Apply directly to the engine!

- Move Engine#intancer to DirectInstancerProvider interface
- InstancerProvider allows access to the DirectInstancerProvider it's
  wrapping. This is to allow mods to change the context or RenderStage
  if they need
- Mark new methods and interfaces as experimental
- Should we mark them for removal in version 2?
- Remove NonExtendable from some context interfaces

src/main/java/com/jozufozu/flywheel/api/backend/DirectInstancerProvider.java

@@ -0,0 +1,30 @@
+package com.jozufozu.flywheel.api.backend;
+
+import org.jetbrains.annotations.ApiStatus;
+
+import com.jozufozu.flywheel.api.BackendImplemented;
+import com.jozufozu.flywheel.api.context.Context;
+import com.jozufozu.flywheel.api.event.RenderStage;
+import com.jozufozu.flywheel.api.instance.Instance;
+import com.jozufozu.flywheel.api.instance.InstanceType;
+import com.jozufozu.flywheel.api.instance.Instancer;
+import com.jozufozu.flywheel.api.instance.InstancerProvider;
+import com.jozufozu.flywheel.api.model.Model;
+
+@BackendImplemented
+@ApiStatus.Experimental
+public interface DirectInstancerProvider {
+	/**
+	 * Get an instancer for the given instance type, model, and render stage.
+	 *
+	 * <p>Calling this method twice with the same arguments will return the same instancer.</p>
+	 *
+	 * <p>If you are writing a visual you should probably be using
+	 * {@link InstancerProvider#instancer(InstanceType, Model)}, which will decide the {@code RenderStage}
+	 * based on what type of visual is getting the instancer as well as hide the Context.</p>
+	 *
+	 * @return An instancer for the given instance type, model, and render stage.
+	 * @see InstancerProvider
+	 */
+	<I extends Instance> Instancer<I> instancer(InstanceType<I> type, Context context, Model model, RenderStage stage);
+}

src/main/java/com/jozufozu/flywheel/api/backend/Engine.java

@@ -3,14 +3,9 @@ package com.jozufozu.flywheel.api.backend;
 import java.util.List;
 
 import com.jozufozu.flywheel.api.BackendImplemented;
-import com.jozufozu.flywheel.api.context.Context;
 import com.jozufozu.flywheel.api.event.RenderContext;
 import com.jozufozu.flywheel.api.event.RenderStage;
 import com.jozufozu.flywheel.api.instance.Instance;
-import com.jozufozu.flywheel.api.instance.InstanceType;
-import com.jozufozu.flywheel.api.instance.Instancer;
-import com.jozufozu.flywheel.api.instance.InstancerProvider;
-import com.jozufozu.flywheel.api.model.Model;
 import com.jozufozu.flywheel.api.task.Plan;
 import com.jozufozu.flywheel.api.task.TaskExecutor;
 
@@ -19,21 +14,7 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.core.Vec3i;
 
 @BackendImplemented
-public interface Engine {
-	/**
-	 * Get an instancer for the given instance type, model, and render stage.
-	 *
-	 * <p>Calling this method twice with the same arguments will return the same instancer.</p>
-	 *
-	 * <p>If you are writing a visual you should probably be using
-	 * {@link InstancerProvider#instancer(InstanceType, Model)}, which will decide the {@code RenderStage}
-	 * based on what type of visual is getting the instancer.</p>
-	 *
-	 * @return An instancer for the given instance type, model, and render stage.
-	 * @see InstancerProvider
-	 */
-	<I extends Instance> Instancer<I> instancer(InstanceType<I> type, Context context, Model model, RenderStage stage);
-
+public interface Engine extends DirectInstancerProvider {
 	/**
 	 * Create a plan that will be executed every frame.
 	 * @return A new plan.

src/main/java/com/jozufozu/flywheel/api/instance/InstancerProvider.java

@@ -1,5 +1,8 @@
 package com.jozufozu.flywheel.api.instance;
 
+import org.jetbrains.annotations.ApiStatus;
+
+import com.jozufozu.flywheel.api.backend.DirectInstancerProvider;
 import com.jozufozu.flywheel.api.model.Model;
 
 public interface InstancerProvider {
@@ -11,4 +14,17 @@ public interface InstancerProvider {
 	 * @return An instancer for the given instance type rendering the given model.
 	 */
 	<I extends Instance> Instancer<I> instancer(InstanceType<I> type, Model model);
+
+	/**
+	 * Get the {@link DirectInstancerProvider} this provider is built on top of.
+	 *
+	 * <p>The direct provider allows for explicit control over the
+	 * {@link com.jozufozu.flywheel.api.context.Context Context} and
+	 * {@link com.jozufozu.flywheel.api.event.RenderStage RenderStage}.
+	 * Generally this is a safe operation, though compatibility issues basically guaranteed
+	 * if you mess with the Context <em>and</em> nest visuals.</p>
+	 * @return A DirectInstancerProvider.
+	 */
+	@ApiStatus.Experimental
+	DirectInstancerProvider _directProvider();
 }

src/main/java/com/jozufozu/flywheel/api/visual/VisualFrameContext.java

@@ -1,11 +1,9 @@
 package com.jozufozu.flywheel.api.visual;
 
-import org.jetbrains.annotations.ApiStatus;
 import org.joml.FrustumIntersection;
 
 import net.minecraft.client.Camera;
 
-@ApiStatus.NonExtendable
 public interface VisualFrameContext {
 	Camera camera();
 

src/main/java/com/jozufozu/flywheel/api/visual/VisualTickContext.java

@@ -1,8 +1,5 @@
 package com.jozufozu.flywheel.api.visual;
 
-import org.jetbrains.annotations.ApiStatus;
-
-@ApiStatus.NonExtendable
 public interface VisualTickContext {
 	// TODO: remove?
 }

src/main/java/com/jozufozu/flywheel/api/visualization/VisualizationContext.java

@@ -1,7 +1,5 @@
 package com.jozufozu.flywheel.api.visualization;
 
-import org.jetbrains.annotations.ApiStatus;
-
 import com.jozufozu.flywheel.api.instance.InstancerProvider;
 
 import net.minecraft.core.Vec3i;
@@ -9,7 +7,6 @@ import net.minecraft.core.Vec3i;
 /**
  * A context object passed on visual creation.
  */
-@ApiStatus.NonExtendable
 public interface VisualizationContext {
 	/**
 	 * @return The {@link InstancerProvider} that the visual can use to get instancers to render models.

src/main/java/com/jozufozu/flywheel/impl/visualization/InstancerProviderImpl.java

@@ -2,6 +2,7 @@ package com.jozufozu.flywheel.impl.visualization;
 
 import java.util.function.Supplier;
 
+import com.jozufozu.flywheel.api.backend.DirectInstancerProvider;
 import com.jozufozu.flywheel.api.backend.Engine;
 import com.jozufozu.flywheel.api.event.RenderStage;
 import com.jozufozu.flywheel.api.instance.Instance;
@@ -19,6 +20,11 @@ public record InstancerProviderImpl(Engine engine,
 		return engine.instancer(type, Contexts.DEFAULT, model, renderStage);
 	}
 
+	@Override
+	public DirectInstancerProvider _directProvider() {
+		return engine;
+	}
+
 	@Override
 	public VisualizationContext get() {
 		return new VisualizationContextImpl(this, engine.renderOrigin());

src/main/java/com/jozufozu/flywheel/impl/visualization/VisualizationContextImpl.java

@@ -12,6 +12,6 @@ import net.minecraft.core.Vec3i;
  * @param renderOrigin      The origin of the renderer as a world position.
  *                          All models render as if this position is (0, 0, 0).
  */
-public record VisualizationContextImpl(InstancerProvider instancerProvider,
+public record VisualizationContextImpl(InstancerProviderImpl instancerProvider,
 									   Vec3i renderOrigin) implements VisualizationContext {
 }