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/misc/sg_path.hxx>
44 #include <simgear/props/props.hxx>
45 #include <simgear/scene/model/model.hxx>
46 #include <simgear/scene/util/SGReaderWriterOptions.hxx>
47 #include <simgear/scene/util/StateAttributeFactory.hxx>
48 #include <simgear/scene/util/SGUpdateVisitor.hxx>
49 #include <simgear/scene/util/RenderConstants.hxx>
52 #include <osg/BlendFunc>
54 #include <osg/ShadeModel>
56 #include "cloudfield.hxx"
57 #include "newcloud.hxx"
58 #include "CloudShaderGeometry.hxx"
60 using namespace simgear;
67 typedef std::map<std::string, osg::observer_ptr<Effect> > EffectMap;
71 float SGNewCloud::sprite_density = 1.0;
73 SGNewCloud::SGNewCloud(const SGPath &texture_root, const SGPropertyNode *cld_def, mt* s)
75 // Set up the RNG with the passed in seed. This allows us to make the RNG repeatable
79 min_width = cld_def->getFloatValue("min-cloud-width-m", 500.0);
80 max_width = cld_def->getFloatValue("max-cloud-width-m", min_width*2);
81 min_height = cld_def->getFloatValue("min-cloud-height-m", 400.0);
82 max_height = cld_def->getFloatValue("max-cloud-height-m", min_height*2);
83 min_sprite_width = cld_def->getFloatValue("min-sprite-width-m", 200.0);
84 max_sprite_width = cld_def->getFloatValue("max-sprite-width-m", min_sprite_width*1.5);
85 min_sprite_height = cld_def->getFloatValue("min-sprite-height-m", 150);
86 max_sprite_height = cld_def->getFloatValue("max-sprite-height-m", min_sprite_height*1.5);
87 num_sprites = cld_def->getIntValue("num-sprites", 20);
88 num_textures_x = cld_def->getIntValue("num-textures-x", 4);
89 num_textures_y = cld_def->getIntValue("num-textures-y", 4);
90 height_map_texture = cld_def->getBoolValue("height-map-texture", false);
92 min_bottom_lighting_factor = cld_def->getFloatValue("min-bottom-lighting-factor", 1.0);
93 max_bottom_lighting_factor = cld_def->getFloatValue("max-bottom-lighting-factor", min(min_bottom_lighting_factor + 0.1, 1.0));
95 min_middle_lighting_factor = cld_def->getFloatValue("min-middle-lighting-factor", 1.0);
96 max_middle_lighting_factor = cld_def->getFloatValue("max-middle-lighting-factor", min(min_middle_lighting_factor + 0.1, 1.0));
98 min_top_lighting_factor = cld_def->getFloatValue("min-top-lighting-factor", 1.0);
99 max_top_lighting_factor = cld_def->getFloatValue("max-top-lighting-factor", min(min_top_lighting_factor + 0.1, 1.0));
101 min_shade_lighting_factor = cld_def->getFloatValue("min-shade-lighting-factor", 0.5);
102 max_shade_lighting_factor = cld_def->getFloatValue("max-shade-lighting-factor", min(min_shade_lighting_factor + 0.1, 1.0));
104 zscale = cld_def->getFloatValue("z-scale", 1.0);
105 texture = cld_def->getStringValue("texture", "cl_cumulus.png");
107 // Create a new Effect for the texture, if required.
108 EffectMap::iterator iter = effectMap.find(texture);
110 if ((iter == effectMap.end())||
111 (!iter->second.lock(effect)))
113 SGPropertyNode_ptr pcloudEffect = new SGPropertyNode;
114 makeChild(pcloudEffect, "inherits-from")->setValue("Effects/cloud");
115 setValue(makeChild(makeChild(makeChild(pcloudEffect, "parameters"),
119 ref_ptr<SGReaderWriterOptions> options;
120 options = SGReaderWriterOptions::fromPath(texture_root.str());
121 effect = makeEffect(pcloudEffect, true, options.get());
124 if (iter == effectMap.end())
125 effectMap.insert(EffectMap::value_type(texture, effect));
127 iter->second = effect; // update existing, but empty observer
132 SGNewCloud::~SGNewCloud() {
136 // return a random number between -n/2 and n/2, tending to 0
137 static float Rnd(float n) {
138 return n * (-0.5f + (mt_rand(seed) + mt_rand(seed)) / 2.0f);
142 osg::ref_ptr<EffectGeode> SGNewCloud::genCloud() {
144 osg::ref_ptr<EffectGeode> geode = new EffectGeode;
146 // Determine how big this specific cloud instance is. Note that we subtract
147 // the sprite size because the width/height is used to define the limits of
148 // the center of the sprites, not their edges.
149 float width = min_width + mt_rand(seed) * (max_width - min_width) - min_sprite_width;
150 float height = min_height + mt_rand(seed) * (max_height - min_height) - min_sprite_height;
152 if (width < 0.0) { width = 0.0; }
153 if (height < 0.0) { height = 0.0; }
155 // Determine appropriate shading factors
156 float top_factor = min_top_lighting_factor + mt_rand(seed) * (max_top_lighting_factor - min_top_lighting_factor);
157 float middle_factor = min_middle_lighting_factor + mt_rand(seed) * (max_middle_lighting_factor - min_middle_lighting_factor);
158 float bottom_factor = min_bottom_lighting_factor + mt_rand(seed) * (max_bottom_lighting_factor - min_bottom_lighting_factor);
159 float shade_factor = min_shade_lighting_factor + mt_rand(seed) * (max_shade_lighting_factor - min_shade_lighting_factor);
161 //printf("Cloud: %2f, %2f, %2f, %2f\n", top_factor, middle_factor, bottom_factor, shade_factor);
163 CloudShaderGeometry* sg = new CloudShaderGeometry(num_textures_x,
165 max_width + max_sprite_width,
166 max_height + max_sprite_height,
174 // Determine the cull distance. This is used to remove sprites that are too close together.
175 // The value is squared as we use vector calculations.
176 float cull_distance_squared = min_sprite_height * min_sprite_height * 0.1f;
178 // The number of sprites we actually use is a function of the (user-controlled) density
179 int n_sprites = num_sprites * sprite_density * (0.5f + mt_rand(seed));
181 for (int i = 0; i < n_sprites; i++)
183 // Determine the position of the sprite. Rather than being completely random,
184 // we place them on the surface of a distorted sphere. However, we place
185 // the first sprite in the center of the sphere (and at maximum size) to
186 // ensure good coverage and reduce the chance of there being "holes" in the
187 // middle of our cloud. Also note that (0,0,0) defines the _bottom_ of the
188 // cloud, not the middle.
197 float theta = mt_rand(seed) * SGD_2PI;
198 float elev = mt_rand(seed) * SGD_PI;
199 x = width * cos(theta) * 0.5f * sin(elev);
200 y = width * sin(theta) * 0.5f * sin(elev);
201 z = height * cos(elev) * 0.5f + height * 0.5f;
204 // Determine the height and width
205 float sprite_width = min_sprite_width + mt_rand(seed) * (max_sprite_width - min_sprite_width);
206 float sprite_height = min_sprite_height + mt_rand(seed) * (max_sprite_height - min_sprite_height);
208 // Sprites are never taller than square.
209 if (sprite_height > sprite_width )
211 sprite_height = sprite_width;
215 // The center sprite is always maximum size to fill up any holes.
216 sprite_width = max_sprite_width;
217 sprite_height = max_sprite_height;
220 // If the center of the sprite is less than half the sprite heightthe sprite will extend
221 // below the bottom of the cloud and must be shifted upwards. This is particularly important
222 // for cumulus clouds which have a very well defined base.
223 if (z < 0.5f * sprite_height)
225 z = 0.5f * sprite_height;
228 // Determine the sprite texture indexes.
229 int index_x = (int) floor(mt_rand(seed) * num_textures_x);
230 if (index_x >= num_textures_x) { index_x = num_textures_x - 1; }
232 int index_y = (int) floor(mt_rand(seed) * num_textures_y);
234 if (height_map_texture) {
235 // The y index depends on the position of the sprite within the cloud.
236 // This allows cloud designers to have particular sprites for the base
237 // and tops of the cloud.
238 index_y = (int) floor((z / height) * num_textures_y);
241 if (index_y >= num_textures_y) { index_y = num_textures_y - 1; }
243 sg->addSprite(SGVec3f(x, y, z),
248 cull_distance_squared);
251 sg->generateGeometry();
252 geode->addDrawable(sg);
253 geode->setName("3D cloud");
254 geode->setEffect(effect.get());
255 geode->setNodeMask( ~simgear::MODELLIGHT_BIT );