Better state restore in InstancingEngine

- Attempt to fix optifine issues
 - Replace <code> with {@code}

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

@@ -30,7 +30,7 @@ public interface DynamicInstance extends Instance {
 	 * <br> You might want to opt out of this if you want your animations to remain smooth
 	 * even when far away from the camera. It is recommended to keep this as is, however.
 	 *
-	 * @return <code>true</code> if your instance should be slow ticked.
+	 * @return {@code true} if your instance should be slow ticked.
 	 */
 	default boolean decreaseFramerateWithDistance() {
 		return true;

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

@@ -38,7 +38,7 @@ public interface TickableInstance extends Instance {
 	 * <br> You might want to opt out of this if you want your animations to remain smooth
 	 * even when far away from the camera. It is recommended to keep this as is, however.
 	 *
-	 * @return <code>true</code> if your instance should be slow ticked.
+	 * @return {@code true} if your instance should be slow ticked.
 	 */
 	default boolean decreaseTickRateWithDistance() {
 		return true;

src/main/java/com/jozufozu/flywheel/backend/gl/GlVertexArray.java

@@ -12,10 +12,17 @@ public class GlVertexArray extends GlObject {
 		setHandle(GlStateManager._glGenVertexArrays());
 	}
 
+	public static void bind(int vao) {
+		GlStateManager._glBindVertexArray(vao);
+		BufferUploaderAccessor.flywheel$setLastVAO(vao);
+	}
+
 	public void bind() {
-		int handle = handle();
-		GlStateManager._glBindVertexArray(handle);
-		BufferUploaderAccessor.flywheel$setLastVAO(handle);
+		bind(handle());
+	}
+
+	public static int getBoundVertexArray() {
+		return BufferUploaderAccessor.flywheel$getLastVAO();
 	}
 
 	public static void unbind() {

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/GlBufferType.java

@@ -50,4 +50,12 @@ public enum GlBufferType {
 		case GL15C.GL_ARRAY_BUFFER -> BufferUploaderAccessor.flywheel$setLastVBO(0);
 		}
 	}
+
+	public int getBoundBuffer() {
+		return switch (this.glEnum) {
+		case GL15C.GL_ELEMENT_ARRAY_BUFFER -> BufferUploaderAccessor.flywheel$getLastEBO();
+		case GL15C.GL_ARRAY_BUFFER -> BufferUploaderAccessor.flywheel$getLastVBO();
+		default -> -1;
+		};
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/gl/versioned/GlVersioned.java

@@ -4,7 +4,7 @@ import org.lwjgl.opengl.GLCapabilities;
 
 /**
  * This interface should be implemented by enums such that the
- * last defined variant <em>always</em> returns <code>true</code>.
+ * last defined variant <em>always</em> returns {@code true}
  */
 public interface GlVersioned {
 	/**

src/main/java/com/jozufozu/flywheel/backend/instancing/AbstractInstance.java

@@ -65,13 +65,13 @@ public abstract class AbstractInstance implements Instance, LightListener {
 	 * When an instance is reset, the instance is deleted and re-created.
 	 *
 	 * <p>
-	 *     Just before {@link #update()} would be called, <code>shouldReset()</code> is checked.
-	 *     If this function returns <code>true</code>, then this instance will be {@link #remove removed},
+	 *     Just before {@link #update()} would be called, {@code shouldReset()} is checked.
+	 *     If this function returns {@code true}, then this instance will be {@link #remove removed},
 	 *     and another instance will be constructed to replace it. This allows for more sane resource
 	 *     acquisition compared to trying to update everything within the lifetime of an instance.
 	 * </p>
 	 *
-	 * @return <code>true</code> if this instance should be discarded and refreshed.
+	 * @return {@code true} if this instance should be discarded and refreshed.
 	 */
 	public boolean shouldReset() {
 		return false;

src/main/java/com/jozufozu/flywheel/backend/instancing/blockentity/BlockEntityInstance.java

@@ -48,12 +48,12 @@ public abstract class BlockEntityInstance<T extends BlockEntity> extends Abstrac
 	}
 
 	/**
-	 * Just before {@link #update()} would be called, <code>shouldReset()</code> is checked.
-	 * If this function returns <code>true</code>, then this instance will be {@link #remove removed},
+	 * Just before {@link #update()} would be called, {@code shouldReset()} is checked.
+	 * If this function returns {@code true}, then this instance will be {@link #remove removed},
 	 * and another instance will be constructed to replace it. This allows for more sane resource
 	 * acquisition compared to trying to update everything within the lifetime of an instance.
 	 *
-	 * @return <code>true</code> if this instance should be discarded and refreshed.
+	 * @return {@code true} if this instance should be discarded and refreshed.
 	 */
 	public boolean shouldReset() {
 		return blockEntity.getBlockState() != blockState;

src/main/java/com/jozufozu/flywheel/backend/instancing/instancing/InstancingEngine.java

@@ -79,6 +79,10 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 	 */
 	@Override
 	public void render(TaskEngine taskEngine, RenderLayerEvent event) {
+		int ebo = GlBufferType.ELEMENT_ARRAY_BUFFER.getBoundBuffer();
+		int vbo = GlBufferType.ARRAY_BUFFER.getBoundBuffer();
+		int vao = GlVertexArray.getBoundVertexArray();
+
 		double camX;
 		double camY;
 		double camZ;
@@ -99,9 +103,9 @@ public class InstancingEngine<P extends WorldProgram> implements Engine {
 
 		getGroupsToRender(event.getLayer()).forEach(group -> group.render(viewProjection, camX, camY, camZ));
 
-		GlBufferType.ELEMENT_ARRAY_BUFFER.unbind();
-		GlBufferType.ARRAY_BUFFER.unbind();
-		GlVertexArray.unbind();
+		GlBufferType.ELEMENT_ARRAY_BUFFER.bind(ebo);
+		GlBufferType.ARRAY_BUFFER.bind(vbo);
+		GlVertexArray.bind(vao);
 	}
 
 	private Stream<InstancedMaterialGroup<P>> getGroupsToRender(@Nullable RenderLayer layer) {

src/main/java/com/jozufozu/flywheel/backend/source/SourceFile.java

@@ -217,7 +217,7 @@ public class SourceFile {
 	}
 
 	/**
-	 * Scan the source for <code>#use "..."</code> directives.
+	 * Scan the source for {@code #use "..."} directives.
 	 * Records the contents of the directive into an {@link Import} object, and marks the directive for elision.
 	 * @param elisions
 	 */

src/main/java/com/jozufozu/flywheel/core/materials/FlatLit.java

@@ -14,14 +14,14 @@ public interface FlatLit<D extends InstanceData & FlatLit<D>> {
 	/**
 	 * @param blockLight An integer in the range [0, 15] representing the
 	 *                   amount of block light this instance should receive.
-	 * @return <code>this</code>
+	 * @return {@code this}
 	 */
 	D setBlockLight(int blockLight);
 
 	/**
 	 * @param skyLight An integer in the range [0, 15] representing the
 	 *                 amount of sky light this instance should receive.
-	 * @return <code>this</code>
+	 * @return {@code this}
 	 */
 	D setSkyLight(int skyLight);
 

src/main/java/com/jozufozu/flywheel/core/model/WorldModel.java

@@ -16,7 +16,7 @@ public class WorldModel implements Model {
 	private final String name;
 
 	/**
-	 * It is expected that <code>renderWorld.getShade(...)</code> returns a constant.
+	 * It is expected that {@code renderWorld.getShade(...)} returns a constant.
 	 */
 	public WorldModel(BlockAndTintGetter renderWorld, RenderType layer, Collection<StructureTemplate.StructureBlockInfo> blocks, String name) {
 		reader = Formats.BLOCK.createReader(ModelUtil.getBufferBuilderFromTemplate(renderWorld, layer, blocks));

src/main/java/com/jozufozu/flywheel/core/shader/spec/ProgramSpec.java

@@ -15,11 +15,11 @@ import net.minecraft.resources.ResourceLocation;
  * An object describing a shader program that can be loaded by flywheel.
  *
  * <p>
- *     These are defined through json. All ProgramSpecs in <code>assets/modid/flywheel/programs</code> are parsed and
+ *     These are defined through json. All ProgramSpecs in {@code assets/modid/flywheel/programs} are parsed and
  *     processed. One ProgramSpec typically specifies one "material" that can be used in game to render things.
  * </p>
  * <p>
- *     All shader source files in <code>assets/modid/flywheel/shaders</code> are completely loaded and parsed into
+ *     All shader source files in {@code assets/modid/flywheel/shaders} are completely loaded and parsed into
  *     {@link SourceFile SourceFiles}, but not compiled until one of them is
  *     referenced by a ProgramSpec.
  * </p>

src/main/java/com/jozufozu/flywheel/mixin/BufferUploaderAccessor.java

@@ -21,4 +21,19 @@ public interface BufferUploaderAccessor {
 	static void flywheel$setLastEBO(int id) {
 		throw new AssertionError();
 	}
+
+	@Accessor("lastIndexBufferObject")
+	static int flywheel$getLastEBO() {
+		throw new AssertionError();
+	}
+
+	@Accessor("lastVertexBufferObject")
+	static int flywheel$getLastVBO() {
+		throw new AssertionError();
+	}
+
+	@Accessor("lastVertexArrayObject")
+	static int flywheel$getLastVAO() {
+		throw new AssertionError();
+	}
 }