Merge pull request #1711 from mitchellh/strikesprite

Strikethrough should be sprite-rendered

src/font/SharedGrid.zig

@@ -129,6 +129,7 @@ fn reloadMetrics(self: *SharedGrid, thicken: bool) !void {
         .thickness = self.metrics.underline_thickness *
             @as(u32, if (thicken) 2 else 1),
         .underline_position = self.metrics.underline_position,
+        .strikethrough_position = self.metrics.strikethrough_position,
     };
 }
 

src/font/sprite.zig

@@ -20,6 +20,8 @@ pub const Sprite = enum(u32) {
     underline_dashed,
     underline_curly,
 
+    strikethrough,
+
     cursor_rect,
     cursor_hollow_rect,
     cursor_bar,

src/font/sprite/Face.zig

@@ -30,11 +30,17 @@ height: u32,
 
 /// Base thickness value for lines of sprites. This is in pixels. If you
 /// want to do any DPI scaling, it is expected to be done earlier.
-thickness: u32,
+thickness: u32 = 1,
 
 /// The position of the underline.
 underline_position: u32 = 0,
 
+/// The position of the strikethrough.
+// NOTE(mitchellh): We don't use a dedicated strikethrough thickness
+// setting yet but fonts can in theory set this. If this becomes an
+// issue in practice we can add it here.
+strikethrough_position: u32 = 0,
+
 /// Returns true if the codepoint exists in our sprite font.
 pub fn hasCodepoint(self: Face, cp: u32, p: ?font.Presentation) bool {
     // We ignore presentation. No matter what presentation is requested
@@ -113,6 +119,16 @@ pub fn renderGlyph(
             self.thickness,
         ),
 
+        .strikethrough => try underline.renderGlyph(
+            alloc,
+            atlas,
+            @enumFromInt(cp),
+            width,
+            self.height,
+            self.strikethrough_position,
+            self.thickness,
+        ),
+
         .powerline => powerline: {
             const f: Powerline = .{
                 .width = width,
@@ -129,6 +145,7 @@ pub fn renderGlyph(
 const Kind = enum {
     box,
     underline,
+    strikethrough,
     powerline,
 
     pub fn init(cp: u32) ?Kind {
@@ -141,6 +158,9 @@ const Kind = enum {
                 .underline_curly,
                 => .underline,
 
+                .strikethrough,
+                => .strikethrough,
+
                 .cursor_rect,
                 .cursor_hollow_rect,
                 .cursor_bar,
@@ -189,3 +209,7 @@ const Kind = enum {
         };
     }
 };
+
+test {
+    @import("std").testing.refAllDecls(@This());
+}

src/font/sprite/underline.zig

@@ -7,6 +7,9 @@
 //! to maintain and debug another set of shaders for each renderer instead of
 //! just relying on the glyph system we already need to support for text
 //! anyways.
+//!
+//! This also renders strikethrough, so its really more generally a
+//! "horizontal line" renderer.
 const std = @import("std");
 const builtin = @import("builtin");
 const assert = std.debug.assert;
@@ -71,6 +74,7 @@ const Draw = struct {
             .underline_dotted => self.drawDotted(canvas),
             .underline_dashed => self.drawDashed(canvas),
             .underline_curly => self.drawCurly(canvas),
+            .strikethrough => self.drawSingle(canvas),
             else => unreachable,
         }
     }
@@ -225,6 +229,24 @@ test "single" {
     );
 }
 
+test "strikethrough" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    var atlas_greyscale = try font.Atlas.init(alloc, 512, .greyscale);
+    defer atlas_greyscale.deinit(alloc);
+
+    _ = try renderGlyph(
+        alloc,
+        &atlas_greyscale,
+        .strikethrough,
+        36,
+        18,
+        9,
+        2,
+    );
+}
+
 test "single large thickness" {
     const testing = std.testing;
     const alloc = testing.allocator;

src/renderer/Metal.zig

@@ -452,8 +452,6 @@ pub fn init(alloc: Allocator, options: renderer.Options) !Metal {
         .uniforms = .{
             .projection_matrix = undefined,
             .cell_size = undefined,
-            .strikethrough_position = @floatFromInt(font_critical.metrics.strikethrough_position),
-            .strikethrough_thickness = @floatFromInt(font_critical.metrics.strikethrough_thickness),
             .min_contrast = options.config.min_contrast,
         },
 
@@ -584,8 +582,6 @@ pub fn setFontGrid(self: *Metal, grid: *font.SharedGrid) void {
             @floatFromInt(metrics.cell_width),
             @floatFromInt(metrics.cell_height),
         },
-        .strikethrough_position = @floatFromInt(metrics.strikethrough_position),
-        .strikethrough_thickness = @floatFromInt(metrics.strikethrough_thickness),
         .min_contrast = self.uniforms.min_contrast,
     };
 }
@@ -1436,8 +1432,6 @@ pub fn setScreenSize(
             @floatFromInt(self.grid_metrics.cell_width),
             @floatFromInt(self.grid_metrics.cell_height),
         },
-        .strikethrough_position = old.strikethrough_position,
-        .strikethrough_thickness = old.strikethrough_thickness,
         .min_contrast = old.min_contrast,
     };
 
@@ -1914,12 +1908,25 @@ fn updateCell(
     }
 
     if (style.flags.strikethrough) {
+        const render = try self.font_grid.renderGlyph(
+            self.alloc,
+            font.sprite_index,
+            @intFromEnum(font.Sprite.strikethrough),
+            .{
+                .cell_width = if (cell.wide == .wide) 2 else 1,
+                .grid_metrics = self.grid_metrics,
+            },
+        );
+
         self.cells.appendAssumeCapacity(.{
-            .mode = .strikethrough,
+            .mode = .fg,
             .grid_pos = .{ @as(f32, @floatFromInt(x)), @as(f32, @floatFromInt(y)) },
             .cell_width = cell.gridWidth(),
             .color = .{ colors.fg.r, colors.fg.g, colors.fg.b, alpha },
             .bg_color = bg,
+            .glyph_pos = .{ render.glyph.atlas_x, render.glyph.atlas_y },
+            .glyph_size = .{ render.glyph.width, render.glyph.height },
+            .glyph_offset = .{ render.glyph.offset_x, render.glyph.offset_y },
         });
     }
 

src/renderer/OpenGL.zig

@@ -207,17 +207,6 @@ const SetFontSize = struct {
                 },
             );
         }
-
-        const bind = try gl_state.cell_program.program.use();
-        defer bind.unbind();
-        try gl_state.cell_program.program.setUniform(
-            "strikethrough_position",
-            @as(f32, @floatFromInt(self.metrics.strikethrough_position)),
-        );
-        try gl_state.cell_program.program.setUniform(
-            "strikethrough_thickness",
-            @as(f32, @floatFromInt(self.metrics.strikethrough_thickness)),
-        );
     }
 };
 
@@ -1491,17 +1480,27 @@ fn updateCell(
     }
 
     if (style.flags.strikethrough) {
+        const render = try self.font_grid.renderGlyph(
+            self.alloc,
+            font.sprite_index,
+            @intFromEnum(font.Sprite.strikethrough),
+            .{
+                .cell_width = if (cell.wide == .wide) 2 else 1,
+                .grid_metrics = self.grid_metrics,
+            },
+        );
+
         self.cells.appendAssumeCapacity(.{
-            .mode = .strikethrough,
+            .mode = .fg,
             .grid_col = @intCast(x),
             .grid_row = @intCast(y),
             .grid_width = cell.gridWidth(),
-            .glyph_x = 0,
-            .glyph_y = 0,
-            .glyph_width = 0,
-            .glyph_height = 0,
-            .glyph_offset_x = 0,
-            .glyph_offset_y = 0,
+            .glyph_x = render.glyph.atlas_x,
+            .glyph_y = render.glyph.atlas_y,
+            .glyph_width = render.glyph.width,
+            .glyph_height = render.glyph.height,
+            .glyph_offset_x = render.glyph.offset_x,
+            .glyph_offset_y = render.glyph.offset_y,
             .r = colors.fg.r,
             .g = colors.fg.g,
             .b = colors.fg.b,

src/renderer/metal/shaders.zig

@@ -103,7 +103,6 @@ pub const Cell = extern struct {
         fg = 2,
         fg_constrained = 3,
         fg_color = 7,
-        strikethrough = 8,
     };
 };
 
@@ -124,10 +123,6 @@ pub const Uniforms = extern struct {
     /// Size of a single cell in pixels, unscaled.
     cell_size: [2]f32,
 
-    /// Metrics for underline/strikethrough
-    strikethrough_position: f32,
-    strikethrough_thickness: f32,
-
     /// The minimum contrast ratio for text. The contrast ratio is calculated
     /// according to the WCAG 2.0 spec.
     min_contrast: f32,

src/renderer/opengl/CellProgram.zig

@@ -53,7 +53,6 @@ pub const CellMode = enum(u8) {
     fg = 2,
     fg_constrained = 3,
     fg_color = 7,
-    strikethrough = 8,
 
     // Non-exhaustive because masks change it
     _,

src/renderer/shaders/cell.f.glsl

@@ -28,7 +28,6 @@ const uint MODE_BG = 1u;
 const uint MODE_FG = 2u;
 const uint MODE_FG_CONSTRAINED = 3u;
 const uint MODE_FG_COLOR = 7u;
-const uint MODE_STRIKETHROUGH = 8u;
 
 void main() {
     float a;
@@ -48,9 +47,5 @@ void main() {
     case MODE_FG_COLOR:
         out_FragColor = texture(text_color, glyph_tex_coords);
         break;
-
-    case MODE_STRIKETHROUGH:
-        out_FragColor = color;
-        break;
     }
 }

src/renderer/shaders/cell.metal

@@ -6,14 +6,11 @@ enum Mode : uint8_t {
   MODE_FG = 2u,
   MODE_FG_CONSTRAINED = 3u,
   MODE_FG_COLOR = 7u,
-    MODE_STRIKETHROUGH = 8u,
 };
 
 struct Uniforms {
   float4x4 projection_matrix;
   float2 cell_size;
-  float strikethrough_position;
-  float strikethrough_thickness;
   float min_contrast;
 };
 
@@ -110,11 +107,9 @@ float4 contrasted_color(float min, float4 fg, float4 bg) {
 //-------------------------------------------------------------------
 #pragma mark - Terminal Grid Cell Shader
 
-vertex VertexOut uber_vertex(
-  unsigned int vid [[ vertex_id ]],
+vertex VertexOut uber_vertex(unsigned int vid [[vertex_id]],
                              VertexIn input [[stage_in]],
-  constant Uniforms &uniforms [[ buffer(1) ]]
-) {
+                             constant Uniforms& uniforms [[buffer(1)]]) {
   // Convert the grid x,y into world space x, y by accounting for cell size
   float2 cell_pos = uniforms.cell_size * input.grid_pos;
 
@@ -147,7 +142,8 @@ vertex VertexOut uber_vertex(
       // one cell up and to the left. (Do the math to verify yourself)
       cell_pos = cell_pos + cell_size_scaled * position;
 
-    out.position = uniforms.projection_matrix * float4(cell_pos.x, cell_pos.y, 0.0f, 1.0f);
+      out.position = uniforms.projection_matrix *
+                     float4(cell_pos.x, cell_pos.y, 0.0f, 1.0f);
       break;
 
     case MODE_FG:
@@ -176,49 +172,33 @@ vertex VertexOut uber_vertex(
       // Calculate the final position of the cell which uses our glyph size
       // and glyph offset to create the correct bounding box for the glyph.
       cell_pos = cell_pos + glyph_size * position + glyph_offset;
-    out.position = uniforms.projection_matrix * float4(cell_pos.x, cell_pos.y, 0.0f, 1.0f);
+      out.position = uniforms.projection_matrix *
+                     float4(cell_pos.x, cell_pos.y, 0.0f, 1.0f);
 
       // Calculate the texture coordinate in pixels. This is NOT normalized
       // (between 0.0 and 1.0) and must be done in the fragment shader.
-    out.tex_coord = float2(input.glyph_pos) + float2(input.glyph_size) * position;
+      out.tex_coord =
+          float2(input.glyph_pos) + float2(input.glyph_size) * position;
 
       // If we have a minimum contrast, we need to check if we need to
       // change the color of the text to ensure it has enough contrast
       // with the background.
       if (uniforms.min_contrast > 1.0f && input.mode == MODE_FG) {
         float4 bg_color = float4(input.bg_color) / 255.0f;
-      out.color = contrasted_color(uniforms.min_contrast, out.color, bg_color);
+        out.color =
+            contrasted_color(uniforms.min_contrast, out.color, bg_color);
       }
 
       break;
     }
-
-  case MODE_STRIKETHROUGH: {
-    // Strikethrough Y value is just our thickness
-    float2 strikethrough_size = float2(cell_size_scaled.x, uniforms.strikethrough_thickness);
-
-    // Position the strikethrough where we are told to
-    float2 strikethrough_offset = float2(cell_size_scaled.x, uniforms.strikethrough_position);
-
-    // Go to the bottom of the cell, take away the size of the
-    // strikethrough, and that is our position. We also float it slightly
-    // above the bottom.
-    cell_pos = cell_pos + strikethrough_offset - (strikethrough_size * position);
-
-    out.position = uniforms.projection_matrix * float4(cell_pos, 0.0f, 1.0);
-    break;
-  }
-
   }
 
   return out;
 }
 
-fragment float4 uber_fragment(
-  VertexOut in [[ stage_in ]],
+fragment float4 uber_fragment(VertexOut in [[stage_in]],
                               texture2d<float> textureGreyscale [[texture(0)]],
-  texture2d<float> textureColor [[ texture(1) ]]
-) {
+                              texture2d<float> textureColor [[texture(1)]]) {
   constexpr sampler textureSampler(address::clamp_to_edge, filter::linear);
 
   switch (in.mode) {
@@ -228,7 +208,8 @@ fragment float4 uber_fragment(
     case MODE_FG_CONSTRAINED:
     case MODE_FG: {
       // Normalize the texture coordinates to [0,1]
-    float2 size = float2(textureGreyscale.get_width(), textureGreyscale.get_height());
+      float2 size =
+          float2(textureGreyscale.get_width(), textureGreyscale.get_height());
       float2 coord = in.tex_coord / size;
 
       // We premult the alpha to our whole color since our blend function
@@ -247,9 +228,6 @@ fragment float4 uber_fragment(
       float2 coord = in.tex_coord / size;
       return textureColor.sample(textureSampler, coord);
     }
-
-  case MODE_STRIKETHROUGH:
-    return in.color;
   }
 }
 
@@ -279,12 +257,10 @@ struct ImageVertexOut {
   float2 tex_coord;
 };
 
-vertex ImageVertexOut image_vertex(
-  unsigned int vid [[ vertex_id ]],
+vertex ImageVertexOut image_vertex(unsigned int vid [[vertex_id]],
                                    ImageVertexIn input [[stage_in]],
                                    texture2d<uint> image [[texture(0)]],
-  constant Uniforms &uniforms [[ buffer(1) ]]
-) {
+                                   constant Uniforms& uniforms [[buffer(1)]]) {
   // The size of the image in pixels
   float2 image_size = float2(image.get_width(), image.get_height());
 
@@ -315,15 +291,14 @@ vertex ImageVertexOut image_vertex(
   float2 image_pos = (uniforms.cell_size * input.grid_pos) + input.cell_offset;
   image_pos += input.dest_size * position;
 
-  out.position = uniforms.projection_matrix * float4(image_pos.x, image_pos.y, 0.0f, 1.0f);
+  out.position =
+      uniforms.projection_matrix * float4(image_pos.x, image_pos.y, 0.0f, 1.0f);
   out.tex_coord = tex_coord;
   return out;
 }
 
-fragment float4 image_fragment(
-  ImageVertexOut in [[ stage_in ]],
-  texture2d<uint> image [[ texture(0) ]]
-) {
+fragment float4 image_fragment(ImageVertexOut in [[stage_in]],
+                               texture2d<uint> image [[texture(0)]]) {
   constexpr sampler textureSampler(address::clamp_to_edge, filter::linear);
 
   // Ehhhhh our texture is in RGBA8Uint but our color attachment is

src/renderer/shaders/cell.v.glsl

@@ -8,7 +8,6 @@ const uint MODE_BG = 1u;
 const uint MODE_FG = 2u;
 const uint MODE_FG_CONSTRAINED = 3u;
 const uint MODE_FG_COLOR = 7u;
-const uint MODE_STRIKETHROUGH = 8u;
 
 // The grid coordinates (x, y) where x < columns and y < rows
 layout (location = 0) in vec2 grid_coord;
@@ -57,8 +56,6 @@ uniform sampler2D text;
 uniform sampler2D text_color;
 uniform vec2 cell_size;
 uniform mat4 projection;
-uniform float strikethrough_position;
-uniform float strikethrough_thickness;
 uniform float min_contrast;
 
 /********************************************************************
@@ -233,21 +230,5 @@ void main() {
         }
         color = color_final;
         break;
-
-    case MODE_STRIKETHROUGH:
-        // Strikethrough Y value is just our thickness
-        vec2 strikethrough_size = vec2(cell_size_scaled.x, strikethrough_thickness);
-
-        // Position the strikethrough where we are told to
-        vec2 strikethrough_offset = vec2(cell_size_scaled.x, strikethrough_position) ;
-
-        // Go to the bottom of the cell, take away the size of the
-        // strikethrough, and that is our position. We also float it slightly
-        // above the bottom.
-        cell_pos = cell_pos + strikethrough_offset - (strikethrough_size * position);
-
-        gl_Position = projection * vec4(cell_pos, cell_z, 1.0);
-        color = color_in / 255.0;
-        break;
     }
 }