3 * Copyright (C) 2006-2007 Mathias Froehlich, Tim Moore
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
23 # include <simgear_config.h>
26 #include "SGOceanTile.hxx"
29 #include <simgear/compiler.h>
32 #include <osg/Geometry>
33 #include <osg/MatrixTransform>
34 #include <osg/StateSet>
36 #include <simgear/bucket/newbucket.hxx>
37 #include <simgear/math/sg_geodesy.hxx>
38 #include <simgear/math/sg_types.hxx>
39 #include <simgear/misc/texcoord.hxx>
40 #include <simgear/scene/material/Effect.hxx>
41 #include <simgear/scene/material/EffectGeode.hxx>
42 #include <simgear/scene/material/mat.hxx>
43 #include <simgear/scene/material/matlib.hxx>
45 #include <simgear/scene/util/VectorArrayAdapter.hxx>
47 using namespace simgear;
48 // Ocean tile with curvature and apron to hide cracks. The cracks are
49 // mostly with adjoining coastal tiles that assume a flat ocean
50 // between corners of a tile; they also hide the micro cracks between
51 // adjoining ocean tiles. This is probably over-engineered, but it
52 // serves as a testbed for some things that will come later.
54 // Helper class for building and accessing the mesh. The layout of the
55 // points in the mesh is a little wacky. First is the bottom row of
56 // the points for the apron. Next is the left apron point, the points
57 // in the mesh, and the right apron point, for each of the rows of the
58 // mesh; the points for the top apron come last. This order should
59 // help with things like vertex caching in the OpenGL driver, though
60 // it may be superfluous for such a small mesh.
65 OceanMesh(int latP, int lonP):
68 geoPoints(latPoints * lonPoints + 2 * (lonPoints + latPoints)),
69 geod_nodes(latPoints * lonPoints),
70 vl(new osg::Vec3Array(geoPoints)),
71 nl(new osg::Vec3Array(geoPoints)),
72 tl(new osg::Vec2Array(geoPoints)),
73 vlArray(*vl, lonPoints + 2, lonPoints, 1),
74 nlArray(*nl, lonPoints + 2, lonPoints, 1),
75 tlArray(*tl, lonPoints + 2, lonPoints, 1)
77 int numPoints = latPoints * lonPoints;
78 geod = new SGGeod[numPoints];
79 normals = new SGVec3f[numPoints];
80 rel = new SGVec3d[numPoints];
90 const int latPoints, lonPoints;
96 std::vector<SGGeod> geod_nodes;
101 VectorArrayAdapter<osg::Vec3Array> vlArray;
102 VectorArrayAdapter<osg::Vec3Array> nlArray;
103 VectorArrayAdapter<osg::Vec2Array> tlArray;
105 void calcMesh(const SGVec3d& cartCenter, const SGQuatd& orient,
106 double clon, double clat,
107 double height, double width, double tex_width);
108 void calcApronPt(int latIdx, int lonIdx, int latInner, int lonInner,
109 int destIdx, double tex_width);
110 void calcApronPts(double tex_width);
115 void OceanMesh::calcMesh(const SGVec3d& cartCenter, const SGQuatd& orient,
116 double clon, double clat,
117 double height, double width, double tex_width)
119 // Calculate vertices. By splitting the tile up into 4 quads on a
120 // side we avoid curvature-of-the-earth problems; the error should
121 // be less than .5 meters.
122 double longInc = width * .25;
123 double latInc = height * .25;
124 double startLat = clat - height * .5;
125 double startLon = clon - width * .5;
126 for (int j = 0; j < latPoints; j++) {
127 double lat = startLat + j * latInc;
128 for (int i = 0; i < lonPoints; i++) {
129 int index = (j * lonPoints) + i;
130 geod[index] = SGGeod::fromDeg(startLon + i * longInc, lat);
131 SGVec3d cart = SGVec3d::fromGeod(geod[index]);
132 rel[index] = orient.transform(cart - cartCenter);
133 normals[index] = toVec3f(orient.transform(normalize(cart)));
137 // Calculate texture coordinates
138 typedef std::vector<SGGeod> GeodVector;
140 GeodVector geod_nodes(latPoints * lonPoints);
141 VectorArrayAdapter<GeodVector> geodNodesArray(geod_nodes, lonPoints);
142 int_list rectangle(latPoints * lonPoints);
143 VectorArrayAdapter<int_list> rectArray(rectangle, lonPoints);
144 for (int j = 0; j < latPoints; j++) {
145 for (int i = 0; i < lonPoints; i++) {
146 int index = (j * lonPoints) + i;
147 geodNodesArray(j, i) = geod[index];
148 rectArray(j, i) = index;
152 typedef std::vector<SGVec2f> Vec2Array;
153 Vec2Array texs = sgCalcTexCoords( clat, geod_nodes, rectangle,
154 1000.0 / tex_width );
157 VectorArrayAdapter<Vec2Array> texsArray(texs, lonPoints);
159 for (int j = 0; j < latPoints; j++) {
160 for (int i = 0; i < lonPoints; ++i) {
161 int index = (j * lonPoints) + i;
162 vlArray(j, i) = toOsg(rel[index]);
163 nlArray(j, i) = toOsg(normals[index]);
164 tlArray(j, i) = toOsg(texsArray(j, i));
170 // Apron points. For each point on the edge we'll go 150
171 // metres "down" and 40 metres "out" to create a nice overlap. The
172 // texture should be applied according to this dimension. The
173 // normals of the apron polygons will be the same as the those of
174 // the points on the edge to better disguise the apron.
175 void OceanMesh::calcApronPt(int latIdx, int lonIdx, int latInner, int lonInner,
176 int destIdx, double tex_width)
178 static const float downDist = 150.0f;
179 static const float outDist = 40.0f;
180 // Get vector along edge, in the right direction to make a cross
181 // product with the normal vector that will point out from the
183 osg::Vec3f edgePt = vlArray(latIdx, lonIdx);
185 if (lonIdx == lonInner) { // bottom or top edge
187 edgeVec = vlArray(latIdx, lonIdx - 1) - edgePt;
189 edgeVec = edgePt - vlArray(latIdx, lonIdx + 1);
190 if (latIdx > latInner)
191 edgeVec = -edgeVec; // Top edge
192 } else { // right or left edge
194 edgeVec = edgePt - vlArray(latIdx - 1, lonIdx);
196 edgeVec = vlArray(latIdx + 1, lonIdx) - edgePt;
197 if (lonIdx > lonInner) // right edge
201 osg::Vec3f outVec = nlArray(latIdx, lonIdx) ^ edgeVec;
203 = edgePt - nlArray(latIdx, lonIdx) * downDist + outVec * outDist;
204 (*nl)[destIdx] = nlArray(latIdx, lonIdx);
205 static const float apronDist
206 = sqrtf(downDist * downDist + outDist * outDist);
207 float texDelta = apronDist / tex_width;
208 if (lonIdx == lonInner) {
209 if (latIdx > latInner)
211 = tlArray(latIdx, lonIdx) + osg::Vec2f(0.0f, texDelta);
214 = tlArray(latIdx, lonIdx) - osg::Vec2f(0.0f, texDelta);
216 if (lonIdx > lonInner)
218 = tlArray(latIdx, lonIdx) + osg::Vec2f(texDelta, 0.0f);
221 = tlArray(latIdx, lonIdx) - osg::Vec2f(texDelta, 0.0f);
225 void OceanMesh::calcApronPts(double tex_width)
227 for (int i = 0; i < lonPoints; i++)
228 calcApronPt(0, i, 1, i, i, tex_width);
229 int topApronOffset = latPoints + (2 + lonPoints) * latPoints;
230 for (int i = 0; i < lonPoints; i++)
231 calcApronPt(latPoints - 1, i, latPoints - 2, i,
232 i + topApronOffset, tex_width);
233 for (int i = 0; i < latPoints; i++) {
234 calcApronPt(i, 0, i, 1, lonPoints + i * (lonPoints + 2), tex_width);
235 calcApronPt(i, lonPoints - 1, i, lonPoints - 2,
236 lonPoints + i * (lonPoints + 2) + 1 + lonPoints, tex_width);
242 // Enter the vertices of triangles that fill one row of the
243 // mesh. The vertices are entered in counter-clockwise order.
244 void fillDrawElementsRow(int width, short row0Start, short row1Start,
245 osg::DrawElementsUShort::vector_type::iterator&
248 short row0Idx = row0Start;
249 short row1Idx = row1Start;
250 for (int i = 0; i < width - 1; i++, row0Idx++, row1Idx++) {
251 *elements++ = row0Idx;
252 *elements++ = row0Idx + 1;
253 *elements++ = row1Idx;
254 *elements++ = row1Idx;
255 *elements++ = row0Idx + 1;
256 *elements++ = row1Idx + 1;
260 void fillDrawElementsWithApron(short height, short width,
261 osg::DrawElementsUShort::vector_type::iterator
265 fillDrawElementsRow(width, 0, width + 1, elements);
266 for (short i = 0; i < height - 1; i++)
267 fillDrawElementsRow(width + 2, width + i * (width + 2),
268 width + (i + 1) * (width + 2),
271 short topApronBottom = width + (height - 1) * (width + 2) + 1;
272 fillDrawElementsRow(width, topApronBottom, topApronBottom + width + 1,
277 osg::Node* SGOceanTile(const SGBucket& b, SGMaterialLib *matlib, int latPoints, int lonPoints)
281 double tex_width = 1000.0;
283 // find Ocean material in the properties list
284 SGMaterial *mat = matlib->find( "Ocean" );
286 // set the texture width and height values for this
288 tex_width = mat->get_xsize();
291 effect = mat->get_effect();
293 SG_LOG( SG_TERRAIN, SG_ALERT, "Ack! unknown use material name = Ocean");
295 OceanMesh grid(latPoints, lonPoints);
296 // Calculate center point
297 SGVec3d cartCenter = SGVec3d::fromGeod(b.get_center());
298 SGGeod geodPos = SGGeod::fromCart(cartCenter);
299 SGQuatd hlOr = SGQuatd::fromLonLat(geodPos)*SGQuatd::fromEulerDeg(0, 0, 180);
301 double clon = b.get_center_lon();
302 double clat = b.get_center_lat();
303 double height = b.get_height();
304 double width = b.get_width();
306 grid.calcMesh(cartCenter, hlOr, clon, clat, height, width, tex_width);
307 grid.calcApronPts(tex_width);
309 osg::Vec4Array* cl = new osg::Vec4Array;
310 cl->push_back(osg::Vec4(1, 1, 1, 1));
312 osg::Geometry* geometry = new osg::Geometry;
313 geometry->setVertexArray(grid.vl);
314 geometry->setNormalArray(grid.nl);
315 geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
316 geometry->setColorArray(cl);
317 geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
318 geometry->setTexCoordArray(0, grid.tl);
320 // Allocate the indices for triangles in the mesh and the apron
321 osg::DrawElementsUShort* drawElements
322 = new osg::DrawElementsUShort(GL_TRIANGLES,
323 6 * ((latPoints - 1) * (lonPoints + 1)
324 + 2 * (latPoints - 1)));
325 fillDrawElementsWithApron(latPoints, lonPoints, drawElements->begin());
326 geometry->addPrimitiveSet(drawElements);
328 EffectGeode* geode = new EffectGeode;
329 geode->setName("Ocean tile");
330 geode->setEffect(effect);
331 geode->addDrawable(geometry);
332 geode->runGenerators(geometry);
334 osg::MatrixTransform* transform = new osg::MatrixTransform;
335 transform->setName("Ocean");
336 transform->setMatrix(osg::Matrix::rotate(toOsg(hlOr))*
337 osg::Matrix::translate(toOsg(cartCenter)));
338 transform->addChild(geode);