1 files changed, 77 insertions, 0 deletions
diff --git a/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/Game.kt b/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/Game.kt
new file mode 100644
index 0000000..9490f83
--- /dev/null
+++ b/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/Game.kt
@@ -0,0 +1,77 @@
+package coffee.liz.abstractionengine.game
+
+import androidx.compose.foundation.Canvas
+import androidx.compose.runtime.*
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import coffee.liz.ecs.World
+import kotlinx.coroutines.isActive
+
+/**
+ * Manages the game loop for an ECS world.
+ * Syncs with Compose's frame rate (like requestAnimationFrame) and provides
+ * the world to child content for custom rendering/UI.
+ *
+ * @param world The ECS world containing entities and systems
+ * @param content Composable content that can use the world for rendering
+ */
+@Composable
+fun Game(
+    world: World,
+    content: @Composable () -> Unit
+) {
+    // Trigger recomposition when we need to redraw
+    var frameCount by remember { mutableStateOf(0) }
+
+    // Game loop - syncs with Compose's frame rate like requestAnimationFrame
+    LaunchedEffect(world) {
+        var lastFrameTimeNanos = 0L
+
+        while (isActive) {
+            // Wait for next frame (like requestAnimationFrame)
+            withFrameNanos { frameTimeNanos ->
+                val deltaTime = if (lastFrameTimeNanos != 0L) {
+                    (frameTimeNanos - lastFrameTimeNanos) / 1_000_000_000f
+                } else {
+                    0f
+                }
+                lastFrameTimeNanos = frameTimeNanos
+
+                // Update ECS world (runs all systems)
+                if (deltaTime > 0f) {
+                    world.update(deltaTime)
+                }
+
+                // Trigger recomposition to redraw
+                frameCount++
+            }
+        }
+    }
+
+    // Render content
+    content()
+}
+
+/**
+ * A Canvas that renders sprites from an ECS world using a RenderSystem.
+ *
+ * @param world The ECS world containing entities to render
+ * @param renderSystem The system responsible for rendering sprites
+ * @param backgroundColor Background color for the canvas
+ * @param modifier Modifier for the Canvas
+ */
+@Composable
+fun GameCanvas(
+    world: World,
+    renderSystem: RenderSystem,
+    backgroundColor: Color = Color.Transparent,
+    modifier: Modifier = Modifier
+) {
+    Canvas(modifier = modifier) {
+        // Clear background
+        drawRect(backgroundColor)
+
+        // Render all sprites
+        renderSystem.render(world, this)
+    }
+}