bool basic_builder::BuildScene( string file_name, Camera &camera, Scene &scene ) const
{
int line_num = 0;
char input_line[512];
Plugin *dat = NULL; // A container for arbitrary data.
Object *obj = NULL; // The current object, which was the last object created.
Shader *shd = NULL; // The current shader.
Aggregate *agg = NULL; // Current aggregate object, to which all objects are now added.
Envmap *env = NULL; // Current environment map.
Material *mat = NULL; // Current material pointer.
Material material; // Current material.
scene.object = NULL;
scene.envmap = NULL;
scene.rasterize = NULL;
// Attempt to open the input file.
file_name += ".sdf";
std::ifstream fin;
fin.open( file_name.c_str() );
if( fin.fail() )
{
cerr << "Error: Could not open file " << file_name << endl;
return false; // Report failure.
}
cout << "Reading " << file_name << "... ";
cout.flush();
// Set some defaults.
material.diffuse = White;
material.emission = Black;
material.specular = White;
material.ambient = Black;
material.reflectivity = Black;
material.translucency = Black;
material.ref_index = 0.0;
material.Phong_exp = 0.0;
camera.x_res = default_image_width;
camera.y_res = default_image_height;
camera.x_win = Interval( -1.0, 1.0 );
camera.y_win = Interval( -1.0, 1.0 );
// Process lines until the end of file is reached.
// Print a warning for all lines that are unrecognizable.
while( fin.getline( input_line, 512 ) )
{
line_num++;
if( Skip( input_line ) ) continue;
// Ask each registered object if it recognizes the line. If it does, it will
// create a new instance of the object and return it as the function value.
Plugin *plg = Instance_of_Plugin( input_line );
if( plg != NULL )
{
switch( plg->PluginType() )
{
case data_plugin:
if( obj == NULL ) cerr << "Error: data ignored. Line " << line_num << endl;
else obj->AddData( obj );
break;
case shader_plugin:
shd = (Shader*)plg;
break;
case aggregate_plugin:
obj = (Object*)plg;
obj->shader = shd;
obj->envmap = env;
obj->material = Copy( mat, material );
obj->parent = agg;
if( Emitter( material ) )
{
cerr << "Error: An aggregate object cannot be an emitter. Line "
<< line_num << ": "
<< input_line << endl;
return false;
}
if( agg != NULL ) // If there is alrealy an agg obj, this one is a child.
{
// agg->AddChild( obj );
// Do not add aggregates as children until they are complete.
agg->material = Copy( mat, material );
}
else if( scene.object == NULL ) scene.object = obj;
agg = (Aggregate *)obj;
break;
case primitive_plugin:
obj = (Object*)plg;
obj->shader = shd;
obj->envmap = env;
obj->material = Copy( mat, material );
obj->parent = agg;
if( Emitter( material ) ) scene.lights.push_back( obj );
if( agg != NULL )
{
agg->AddChild( obj );
agg->material = Copy( mat, material );
}
else if( scene.object == NULL ) scene.object = obj;
break;
case envmap_plugin:
env = (Envmap*)plg;
// If an environment map is set before any object is created, use it as
// the background.
if( obj == NULL ) scene.envmap = env;
break;
case rasterizer_plugin:
if( scene.rasterize != NULL )
{
cerr << "Error: More than one rasterizer specified. Line "
<< line_num << ": "
<< input_line << endl;
return false;
}
scene.rasterize = (Rasterizer *)plg;
break;
}
continue;
}
// Now look for all the other stuff... materials, camera, lights, etc.
ParamReader get( input_line );
if( get["eye"] && get[camera.eye] ) continue;
if( get["lookat"] && get[camera.lookat] ) continue;
if( get["up"] && get[camera.up] ) continue;
if( get["vpdist"] && get[camera.vpdist] ) continue;
if( get["x_res"] && get[camera.x_res] ) continue;
if( get["y_res"] && get[camera.y_res] ) continue;
if( get["x_win"] && get[camera.x_win] ) continue;
if( get["y_win"] && get[camera.y_win] ) continue;
if( get["ambient"] && get[material.ambient] ) continue;
if( get["diffuse"] && get[material.diffuse] ) continue;
if( get["specular"] && get[material.specular] ) continue;
if( get["emission"] && get[material.emission] ) continue;
if( get["reflectivity"] && get[material.reflectivity] ) continue;
if( get["translucency"] && get[material.translucency] ) continue;
if( get["Phong_exp"] && get[material.Phong_exp] ) continue;
if( get["ref_index"] && get[material.ref_index] ) continue;
// If no object is defined at this point, it's an error.
if( obj == NULL )
{
cerr << "Error reading scene file; No object defined at line "
<< line_num << ": "
<< input_line << endl;
return false;
}
// Look for an end statement that closes the current aggregate. This allows us to nest aggregates.
if( get["end"] )
{
if( agg == NULL )
{
cerr << "Error: end statement found outside an aggregate object at line "
<< line_num << ": "
<< input_line << endl;
return false;
}
// Go back to adding objects to the parent object (if there is one).
agg->Close(); // Signal the aggregate that it is now complete.
Object *closed_agg = agg;
agg = agg->parent;
if( agg != NULL )
{
material = *(agg->material);
mat = agg->material;
shd = agg->shader;
env = agg->envmap;
agg->AddChild( closed_agg ); // Add the agg that just ended.
}
continue;
}
// If nothing matched, it's an error. Print a warning and continue processing.
cerr << "Warning: Unrecognized or ill-formed command at line "
<< line_num << ": "
<< input_line << endl;
}
if( agg != NULL )
{
cerr << "Error: Top-most aggregate object has no 'end' statement." << endl;
return false;
}
cout << "done." << endl;
return true;
}
