)x, (.)y);
-
-			MSDFGeneratorConfig config = .();
-
-			msdfgen.GenerateMSDF(*(Bitmap<float, const 3>*)&bitmap, shape, projection, range, config);
-			
-			// Save png
-			/*
-			uint8[] data = new uint8[x * y * 3];
-
-			for(int i = 0; i < x * y * 3; i++)
-			{
-				float f = bitmap.Pixels[i / 3].Red / 2f + 0.5f;
-				float f2 = bitmap.Pixels[i / 3].Green / 2f + 0.5f;
-				float f3 = bitmap.Pixels[i / 3].Blue / 2f + 0.5f;
-
-				data[i++] = (uint8)Math.Clamp(256.0f * f, 0, 255);
-				data[i++] = (uint8)Math.Clamp(256.0f * f2, 0, 255);
-				data[i] = (uint8)Math.Clamp(256.0f * f3, 0, 255);
-			}
-
-			// TODO: free shape
-
-			LodePng.LodePng.EncodeFile("test.png", data.Ptr, (.)x, (.)y, .RGB, 8);
-			*/
-			Texture2DDesc desc;
-			desc.Width = (.)x;
-			desc.Height = (.)y;
-			desc.Format = .R8G8B8A8_SNorm;
-			desc.MipLevels = 1;
-			desc.Usage = .Immutable;
-			desc.CpuAccess = .None;
-			desc.ArraySize = 1;
-
-			_dasTestA = new Texture2D(_context, desc);
-
-			int8[] pixels = new int8[x * y * 4];
-			
-			int8 ToInt8(float f) => (.)Math.Clamp(127f * f, int8.MinValue, int8.MaxValue);
-
-			//for(int i = 0; i < x * y; i++)
-			for(int iy = 0; iy < y; iy++)
-			for(int ix = 0; ix < x; ix++)
-			{
-				ColorRGB pixel = bitmap.Pixels[iy * y + ix];
-
-				float f = pixel.Red;// / 2f + 0.5f;
-				float f2 = pixel.Green;// / 2f + 0.5f;
-				float f3 = pixel.Blue;// / 2f + 0.5f;
-
-				int index = ((y - iy - 1) * y + ix) * 4;
-
-				pixels[index + 0] = ToInt8(f);
-				pixels[index + 1] = ToInt8(f2);
-				pixels[index + 2] = ToInt8(f3);
-				pixels[index + 3] = 0;
-
-				//pixels[(y - iy - 1) * y + ix] = Color(f, f2, f3);
-			}
-
-			_dasTestA.SetData<Color>((.)pixels.Ptr, 0, 0, (.)x, (.)y);
-			//_dasTestA.SetData<uint8>(pixelData.Ptr, 0, 0, (.)x, (.)y);
-		}
-
-		Texture2D _dasTestA ~ _.ReleaseRef();
-
 		Font fonty ~ _.ReleaseRef();
 
 		VertexLayout layout ~ _?.ReleaseRef();
@@ -395,6 +222,11 @@ namespace Sandbox
 
 		public override void Update(GameTime gameTime)
 		{
+			if(Input.IsKeyPressing(Key.P))
+			{
+				fonty.RedrawAtlas();
+			}
+
 			var cameraTransform = _world.GetComponent<TransformComponent>(_cameraEntity);
 
 			if(Application.Get().Window.IsActive)
@@ -496,20 +328,19 @@ namespace Sandbox
 			_alphaBlendState.Bind();
 			Renderer2D.Begin(.FrontToBack, .(_context.SwapChain.Width, _context.SwapChain.Height));
 			
-			Renderer2D.Draw(null, 0, 0, 502, 502, .Black, 5);
+			//Renderer2D.Draw(null, 0, 0, fonty.[Friend]_atlas.Width * 10, fonty.[Friend]_atlas.Height * 10, .Red, 5);
-			
+
 			// Hallo Welt, wie geht es dir? 😂😂😂\nMir geht es gut, danke der Nachfrage. Wie geht es dir?\nMir geht es hervorragend und besser noch: meine Engine kann endlich Text rendern!💕❤\n und es scheint ganz in ordnung zu sein.
 			//FontRenderer.DrawText(Renderer2D, fonty, testText, 0, 0, .White, .White, 32);
 
 			Renderer2D.End();
-
+			
+			_msdfEffect.Variables["screenPixelRange"].SetData(size / 64f * 4.0f);
+			
+			_alphaBlendState.Bind();
 			Renderer2D.Begin(.FrontToBack, .(_context.SwapChain.Width, _context.SwapChain.Height), 100, _msdfEffect);
 
-			_msdfEffect.Variables["screenPixelRange"].SetData(size / 64f * 4.0f);
+			FontRenderer.DrawText(Renderer2D, fonty, "Hallo", 0, 0, .White, .White, 256);
-
-			Renderer2D.Draw(_dasTestA, 1, 1, size, size);
-
-			// TODO: SDFs in Font Atlas packen
 
 			Renderer2D.End();
 		}
@@ -570,23 +401,6 @@ namespace Sandbox
 			return false;
 		}
 
-		float zoom = 1.0f;
-
-		private void TextureViewer()
-		{
-			ImGui.Begin("Texture Viewer");
-
-			ImGui.SliderFloat("Zoom", &zoom, 0.01f, 100.0f);
-
-			ImGui.BeginChild("imageChild", default, true, .HorizontalScrollbar);
-
-			ImGui.Image(fonty.[Friend]_atlas.[Friend]nativeResourceView, .(fonty.[Friend]_atlas.Width * zoom, fonty.[Friend]_atlas.Height * zoom), .(0.0f, 0.0f), .(1.0f, 1.0f), .(1.0f, 1.0f, 1.0f, 1.0f), .(1.0f, 0, 0, 1));
-
-			ImGui.EndChild();
-
-			ImGui.End();
-		}
-
 		private bool OnWindowResize(WindowResizeEvent e)
 		{
 			_depthTarget.ReleaseRef();