From d43e0b83f715575123ea23eb72d33dd2ae436096 Mon Sep 17 00:00:00 2001
From: timoore <timoore>
Date: Sat, 27 Dec 2008 14:35:33 +0000
Subject: [PATCH] Expose the CameraGroup near, far, and near/far boundry as
 properties

The near/far boundary, called "near-field", can be set to 0 which
disables the far camera and renders the whole scene using only one
camera. I'm hoping that this may be useful in resolving some
system-specific rendering bugs.

Various fixes were made to correctly render the scene using only the
near camera.
---
 src/Main/CameraGroup.cxx     | 40 ++++++++++++++++++++++++------------
 src/Main/CameraGroup.hxx     |  4 ++++
 src/Main/fg_os_osgviewer.cxx |  6 +++---
 3 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/src/Main/CameraGroup.cxx b/src/Main/CameraGroup.cxx
index 4e968fc2d..938008967 100644
--- a/src/Main/CameraGroup.cxx
+++ b/src/Main/CameraGroup.cxx
@@ -146,8 +146,8 @@ CameraInfo* CameraGroup::addCamera(unsigned flags, Camera* camera,
         info->farSlaveIndex = _viewer->getNumSlaves() - 1;
         farCamera->setRenderOrder(Camera::NESTED_RENDER, info->farSlaveIndex);
         camera->setCullMask(camera->getCullMask() & ~simgear::BACKGROUND_BIT);
+        camera->setClearMask(GL_DEPTH_BUFFER_BIT);
     }
-    camera->setClearMask(GL_DEPTH_BUFFER_BIT);
     _viewer->addSlave(camera, view, projection, useMasterSceneData);
     installCullVisitor(camera);
     info->camera = camera;
@@ -190,18 +190,22 @@ void CameraGroup::update(const osg::Vec3d& position,
             double left, right, bottom, top, parentNear, parentFar;
             projectionMatrix.getFrustum(left, right, bottom, top,
                                         parentNear, parentFar);
-            if (parentFar < 100.0) {
+            if (parentFar < _nearField || _nearField == 0.0f) {
                 camera->setProjectionMatrix(projectionMatrix);
                 camera->setCullMask(camera->getCullMask()
                                     | simgear::BACKGROUND_BIT);
+                camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
                 farCamera->setNodeMask(0);
             } else {
                 Matrix nearProj, farProj;
-                makeNewProjMat(projectionMatrix, parentNear, 100.0, nearProj);
-                makeNewProjMat(projectionMatrix, 100.0, parentFar, farProj);
+                makeNewProjMat(projectionMatrix, parentNear, _nearField,
+                               nearProj);
+                makeNewProjMat(projectionMatrix, _nearField, parentFar,
+                               farProj);
                 camera->setProjectionMatrix(nearProj);
                 camera->setCullMask(camera->getCullMask()
                                     & ~simgear::BACKGROUND_BIT);
+                camera->setClearMask(GL_DEPTH_BUFFER_BIT);
                 farCamera->setProjectionMatrix(farProj);
                 farCamera->setNodeMask(camera->getNodeMask());
             }
@@ -211,11 +215,9 @@ void CameraGroup::update(const osg::Vec3d& position,
 
 void CameraGroup::setCameraParameters(float vfov, float aspectRatio)
 {
-    const float zNear = .1f;
-    const float zFar = 120000.0f;
     _viewer->getCamera()->setProjectionMatrixAsPerspective(vfov,
                                                            1.0f / aspectRatio,
-                                                           zNear, zFar);
+                                                           _zNear, _zFar);
 }
 }
 
@@ -444,16 +446,25 @@ CameraGroup* CameraGroup::buildCameraGroup(osgViewer::Viewer* viewer,
             cgroup->buildGUICamera(pNode);
         }
     }
+    bindMemberToNode(gnode, "znear", cgroup, &CameraGroup::_zNear, .4f);
+    bindMemberToNode(gnode, "zfar", cgroup, &CameraGroup::_zFar, 120000.0f);
+    bindMemberToNode(gnode, "near-field", cgroup, &CameraGroup::_nearField,
+                     100.0f);
     return cgroup;
 }
 
 void CameraGroup::setCameraCullMasks(Node::NodeMask nm)
 {
     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
-        if ((*i)->flags & GUI)
+        CameraInfo* info = i->get();
+        if (info->flags & GUI)
             continue;
-        (*i)->camera->setCullMask(nm & ~simgear::BACKGROUND_BIT);
-        (*i)->farCamera->setCullMask(nm);
+        if (info->farCamera.valid() && info->farCamera->getNodeMask() != 0) {
+            info->camera->setCullMask(nm & ~simgear::BACKGROUND_BIT);
+            info->farCamera->setCullMask(nm);
+        } else {
+            info->camera->setCullMask(nm);
+        }
     }
 }
 
@@ -512,9 +523,12 @@ bool computeIntersections(const CameraGroup* cgroup,
         Matrix windowMat = viewport->computeWindowMatrix();
         Matrix startPtMat = Matrix::inverse(camera->getProjectionMatrix()
                                             * windowMat);
-        Matrix endPtMat
-            = Matrix::inverse(cinfo->farCamera->getProjectionMatrix()
-                              * windowMat);
+        Matrix endPtMat;
+        if (!cinfo->farCamera.valid() || cinfo->farCamera->getNodeMask() == 0)
+            endPtMat = startPtMat;
+        else
+            endPtMat = Matrix::inverse(cinfo->farCamera->getProjectionMatrix()
+                                       * windowMat);
         start = start * startPtMat;
         start /= start.w();
         end = end * endPtMat;
diff --git a/src/Main/CameraGroup.hxx b/src/Main/CameraGroup.hxx
index d44b90226..79d0d33d4 100644
--- a/src/Main/CameraGroup.hxx
+++ b/src/Main/CameraGroup.hxx
@@ -182,6 +182,10 @@ protected:
     CameraList _cameras;
     osg::ref_ptr<osgViewer::Viewer> _viewer;
     static osg::ref_ptr<CameraGroup> _defaultGroup;
+    // Near, far for the master camera if used.
+    float _zNear;
+    float _zFar;
+    float _nearField;
 };
 
 }
diff --git a/src/Main/fg_os_osgviewer.cxx b/src/Main/fg_os_osgviewer.cxx
index 628be1612..af92bc82f 100644
--- a/src/Main/fg_os_osgviewer.cxx
+++ b/src/Main/fg_os_osgviewer.cxx
@@ -103,9 +103,9 @@ void fgOSOpenWindow(bool stencil)
     // Look for windows, camera groups, and the old syntax of
     // top-level cameras
     SGPropertyNode* renderingNode = fgGetNode("/sim/rendering");
-    SGPropertyNode* cgroupNode = renderingNode->getChild("camera-group");
-    if (!cgroupNode) {
-        cgroupNode = renderingNode->getNode("camera-group", true);
+    SGPropertyNode* cgroupNode = renderingNode->getNode("camera-group", true);
+    bool oldSyntax = !cgroupNode->hasChild("camera");
+    if (oldSyntax) {
         for (int i = 0; i < renderingNode->nChildren(); ++i) {
             SGPropertyNode* propNode = renderingNode->getChild(i);
             const char* propName = propNode->getName();
-- 
2.39.5