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>
44 #include <simgear/math/sg_random.h>
45 #include <simgear/misc/sg_path.hxx>
46 #include <simgear/misc/PathOptions.hxx>
47 #include <simgear/props/props.hxx>
48 #include <simgear/scene/model/model.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 osg::ref_ptr<osgDB::ReaderWriter::Options> options
112 = makeOptionsFromPath(tex_path);
113 if ((effect = makeEffect(pcloudEffect, true, options)))
114 effectMap.insert(EffectMap::value_type(texture, effect));
116 effect = iter->second.get();
118 quad = createOrthQuad(min_sprite_width, min_sprite_height,
119 num_textures_x, num_textures_y);
122 SGNewCloud::~SGNewCloud() {
125 osg::Geometry* SGNewCloud::createOrthQuad(float w, float h, int varieties_x, int varieties_y)
127 // Create front and back polygons so we don't need to screw around
128 // with two-sided lighting in the shader.
129 osg::Vec3Array& v = *(new osg::Vec3Array(4));
130 osg::Vec3Array& n = *(new osg::Vec3Array(4));
131 osg::Vec2Array& t = *(new osg::Vec2Array(4));
135 v[0].set(0.0f, -cw, 0.0f);
136 v[1].set(0.0f, cw, 0.0f);
137 v[2].set(0.0f, cw, h);
138 v[3].set(0.0f, -cw, h);
140 // The texture coordinate range is not the
141 // entire coordinate space - as the texture
142 // has a number of different clouds on it.
143 float tx = 1.0f/varieties_x;
144 float ty = 1.0f/varieties_y;
146 t[0].set(0.0f, 0.0f);
151 // The normal isn't actually use in lighting.
152 n[0].set(1.0f, -1.0f, -1.0f);
153 n[1].set(1.0f, 1.0f, -1.0f);
154 n[2].set(1.0f, 1.0f, 1.0f);
155 n[3].set(1.0f, -1.0f, 1.0f);
157 osg::Geometry *geom = new osg::Geometry;
159 geom->setVertexArray(&v);
160 geom->setTexCoordArray(0, &t);
161 geom->setNormalArray(&n);
162 geom->setNormalBinding(Geometry::BIND_PER_VERTEX);
163 // No color for now; that's used to pass the position.
164 geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4));
170 // return a random number between -n/2 and n/2, tending to 0
171 static float Rnd(float n) {
172 return n * (-0.5f + (sg_random() + sg_random()) / 2.0f);
176 osg::ref_ptr<EffectGeode> SGNewCloud::genCloud() {
178 osg::ref_ptr<EffectGeode> geode = new EffectGeode;
180 CloudShaderGeometry* sg = new CloudShaderGeometry(num_textures_x, num_textures_y, max_width, max_height);
182 // Determine how big this specific cloud instance is. Note that we subtract
183 // the sprite size because the width/height is used to define the limits of
184 // the center of the sprites, not their edges.
185 float width = min_width + sg_random() * (max_width - min_width) - min_sprite_width;
186 float height = min_height + sg_random() * (max_height - min_height) - min_sprite_height;
188 // Determine the cull distance. This is used to remove sprites that are too close together.
189 // The value is squared as we use vector calculations.
190 float cull_distance_squared = min_sprite_height * min_sprite_height * 0.1f;
192 // The number of sprites we actually use is a function of the (user-controlled) density
193 int n_sprites = num_sprites * sprite_density * (0.5 + sg_random());
195 for (int i = 0; i < n_sprites; i++)
197 // Determine the position of the sprite. Rather than being completely random,
198 // we place them on the surface of a distorted sphere. However, we place
199 // the first sprite in the center of the sphere (and at maximum size) to
200 // ensure good coverage and reduce the chance of there being "holes" in our
209 double theta = sg_random() * SGD_2PI;
210 double elev = sg_random() * SGD_PI;
211 x = width * cos(theta) * 0.5f * sin(elev);
212 y = width * sin(theta) * 0.5f * sin(elev);
213 z = height * cos(elev) * 0.5f;
216 // Determine the height and width as scaling factors on the minimum size (used to create the quad).
217 float sprite_width = 1.0f + sg_random() * (max_sprite_width - min_sprite_width) / min_sprite_width;
218 float sprite_height = 1.0f + sg_random() * (max_sprite_height - min_sprite_height) / min_sprite_height;
220 // Sprites are never taller than square.
221 if (sprite_height * min_sprite_height > sprite_width * min_sprite_width)
223 sprite_height = sprite_width * min_sprite_width / min_sprite_height;
227 // The center sprite is always maximum size to fill up any holes.
228 sprite_width = 1.0f + (max_sprite_width - min_sprite_width) / min_sprite_width;
229 sprite_height = 1.0f + (max_sprite_height - min_sprite_height) / min_sprite_height;
232 // Determine the sprite texture indexes.
233 int index_x = (int) floor(sg_random() * num_textures_x);
234 if (index_x == num_textures_x) { index_x--; }
236 // The y index depends on the positing of the sprite within the cloud.
237 // This allows cloud designers to have particular sprites for the base
238 // and tops of the cloud.
239 int index_y = (int) floor((z / height + 0.5f) * num_textures_y);
240 if (index_y == num_textures_y) { index_y--; }
242 sg->addSprite(SGVec3f(x, y, z),
248 cull_distance_squared,
252 sg->setGeometry(quad);
253 geode->addDrawable(sg);
254 geode->setName("3D cloud");
255 geode->setEffect(effect.get());