1 files changed, 70 insertions, 0 deletions
diff --git a/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/RenderSystem.kt b/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/RenderSystem.kt
new file mode 100644
index 0000000..1d22ae6
--- /dev/null
+++ b/composeApp/src/commonMain/kotlin/coffee/liz/abstractionengine/game/RenderSystem.kt
@@ -0,0 +1,70 @@
+package coffee.liz.abstractionengine.game
+
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.drawscope.DrawScope
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.unit.IntSize
+import coffee.liz.ecs.System
+import coffee.liz.ecs.World
+import coffee.liz.ecs.animation.AnimationSystem
+import coffee.liz.ecs.animation.Animator
+import coffee.liz.ecs.animation.Position
+import coffee.liz.ecs.animation.SpriteSheet
+import kotlin.reflect.KClass
+
+/**
+ * System that renders sprites to a DrawScope.
+ *
+ * This system queries all entities with Position, SpriteSheet, and Animator components,
+ * then draws their current animation frame to the provided DrawScope.
+ *
+ * Depends on AnimationSystem to ensure animations are updated before rendering.
+ */
+class RenderSystem(
+    private val imageCache: ImageCache
+) : System {
+
+    override val dependencies: Set<KClass<out System>> = setOf(AnimationSystem::class)
+
+    /**
+     * The update method is required by the System interface, but rendering
+     * happens synchronously during Compose's draw phase via the render() method.
+     */
+    override fun update(world: World, deltaTime: Float) {
+        // Rendering happens in render() method, not here
+    }
+
+    /**
+     * Renders all entities with sprites to the given DrawScope.
+     * This should be called from a Compose Canvas during the draw phase.
+     */
+    fun render(world: World, drawScope: DrawScope) {
+        // Query all entities that can be rendered
+        world.query(Position::class, SpriteSheet::class, Animator::class).forEach { entity ->
+            val position = entity.get(Position::class) ?: return@forEach
+            val spriteSheet = entity.get(SpriteSheet::class) ?: return@forEach
+            val animator = entity.get(Animator::class) ?: return@forEach
+
+            // Get the current frame name from the animator
+            val frameName = animator.getCurrentFrameName() ?: return@forEach
+
+            // Look up the frame rectangle in the sprite sheet
+            val frameRect = spriteSheet.frames[frameName] ?: return@forEach
+
+            // Get the image from cache
+            val image = imageCache.getImage(spriteSheet.imagePath) ?: return@forEach
+
+            // Draw the sprite
+            with(drawScope) {
+                drawImage(
+                    image = image,
+                    srcOffset = IntOffset(frameRect.x, frameRect.y),
+                    srcSize = IntSize(frameRect.width, frameRect.height),
+                    dstOffset = IntOffset(position.x.toInt(), position.y.toInt()),
+                    dstSize = IntSize(frameRect.width, frameRect.height)
+                )
+            }
+        }
+    }
+}