3 // Written by Harald JOHNSEN, started April 2005.
5 // Copyright (C) 2005 Harald JOHNSEN - hjohnsen@evc.net
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 # include <simgear_config.h>
27 #include <osg/AlphaFunc>
29 #include <osg/Program>
30 #include <osg/Uniform>
31 #include <osg/ref_ptr>
32 #include <osg/Texture2D>
33 #include <osg/NodeVisitor>
34 #include <osg/PositionAttitudeTransform>
35 #include <osg/Material>
36 #include <osgUtil/UpdateVisitor>
37 #include <osgDB/ReadFile>
38 #include <osgDB/FileUtils>
41 #include <simgear/compiler.h>
43 #include <simgear/math/sg_random.h>
44 #include <simgear/misc/sg_path.hxx>
45 #include <simgear/misc/PathOptions.hxx>
46 #include <simgear/props/props.hxx>
47 #include <simgear/scene/model/model.hxx>
48 #include <simgear/scene/model/SGReaderWriterXMLOptions.hxx>
49 #include <simgear/scene/util/StateAttributeFactory.hxx>
50 #include <simgear/scene/util/SGUpdateVisitor.hxx>
53 #include <osg/BlendFunc>
55 #include <osg/ShadeModel>
57 #include "cloudfield.hxx"
58 #include "newcloud.hxx"
59 #include "CloudShaderGeometry.hxx"
61 using namespace simgear;
66 typedef std::map<std::string, osg::ref_ptr<Effect> > EffectMap;
70 double SGNewCloud::sprite_density = 1.0;
72 SGNewCloud::SGNewCloud(string type,
73 const SGPath &tex_path,
91 min_sprite_width(min_sprite_w),
92 max_sprite_width(max_sprite_w),
93 min_sprite_height(min_sprite_h),
94 max_sprite_height(max_sprite_h),
102 // Create a new Effect for the texture, if required.
103 EffectMap::iterator iter = effectMap.find(texture);
104 if (iter == effectMap.end()) {
105 SGPropertyNode_ptr pcloudEffect = new SGPropertyNode;
106 makeChild(pcloudEffect, "inherits-from")->setValue("Effects/cloud");
107 setValue(makeChild(makeChild(makeChild(pcloudEffect, "parameters"),
111 ref_ptr<osgDB::ReaderWriter::Options> options
112 = makeOptionsFromPath(tex_path);
113 ref_ptr<SGReaderWriterXMLOptions> sgOptions
114 = new SGReaderWriterXMLOptions(*options.get());
115 if ((effect = makeEffect(pcloudEffect, true, sgOptions.get())))
116 effectMap.insert(EffectMap::value_type(texture, effect));
118 effect = iter->second.get();
120 quad = createOrthQuad(min_sprite_width, min_sprite_height,
121 num_textures_x, num_textures_y);
124 SGNewCloud::~SGNewCloud() {
127 osg::Geometry* SGNewCloud::createOrthQuad(float w, float h, int varieties_x, int varieties_y)
129 // Create front and back polygons so we don't need to screw around
130 // with two-sided lighting in the shader.
131 osg::Vec3Array& v = *(new osg::Vec3Array(4));
132 osg::Vec3Array& n = *(new osg::Vec3Array(4));
133 osg::Vec2Array& t = *(new osg::Vec2Array(4));
137 v[0].set(0.0f, -cw, 0.0f);
138 v[1].set(0.0f, cw, 0.0f);
139 v[2].set(0.0f, cw, h);
140 v[3].set(0.0f, -cw, h);
142 // The texture coordinate range is not the
143 // entire coordinate space - as the texture
144 // has a number of different clouds on it.
145 float tx = 1.0f/varieties_x;
146 float ty = 1.0f/varieties_y;
148 t[0].set(0.0f, 0.0f);
153 // The normal isn't actually use in lighting.
154 n[0].set(1.0f, -1.0f, -1.0f);
155 n[1].set(1.0f, 1.0f, -1.0f);
156 n[2].set(1.0f, 1.0f, 1.0f);
157 n[3].set(1.0f, -1.0f, 1.0f);
159 osg::Geometry *geom = new osg::Geometry;
161 geom->setVertexArray(&v);
162 geom->setTexCoordArray(0, &t);
163 geom->setNormalArray(&n);
164 geom->setNormalBinding(Geometry::BIND_PER_VERTEX);
165 // No color for now; that's used to pass the position.
166 geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4));
172 // return a random number between -n/2 and n/2, tending to 0
173 static float Rnd(float n) {
174 return n * (-0.5f + (sg_random() + sg_random()) / 2.0f);
178 osg::ref_ptr<EffectGeode> SGNewCloud::genCloud() {
180 osg::ref_ptr<EffectGeode> geode = new EffectGeode;
182 CloudShaderGeometry* sg = new CloudShaderGeometry(num_textures_x, num_textures_y, max_width, max_height);
184 // Determine how big this specific cloud instance is. Note that we subtract
185 // the sprite size because the width/height is used to define the limits of
186 // the center of the sprites, not their edges.
187 float width = min_width + sg_random() * (max_width - min_width) - min_sprite_width;
188 float height = min_height + sg_random() * (max_height - min_height) - min_sprite_height;
190 // Determine the cull distance. This is used to remove sprites that are too close together.
191 // The value is squared as we use vector calculations.
192 float cull_distance_squared = min_sprite_height * min_sprite_height * 0.1f;
194 // The number of sprites we actually use is a function of the (user-controlled) density
195 int n_sprites = num_sprites * sprite_density * (0.5 + sg_random());
197 for (int i = 0; i < n_sprites; i++)
199 // Determine the position of the sprite. Rather than being completely random,
200 // we place them on the surface of a distorted sphere. However, we place
201 // the first sprite in the center of the sphere (and at maximum size) to
202 // ensure good coverage and reduce the chance of there being "holes" in our
211 double theta = sg_random() * SGD_2PI;
212 double elev = sg_random() * SGD_PI;
213 x = width * cos(theta) * 0.5f * sin(elev);
214 y = width * sin(theta) * 0.5f * sin(elev);
215 z = height * cos(elev) * 0.5f;
218 // Determine the height and width as scaling factors on the minimum size (used to create the quad).
219 float sprite_width = 1.0f + sg_random() * (max_sprite_width - min_sprite_width) / min_sprite_width;
220 float sprite_height = 1.0f + sg_random() * (max_sprite_height - min_sprite_height) / min_sprite_height;
222 // Sprites are never taller than square.
223 if (sprite_height * min_sprite_height > sprite_width * min_sprite_width)
225 sprite_height = sprite_width * min_sprite_width / min_sprite_height;
229 // The center sprite is always maximum size to fill up any holes.
230 sprite_width = 1.0f + (max_sprite_width - min_sprite_width) / min_sprite_width;
231 sprite_height = 1.0f + (max_sprite_height - min_sprite_height) / min_sprite_height;
234 // Determine the sprite texture indexes.
235 int index_x = (int) floor(sg_random() * num_textures_x);
236 if (index_x == num_textures_x) { index_x--; }
238 // The y index depends on the positing of the sprite within the cloud.
239 // This allows cloud designers to have particular sprites for the base
240 // and tops of the cloud.
241 int index_y = (int) floor((z / height + 0.5f) * num_textures_y);
242 if (index_y == num_textures_y) { index_y--; }
244 sg->addSprite(SGVec3f(x, y, z),
250 cull_distance_squared,
254 sg->setGeometry(quad);
255 geode->addDrawable(sg);
256 geode->setName("3D cloud");
257 geode->setEffect(effect.get());