Fix rendering according to test

.github/workflows/main.yml

@@ -246,7 +246,7 @@ jobs:
           path: docs/demo
 
   test:
-    name: Test (${{ matrix.platform }}, ${{ matrix.arch }}, debug)
+    name: Test (${{ matrix.test-type }}, ${{ matrix.platform }}, ${{ matrix.arch }}, debug)
     needs: [check-archive, check-pre-commit]
     runs-on: ${{ matrix.os }}
     strategy:
@@ -254,6 +254,10 @@ jobs:
       matrix:
         platform: [linux, windows] # Testing not currently supported on macOS.
         bits: [64, 32]
+        test-type: [headless, rendering]
+        exclude:
+          - platform: windows
+            test-type: rendering
         include:
           - platform: linux
             os: ubuntu-22.04
@@ -302,7 +306,13 @@ jobs:
           name: libgodot-xterm-debug
           path: addons/godot_xterm/native/bin
       - name: Test
-        run: just test
+        shell: bash
+        run: |
+          if [ "${{ matrix.test-type }}" = "headless" ]; then
+            just test
+          else
+            just test-${{ matrix.test-type }}
+          fi
 
   delete-asset-imports:
     name: Delete Asset Imports

Justfile

@@ -12,7 +12,10 @@ install:
     {{godot}} --headless -s plug.gd install
 
 test:
-    {{godot}} --headless -s addons/gut/gut_cmdln.gd -gdir=res://test -gexit
+    {{godot}} --headless -s addons/gut/gut_cmdln.gd -gtest=res://test/test_terminal.gd -gexit
+
+test-rendering:
+    {{godot}} --windowed --resolution 400x200 --position 0,0 -s addons/gut/gut_cmdln.gd -gtest=res://test/test_rendering.gd -gopacity=0 -gexit
 
 uninstall:
     {{godot}} --headless -s plug.gd uninstall

addons/godot_xterm/native/src/terminal.cpp

@@ -70,6 +70,7 @@ void Terminal::_bind_methods()
 	ClassDB::bind_method(D_METHOD("write", "data"), &Terminal::write);
 	ClassDB::bind_method(D_METHOD("get_cursor_pos"), &Terminal::get_cursor_pos);
 	ClassDB::bind_method(D_METHOD("get_cell_size"), &Terminal::get_cell_size);
+	ClassDB::bind_method(D_METHOD("_on_frame_post_draw"), &Terminal::_on_frame_post_draw);
 	ClassDB::bind_method(D_METHOD("_on_gui_input", "event"), &Terminal::_gui_input);
 	ClassDB::bind_method(D_METHOD("_on_selection_held"), &Terminal::_on_selection_held);
 }
@@ -173,7 +174,7 @@ String Terminal::write(const Variant data)
 
 	response.clear();
 	tsm_vte_input(vte, (char *)bytes.ptr(), bytes.size());
-	queue_redraw();
+	redraw_requested = true;
 
 	return response.get_string_from_utf8();
 }
@@ -489,7 +490,7 @@ void Terminal::initialize_rendering() {
 	rs->viewport_set_disable_3d(viewport, true);
 	rs->viewport_set_transparent_background(viewport, true);
 	rs->viewport_set_clear_mode(viewport, RenderingServer::ViewportClearMode::VIEWPORT_CLEAR_NEVER);
-	rs->viewport_set_update_mode(viewport, RenderingServer::ViewportUpdateMode::VIEWPORT_UPDATE_WHEN_VISIBLE);
+	rs->viewport_set_update_mode(viewport, RenderingServer::ViewportUpdateMode::VIEWPORT_UPDATE_ALWAYS);
 	rs->viewport_set_active(viewport, true);
 
 	fore_shader = rl->load(FOREGROUND_SHADER_PATH);
@@ -501,6 +502,8 @@ void Terminal::initialize_rendering() {
 	fore_canvas_item = rs->canvas_item_create();
 	rs->canvas_item_set_material(fore_canvas_item, fore_material->get_rid());
 	rs->canvas_item_set_parent(fore_canvas_item, get_canvas_item());
+
+	rs->connect("frame_post_draw", Callable(this, "_on_frame_post_draw"));
 }
 
 void Terminal::update_theme() {
@@ -521,6 +524,13 @@ void Terminal::update_theme() {
 	refresh();
 }
 
+void Terminal::_on_frame_post_draw() {
+	if (redraw_requested) {
+		queue_redraw();
+		redraw_requested = false;
+	}
+}
+
 void Terminal::draw_screen() {
 	if (framebuffer_age == 0) {
 		Rect2 rect = Rect2(Vector2(), size);

addons/godot_xterm/native/src/terminal.h

@@ -143,6 +143,8 @@ namespace godot
     void update_theme();
     void update_sizes(bool force = false);
     void update_shader_parameters(Ref<ShaderMaterial> material);
+    bool redraw_requested = false;
+    void _on_frame_post_draw();
     void draw_screen();
     void refresh();
     void cleanup_rendering();

test/test_rendering.gd

@@ -0,0 +1,35 @@
+# SPDX-FileCopyrightText: 2024 Leroy Hopson <godot-xterm@leroy.nix.nz>
+# SPDX-License-Identifier: MIT
+
+class_name RenderingTest extends GutTest
+
+var terminal: Terminal
+
+
+# Return the color in the center of the given cell.
+func pick_cell_color(cell := Vector2i(0, 0)) -> Color:
+	var cell_size = terminal.get_cell_size()
+	var pixelv = Vector2(cell) * cell_size + (cell_size / 2)
+	return get_viewport().get_texture().get_image().get_pixelv(cell_size / 2)
+
+
+func before_each():
+	terminal = Terminal.new()
+	terminal.add_theme_font_override("normal_font", preload("res://themes/fonts/regular.tres"))
+	terminal.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
+	call_deferred("add_child_autofree", terminal)
+	await wait_for_signal(terminal.ready, 5)
+
+
+class TestRendering:
+	extends RenderingTest
+
+	func test_update():
+		terminal.write("\u001b[38;2;255;0;0m")
+		terminal.write("█".repeat(terminal.get_cols() * terminal.get_rows()))
+		await get_tree().physics_frame
+		terminal.queue_redraw()
+		await wait_for_signal(terminal.draw, 3)
+		await wait_frames(10)
+		var cell_color = pick_cell_color(Vector2i(0, 0))
+		assert_eq(cell_color, Color.RED)