From 61082c8331d5de0ac41b3712b835c3a588a168c9 Mon Sep 17 00:00:00 2001
From: papush! <contact@ccolin.fr>
Date: Sat, 27 Nov 2021 11:38:14 +0100
Subject: [PATCH] add right click panning to the view

---
 src/mesh_viewer.cpp | 16 ++++++++++++----
 src/mesh_viewer.h   | 11 ++++++-----
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/mesh_viewer.cpp b/src/mesh_viewer.cpp
index bd32d5f..eaebd80 100644
--- a/src/mesh_viewer.cpp
+++ b/src/mesh_viewer.cpp
@@ -13,7 +13,7 @@ MeshViewer::MeshViewer(QWidget *parent) : QOpenGLWidget(parent) {
 
 
 void MeshViewer::updateViewMatrix() {
-	view = trans * rot;
+	view = trans * zoom * rot;
 }
 
 
@@ -119,8 +119,9 @@ void MeshViewer::updateForReal() {
 
 
 void MeshViewer::mousePressEvent(QMouseEvent *e) {
-	if (e->button() == Qt::MiddleButton) {
+	if (e->button() & Qt::MiddleButton || e->button() & Qt::RightButton) {
 		mouse_pos = e->pos();
+		trans_start = trans;
 	} else if (e->button() == Qt::LeftButton) {
 		float x = e->x();
 		float y = height() - e->y();
@@ -153,12 +154,19 @@ void MeshViewer::mouseMoveEvent(QMouseEvent *e) {
 		updateViewMatrix();
 		update();
 	}
+	if (e->buttons() & Qt::RightButton) {
+		trans = trans_start;
+		trans(0, 3) += (e->pos() - mouse_pos).x() / 1000.;
+		trans(1, 3) -= (e->pos() - mouse_pos).y() / 1000.;
+		updateViewMatrix();
+		update();
+	}
 }
 
 
 void MeshViewer::wheelEvent(QWheelEvent *e) {
-	trans(2, 3) -= e->angleDelta().y() / 1000. * trans(2, 3);
-	trans.optimize();
+	zoom(2, 3) -= e->angleDelta().y() / 1000. * zoom(2, 3);
+	zoom.optimize();
 	updateViewMatrix();
 	update();
 }
diff --git a/src/mesh_viewer.h b/src/mesh_viewer.h
index 609fe85..e626b78 100644
--- a/src/mesh_viewer.h
+++ b/src/mesh_viewer.h
@@ -27,12 +27,13 @@ class MeshViewer : public QOpenGLWidget {
 	std::list<MeshView> meshes;
 	QOpenGLShaderProgram program;
 	QMatrix4x4 proj;
-	QMatrix4x4 trans = QMatrix4x4(1, 0, 0, 0,
-								  0, 1, 0, 0,
-								  0, 0, 1, -1,
-								  0, 0, 0, 1);
+	QMatrix4x4 zoom = QMatrix4x4(1, 0, 0, 0,
+								 0, 1, 0, 0,
+								 0, 0, 1, -1,
+								 0, 0, 0, 1);
+	QMatrix4x4 trans, trans_start;
 	QMatrix4x4 rot, rot_start;
-	QMatrix4x4 view = trans * rot;
+	QMatrix4x4 view = trans * zoom * rot;
 	QPoint mouse_pos;
 	void updateViewMatrix();
 	bool is_initialized = false;