text rendering OK

.gitignore

@@ -12,3 +12,5 @@ desktop.ini
 *.zip
 native/**/build
 .ccls-cache
+
+.fake

.vscode/launch.json

@@ -9,12 +9,14 @@
             "type": "coreclr",
             "request": "launch",
             "preLaunchTask": "build",
-            "program": "${workspaceFolder}/bin/Release/netcoreapp3.0/fvim.dll",
+            "program": "${workspaceFolder}/bin/Debug/netcoreapp3.1/FVim.dll",
             "args": [],
-            "cwd": "${workspaceFolder}/bin/Release/netcoreapp3.0/",
+            "cwd": "${workspaceFolder}",
             "stopAtEntry": false,
-            "console": "internalConsole",
-            "justMyCode": false
-        },
+            "console": "integratedTerminal",
+            "justMyCode": false,
+            "enableStepFiltering": false
+        }
+
     ]
 }

.vscode/tasks.json

@@ -5,12 +5,22 @@
     "tasks": [
         {
             "label": "build",
-            "command": "dotnet build -c Release",
             "type": "shell",
+            "command": "dotnet",
+            "args": [
+                "msbuild",
+                // Ask msbuild to generate full paths for file names.
+                "/property:GenerateFullPaths=true",
+                "/t:build",
+                // Do not generate summary otherwise it leads to duplicate errors in Problems panel
+                "/consoleloggerparameters:NoSummary"
+            ],
             "group": "build",
             "presentation": {
+                // Reveal the output only if unrecognized errors occur.
                 "reveal": "silent"
             },
+            // Use the standard MS compiler pattern to detect errors, warnings and infos
             "problemMatcher": "$msCompile"
         }
     ]

Views/Cursor.xaml.fs

@@ -29,9 +29,10 @@ type Cursor() as this =
     static let IsActiveProperty = AvaloniaProperty.Register<Cursor, bool>("IsActive")
 
     let mutable cursor_timer: IDisposable = null
-    let mutable bgbrush: SolidColorBrush  = SolidColorBrush(Colors.Black)
-    let mutable fgbrush: SolidColorBrush  = SolidColorBrush(Colors.White)
-    let mutable spbrush: SolidColorBrush  = SolidColorBrush(Colors.Red)
+    let mutable fg = Colors.White
+    let mutable bg = Colors.Black
+    let mutable sp = Colors.Red
+
     let mutable cursor_fb = AllocateFramebuffer (20.0) (20.0) 1.0
     let mutable cursor_fb_vm = CursorViewModel(Some -1)
     let mutable cursor_fb_s = 1.0
@@ -49,10 +50,6 @@ type Cursor() as this =
             true
         else false
 
-    let fgpaint = SolidColorBrush()
-    let bgpaint = SolidColorBrush()
-    let sppaint = SolidColorBrush()
-
     let _buffer_glyph = [| 0u |]
 
     let cursorTimerRun action time =
@@ -83,12 +80,9 @@ type Cursor() as this =
         then ()
         else
             (* update the settings *)
-            if this.ViewModel.fg <> fgbrush.Color then
-                fgbrush <- SolidColorBrush(this.ViewModel.fg)
-            if this.ViewModel.bg <> bgbrush.Color then
-                bgbrush <- SolidColorBrush(this.ViewModel.bg)
-            if this.ViewModel.sp <> spbrush.Color then
-                spbrush <- SolidColorBrush(this.ViewModel.sp)
+            fg <- this.ViewModel.fg
+            bg <- this.ViewModel.bg
+            sp <- this.ViewModel.sp
             (* reconfigure the cursor *)
             showCursor true
             cursorTimerRun blinkon this.ViewModel.blinkwait
@@ -150,7 +144,7 @@ type Cursor() as this =
                 if this.IsActive then
                     _buffer_glyph.[0] <- this.ViewModel.text.Codepoint
                     let _buffer_glyph_span = ReadOnlySpan(_buffer_glyph)
-                    RenderText(ctx, bounds, scale, fgpaint, bgpaint, sppaint, this.ViewModel.underline, this.ViewModel.undercurl, _buffer_glyph_span, typeface, this.ViewModel.fontSize)
+                    RenderText(ctx, bounds, scale, fg, bg, sp, this.ViewModel.underline, this.ViewModel.undercurl, _buffer_glyph_span, typeface, this.ViewModel.fontSize)
                 else
                     let brush = SolidColorBrush(this.ViewModel.bg)
                     ctx.DrawRectangle(brush, Pen(brush), RoundedRect(bounds))
@@ -159,9 +153,9 @@ type Cursor() as this =
                 match ctx.PlatformImpl with
                 | :? ISkiaDrawingContextImpl ->
                     // immediate
-                    SetOpacity fgpaint this.Opacity
-                    SetOpacity bgpaint this.Opacity
-                    SetOpacity sppaint this.Opacity
+                    fg <- UpdateOpacity fg this.Opacity
+                    bg <- UpdateOpacity bg this.Opacity
+                    sp <- UpdateOpacity sp this.Opacity
                     render_block ctx.PlatformImpl
                 | _ ->
                     // deferred

Views/Editor.xaml.fs

@@ -81,10 +81,6 @@ type Editor() as this =
     let px = pt * grid_scale
     Point(Math.Ceiling px.X, Math.Ceiling px.Y) / grid_scale
 
-  let fgpaint = SolidColorBrush()
-  let bgpaint = SolidColorBrush()
-  let sppaint = SolidColorBrush()
-
   let mutable _buffer_glyphs = [||]
 
   let drawBuffer (ctx: IDrawingContextImpl) row col colend hlid (issym: bool) =
@@ -112,7 +108,7 @@ type Editor() as this =
     let txt = ReadOnlySpan(_buffer_glyphs, 0, colend - col)
 
     try
-      RenderText(ctx, bg_region, grid_scale, fgpaint, bgpaint, sppaint, attrs.underline, attrs.undercurl, txt, typeface, fontsize)
+      RenderText(ctx, bg_region, grid_scale, fg, bg, sp, attrs.underline, attrs.undercurl, txt, typeface, fontsize)
     with ex -> trace grid_vm "drawBuffer: %s" (ex.ToString())
 
   // assembles text from grid and draw onto the context.

Views/MainWindow.xaml.fs

@@ -17,6 +17,8 @@ open Avalonia.Rendering
 open Avalonia.Interactivity
 open Avalonia.VisualTree
 
+open Avalonia.Diagnostics
+
 #nowarn "0025"
 
 open System.Runtime.InteropServices

fvim.fsproj

@@ -65,20 +65,17 @@
     <AvaloniaResource Include="**\*.xaml">
       <SubType>Designer</SubType>
     </AvaloniaResource>
-    <EmbeddedResource Include="nerd.ttf" />
+    <EmbeddedResource Include="Fonts\nerd.ttf" />
     <Content Include="Assets\*" />
     <None Include="icons\*.ico" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(Configuration)' == 'Debug'">
-    <PackageReference Include="Avalonia.Diagnostics" Version="0.10.0-preview2" />
-  </ItemGroup>
-
   <ItemGroup>
     <PackageReference Include="Avalonia" Version="0.10.0-preview2" />
     <PackageReference Include="Avalonia.Desktop" Version="0.10.0-preview2" />
     <PackageReference Include="Avalonia.ReactiveUI" Version="0.10.0-preview2" />
     <PackageReference Include="Avalonia.Angle.Windows.Natives" Version="2.1.0.2019013001" />
+    <PackageReference Include="Avalonia.Diagnostics" Version="0.10.0-preview2" />
 
     <PackageReference Include="FSharp.Control.Reactive" Version="4.4.2" />
     <PackageReference Include="FSharp.Data" Version="3.3.3" />

ui.fs

@@ -11,11 +11,10 @@ open Avalonia.Input
 open Avalonia.Media
 open Avalonia.Media.Imaging
 open Avalonia.Platform
-open Avalonia.Skia
-open SkiaSharp
-open SkiaSharp.HarfBuzz
 open System
 open System.Reflection
+open Avalonia.Controls.Shapes
+open Avalonia.Media.TextFormatting
 
 #nowarn "0009"
 
@@ -153,7 +152,7 @@ let DefaultFontEmoji =
     elif RuntimeInformation.IsOSPlatform(OSPlatform.OSX)   then "Apple Color Emoji"
     else "Noto Color Emoji"
 
-let private nerd_typeface = Typeface("fvim.nerd.ttf#Iosevka Nerd Font Complete")
+let private nerd_typeface = Typeface("resm:FVim.Fonts.nerd.ttf?assembly=FVim")
 let private emoji_typeface = Typeface(DefaultFontEmoji)
 let private fontcache = System.Collections.Generic.Dictionary<string*bool*bool, Typeface>()
 
@@ -178,7 +177,9 @@ let GetTypeface(txt, italic, bold, font, wfont) =
             trace "ui" "GetTypeface: allocating new typeface %s:%b:%b" fname italic bold
             let weight   = if bold then States.font_weight_bold else States.font_weight_normal
             let slang    = if italic then FontStyle.Italic else FontStyle.Normal
-            let typeface = Typeface(fname, slang, weight)
+            let typeface = 
+                try Typeface(fname, slang, weight)
+                with | _ -> Typeface.Default
             fontcache.[(fname, italic, bold)] <- typeface
             typeface
 
@@ -192,25 +193,29 @@ let GetTypeface(txt, italic, bold, font, wfont) =
     | _              -> _get font
 
 let MeasureText (rune: Rune, font: string, wfont: string, fontSize: float, scaling: float) =
-    use typeface = GetTypeface(rune, false, false, font, wfont).GlyphTypeface
+    let typeface = GetTypeface(rune, false, false, font, wfont).GlyphTypeface
 
     let mutable score = 999999999999.0
     let mutable s = fontSize
     let mutable w = 0.0
     let mutable h = 0.0
 
     let search (sizeStep: int) =
+        // s' is pixels per em
         let s' = fontSize + float(sizeStep) * 0.01
+        // u' is pixels per font design unit
+        let u' = s' / float typeface.DesignEmHeight
         let glyph = [| typeface.GetGlyph(rune.Codepoint) |]
         use run = new GlyphRun(typeface, s', Utilities.ReadOnlySlice(ReadOnlyMemory(glyph)))
         let bounds = run.Bounds
 
+
         let w' = bounds.Width
         let h'' = 
             match States.font_lineheight with
-            | States.Absolute h' -> h'
-            | States.Default -> float(typeface.LineHeight + typeface.LineGap)
-            | States.Add h' -> float(typeface.LineHeight + typeface.LineGap) + h'
+            | States.Absolute lh -> lh
+            | States.Default -> float typeface.LineHeight * u'
+            | States.Add lh -> float typeface.LineHeight * u' + lh
         let h' = round(h'' * scaling) / scaling
         let h' = max h' 1.0
 
@@ -234,94 +239,86 @@ let AllocateFramebuffer w h scale =
     let pxsize        = PixelSize(int <| (w * scale), int <| (h * scale))
     new RenderTargetBitmap(pxsize, Vector(96.0 * scale, 96.0 * scale))
 
-let SetOpacity (paint: SolidColorBrush) (opacity: float) =
-    let c = paint.Color
-    paint.Color <- Color(byte <| opacity * 255.0, c.R, c.G, c.B)
-
-let SetForegroundBrush(fgpaint: SolidColorBrush, c: Color) =
-    fgpaint.Color                <- c
-    ()
+let UpdateOpacity (color: Color) opacity = 
+    Color(byte(255.0 * opacity), color.R, color.G, color.B)
 
 let mutable _render_glyph_buf = [||]
+let mutable _render_char_buf = [||]
 
-let RenderText (ctx: IDrawingContextImpl, region: Rect, scale: float, fg: SolidColorBrush, bg: SolidColorBrush, sp: SolidColorBrush, underline: bool, undercurl: bool, text: ReadOnlySpan<uint>, font: Typeface, fontSize: float) =
+let _render_brush = SolidColorBrush()
+let _sp_brush = SolidColorBrush()
+let _sp_pen = Pen(_sp_brush)
+let _sp_points = ResizeArray()
 
-    //  don't clip all along. see #60
+let RenderText (ctx: IDrawingContextImpl, region: Rect, scale: float, fg: Color, bg: Color, sp: Color, underline: bool, undercurl: bool, text: ReadOnlySpan<uint>, font: Typeface, fontSize: float) =
+
+    let glyphTypeface = font.GlyphTypeface
+    let px_per_unit = fontSize /  float glyphTypeface.DesignEmHeight
 
-    //  DrawText accepts the coordinate of the baseline.
     //  h = [padding space 1] + above baseline | below baseline + [padding space 2]
-//    let h = region.Bottom - region.Top
+    let h = region.Bottom - region.Top
+
+    //  fh = [above baseline + below baseline]
+    let fh = float (glyphTypeface.Descent - glyphTypeface.Ascent) * px_per_unit
     //  total_padding = padding space 1 + padding space 2
-//    let total_padding = h - ((fg.FontMetrics.Bottom - fg.FontMetrics.Top))
-//    let baseline      = region.Top + ceil((total_padding / 2.0f) - fg.FontMetrics.Top)
+    let total_padding = h - fh
+    let ascent = float glyphTypeface.Ascent * px_per_unit
+    //  Text drawing is done at the coordinate of the baseline.
+    let baseline = region.Top + ceil((total_padding / 2.0) - ascent)
     (*printfn "scale=%A pad=%A base=%A region=%A" scale total_padding baseline region*)
-//    let fontPos       = SKPoint(region.Left, baseline)
+    let fontPos = Point(region.Left, baseline)
 
-//   let skia = ctx :?> ISkiaDrawingContextImpl
-
-    //lol wat??
-    //fg.Shader <- SKShader.CreateCompose(SKShader.CreateColor(fg.Color), SKShader.CreatePerlinNoiseFractalNoise(0.1F, 0.1F, 1, 6.41613F))
-
-    // push clip and fill bg
+    //  push clip and fill bg
     ctx.PushClip region
-    ctx.Clear bg.Color
+    ctx.Clear bg
+    //  don't clip all along. see #60
     ctx.PopClip ()
 
-    let glyphTypeface = font.GlyphTypeface
     if _render_glyph_buf.Length < text.Length then
       _render_glyph_buf <- Array.zeroCreate text.Length
     for i in 0..text.Length-1 do
       _render_glyph_buf.[i] <- glyphTypeface.GetGlyph(text.[i])
     let slice = ReadOnlyMemory(_render_glyph_buf, 0, text.Length)
     use glyphrun = new GlyphRun(glyphTypeface, fontSize, Utilities.ReadOnlySlice(slice))
-    ctx.DrawGlyphRun(fg, glyphrun, region.TopLeft)
-
-    // Text bounding box drawing:
-    // --------------------------------------------------
-    // if States.font_drawBounds then
-    //     let mutable bounds = SKRect()
-    //     let text = if String.IsNullOrEmpty text then " " else text
-    //     ignore <| fg.MeasureText(text, &bounds)
-    //     bounds.Left <- bounds.Left + single (fontPos.X)
-    //     bounds.Top <- bounds.Top + single (fontPos.Y)
-    //     bounds.Right <- bounds.Right + single (fontPos.X)
-    //     bounds.Bottom <- bounds.Bottom + single (fontPos.Y)
-    //     fg.Style <- SKPaintStyle.Stroke
-    //     skia.SkCanvas.DrawRect(bounds, fg)
-    // --------------------------------------------------
-
-//     let sp_thickness = fg.FontMetrics.UnderlineThickness.GetValueOrDefault(1.0F)
-// 
-//     if underline then
-//         let underline_pos = fg.FontMetrics.UnderlinePosition.GetValueOrDefault()
-//         let p1 = fontPos + SKPoint(0.0f, underline_pos)
-//         let p2 = p1 + SKPoint(region.Width, 0.0f)
-//         sp.Style <- SKPaintStyle.Stroke
-//         //sppaint.StrokeWidth <- sp_thickness
-//         skia.SkCanvas.DrawLine(p1, p2, sp)
-// 
-//     if undercurl then
-//         let underline_pos  = fg.FontMetrics.UnderlinePosition.GetValueOrDefault()
-//         let mutable px, py = single fontPos.X, single fontPos.Y 
-//         py <- py + underline_pos
-//         let qf             = 1.5F
-//         let hf             = qf * 2.0F
-//         let q3f            = qf * 3.0F
-//         let ff             = qf * 4.0F
-//         let r              = single region.Right
-//         let py1            = py - 2.0f
-//         let py2            = py + 2.0f
-//         sp.Style <- SKPaintStyle.Stroke
-//         sp.StrokeWidth <- sp_thickness
-//         use path = new SKPath()
-//         path.MoveTo(px, py)
-//         while px < r do
-//             path.LineTo(px,       py)
-//             path.LineTo(px + qf,  py1)
-//             path.LineTo(px + hf,  py)
-//             path.LineTo(px + q3f, py2)
-//             px <- px + ff
-//         skia.SkCanvas.DrawPath(path , sp)
+
+    _render_brush.Color <- fg
+
+    ctx.DrawGlyphRun(_render_brush, glyphrun, fontPos)
+
+    let shaper = TextShaper.Current
+
+    //  Text bounding box drawing:
+    if States.font_drawBounds then
+        ctx.DrawRectangle(Brushes.Transparent, Pen(_render_brush), RoundedRect(Rect(glyphrun.Bounds.TopLeft + region.TopLeft, glyphrun.Bounds.BottomRight + region.TopLeft)))
+
+    let sp_thickness = float glyphTypeface.UnderlineThickness * px_per_unit
+    let underline_pos = float glyphTypeface.UnderlinePosition * px_per_unit
+    _sp_pen.Thickness <- sp_thickness
+    _sp_brush.Color <- sp
+
+    if underline then
+        let p1 = fontPos + Point(0.0, underline_pos)
+        let p2 = p1 + Point(region.Width, 0.0)
+        ctx.DrawLine(_sp_pen, p1, p2)
+
+    if undercurl then
+        let mutable p = fontPos + Point(0.0, underline_pos)
+        let qf             = 1.5
+        let hf             = qf * 2.0
+        let q3f            = qf * 3.0
+        let v1             = Point(qf, -2.0)
+        let v2             = Point(hf, 0.0)
+        let v3             = Point(q3f, 2.0)
+        let ff             = Point(qf * 4.0, 0.0)
+        let r              = region.Right
+        _sp_points.Clear()
+        while p.X < r do
+            _sp_points.Add(p)
+            _sp_points.Add(p + v1)
+            _sp_points.Add(p + v2)
+            _sp_points.Add(p + v3)
+            p <- p + ff
+        ctx.DrawGeometry(Brushes.Transparent, _sp_pen, PolylineGeometry(_sp_points, false).PlatformImpl)
 
 type WindowBackgroundComposition =
     | SolidBackground of opacity: float * color: Color