Use VAOs for contraption structures

src/main/java/com/jozufozu/flywheel/backend/core/BufferedArrayModel.java

@@ -0,0 +1,48 @@
+package com.jozufozu.flywheel.backend.core;
+
+import java.nio.ByteBuffer;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL20;
+
+import com.jozufozu.flywheel.backend.gl.GlVertexArray;
+import com.jozufozu.flywheel.backend.gl.attrib.VertexFormat;
+import com.jozufozu.flywheel.util.AttribUtil;
+
+public class BufferedArrayModel extends BufferedModel {
+
+	protected GlVertexArray vao;
+
+	public BufferedArrayModel(VertexFormat format, ByteBuffer data, int vertices) {
+		super(format, data, vertices);
+
+		vao = new GlVertexArray();
+
+		vao.bind();
+
+		// bind the model's vbo to our vao
+		vbo.bind();
+		getFormat().vertexAttribPointers(0);
+		vbo.unbind();
+
+		// enable all the attribute arrays in our vao. we only need to do this once
+		AttribUtil.enableArrays(getAttributeCount());
+		vao.unbind();
+	}
+
+	public void render() {
+		if (vertexCount <= 0 || deleted) return;
+
+		vao.bind();
+
+		GL20.glDrawArrays(GL11.GL_QUADS, 0, vertexCount);
+
+		vao.unbind();
+	}
+
+	@Override
+	public void delete() {
+		super.delete();
+		vao.delete();
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/core/BufferedModel.java

@@ -22,7 +22,7 @@ public class BufferedModel {
 	protected final VertexFormat format;
 	protected final int vertexCount;
 	protected GlBuffer vbo;
-	private boolean removed;
+	protected boolean deleted;
 
 	public BufferedModel(VertexFormat format, ByteBuffer data, int vertices) {
 		this.data = data;
@@ -62,7 +62,7 @@ public class BufferedModel {
 	 * Renders this model, checking first if there is anything to render.
 	 */
 	public void render() {
-		if (vertexCount <= 0 || removed) return;
+		if (vertexCount <= 0 || deleted) return;
 
 		// TODO: minecraft sometimes leaves its state dirty on launch. this is a hack
 		glDisableClientState(GL_VERTEX_ARRAY);
@@ -84,9 +84,9 @@ public class BufferedModel {
 	}
 
 	public void delete() {
-		if (removed) return;
+		if (deleted) return;
 
-		removed = true;
+		deleted = true;
 		vbo.delete();
 	}
 

src/main/java/com/simibubi/create/content/contraptions/components/structureMovement/render/RenderedContraption.java

@@ -10,6 +10,7 @@ import java.util.Map;
 import javax.annotation.Nullable;
 
 import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.core.BufferedArrayModel;
 import com.jozufozu.flywheel.backend.core.BufferedModel;
 import com.jozufozu.flywheel.backend.gl.attrib.CommonAttributes;
 import com.jozufozu.flywheel.backend.gl.attrib.VertexFormat;
@@ -192,6 +193,9 @@ public class RenderedContraption extends ContraptionWorldHolder {
 
 		to.rewind();
 
-		return new BufferedModel(format, to, vertexCount);
+		if (Backend.compat.vertexArrayObjectsSupported())
+			return new BufferedArrayModel(format, to, vertexCount);
+		else
+			return new BufferedModel(format, to, vertexCount);
 	}
 }