diff -r 0f221121849b -r 4585d8d7a7ec src/ui/canvas.h
--- a/src/ui/canvas.h	Thu Feb 27 14:38:58 2020 +0200
+++ b/src/ui/canvas.h	Thu Feb 27 22:46:39 2020 +0200
@@ -1,5 +1,6 @@
 #pragma once
 #include "gl/partrenderer.h"
+#include "gl/gridprogram.h"
 
 class Canvas : public PartRenderer
 {
@@ -16,12 +17,13 @@
 	void mouseMoveEvent(QMouseEvent* event) override;
 	void mousePressEvent(QMouseEvent* event) override;
 	void mouseReleaseEvent(QMouseEvent* event) override;
+	void initializeGL() override;
 	void paintGL() override;
 signals:
 	void newStatusText(const QString& newStatusText);
 	void selectionChanged(const QSet<ldraw::Id>& newSelection);
 private:
-	QPoint lastMousePosition;
+	std::optional<GridProgram> gridProgram;
 	std::optional<glm::vec3> worldPosition;
 	int totalMouseMove = 0;
 	QSet<ldraw::Id> selection;