Files
stk/src/Mesh2D.cpp
Gary Scavone 81475b04c5 Version 4.0
2013-09-29 23:04:45 +02:00

389 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 "SKINI.msg"
#include <stdlib.h>
Mesh2D :: Mesh2D(short nX, short nY)
{
this->setNX(nX);
this->setNY(nY);
MY_FLOAT pole = 0.05;
short i;
for (i=0; i<NYMAX; i++) {
filterY[i] = new OnePole(pole);
filterY[i]->setGain(0.99);
}
for (i=0; i<NXMAX; i++) {
filterX[i] = new OnePole(pole);
filterX[i]->setGain(0.99);
}
this->clearMesh();
counter=0;
xInput = 0;
yInput = 0;
}
Mesh2D :: ~Mesh2D()
{
short i;
for (i=0; i<NYMAX; i++)
delete filterY[i];
for (i=0; i<NXMAX; i++)
delete filterX[i];
}
void Mesh2D :: clear()
{
this->clearMesh();
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()
{
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;
}
}
}
MY_FLOAT Mesh2D :: energy()
{
// Return total energy contained in wave variables Note that some
// energy is also contained in any filter delay elements.
int x, y;
MY_FLOAT t;
MY_FLOAT 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(short lenX)
{
NX = lenX;
if ( lenX < 2 ) {
cerr << "Mesh2D::setNX(" << lenX << "): Minimum length is 2!" << endl;
NX = 2;
}
else if ( lenX > NXMAX ) {
cerr << "Mesh2D::setNX(" << lenX << "): Maximum length is " << NXMAX << "!" << endl;
NX = NXMAX;
}
}
void Mesh2D :: setNY(short lenY)
{
NY = lenY;
if ( lenY < 2 ) {
cerr << "Mesh2D::setNY(" << lenY << "): Minimum length is 2!" << endl;
NY = 2;
}
else if ( lenY > NYMAX ) {
cerr << "Mesh2D::setNY(" << lenY << "): Maximum length is " << NYMAX << "!" << endl;
NY = NYMAX;
}
}
void Mesh2D :: setDecay(MY_FLOAT decayFactor)
{
MY_FLOAT gain = decayFactor;
if ( decayFactor < 0.0 ) {
cerr << "Mesh2D::setDecay decayFactor value is less than 0.0!" << endl;
gain = 0.0;
}
else if ( decayFactor > 1.0 ) {
cerr << "Mesh2D::setDecay decayFactor value is greater than 1.0!" << endl;
gain = 1.0;
}
int i;
for (i=0; i<NYMAX; i++)
filterY[i]->setGain(gain);
for (i=0; i<NXMAX; i++)
filterX[i]->setGain(gain);
}
void Mesh2D :: setInputPosition(MY_FLOAT xFactor, MY_FLOAT yFactor)
{
if ( xFactor < 0.0 ) {
cerr << "Mesh2D::setInputPosition xFactor value is less than 0.0!" << endl;
xInput = 0;
}
else if ( xFactor > 1.0 ) {
cerr << "Mesh2D::setInputPosition xFactor value is greater than 1.0!" << endl;
xInput = NX - 1;
}
else
xInput = (short) (xFactor * (NX - 1));
if ( yFactor < 0.0 ) {
cerr << "Mesh2D::setInputPosition yFactor value is less than 0.0!" << endl;
yInput = 0;
}
else if ( yFactor > 1.0 ) {
cerr << "Mesh2D::setInputPosition yFactor value is greater than 1.0!" << endl;
yInput = NY - 1;
}
else
yInput = (short) (yFactor * (NY - 1));
}
void Mesh2D :: noteOn(MY_FLOAT frequency, MY_FLOAT amplitude)
{
// Input at corner.
if ( counter & 1 ) {
vxp1[xInput][yInput] += amplitude;
vyp1[xInput][yInput] += amplitude;
}
else {
vxp[xInput][yInput] += amplitude;
vyp[xInput][yInput] += amplitude;
}
#if defined(_STK_DEBUG_)
cerr << "Mesh2D: NoteOn frequency = " << frequency << ", amplitude = " << amplitude << endl;
#endif
}
void Mesh2D :: noteOff(MY_FLOAT amplitude)
{
#if defined(_STK_DEBUG_)
cerr << "Mesh2D: NoteOff amplitude = " << amplitude << endl;
#endif
}
MY_FLOAT Mesh2D :: tick(MY_FLOAT input)
{
if ( counter & 1 ) {
vxp1[xInput][yInput] += input;
vyp1[xInput][yInput] += input;
lastOutput = tick1();
}
else {
vxp[xInput][yInput] += input;
vyp[xInput][yInput] += input;
lastOutput = tick0();
}
counter++;
return lastOutput;
}
MY_FLOAT Mesh2D :: tick()
{
lastOutput = ((counter & 1) ? this->tick1() : this->tick0());
counter++;
return lastOutput;
}
#define VSCALE ((MY_FLOAT) (0.5))
MY_FLOAT Mesh2D :: tick0()
{
int x, y;
MY_FLOAT 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++) {
MY_FLOAT 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;
}
MY_FLOAT Mesh2D :: tick1()
{
int x, y;
MY_FLOAT 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++) {
MY_FLOAT 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, MY_FLOAT value)
{
MY_FLOAT norm = value * ONE_OVER_128;
if ( norm < 0 ) {
norm = 0.0;
cerr << "Mesh2D: Control value less than zero!" << endl;
}
else if ( norm > 1.0 ) {
norm = 1.0;
cerr << "Mesh2D: Control value greater than 128.0!" << endl;
}
if (number == 2) // 2
setNX( (short) (norm * (NXMAX-2) + 2) );
else if (number == 4) // 4
setNY( (short) (norm * (NYMAX-2) + 2) );
else if (number == 11) // 11
setDecay( 0.9 + (norm * 0.1) );
else if (number == __SK_ModWheel_) // 1
setInputPosition(norm, norm);
else if (number == __SK_AfterTouch_Cont_) // 128
;
else
cerr << "Mesh2D: Undefined Control Number (" << number << ")!!" << endl;
#if defined(_STK_DEBUG_)
cerr << "Mesh2D: controlChange number = " << number << ", value = " << value << endl;
#endif
}