OpenGL读取3DS文件并重现原图形

#include "MyLoader.h" #include <stdexcept> #include <fstream> #include <cmath> #include <iostream> #include "3dsId.h" using namespace std; MyLoader::MyLoader() : NowPos( 0 ),FileLength( 0 ), Version( 0 ) {} //加载3DS文件 void MyLoader::LoadFile() { Chunk MyChunk; ReadChunk( &MyChunk ); if( FileLength != MyChunk.Len ) throw runtime_error( "文件损坏" ); ReadChunk( &MyChunk ); Version = ReadNByte( 4 ); while( NowPos < FileLength ) { ReadChunk( &MyChunk ); if( OBJECTINFO == MyChunk.ID ) LoadObjectInfo( MyChunk ); else SkipNByte( MyChunk.Len - 6 ); } ComputeNormals(); } void MyLoader::LoadObjectInfo( const Chunk& MyChunk ) { size_t BeginPos( NowPos - 6 ); Chunk TempChunk; while( NowPos - BeginPos < MyChunk.Len ) { ReadChunk( &TempChunk ); switch( TempChunk.ID ) { case MATERIAL: LoadMaterial( TempChunk ); break; case OBJECT: LoadObject( TempChunk ); break; default: SkipNByte( TempChunk.Len - 6 ); } } } void MyLoader::LoadObject( const Chunk& MyChunk ) { Object object; object.Name = ReadString(); size_t BeginPos( NowPos - 7 - object.Name.size() ); Chunk ThisChunk; while( NowPos - BeginPos < MyChunk.Len ) { ReadChunk( &ThisChunk ); if( OBJECT_MESH == ThisChunk.ID ) LoadMesh( &object, ThisChunk ); else SkipNByte( ThisChunk.Len - 6 ); } MyModel.MyObject.push_back( object ); } void MyLoader::LoadMesh( Object* object ,const Chunk& MyChunk ) { size_t BeginPos( NowPos - 6 ); size_t End( MyChunk.Len ); Chunk ThisChunk; while( NowPos - BeginPos < End ) { ReadChunk( &ThisChunk ); switch( ThisChunk.ID ) { case OBJECT_VERTICES: LoadVertex( object ); break; case OBJECT_FACES: LoadFaces( object ); break; case OBJECT_MATERIAL: LoadObjectMaterial( object ); break; default: SkipNByte( ThisChunk.Len - 6 ); } } } void MyLoader::LoadMaterial( const Chunk& MyChunk ) { size_t BeginPos( NowPos - 6 ); Chunk TempChunk; Material Here; while( NowPos - BeginPos < MyChunk.Len ) { ReadChunk( &TempChunk ); switch( TempChunk.ID ) { case MATNAME: Here.name = ReadString(); break; case MAT_AMBIENT: LoadColor( Here.ambientColor ); break; case MAT_DIFFUSE: LoadColor( Here.diffuseColor ); break; case MAT_SPECULAR: LoadColor( Here.specularColor ); break; case MAT_SHININESS: Here.shininess = LoadPercent(); break; case MAT_TRANSPARENCY: Here.transparency = LoadPercent(); break; default: SkipNByte( TempChunk.Len - 6 ); } } MyModel.ThisMaterial.push_back( Here ); } float MyLoader::LoadPercent() { Chunk TempChunk;float Temp( -1 ); ReadChunk( &TempChunk ); switch( TempChunk.ID ) { case INT_PERCENTAGE: Temp = ReadNByte( 2 ); Temp /= 100.0; break; case FLOAT_PERCENTAGE: Temp = ReadFloat(); break; default: SkipNByte( TempChunk.Len - 6 ); } return Temp; } void MyLoader::LoadColor( float* color ) { Chunk TempChunk; ReadChunk( &TempChunk ); switch( TempChunk.ID ) { case COLOR_F: color[ 0 ] = ReadFloat(); color[ 1 ] = ReadFloat(); color[ 2 ] = ReadFloat(); break; case COLOR_24: color[ 0 ] = static_cast< float >( ReadNByte( 1 ) ) / 255.0; color[ 1 ] = static_cast< float >( ReadNByte( 1 ) ) / 255.0; color[ 2 ] = static_cast< float >( ReadNByte( 1 ) ) / 255.0; break; default: SkipNByte( TempChunk.Len - 6 ); } } void MyLoader::LoadObjectMaterial( Object* object ) { string Name = ReadString(); Material* ThisMaterial; int Pos( -1 ); for( size_t i = 0; i != MyModel.ThisMaterial.size(); ++ i ) { if( MyModel.ThisMaterial[ i ].name == Name ) Pos = i; } if( Pos == -1 ) { cerr << "Waining: 没有找到该材质" << endl; return; } size_t Sum = ReadNByte( 2 ); size_t Temp( 0 ); for( size_t i = 0; i != Sum; ++ i ) { Temp = ReadNByte( 2 ); object->Faces[ Temp ].MaterialPos = Pos; } } Vertex MyLoader::Vectors( const Vertex& lPoint, const Vertex& rPoint ) { Vertex Point; Point.x = lPoint.x - rPoint.x; Point.y = lPoint.y - rPoint.y; Point.z = lPoint.z - rPoint.z; return Point; } Vertex MyLoader::Cross( const Vertex& lPoint, const Vertex& rPoint ) { Vertex Point; Point.x = lPoint.y * rPoint.z - lPoint.z * rPoint.y; Point.y = lPoint.z * rPoint.x - lPoint.x * rPoint.z; Point.z = lPoint.x * rPoint.y - lPoint.y * rPoint.x; return Point; } Vertex MyLoader::Normalize( const Vertex& point ) { float Magnitude = sqrt( point.x * point.x + point.y * point.y + point.z * point.z ); if( Magnitude == 0 ) Magnitude = 1; Vertex Point( point ); Point.x /= (float)Magnitude; Point.y /= (float)Magnitude; Point.z /= (float)Magnitude; return point; } void MyLoader::ComputeNormals() { for( size_t i = 0; i != MyModel.MyObject.size(); ++ i ) { Object& TempObject = MyModel.MyObject[ i ]; for( size_t i = 0; i != TempObject.Faces.size(); ++ i ) { Vertex Point1 = TempObject.Vertexs[ TempObject.Faces[ i ].Index[ 0 ] ]; Vertex Point2 = TempObject.Vertexs[ TempObject.Faces[ i ].Index[ 1 ] ]; Vertex Point3 = TempObject.Vertexs[ TempObject.Faces[ i ].Index[ 2 ] ]; Vertex Vector1 = Vectors( Point1, Point3 ); Vertex Vector2 = Vectors( Point3, Point2 ); Vertex Normal = Cross( Vector1, Vector2 ); TempObject.Faces[ i ].Normal = Normalize( Normal ); ; } } } /* *功能：读取文件 *说明：打开文件前需要加locale::global以保证可以正确打开中文名称文件 */ void MyLoader::ReadFile( const string& FileRoad ) { locale::global( locale("") ); ifstream fin( FileRoad.c_str(), ifstream::binary ); locale::global( locale("C") ); if( !fin ) throw std::runtime_error( "打开文件失败" ); char Byte; while( fin.get( Byte ) ) File += Byte; fin.close(); FileLength = File.size(); } /* *功能：读取一个Chunk *说明：此处修改了实参 */ void MyLoader::ReadChunk( Chunk* MyChunk ) { MyChunk->ID = ReadNByte( 2 ); MyChunk->Len = ReadNByte( 4 ); } /* *功能：检测行动会不会超出文件末端 *说明：暂无 */ void MyLoader::Test( const size_t& Num ) { if( Num > FileLength - NowPos ) throw std::runtime_error( "读取超出文件末端" ); } /* *功能：读取Num个字节转换为无符号数 *说明：由于没有找到合适的流函数，采用如下手段，此处请政府采取更好措施 */ size_t MyLoader::ReadNByte( const size_t& Num ) { Test( Num ); size_t Temp( 0 );size_t Next( 0 ); for( size_t i = 1; i <= Num; ++ i ) { Next = static_cast< unsigned char >( File[ NowPos + Num - i ] ); if( Next > 255 ) Next = 0; Temp = 256 * Temp + Next; } NowPos += Num; return Temp; } /* *功能：跳过Num个字节 *说明：暂无 */ void MyLoader::SkipNByte( const size_t& Num ) { Test( Num ); NowPos += Num; } /* *功能：读取字节直到NULL，并以string返回 *说明：暂无 */ std::string MyLoader::ReadString() { size_t BeginPos( NowPos ); string TempWord; while( File[ NowPos ] != 0 ) { TempWord += File[ NowPos ]; ++ NowPos; } ++ NowPos; return TempWord; } /* *功能：返回模型对象 *说明：此处以引用方式返回，容易造成外值被修改 */ Model& MyLoader::GetModel() { return MyModel; } /* *功能：加载图形所有的面（3ds max是以三角形面存储的） *说明：面是以顶点索引的形式存储在文件中的，每三个索引是一个面， * 但两组索引之间有一个两个字节的边界，需要跳过 */ void MyLoader::LoadFaces( Object* ThisObject ) { size_t Sum = ReadNByte( 2 ); Face face; size_t Temp( 0 ); for( size_t i = 0; i != Sum; ++ i ) { for( size_t j = 0; j != 4; ++ j ) { Temp = ReadNByte( 2 ); if( j < 3 ) face.Index[ j ] = Temp; } ThisObject->Faces.push_back( face ); } } /* *功能：读取浮点型数据 *说明：由于没有找到合理的流函数，采用下面的良种手段使浮点数的读取能够 * 正确进行，此处需要政府进行规划 */ GLfloat MyLoader::ReadFloat( ) { /* unsigned char* p = reinterpret