--- /dev/null
+// userdata.hxx -- two classes for populating ssg user data slots in association
+// with our implimenation of random surface objects.
+//
+// Written by David Megginson, started December 2001.
+//
+// Copyright (C) 2001 - 2003 Curtis L. Olson - curt@flightgear.org
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#include <plib/sg.h>
+#include <plib/ssg.h>
+
+#include <simgear/sg_inlines.h>
+#include <simgear/math/point3d.hxx>
+#include <simgear/math/sg_geodesy.hxx>
+#include <simgear/math/sg_random.h>
+#include <simgear/scene/material/mat.hxx>
+#include <simgear/scene/material/matmodel.hxx>
+
+#include "userdata.hxx"
+
+
+// the following are static values needed by the runtime object
+// loader. However, the loading is done via a call back so these
+// values cannot be passed as parameters. The calling application
+// needs to call sgUserDataInit() with the appropriate values before
+// building / drawing any scenery.
+
+static bool _inited = false;
+static SGModelLib *modellib = NULL;
+static string model_root = "";
+static SGPropertyNode *root_props = NULL;
+static double sim_time_sec = 0.0;
+
+void sgUserDataInit( SGModelLib *m, const string &r,
+ SGPropertyNode *p, double t ) {
+ _inited = true;
+ modellib = m;
+ model_root = r;
+ root_props = p;
+ sim_time_sec = t;
+}
+
+
+static void random_pt_inside_tri( float *res,
+ float *n1, float *n2, float *n3 )
+{
+ double a = sg_random();
+ double b = sg_random();
+ if ( a + b > 1.0 ) {
+ a = 1.0 - a;
+ b = 1.0 - b;
+ }
+ double c = 1 - a - b;
+
+ res[0] = n1[0]*a + n2[0]*b + n3[0]*c;
+ res[1] = n1[1]*a + n2[1]*b + n3[1]*c;
+ res[2] = n1[2]*a + n2[2]*b + n3[2]*c;
+}
+
+
+/**
+ * Fill in a triangle with randomly-placed objects.
+ *
+ * This method is invoked by a callback when the triangle is in range
+ * but not yet populated.
+ *
+ */
+
+void sgTriUserData::fill_in_triangle ()
+{
+ // generate a repeatable random seed
+ sg_srandom(seed);
+
+ int nObjects = object_group->get_object_count();
+
+ for (int i = 0; i < nObjects; i++) {
+ SGMatModel * object = object_group->get_object(i);
+ double num = area / object->get_coverage_m2();
+
+ // place an object each unit of area
+ while ( num > 1.0 ) {
+ add_object_to_triangle(object);
+ num -= 1.0;
+ }
+ // for partial units of area, use a zombie door method to
+ // create the proper random chance of an object being created
+ // for this triangle
+ if ( num > 0.0 ) {
+ if ( sg_random() <= num ) {
+ // a zombie made it through our door
+ add_object_to_triangle(object);
+ }
+ }
+ }
+}
+
+void sgTriUserData::add_object_to_triangle (SGMatModel * object)
+{
+ // Set up the random heading if required.
+ double hdg_deg = 0;
+ if (object->get_heading_type() == SGMatModel::HEADING_RANDOM)
+ hdg_deg = sg_random() * 360;
+
+ sgMat4 mat;
+ makeWorldMatrix(mat, hdg_deg);
+
+ ssgTransform * pos = new ssgTransform;
+ pos->setTransform(mat);
+ // the parameters to get_random_model() are set in local static
+ // data via the ssgUserDataInit() function. This function must be
+ // called before any scenery is drawn.
+ pos->addKid( object->get_random_model( modellib, model_root,
+ root_props, sim_time_sec )
+ );
+ branch->addKid(pos);
+}
+
+void sgTriUserData::makeWorldMatrix (sgMat4 mat, double hdg_deg )
+{
+ if (hdg_deg == 0) {
+ mat[0][0] = leafData->sin_lat * leafData->cos_lon;
+ mat[0][1] = leafData->sin_lat * leafData->sin_lon;
+ mat[0][2] = -leafData->cos_lat;
+ mat[0][3] = SG_ZERO;
+
+ mat[1][0] = -leafData->sin_lon;
+ mat[1][1] = leafData->cos_lon;
+ mat[1][2] = SG_ZERO;
+ mat[1][3] = SG_ZERO;
+ } else {
+ float sin_hdg = sin( hdg_deg * SGD_DEGREES_TO_RADIANS ) ;
+ float cos_hdg = cos( hdg_deg * SGD_DEGREES_TO_RADIANS ) ;
+ mat[0][0] = cos_hdg * leafData->sin_lat * leafData->cos_lon - sin_hdg * leafData->sin_lon;
+ mat[0][1] = cos_hdg * leafData->sin_lat * leafData->sin_lon + sin_hdg * leafData->cos_lon;
+ mat[0][2] = -cos_hdg * leafData->cos_lat;
+ mat[0][3] = SG_ZERO;
+
+ mat[1][0] = -sin_hdg * leafData->sin_lat * leafData->cos_lon - cos_hdg * leafData->sin_lon;
+ mat[1][1] = -sin_hdg * leafData->sin_lat * leafData->sin_lon + cos_hdg * leafData->cos_lon;
+ mat[1][2] = sin_hdg * leafData->cos_lat;
+ mat[1][3] = SG_ZERO;
+ }
+
+ mat[2][0] = leafData->cos_lat * leafData->cos_lon;
+ mat[2][1] = leafData->cos_lat * leafData->sin_lon;
+ mat[2][2] = leafData->sin_lat;
+ mat[2][3] = SG_ZERO;
+
+ // translate to random point in triangle
+ sgVec3 result;
+ random_pt_inside_tri(result, p1, p2, p3);
+ sgSubVec3(mat[3], result, center);
+
+ mat[3][3] = SG_ONE ;
+}
+
+/**
+ * SSG callback for an in-range triangle of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is traversed
+ * only when a triangle is in range. If the triangle is not currently
+ * populated with randomly-placed objects, this callback will populate
+ * it.
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 1, to allow traversal and culling to continue.
+ */
+static int
+tri_in_range_callback (ssgEntity * entity, int mask)
+{
+ sgTriUserData * data = (sgTriUserData *)entity->getUserData();
+ if (!data->is_filled_in) {
+ data->fill_in_triangle();
+ data->is_filled_in = true;
+ }
+ return 1;
+}
+
+
+/**
+ * SSG callback for an out-of-range triangle of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is traversed
+ * only when a triangle is out of range. If the triangle is currently
+ * populated with randomly-placed objects, the objects will be removed.
+ *
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 0, to prevent any further traversal or culling.
+ */
+static int
+tri_out_of_range_callback (ssgEntity * entity, int mask)
+{
+ sgTriUserData * data = (sgTriUserData *)entity->getUserData();
+ if (data->is_filled_in) {
+ data->branch->removeAllKids();
+ data->is_filled_in = false;
+ }
+ return 0;
+}
+
+
+/**
+ * Calculate the bounding radius of a triangle from its center.
+ *
+ * @param center The triangle center.
+ * @param p1 The first point in the triangle.
+ * @param p2 The second point in the triangle.
+ * @param p3 The third point in the triangle.
+ * @return The greatest distance any point lies from the center.
+ */
+static inline float
+get_bounding_radius( sgVec3 center, float *p1, float *p2, float *p3)
+{
+ return sqrt( SG_MAX3( sgDistanceSquaredVec3(center, p1),
+ sgDistanceSquaredVec3(center, p2),
+ sgDistanceSquaredVec3(center, p3) ) );
+}
+
+
+/**
+ * Set up a triangle for randomly-placed objects.
+ *
+ * No objects will be added unless the triangle comes into range.
+ *
+ */
+
+void sgLeafUserData::setup_triangle (int i )
+{
+ short n1, n2, n3;
+ leaf->getTriangle(i, &n1, &n2, &n3);
+
+ float * p1 = leaf->getVertex(n1);
+ float * p2 = leaf->getVertex(n2);
+ float * p3 = leaf->getVertex(n3);
+
+ // Set up a single center point for LOD
+ sgVec3 center;
+ sgSetVec3(center,
+ (p1[0] + p2[0] + p3[0]) / 3.0,
+ (p1[1] + p2[1] + p3[1]) / 3.0,
+ (p1[2] + p2[2] + p3[2]) / 3.0);
+ double area = sgTriArea(p1, p2, p3);
+
+ // maximum radius of an object from center.
+ double bounding_radius = get_bounding_radius(center, p1, p2, p3);
+
+ // Set up a transformation to the center
+ // point, so that everything else can
+ // be specified relative to it.
+ ssgTransform * location = new ssgTransform;
+ sgMat4 TRANS;
+ sgMakeTransMat4(TRANS, center);
+ location->setTransform(TRANS);
+ branch->addKid(location);
+
+ // Iterate through all the object types.
+ int num_groups = mat->get_object_group_count();
+ for (int j = 0; j < num_groups; j++) {
+ // Look up the random object.
+ SGMatModelGroup * group = mat->get_object_group(j);
+
+ // Set up the range selector for the entire
+ // triangle; note that we use the object
+ // range plus the bounding radius here, to
+ // allow for objects far from the center.
+ float ranges[] = { 0,
+ group->get_range_m() + bounding_radius,
+ SG_MAX };
+ ssgRangeSelector * lod = new ssgRangeSelector;
+ lod->setRanges(ranges, 3);
+ location->addKid(lod);
+
+ // Create the in-range and out-of-range
+ // branches.
+ ssgBranch * in_range = new ssgBranch;
+ ssgBranch * out_of_range = new ssgBranch;
+
+ // Set up the user data for if/when
+ // the random objects in this triangle
+ // are filled in.
+ sgTriUserData * data = new sgTriUserData;
+ data->is_filled_in = false;
+ data->p1 = p1;
+ data->p2 = p2;
+ data->p3 = p3;
+ sgCopyVec3 (data->center, center);
+ data->area = area;
+ data->object_group = group;
+ data->branch = in_range;
+ data->leafData = this;
+ data->seed = (unsigned int)(p1[0] * j);
+
+ // Set up the in-range node.
+ in_range->setUserData(data);
+ in_range->setTravCallback(SSG_CALLBACK_PRETRAV,
+ tri_in_range_callback);
+ lod->addKid(in_range);
+
+ // Set up the out-of-range node.
+ out_of_range->setUserData(data);
+ out_of_range->setTravCallback(SSG_CALLBACK_PRETRAV,
+ tri_out_of_range_callback);
+ out_of_range->addKid(new sgDummyBSphereEntity(bounding_radius));
+ lod->addKid(out_of_range);
+ }
+}
--- /dev/null
+// userdata.hxx -- two classes for populating ssg user data slots in association
+// with our implimenation of random surface objects.
+//
+// Written by David Megginson, started December 2001.
+//
+// Copyright (C) 2001 - 2003 Curtis L. Olson - curt@flightgear.org
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+//
+// $Id$
+
+
+#ifndef _SG_USERDATA_HXX
+#define _SG_USERDATA_HXX
+
+#include <simgear/compiler.h>
+
+#include STL_STRING
+
+#include <plib/ssg.h>
+
+SG_USING_STD(string);
+
+class SGMaterial;
+class SGMatModel;
+class SGMatModelGroup;
+class SGModelLib;
+class SGPropertyNode;
+
+
+/**
+ * the application must call sgUserDataInit() and specify the
+ * following values (needed by the model loader callback at draw time)
+ * before drawing any scenery.
+ */
+void sgUserDataInit( SGModelLib *m, const string &r,
+ SGPropertyNode *p, double t );
+
+
+/**
+ * User data for populating leaves when they come in range.
+ */
+class sgLeafUserData : public ssgBase
+{
+public:
+ bool is_filled_in;
+ ssgLeaf *leaf;
+ SGMaterial *mat;
+ ssgBranch *branch;
+ float sin_lat;
+ float cos_lat;
+ float sin_lon;
+ float cos_lon;
+
+ void setup_triangle( int i );
+};
+
+
+/**
+ * User data for populating triangles when they come in range.
+ */
+class sgTriUserData : public ssgBase
+{
+public:
+ bool is_filled_in;
+ float * p1;
+ float * p2;
+ float * p3;
+ sgVec3 center;
+ double area;
+ SGMatModelGroup * object_group;
+ ssgBranch * branch;
+ sgLeafUserData * leafData;
+ unsigned int seed;
+
+ void fill_in_triangle();
+ void add_object_to_triangle(SGMatModel * object);
+ void makeWorldMatrix (sgMat4 ROT, double hdg_deg );
+};
+
+
+/**
+ * ssgEntity with a dummy bounding sphere, to fool culling.
+ *
+ * This forces the in-range and out-of-range branches to be visited
+ * when appropriate, even if they have no children. It's ugly, but
+ * it works and seems fairly efficient (since branches can still
+ * be culled when they're out of the view frustum).
+ */
+class sgDummyBSphereEntity : public ssgBranch
+{
+public:
+ sgDummyBSphereEntity (float radius)
+ {
+ bsphere.setCenter(0, 0, 0);
+ bsphere.setRadius(radius);
+ }
+ virtual ~sgDummyBSphereEntity () {}
+ virtual void recalcBSphere () { bsphere_is_invalid = false; }
+};
+
+
+#endif // _SG_USERDATA_HXX
projects / simgear.git / commitdiff