/*
=================
idSurface_Patch::PutOnCurve
Expects an expanded patch.
=================
*/
void idSurface_Patch::PutOnCurve()
{
int i, j;
idDrawVert prev, next;
assert( expanded == true );
// put all the approximating points on the curve
for( i = 0; i < width; i++ )
{
for( j = 1; j < height; j += 2 )
{
LerpVert( verts[j * maxWidth + i], verts[( j + 1 )*maxWidth + i], prev );
LerpVert( verts[j * maxWidth + i], verts[( j - 1 )*maxWidth + i], next );
LerpVert( prev, next, verts[j * maxWidth + i] );
}
}
for( j = 0; j < height; j++ )
{
for( i = 1; i < width; i += 2 )
{
LerpVert( verts[j * maxWidth + i], verts[j * maxWidth + i + 1], prev );
LerpVert( verts[j * maxWidth + i], verts[j * maxWidth + i - 1], next );
LerpVert( prev, next, verts[j * maxWidth + i] );
}
}
}
/*
=================
idSurface_Patch::Subdivide
=================
*/
void idSurface_Patch::Subdivide( float maxHorizontalError, float maxVerticalError, float maxLength, bool genNormals ) {
int i, j, k, l;
idDrawVert prev, next, mid;
idVec3 prevxyz, nextxyz, midxyz;
idVec3 delta;
float maxHorizontalErrorSqr, maxVerticalErrorSqr, maxLengthSqr;
// generate normals for the control mesh
if ( genNormals ) {
GenerateNormals();
}
maxHorizontalErrorSqr = Square( maxHorizontalError );
maxVerticalErrorSqr = Square( maxVerticalError );
maxLengthSqr = Square( maxLength );
Expand();
// horizontal subdivisions
for ( j = 0; j + 2 < width; j += 2 ) {
// check subdivided midpoints against control points
for ( i = 0; i < height; i++ ) {
for ( l = 0; l < 3; l++ ) {
prevxyz[l] = verts[i*maxWidth + j+1].xyz[l] - verts[i*maxWidth + j ].xyz[l];
nextxyz[l] = verts[i*maxWidth + j+2].xyz[l] - verts[i*maxWidth + j+1].xyz[l];
midxyz[l] = (verts[i*maxWidth + j ].xyz[l] + verts[i*maxWidth + j+1].xyz[l] * 2.0f +
verts[i*maxWidth + j+2].xyz[l] ) * 0.25f;
}
if ( maxLength > 0.0f ) {
// if the span length is too long, force a subdivision
if ( prevxyz.LengthSqr() > maxLengthSqr || nextxyz.LengthSqr() > maxLengthSqr ) {
break;
}
}
// see if this midpoint is off far enough to subdivide
delta = verts[i*maxWidth + j+1].xyz - midxyz;
if ( delta.LengthSqr() > maxHorizontalErrorSqr ) {
break;
}
}
if ( i == height ) {
continue; // didn't need subdivision
}
if ( width + 2 >= maxWidth ) {
ResizeExpanded( maxHeight, maxWidth + 4 );
}
// insert two columns and replace the peak
width += 2;
for ( i = 0; i < height; i++ ) {
idSurface_Patch::LerpVert( verts[i*maxWidth + j ], verts[i*maxWidth + j+1], prev );
idSurface_Patch::LerpVert( verts[i*maxWidth + j+1], verts[i*maxWidth + j+2], next );
idSurface_Patch::LerpVert( prev, next, mid );
for ( k = width - 1; k > j + 3; k-- ) {
verts[i*maxWidth + k] = verts[i*maxWidth + k-2];
}
verts[i*maxWidth + j+1] = prev;
verts[i*maxWidth + j+2] = mid;
verts[i*maxWidth + j+3] = next;
}
// back up and recheck this set again, it may need more subdivision
j -= 2;
}
// vertical subdivisions
for ( j = 0; j + 2 < height; j += 2 ) {
// check subdivided midpoints against control points
for ( i = 0; i < width; i++ ) {
for ( l = 0; l < 3; l++ ) {
prevxyz[l] = verts[(j+1)*maxWidth + i].xyz[l] - verts[j*maxWidth + i].xyz[l];
nextxyz[l] = verts[(j+2)*maxWidth + i].xyz[l] - verts[(j+1)*maxWidth + i].xyz[l];
midxyz[l] = (verts[j*maxWidth + i].xyz[l] + verts[(j+1)*maxWidth + i].xyz[l] * 2.0f +
verts[(j+2)*maxWidth + i].xyz[l] ) * 0.25f;
}
if ( maxLength > 0.0f ) {
// if the span length is too long, force a subdivision
if ( prevxyz.LengthSqr() > maxLengthSqr || nextxyz.LengthSqr() > maxLengthSqr ) {
break;
}
}
// see if this midpoint is off far enough to subdivide
delta = verts[(j+1)*maxWidth + i].xyz - midxyz;
if ( delta.LengthSqr() > maxVerticalErrorSqr ) {
break;
}
}
if ( i == width ) {
continue; // didn't need subdivision
}
if ( height + 2 >= maxHeight ) {
ResizeExpanded( maxHeight + 4, maxWidth );
}
// insert two columns and replace the peak
height += 2;
for ( i = 0; i < width; i++ ) {
LerpVert( verts[j*maxWidth + i], verts[(j+1)*maxWidth + i], prev );
LerpVert( verts[(j+1)*maxWidth + i], verts[(j+2)*maxWidth + i], next );
LerpVert( prev, next, mid );
for ( k = height - 1; k > j + 3; k-- ) {
verts[k*maxWidth + i] = verts[(k-2)*maxWidth + i];
}
verts[(j+1)*maxWidth + i] = prev;
verts[(j+2)*maxWidth + i] = mid;
verts[(j+3)*maxWidth + i] = next;
}
// back up and recheck this set again, it may need more subdivision
j -= 2;
}
PutOnCurve();
RemoveLinearColumnsRows();
Collapse();
// normalize all the lerped normals
if ( genNormals ) {
for ( i = 0; i < width * height; i++ ) {
verts[i].normal.Normalize();
}
}
GenerateIndexes();
}
