|
- /***************************************************/
- /*! \class Mesh2D
- \brief Two-dimensional rectilinear waveguide mesh class.
-
- This class implements a rectilinear,
- two-dimensional digital waveguide mesh
- structure. For details, see Van Duyne and
- Smith, "Physical Modeling with the 2-D Digital
- Waveguide Mesh", Proceedings of the 1993
- International Computer Music Conference.
-
- This is a digital waveguide model, making its
- use possibly subject to patents held by Stanford
- University, Yamaha, and others.
-
- Control Change Numbers:
- - X Dimension = 2
- - Y Dimension = 4
- - Mesh Decay = 11
- - X-Y Input Position = 1
-
- by Julius Smith, 2000 - 2002.
- Revised by Gary Scavone for STK, 2002.
- */
- /***************************************************/
-
- #include "Mesh2D.h"
- #include "SKINImsg.h"
-
- namespace stk {
-
- Mesh2D :: Mesh2D( unsigned short nX, unsigned short nY )
- {
- if ( nX == 0.0 || nY == 0.0 ) {
- oStream_ << "Mesh2D::Mesh2D: one or more argument is equal to zero!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
-
- this->setNX( nX );
- this->setNY( nY );
-
- StkFloat pole = 0.05;
- unsigned short i;
- for ( i=0; i<NYMAX; i++ ) {
- filterY_[i].setPole( pole );
- filterY_[i].setGain( 0.99 );
- }
-
- for ( i=0; i<NXMAX; i++ ) {
- filterX_[i].setPole( pole );
- filterX_[i].setGain( 0.99 );
- }
-
- this->clearMesh();
-
- counter_ = 0;
- xInput_ = 0;
- yInput_ = 0;
- }
-
- Mesh2D :: ~Mesh2D( void )
- {
- }
-
- void Mesh2D :: clear( void )
- {
- this->clearMesh();
-
- unsigned short i;
- for ( i=0; i<NY_; i++ )
- filterY_[i].clear();
-
- for ( i=0; i<NX_; i++ )
- filterX_[i].clear();
-
- counter_ = 0;
- }
-
- void Mesh2D :: clearMesh( void )
- {
- int x, y;
- for ( x=0; x<NXMAX-1; x++ ) {
- for ( y=0; y<NYMAX-1; y++ ) {
- v_[x][y] = 0;
- }
- }
- for ( x=0; x<NXMAX; x++ ) {
- for ( y=0; y<NYMAX; y++ ) {
-
- vxp_[x][y] = 0;
- vxm_[x][y] = 0;
- vyp_[x][y] = 0;
- vym_[x][y] = 0;
-
- vxp1_[x][y] = 0;
- vxm1_[x][y] = 0;
- vyp1_[x][y] = 0;
- vym1_[x][y] = 0;
- }
- }
- }
-
- StkFloat Mesh2D :: energy( void )
- {
- // Return total energy contained in wave variables Note that some
- // energy is also contained in any filter delay elements.
-
- int x, y;
- StkFloat t;
- StkFloat e = 0;
- if ( counter_ & 1 ) { // Ready for Mesh2D::tick1() to be called.
- for ( x=0; x<NX_; x++ ) {
- for ( y=0; y<NY_; y++ ) {
- t = vxp1_[x][y];
- e += t*t;
- t = vxm1_[x][y];
- e += t*t;
- t = vyp1_[x][y];
- e += t*t;
- t = vym1_[x][y];
- e += t*t;
- }
- }
- }
- else { // Ready for Mesh2D::tick0() to be called.
- for ( x=0; x<NX_; x++ ) {
- for ( y=0; y<NY_; y++ ) {
- t = vxp_[x][y];
- e += t*t;
- t = vxm_[x][y];
- e += t*t;
- t = vyp_[x][y];
- e += t*t;
- t = vym_[x][y];
- e += t*t;
- }
- }
- }
-
- return e;
- }
-
- void Mesh2D :: setNX( unsigned short lenX )
- {
- if ( lenX < 2 ) {
- oStream_ << "Mesh2D::setNX(" << lenX << "): Minimum length is 2!";
- handleError( StkError::WARNING ); return;
- }
- else if ( lenX > NXMAX ) {
- oStream_ << "Mesh2D::setNX(" << lenX << "): Maximum length is " << NXMAX << '!';
- handleError( StkError::WARNING ); return;
- }
-
- NX_ = lenX;
- }
-
- void Mesh2D :: setNY( unsigned short lenY )
- {
- if ( lenY < 2 ) {
- oStream_ << "Mesh2D::setNY(" << lenY << "): Minimum length is 2!";
- handleError( StkError::WARNING ); return;
- }
- else if ( lenY > NYMAX ) {
- oStream_ << "Mesh2D::setNY(" << lenY << "): Maximum length is " << NXMAX << '!';
- handleError( StkError::WARNING ); return;
- }
-
- NY_ = lenY;
- }
-
- void Mesh2D :: setDecay( StkFloat decayFactor )
- {
- if ( decayFactor < 0.0 || decayFactor > 1.0 ) {
- oStream_ << "Mesh2D::setDecay: decayFactor is out of range!";
- handleError( StkError::WARNING ); return;
- }
-
- int i;
- for ( i=0; i<NYMAX; i++ )
- filterY_[i].setGain( decayFactor );
-
- for (i=0; i<NXMAX; i++)
- filterX_[i].setGain( decayFactor );
- }
-
- void Mesh2D :: setInputPosition( StkFloat xFactor, StkFloat yFactor )
- {
- if ( xFactor < 0.0 || xFactor > 1.0 ) {
- oStream_ << "Mesh2D::setInputPosition xFactor value is out of range!";
- handleError( StkError::WARNING ); return;
- }
-
- if ( yFactor < 0.0 || yFactor > 1.0 ) {
- oStream_ << "Mesh2D::setInputPosition yFactor value is out of range!";
- handleError( StkError::WARNING ); return;
- }
-
- xInput_ = (unsigned short) (xFactor * (NX_ - 1));
- yInput_ = (unsigned short) (yFactor * (NY_ - 1));
- }
-
- void Mesh2D :: noteOn( StkFloat frequency, StkFloat amplitude )
- {
- // Input at corner.
- if ( counter_ & 1 ) {
- vxp1_[xInput_][yInput_] += amplitude;
- vyp1_[xInput_][yInput_] += amplitude;
- }
- else {
- vxp_[xInput_][yInput_] += amplitude;
- vyp_[xInput_][yInput_] += amplitude;
- }
- }
-
- void Mesh2D :: noteOff( StkFloat amplitude )
- {
- return;
- }
-
- StkFloat Mesh2D :: inputTick( StkFloat input )
- {
- if ( counter_ & 1 ) {
- vxp1_[xInput_][yInput_] += input;
- vyp1_[xInput_][yInput_] += input;
- lastFrame_[0] = tick1();
- }
- else {
- vxp_[xInput_][yInput_] += input;
- vyp_[xInput_][yInput_] += input;
- lastFrame_[0] = tick0();
- }
-
- counter_++;
- return lastFrame_[0];
- }
-
- StkFloat Mesh2D :: tick( unsigned int )
- {
- lastFrame_[0] = ((counter_ & 1) ? this->tick1() : this->tick0());
- counter_++;
- return lastFrame_[0];
- }
-
- const StkFloat VSCALE = 0.5;
-
- StkFloat Mesh2D :: tick0( void )
- {
- int x, y;
- StkFloat outsamp = 0;
-
- // Update junction velocities.
- for (x=0; x<NX_-1; x++) {
- for (y=0; y<NY_-1; y++) {
- v_[x][y] = ( vxp_[x][y] + vxm_[x+1][y] +
- vyp_[x][y] + vym_[x][y+1] ) * VSCALE;
- }
- }
-
- // Update junction outgoing waves, using alternate wave-variable buffers.
- for (x=0; x<NX_-1; x++) {
- for (y=0; y<NY_-1; y++) {
- StkFloat vxy = v_[x][y];
- // Update positive-going waves.
- vxp1_[x+1][y] = vxy - vxm_[x+1][y];
- vyp1_[x][y+1] = vxy - vym_[x][y+1];
- // Update minus-going waves.
- vxm1_[x][y] = vxy - vxp_[x][y];
- vym1_[x][y] = vxy - vyp_[x][y];
- }
- }
-
- // Loop over velocity-junction boundary faces, update edge
- // reflections, with filtering. We're only filtering on one x and y
- // edge here and even this could be made much sparser.
- for (y=0; y<NY_-1; y++) {
- vxp1_[0][y] = filterY_[y].tick(vxm_[0][y]);
- vxm1_[NX_-1][y] = vxp_[NX_-1][y];
- }
- for (x=0; x<NX_-1; x++) {
- vyp1_[x][0] = filterX_[x].tick(vym_[x][0]);
- vym1_[x][NY_-1] = vyp_[x][NY_-1];
- }
-
- // Output = sum of outgoing waves at far corner. Note that the last
- // index in each coordinate direction is used only with the other
- // coordinate indices at their next-to-last values. This is because
- // the "unit strings" attached to each velocity node to terminate
- // the mesh are not themselves connected together.
- outsamp = vxp_[NX_-1][NY_-2] + vyp_[NX_-2][NY_-1];
-
- return outsamp;
- }
-
- StkFloat Mesh2D :: tick1( void )
- {
- int x, y;
- StkFloat outsamp = 0;
-
- // Update junction velocities.
- for (x=0; x<NX_-1; x++) {
- for (y=0; y<NY_-1; y++) {
- v_[x][y] = ( vxp1_[x][y] + vxm1_[x+1][y] +
- vyp1_[x][y] + vym1_[x][y+1] ) * VSCALE;
- }
- }
-
- // Update junction outgoing waves,
- // using alternate wave-variable buffers.
- for (x=0; x<NX_-1; x++) {
- for (y=0; y<NY_-1; y++) {
- StkFloat vxy = v_[x][y];
-
- // Update positive-going waves.
- vxp_[x+1][y] = vxy - vxm1_[x+1][y];
- vyp_[x][y+1] = vxy - vym1_[x][y+1];
-
- // Update minus-going waves.
- vxm_[x][y] = vxy - vxp1_[x][y];
- vym_[x][y] = vxy - vyp1_[x][y];
- }
- }
-
- // Loop over velocity-junction boundary faces, update edge
- // reflections, with filtering. We're only filtering on one x and y
- // edge here and even this could be made much sparser.
- for (y=0; y<NY_-1; y++) {
- vxp_[0][y] = filterY_[y].tick(vxm1_[0][y]);
- vxm_[NX_-1][y] = vxp1_[NX_-1][y];
- }
- for (x=0; x<NX_-1; x++) {
- vyp_[x][0] = filterX_[x].tick(vym1_[x][0]);
- vym_[x][NY_-1] = vyp1_[x][NY_-1];
- }
-
- // Output = sum of outgoing waves at far corner.
- outsamp = vxp1_[NX_-1][NY_-2] + vyp1_[NX_-2][NY_-1];
-
- return outsamp;
- }
-
- void Mesh2D :: controlChange( int number, StkFloat value )
- {
- #if defined(_STK_DEBUG_)
- if ( Stk::inRange( value, 0.0, 128.0 ) == false ) {
- oStream_ << "Mesh2D::controlChange: value (" << value << ") is out of range!";
- handleError( StkError::WARNING ); return;
- }
- #endif
-
- StkFloat normalizedValue = value * ONE_OVER_128;
- if ( number == 2 ) // 2
- this->setNX( (unsigned short) (normalizedValue * (NXMAX-2) + 2) );
- else if ( number == 4 ) // 4
- this->setNY( (unsigned short) (normalizedValue * (NYMAX-2) + 2) );
- else if ( number == 11 ) // 11
- this->setDecay( 0.9 + (normalizedValue * 0.1) );
- else if ( number == __SK_ModWheel_ ) // 1
- this->setInputPosition( normalizedValue, normalizedValue );
- #if defined(_STK_DEBUG_)
- else {
- oStream_ << "Mesh2D::controlChange: undefined control number (" << number << ")!";
- handleError( StkError::WARNING );
- }
- #endif
- }
-
- } // stk namespace
|