From 30d24405986b54ef4146f2d827d0ea73b5f1aca0 Mon Sep 17 00:00:00 2001
From: Marius Kintel <marius@kintel.net>
Date: Sat, 7 Mar 2015 19:02:51 -0500
Subject: [PATCH] More camera fixes: Better viewall calculation, better
 switching between perspective and ortho

---
 src/Camera.cc | 44 ++++++++++++++++++--------------------------
 src/GLView.cc | 21 ++++++++++-----------
 2 files changed, 28 insertions(+), 37 deletions(-)

diff --git a/src/Camera.cc b/src/Camera.cc
index 567ded87..c166f268 100644
--- a/src/Camera.cc
+++ b/src/Camera.cc
@@ -3,7 +3,7 @@
 #include "printutils.h"
 
 Camera::Camera(enum CameraType camtype) :
-	type(camtype), projection(Camera::PERSPECTIVE), fov(22.5), viewall(false), height(60)
+	type(camtype), projection(Camera::PERSPECTIVE), fov(22.5), viewall(false)
 {
 	PRINTD("Camera()");
 	if (this->type == Camera::GIMBAL) {
@@ -26,7 +26,7 @@ void Camera::setup(std::vector<double> params)
 		type = Camera::GIMBAL;
 		object_trans << params[0], params[1], params[2];
 		object_rot << params[3], params[4], params[5];
-		height = viewer_distance = params[6];
+		viewer_distance = params[6];
 	} else if (params.size() == 6) {
 		type = Camera::VECTOR;
 		eye << params[0], params[1], params[2];
@@ -69,28 +69,20 @@ void Camera::viewAll(const BoundingBox &bbox)
         }
 	}
 
-	switch (this->projection) {
-	case Camera::ORTHOGONAL:
-		this->height = this->viewer_distance = bbox.diagonal().norm();
+	double bboxRadius = bbox.diagonal().norm()/2;
+	double radius = (bbox.center()-this->center).norm() + bboxRadius;
+	double distance = radius / sin(this->fov/2*M_PI/180);
+	switch (this->type) {
+	case Camera::GIMBAL:
+		this->viewer_distance = distance;
+		break;
+	case Camera::VECTOR: {
+		Vector3d cameradir = (this->center - this->eye).normalized();
+		this->eye = this->center - distance*cameradir;
 		break;
-	case Camera::PERSPECTIVE: {	
-		double bboxRadius = bbox.diagonal().norm()/2;
-		double radius = (bbox.center()-this->center).norm() + bboxRadius;
-		double distance = radius / sin(this->fov*M_PI/360);
-		switch (this->type) {
-		case Camera::GIMBAL:
-			this->height = this->viewer_distance = distance;
-			break;
-		case Camera::VECTOR: {
-			Vector3d cameradir = (this->center - this->eye).normalized();
-			this->eye = this->center - distance*cameradir;
-			break;
-		}
-		default:
-			assert(false && "Camera type not specified");
-		}
 	}
-		break;
+	default:
+		assert(false && "Camera type not specified");
 	}
 	PRINTDB("modified center x y z %f %f %f",center.x() % center.y() % center.z());
 	PRINTDB("modified eye    x y z %f %f %f",eye.x() % eye.y() % eye.z());
@@ -100,7 +92,7 @@ void Camera::viewAll(const BoundingBox &bbox)
 
 void Camera::zoom(int delta)
 {
-	this->height = this->viewer_distance *= pow(0.9, delta / 120.0);
+	this->viewer_distance *= pow(0.9, delta / 120.0);
 }
 
 void Camera::setProjection(ProjectionType type)
@@ -113,12 +105,12 @@ void Camera::resetView()
 	type = Camera::GIMBAL;
 	object_rot << 35, 0, -25;
 	object_trans << 0, 0, 0;
-	height = viewer_distance = 140;
+	viewer_distance = 140;
 }
 
 double Camera::zoomValue()
 {
-	return this->projection == PERSPECTIVE ? viewer_distance : height;
+	return viewer_distance;
 }
 
 std::string Camera::statusText()
@@ -126,6 +118,6 @@ std::string Camera::statusText()
 	boost::format fmt(_("Viewport: translate = [ %.2f %.2f %.2f ], rotate = [ %.2f %.2f %.2f ], distance = %.2f"));
 	fmt % object_trans.x() % object_trans.y() % object_trans.z()
 		% object_rot.x() % object_rot.y() % object_rot.z()
-		% (this->projection == PERSPECTIVE ? viewer_distance : height);
+		% viewer_distance;
 	return fmt.str();
 }
diff --git a/src/GLView.cc b/src/GLView.cc
index 9c9e905b..4ea00abd 100644
--- a/src/GLView.cc
+++ b/src/GLView.cc
@@ -95,22 +95,21 @@ void GLView::setupCamera()
 
 	switch (this->cam.type) {
 	case Camera::GIMBAL: {
-		double eyeY = 0.0;
+		double dist = cam.zoomValue();
 		switch (this->cam.projection) {
 		case Camera::PERSPECTIVE: {
-			eyeY = cam.zoomValue();
-			gluPerspective(cam.fov, aspectratio, 0.1 * eyeY, 100 * eyeY);
+			gluPerspective(cam.fov, aspectratio, 0.1*dist, 100*dist);
 			break;
 		}
 		case Camera::ORTHOGONAL: {
-			eyeY = cam.zoomValue();
-			glOrtho(-eyeY/2*aspectratio, eyeY*aspectratio/2,
-							-eyeY/2, eyeY/2,
+			double height = dist * tan(cam.fov/2*M_PI/180);
+			glOrtho(-height*aspectratio, height*aspectratio,
+							-height, height,
 							-far_far_away, +far_far_away);
 			break;
 		}
 		}
-		gluLookAt(0.0, -eyeY, 0.0,
+		gluLookAt(0.0, -dist, 0.0,
 							0.0, 0.0, 0.0,
 							0.0, 0.0, 1.0);
 		glMatrixMode(GL_MODELVIEW);
@@ -121,16 +120,16 @@ void GLView::setupCamera()
 		break;
 	}
 	case Camera::VECTOR: {
+		double dist = (cam.center - cam.eye).norm();
 		switch (this->cam.projection) {
 		case Camera::PERSPECTIVE: {
-			double dist = (cam.center - cam.eye).norm();
 			gluPerspective(cam.fov, aspectratio, 0.1*dist, 100*dist);
 			break;
 		}
 		case Camera::ORTHOGONAL: {
-			double height = cam.zoomValue();
-			glOrtho(-height/2*aspectratio, height*aspectratio/2,
-							-height/2, height/2,
+			double height = dist * tan(cam.fov/2*M_PI/180);
+			glOrtho(-height*aspectratio, height*aspectratio,
+							-height, height,
 							-far_far_away, +far_far_away);
 			break;
 		}