core: begin converting to SharedGridSet, renderers still broken

src/App.zig

@@ -43,7 +43,7 @@ quit: bool,
 
 /// The set of font GroupCache instances shared by surfaces with the
 /// same font configuration.
-font_group_set: font.GroupCacheSet,
+font_grid_set: font.SharedGridSet,
 
 /// Initialize the main app instance. This creates the main window, sets
 /// up the renderer state, compiles the shaders, etc. This is the primary
@@ -54,15 +54,15 @@ pub fn create(
     var app = try alloc.create(App);
     errdefer alloc.destroy(app);
 
-    var font_group_set = try font.GroupCacheSet.init(alloc);
-    errdefer font_group_set.deinit();
+    var font_grid_set = try font.SharedGridSet.init(alloc);
+    errdefer font_grid_set.deinit();
 
     app.* = .{
         .alloc = alloc,
         .surfaces = .{},
         .mailbox = .{},
         .quit = false,
-        .font_group_set = font_group_set,
+        .font_grid_set = font_grid_set,
     };
     errdefer app.surfaces.deinit(alloc);
 
@@ -76,7 +76,7 @@ pub fn destroy(self: *App) void {
 
     // Clean up our font group cache
     // TODO(fontmem): assert all ref counts are zero
-    self.font_group_set.deinit();
+    self.font_grid_set.deinit();
 
     self.alloc.destroy(self);
 }

src/Surface.zig

@@ -54,7 +54,7 @@ rt_app: *apprt.runtime.App,
 rt_surface: *apprt.runtime.Surface,
 
 /// The font structures
-font_group_key: font.GroupCacheSet.Key,
+font_grid_key: font.SharedGridSet.Key,
 font_size: font.face.DesiredSize,
 
 /// The renderer for this surface.
@@ -321,13 +321,13 @@ pub fn init(
 
     // Setup our font group. This will reuse an existing font group if
     // it was already loaded.
-    const font_group_key, const font_group = try app.font_group_set.groupRef(
+    const font_grid_key, const font_grid = try app.font_grid_set.ref(
         config,
         font_size,
     );
 
     // Pre-calculate our initial cell size ourselves.
-    const cell_size = try renderer.CellSize.init(alloc, font_group);
+    const cell_size = font_grid.cellSize();
 
     // Convert our padding from points to pixels
     const padding_x: u32 = padding_x: {
@@ -349,7 +349,7 @@ pub fn init(
     const app_mailbox: App.Mailbox = .{ .rt_app = rt_app, .mailbox = &app.mailbox };
     var renderer_impl = try Renderer.init(alloc, .{
         .config = try Renderer.DerivedConfig.init(alloc, config),
-        .font_group = font_group,
+        .font_grid = font_grid,
         .padding = .{
             .explicit = padding,
             .balance = config.@"window-padding-balance",
@@ -410,7 +410,7 @@ pub fn init(
         .app = app,
         .rt_app = rt_app,
         .rt_surface = rt_surface,
-        .font_group_key = font_group_key,
+        .font_grid_key = font_grid_key,
         .font_size = font_size,
         .renderer = renderer_impl,
         .renderer_thread = render_thread,
@@ -530,8 +530,8 @@ pub fn deinit(self: *Surface) void {
         self.alloc.destroy(v);
     }
 
-    // Clean up our font group
-    self.app.font_group_set.groupDeref(self.font_group_key);
+    // Clean up our font grid
+    self.app.font_grid_set.deref(self.font_grid_key);
 
     // Clean up our render state
     if (self.renderer_state.preedit) |p| self.alloc.free(p.codepoints);

src/font/SharedGrid.zig

@@ -24,6 +24,7 @@ const SharedGrid = @This();
 const std = @import("std");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
+const renderer = @import("../renderer.zig");
 const font = @import("main.zig");
 const Atlas = font.Atlas;
 const CodepointResolver = font.CodepointResolver;
@@ -132,6 +133,16 @@ fn reloadMetrics(self: *SharedGrid, thicken: bool) !void {
     };
 }
 
+/// Returns the grid cell size.
+///
+/// This is not thread safe.
+pub fn cellSize(self: *SharedGrid) renderer.CellSize {
+    return .{
+        .width = self.metrics.cell_width,
+        .height = self.metrics.cell_height,
+    };
+}
+
 const CodepointKey = struct {
     style: Style,
     codepoint: u32,

src/renderer/Options.zig

@@ -9,7 +9,7 @@ const Config = @import("../config.zig").Config;
 config: renderer.Renderer.DerivedConfig,
 
 /// The font group that should be used.
-font_group: *font.GroupCache,
+font_grid: *font.SharedGrid,
 
 /// Padding options for the viewport.
 padding: Padding,

src/renderer/size.zig

@@ -17,26 +17,6 @@ const log = std.log.scoped(.renderer_size);
 pub const CellSize = struct {
     width: u32,
     height: u32,
-
-    /// Initialize the cell size information from a font group. This ensures
-    /// that all renderers use the same cell sizing information for the same
-    /// fonts.
-    pub fn init(alloc: Allocator, group: *font.GroupCache) !CellSize {
-        // Get our cell metrics based on a regular font ascii 'M'. Why 'M'?
-        // Doesn't matter, any normal ASCII will do we're just trying to make
-        // sure we use the regular font.
-        const metrics = metrics: {
-            const index = (try group.indexForCodepoint(alloc, 'M', .regular, .text)).?;
-            const face = try group.group.faceFromIndex(index);
-            break :metrics face.metrics;
-        };
-        log.debug("cell dimensions={}", .{metrics});
-
-        return CellSize{
-            .width = metrics.cell_width,
-            .height = metrics.cell_height,
-        };
-    }
 };
 
 /// The dimensions of the screen that the grid is rendered to. This is the