attach a terminal to the window, start hinting at renderer hookup

src/Grid.zig

@@ -7,6 +7,7 @@ const testing = std.testing;
 const Allocator = std.mem.Allocator;
 const Atlas = @import("Atlas.zig");
 const FontAtlas = @import("FontAtlas.zig");
+const Terminal = @import("terminal/Terminal.zig");
 const gl = @import("opengl.zig");
 const gb = @import("gb_math.zig");
 
@@ -164,6 +165,13 @@ pub fn demoCells(self: *Grid) !void {
     }
 }
 
+/// updateCells updates our GPU cells from the current terminal view.
+/// The updated cells will take effect on the next render.
+pub fn updateCells(self: *Grid, term: Terminal) !void {
+    _ = self;
+    _ = term;
+}
+
 /// 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: *Grid, dim: ScreenSize) !void {

src/Window.zig

@@ -12,6 +12,7 @@ const Grid = @import("Grid.zig");
 const glfw = @import("glfw");
 const gl = @import("opengl.zig");
 const Pty = @import("Pty.zig");
+const Terminal = @import("terminal/Terminal.zig");
 
 const log = std.log.scoped(.window);
 
@@ -24,6 +25,12 @@ grid: Grid,
 /// The underlying pty for this window.
 pty: Pty,
 
+/// The terminal emulator internal state. This is the abstract "terminal"
+/// that manages input, grid updating, etc. and is renderer-agnostic. It
+/// just stores internal state about a grid. This is connected back to
+/// a renderer.
+terminal: Terminal,
+
 /// Create a new window. This allocates and returns a pointer because we
 /// need a stable pointer for user data callbacks. Therefore, a stack-only
 /// initialization is not currently possible.
@@ -79,10 +86,16 @@ pub fn create(alloc: Allocator) !*Window {
     });
     errdefer pty.deinit();
 
+    // Create our terminal
+    var term = Terminal.init(grid.size.columns, grid.size.rows);
+    errdefer term.deinit(alloc);
+    try term.append(alloc, "hello!");
+
     self.* = .{
         .window = window,
         .grid = grid,
         .pty = pty,
+        .terminal = term,
     };
 
     // Setup our callbacks and user data
@@ -93,6 +106,7 @@ pub fn create(alloc: Allocator) !*Window {
 }
 
 pub fn destroy(self: *Window, alloc: Allocator) void {
+    self.terminal.deinit(alloc);
     self.pty.deinit();
     self.grid.deinit();
     self.window.destroy();
@@ -130,6 +144,9 @@ fn sizeCallback(window: glfw.Window, width: i32, height: i32) void {
     // TODO: temp
     win.grid.demoCells() catch unreachable;
 
+    // Update the size of our terminal state
+    win.terminal.resize(win.grid.size.columns, win.grid.size.rows);
+
     // Update the size of our pty
     win.pty.setSize(.{
         .ws_row = @intCast(u16, win.grid.size.rows),

src/terminal/Terminal.zig

@@ -57,6 +57,13 @@ pub fn deinit(self: *Terminal, alloc: Allocator) void {
     self.* = undefined;
 }
 
+/// Resize the underlying terminal.
+pub fn resize(self: *Terminal, cols: usize, rows: usize) void {
+    // TODO: actually doing anything for this
+    self.cols = cols;
+    self.rows = rows;
+}
+
 /// Return the current string value of the terminal. Newlines are
 /// encoded as "\n". This omits any formatting such as fg/bg.
 ///