// Generates the main shader code for rendering the terrain.
void
RexTerrainEngineNode::updateState()
{
if ( _batchUpdateInProgress )
{
_stateUpdateRequired = true;
}
else
{
osg::StateSet* terrainStateSet = _terrain->getOrCreateStateSet(); // everything
osg::StateSet* surfaceStateSet = getSurfaceStateSet(); // just the surface
//terrainStateSet->setRenderBinDetails(0, "SORT_FRONT_TO_BACK");
// required for multipass tile rendering to work
surfaceStateSet->setAttributeAndModes(
new osg::Depth(osg::Depth::LEQUAL, 0, 1, true) );
surfaceStateSet->setAttributeAndModes(
new osg::CullFace(), osg::StateAttribute::ON);
// activate standard mix blending.
terrainStateSet->setAttributeAndModes(
new osg::BlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA),
osg::StateAttribute::ON );
// install patch param if we are tessellation on the GPU.
if ( _terrainOptions.gpuTessellation() == true )
{
#ifdef HAVE_PATCH_PARAMETER
terrainStateSet->setAttributeAndModes( new osg::PatchParameter(3) );
#endif
}
// install shaders, if we're using them.
if ( Registry::capabilities().supportsGLSL() )
{
Shaders package;
VirtualProgram* terrainVP = VirtualProgram::getOrCreate(terrainStateSet);
terrainVP->setName( "Rex Terrain" );
package.load(terrainVP, package.ENGINE_VERT_MODEL);
surfaceStateSet->addUniform(new osg::Uniform("oe_terrain_color", _terrainOptions.color().get()));
if (_terrainOptions.enableBlending() == true)
{
surfaceStateSet->setDefine("OE_TERRAIN_BLEND_IMAGERY");
}
// Funtions that affect only the terrain surface:
VirtualProgram* surfaceVP = VirtualProgram::getOrCreate(surfaceStateSet);
surfaceVP->setName("Rex Surface");
// Functions that affect the terrain surface only:
package.load(surfaceVP, package.ENGINE_VERT_VIEW);
package.load(surfaceVP, package.ENGINE_FRAG);
// Elevation?
if (this->elevationTexturesRequired())
{
surfaceStateSet->setDefine("OE_TERRAIN_RENDER_ELEVATION");
}
// Normal mapping shaders:
if ( this->normalTexturesRequired() )
{
package.load(surfaceVP, package.NORMAL_MAP_VERT);
package.load(surfaceVP, package.NORMAL_MAP_FRAG);
surfaceStateSet->setDefine("OE_TERRAIN_RENDER_NORMAL_MAP");
}
// Morphing?
if (_terrainOptions.morphTerrain() == true ||
_terrainOptions.morphImagery() == true)
{
package.load(surfaceVP, package.MORPHING_VERT);
if (_terrainOptions.morphImagery() == true)
{
surfaceStateSet->setDefine("OE_TERRAIN_MORPH_IMAGERY");
}
if (_terrainOptions.morphTerrain() == true)
{
surfaceStateSet->setDefine("OE_TERRAIN_MORPH_GEOMETRY");
}
}
// assemble color filter code snippets.
bool haveColorFilters = false;
{
// Color filter frag function:
std::string fs_colorfilters =
"#version " GLSL_VERSION_STR "\n"
GLSL_DEFAULT_PRECISION_FLOAT "\n"
"uniform int oe_layer_uid; \n"
"$COLOR_FILTER_HEAD"
"void oe_rexEngine_applyFilters(inout vec4 color) \n"
"{ \n"
"$COLOR_FILTER_BODY"
"} \n";
std::stringstream cf_head;
std::stringstream cf_body;
const char* I = " ";
// second, install the per-layer color filter functions AND shared layer bindings.
bool ifStarted = false;
ImageLayerVector imageLayers;
_update_mapf->getLayers(imageLayers);
for( int i=0; i<imageLayers.size(); ++i )
{
ImageLayer* layer = imageLayers.at(i);
if ( layer->getEnabled() )
{
// install Color Filter function calls:
const ColorFilterChain& chain = layer->getColorFilters();
if ( chain.size() > 0 )
{
haveColorFilters = true;
if ( ifStarted ) cf_body << I << "else if ";
else cf_body << I << "if ";
cf_body << "(oe_layer_uid == " << layer->getUID() << ") {\n";
for( ColorFilterChain::const_iterator j = chain.begin(); j != chain.end(); ++j )
{
const ColorFilter* filter = j->get();
cf_head << "void " << filter->getEntryPointFunctionName() << "(inout vec4 color);\n";
cf_body << I << I << filter->getEntryPointFunctionName() << "(color);\n";
filter->install( surfaceStateSet );
}
cf_body << I << "}\n";
ifStarted = true;
}
}
}
if ( haveColorFilters )
{
std::string cf_head_str, cf_body_str;
cf_head_str = cf_head.str();
cf_body_str = cf_body.str();
replaceIn( fs_colorfilters, "$COLOR_FILTER_HEAD", cf_head_str );
replaceIn( fs_colorfilters, "$COLOR_FILTER_BODY", cf_body_str );
surfaceVP->setFunction(
"oe_rexEngine_applyFilters",
fs_colorfilters,
ShaderComp::LOCATION_FRAGMENT_COLORING,
0.6 );
}
}
// Apply uniforms for sampler bindings:
OE_DEBUG << LC << "Render Bindings:\n";
osg::ref_ptr<osg::Texture> tex = new osg::Texture2D(ImageUtils::createEmptyImage(1,1));
for (unsigned i = 0; i < _renderBindings.size(); ++i)
{
SamplerBinding& b = _renderBindings[i];
if (b.isActive())
{
osg::Uniform* u = new osg::Uniform(b.samplerName().c_str(), b.unit());
terrainStateSet->addUniform( u );
OE_DEBUG << LC << " > Bound \"" << b.samplerName() << "\" to unit " << b.unit() << "\n";
terrainStateSet->setTextureAttribute(b.unit(), tex.get());
}
}
// uniform that controls per-layer opacity
terrainStateSet->addUniform( new osg::Uniform("oe_layer_opacity", 1.0f) );
// uniform that conveys the layer UID to the shaders; necessary
// for per-layer branching (like color filters)
// UID -1 => no image layer (no texture)
terrainStateSet->addUniform( new osg::Uniform("oe_layer_uid", (int)-1 ) );
// uniform that conveys the render order, since the shaders
// need to know which is the first layer in order to blend properly
terrainStateSet->addUniform( new osg::Uniform("oe_layer_order", (int)0) );
// default min/max range uniforms. (max < min means ranges are disabled)
terrainStateSet->addUniform( new osg::Uniform("oe_layer_minRange", 0.0f) );
terrainStateSet->addUniform( new osg::Uniform("oe_layer_maxRange", -1.0f) );
terrainStateSet->addUniform( new osg::Uniform("oe_layer_attenuationRange", _terrainOptions.attentuationDistance().get()) );
terrainStateSet->getOrCreateUniform(
"oe_min_tile_range_factor",
osg::Uniform::FLOAT)->set( *_terrainOptions.minTileRangeFactor() );
terrainStateSet->addUniform(new osg::Uniform("oe_tile_size", (float)_terrainOptions.tileSize().get()));
// special object ID that denotes the terrain surface.
surfaceStateSet->addUniform( new osg::Uniform(
Registry::objectIndex()->getObjectIDUniformName().c_str(), OSGEARTH_OBJECTID_TERRAIN) );
}
_stateUpdateRequired = false;
}
}
