Files
stk/src/Mesh2D.cpp
2019-04-18 08:56:31 -04:00

368 lines
8.9 KiB
C++

/***************************************************/
/*! \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