fix memory leaks

src/Grid.zig

@@ -51,9 +51,9 @@ pub fn init(alloc: Allocator) !Grid {
     // Initialize our font atlas. We will initially populate the
     // font atlas with all the visible ASCII characters since they are common.
     var atlas = try Atlas.init(alloc, 512);
-    errdefer atlas.deinit(alloc);
+    defer atlas.deinit(alloc);
     var font = try FontAtlas.init(atlas);
-    errdefer font.deinit(alloc);
+    defer font.deinit(alloc);
     try font.loadFaceFromMemory(face_ttf, 30);
 
     // Load all visible ASCII characters and build our cell width based on
@@ -104,6 +104,11 @@ pub fn init(alloc: Allocator) !Grid {
     };
 }
 
+pub fn deinit(self: *Grid) void {
+    self.program.destroy();
+    self.* = undefined;
+}
+
 /// 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: ScreenDim) !void {

src/Window.zig

@@ -77,6 +77,7 @@ pub fn create(alloc: Allocator) !*Window {
 }
 
 pub fn destroy(self: *Window, alloc: Allocator) void {
+    self.grid.deinit();
     alloc.destroy(self);
 }
 
@@ -102,8 +103,9 @@ fn sizeCallback(window: glfw.Window, width: i32, height: i32) void {
     win.grid.setScreenSize(.{
         .width = width,
         .height = height,
-    }) catch unreachable;
+    }) catch |err| log.err("error updating grid screen size err={}", .{err});
 
     // Update our viewport for this context to be the entire window
-    try gl.viewport(0, 0, width, height);
+    gl.viewport(0, 0, width, height) catch |err|
+        log.err("error updating OpenGL viewport err={}", .{err});
 }