ga yass poem

3 files changed, 105 insertions, 20 deletions

diff --git a/txtgameengine/__main__.py b/txtgameengine/__main__.py
index 84d71ca..cc4c11c 100644
--- a/txtgameengine/__main__.py
+++ b/txtgameengine/__main__.py
@@ -1,31 +1,49 @@
 import numpy as np
 
-from .app import TxtGameApp
+from .scenes import SceneTxtGameApp, Scene
 from OpenGL.GL import *
 
 
-class TestApp(TxtGameApp):
-    def __init__(self):
-        super().__init__((640, 480), "OpenGL window")
+class TriangleScene(Scene):
+    TRIANGLE_DATA = [
+        -1.0, -1.0, 0.0,
+        1.0, -1.0, 0.0,
+        0.0,  1.0, 0.0,
+    ]
 
-    def init(self):
-        self.render.setup_vertex_arrays()
-        #self.platform.check_debug()
-        self.default_shaders = self.shaders.load_shaders(
+    def on_enter(self):
+        self.default_shaders = self.app.shaders.load_shaders(
             'base_shaders/vertex.glsl', 'base_shaders/fragment.glsl')
-        self.tri_buffer = self.render.setup_triangle(np.array([
-            -1.0, -1.0, 0.0,
-            1.0, -1.0, 0.0,
-            0.0,  1.0, 0.0,
-        ], np.float32))
-
-    def update(self, delta: float):
-        super().update(delta)
+
+        self.tri_buffer = self.app.render.setup_triangle(
+            np.array(self.TRIANGLE_DATA, np.float32))
+        self.t = 0
+
+    def update(self, delta):
+        self.t += delta
+        if self.t > 10:
+            self.push_scene(EvilTriangleScene)
+            self.t = 0
         with self.default_shaders:
-            self.render.triangle(self.tri_buffer)
-        
+            self.app.render.triangle(self.tri_buffer)
+
+
+class EvilTriangleScene(TriangleScene):
+    TRIANGLE_DATA = [
+        -1.0, 1.0, 0.0,
+        1.0, 1.0, 0.0,
+        0.0,  -1.0, 0.0,
+    ]
+
+class TestApp(SceneTxtGameApp):
+    MAIN_SCENE_T = TriangleScene
+
+    def init(self):
+        super().init()
+        self.render.setup_vertex_arrays()
+        # self.platform.check_debug()
 
 
 if __name__ == '__main__':
-    a = TestApp()
+    a = TestApp((640, 480), "OpenGL window")
     a.start()
diff --git a/txtgameengine/app.py b/txtgameengine/app.py
index 9f48479..f3cb711 100644
--- a/txtgameengine/app.py
+++ b/txtgameengine/app.py
@@ -17,6 +17,7 @@ class TxtGameApp:
         self.platform = self.PLATFORM_CLASS(self)
         self.render = self.RENDER_CLASS(self)
         self.shaders = self.SHADER_CLASS(self)
+        self.should_exit = False
 
     def init(self):
         pass
@@ -26,7 +27,7 @@ class TxtGameApp:
         self.init()
         self.platform.set_clear_color(1, 0, 0.75, 1)
         last_update_time = self.platform.monotonic_time()
-        while not self.platform.should_close:
+        while not (self.platform.should_close or self.should_exit):
             update_time = self.platform.monotonic_time()
             self.platform.poll_events()
             self.update(update_time - last_update_time)
@@ -37,3 +38,6 @@ class TxtGameApp:
     def update(self, delta: float):
         print("Running: delta = %.4fs, approx. fps = %ds" % (delta, 1. / (delta or EPSILON)))
         self.platform.clear_background()
+
+    def exit(self):
+        self.should_exit = True
diff --git a/txtgameengine/scenes.py b/txtgameengine/scenes.py
new file mode 100644
index 0000000..c08e8db
--- /dev/null
+++ b/txtgameengine/scenes.py
@@ -0,0 +1,63 @@
+import typing
+
+from .app import TxtGameApp
+
+
+class SceneTxtGameApp(TxtGameApp):
+    MAIN_SCENE_T: typing.Type['Scene'] = None
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.scene_stack = []
+
+    def push_scene(self, scene_t: typing.Type['Scene']):
+        if self.scene_stack:
+            self.scene_stack[-1].on_pause()
+        self.scene_stack += [scene_t(self)]
+        self.scene_stack[-1].on_enter()
+    
+    def pop_scene(self):
+        self.scene_stack[-1].on_exit()
+        del self.scene_stack[-1]
+        if not self.scene_stack:
+            self.exit()
+            return
+        self.scene_stack[-2].on_resume()
+
+    def update(self, delta):
+        if not self.scene_stack: # TODO: better lifecycles in TxtGameApp so we dont have to hack this
+            self.push_scene(self.MAIN_SCENE_T)
+        super().update(delta)
+        print("Scene Stack:", ' > '.join(type(x).__name__ for x in self.scene_stack))
+        self.scene_stack[-1].update(delta)
+
+class Scene:
+    def __init__(self, app: 'SceneTxtGameApp'):
+        self.app = app
+
+    def pop_scene(self):
+        """Exits this scene and returns control to the parent scene"""
+        self.app.pop_scene()
+
+    def push_scene(self, scene_t: typing.Type['Scene']):
+        """Pushes a scene type onto the scene stack"""
+        self.app.push_scene(scene_t)
+
+    def on_exit(self):
+        """Called when the scene is removed from the scene tree"""
+
+    def on_enter(self):
+        """Called when the scene is first entered in the scene tree"""
+        pass
+
+    def on_pause(self):
+        """Called when another scene takes update priority over this scene without unloading this scene"""
+        pass
+
+    def on_resume(self):
+        """Called when this scene takes over update priority after previously using it to another scene"""
+        pass
+
+    def update(self, delta: float):
+        """Render the current scene"""
+        pass
\ No newline at end of file