surface propagates new config to renderer

src/renderer/Metal.zig

@@ -724,6 +724,11 @@ fn drawCells(
     }
 }
 
+/// Update the configuration.
+pub fn changeConfig(self: *Metal, config: DerivedConfig) !void {
+    self.config = config;
+}
+
 /// Resize the screen.
 pub fn setScreenSize(self: *Metal, dim: renderer.ScreenSize) !void {
     // Store our screen size

src/renderer/OpenGL.zig

@@ -1232,6 +1232,11 @@ fn gridSize(self: *const OpenGL, screen_size: renderer.ScreenSize) renderer.Grid
     );
 }
 
+/// Update the configuration.
+pub fn changeConfig(self: *OpenGL, config: DerivedConfig) !void {
+    self.config = config;
+}
+
 /// Set the screen size for rendering. This will update the projection
 /// used for the shader so that the scaling of the grid is correct.
 pub fn setScreenSize(self: *OpenGL, dim: renderer.ScreenSize) !void {

src/renderer/Thread.zig

@@ -255,6 +255,10 @@ fn drainMailbox(self: *Thread) !void {
             .screen_size => |size| {
                 try self.renderer.setScreenSize(size);
             },
+
+            .change_config => |config| {
+                try self.renderer.changeConfig(config);
+            },
         }
     }
 }

src/renderer/message.zig

@@ -22,4 +22,7 @@ pub const Message = union(enum) {
 
     /// Change the screen size.
     screen_size: renderer.ScreenSize,
+
+    /// The derived configuration to update the renderer with.
+    change_config: renderer.Renderer.DerivedConfig,
 };