/*!
\brief Check if point is masked
\param gs pointer to geosurf struct
\param pt point coordinates (X,Y,Z)
\return 1 masked
\return 0 not masked
*/
int gs_point_is_masked(geosurf * gs, float *pt)
{
int vrow, vcol, drow, dcol;
int retmask = 0, npts = 0;
float p2[2];
if (!gs->curmask) {
return (0);
}
vrow = Y2VROW(gs, pt[Y]);
vcol = X2VCOL(gs, pt[X]);
/* check right & bottom edges */
if (pt[X] == VCOL2X(gs, VCOLS(gs))) {
/* right edge */
vcol -= 1;
}
if (pt[Y] == VROW2Y(gs, VROWS(gs))) {
/* bottom edge */
vrow -= 1;
}
drow = VROW2DROW(gs, vrow);
dcol = VCOL2DCOL(gs, vcol);
if (BM_get(gs->curmask, dcol, drow)) {
retmask |= MASK_TL;
npts++;
}
dcol = VCOL2DCOL(gs, vcol + 1);
if (BM_get(gs->curmask, dcol, drow)) {
retmask |= MASK_TR;
npts++;
}
drow = VROW2DROW(gs, vrow + 1);
if (BM_get(gs->curmask, dcol, drow)) {
retmask |= MASK_BR;
npts++;
}
dcol = VCOL2DCOL(gs, vcol);
if (BM_get(gs->curmask, dcol, drow)) {
retmask |= MASK_BL;
npts++;
}
if (npts != 1) {
/* zero or masked */
return (retmask | npts);
}
p2[X] = VCOL2X(gs, vcol);
p2[Y] = VROW2Y(gs, vrow + 1);
switch (retmask) {
case MASK_TL:
if ((pt[X] - p2[X]) / VXRES(gs) > (pt[Y] - p2[Y]) / VYRES(gs)) {
/* lower triangle */
return (0);
}
return (retmask | npts);
case MASK_TR:
return (retmask | npts);
case MASK_BR:
if ((pt[X] - p2[X]) / VXRES(gs) <= (pt[Y] - p2[Y]) / VYRES(gs)) {
/* upper triangle */
return (0);
}
return (retmask | npts);
case MASK_BL:
return (retmask | npts);
}
/* Assume that if we get here it is an error */
return (0);
}
/*!
\brief ADD
In gsd_surf, tmesh draws polys like so:
<pre>
--------------
| /|
| / |
| / |
| / |
| / |
| / |
| / |
| / |
| / |
| / |
| / |
|/ |
--------------
</pre>
UNLESS the top right or bottom left point is masked, in which case a
single triangle with the opposite diagonal is drawn. This case is
not yet handled here & should only occur on edges.
pt has X & Y coordinates in it, we interpolate Z here
This could probably be much shorter, but not much faster.
\return 1 if point is in view region
\return otherwise 0 (if masked)
*/
int viewcell_tri_interp(geosurf * gs, typbuff * buf, Point3 pt,
int check_mask)
{
Point3 p1, p2, p3;
int offset, drow, dcol, vrow, vcol;
float xmax, ymin, ymax, alpha;
xmax = VCOL2X(gs, VCOLS(gs));
ymax = VROW2Y(gs, 0);
ymin = VROW2Y(gs, VROWS(gs));
if (check_mask) {
if (gs_point_is_masked(gs, pt)) {
return (0);
}
}
if (pt[X] < 0.0 || pt[Y] > ymax) {
/* outside on left or top */
return (0);
}
if (pt[Y] < ymin || pt[X] > xmax) {
/* outside on bottom or right */
return (0);
}
if (CONST_ATT == gs_get_att_src(gs, ATT_TOPO)) {
pt[Z] = gs->att[ATT_TOPO].constant;
return (1);
}
else if (MAP_ATT != gs_get_att_src(gs, ATT_TOPO)) {
return (0);
}
vrow = Y2VROW(gs, pt[Y]);
vcol = X2VCOL(gs, pt[X]);
if (vrow < VROWS(gs) && vcol < VCOLS(gs)) {
/*not on bottom or right edge */
if (pt[X] > 0.0 && pt[Y] < ymax) {
/* not on left or top edge */
p1[X] = VCOL2X(gs, vcol + 1);
p1[Y] = VROW2Y(gs, vrow);
drow = VROW2DROW(gs, vrow);
dcol = VCOL2DCOL(gs, vcol + 1);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p1[Z]); /* top right */
p2[X] = VCOL2X(gs, vcol);
p2[Y] = VROW2Y(gs, vrow + 1);
drow = VROW2DROW(gs, vrow + 1);
dcol = VCOL2DCOL(gs, vcol);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p2[Z]); /* bottom left */
if ((pt[X] - p2[X]) / VXRES(gs) > (pt[Y] - p2[Y]) / VYRES(gs)) {
/* lower triangle */
p3[X] = VCOL2X(gs, vcol + 1);
p3[Y] = VROW2Y(gs, vrow + 1);
drow = VROW2DROW(gs, vrow + 1);
dcol = VCOL2DCOL(gs, vcol + 1);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p3[Z]); /* bottom right */
}
else {
/* upper triangle */
p3[X] = VCOL2X(gs, vcol);
p3[Y] = VROW2Y(gs, vrow);
drow = VROW2DROW(gs, vrow);
dcol = VCOL2DCOL(gs, vcol);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p3[Z]); /* top left */
}
return (Point_on_plane(p1, p2, p3, pt));
}
else if (pt[X] == 0.0) {
/* on left edge */
if (pt[Y] < ymax) {
vrow = Y2VROW(gs, pt[Y]);
drow = VROW2DROW(gs, vrow);
offset = DRC2OFF(gs, drow, 0);
GET_MAPATT(buf, offset, p1[Z]);
drow = VROW2DROW(gs, vrow + 1);
offset = DRC2OFF(gs, drow, 0);
GET_MAPATT(buf, offset, p2[Z]);
alpha = (VROW2Y(gs, vrow) - pt[Y]) / VYRES(gs);
pt[Z] = LERP(alpha, p1[Z], p2[Z]);
}
else {
/* top left corner */
GET_MAPATT(buf, 0, pt[Z]);
}
return (1);
}
else if (pt[Y] == gs->yrange) {
/* on top edge, not a corner */
vcol = X2VCOL(gs, pt[X]);
dcol = VCOL2DCOL(gs, vcol);
GET_MAPATT(buf, dcol, p1[Z]);
dcol = VCOL2DCOL(gs, vcol + 1);
GET_MAPATT(buf, dcol, p2[Z]);
alpha = (pt[X] - VCOL2X(gs, vcol)) / VXRES(gs);
pt[Z] = LERP(alpha, p1[Z], p2[Z]);
return (1);
}
}
else if (vrow == VROWS(gs)) {
/* on bottom edge */
drow = VROW2DROW(gs, VROWS(gs));
if (pt[X] > 0.0 && pt[X] < xmax) {
/* not a corner */
vcol = X2VCOL(gs, pt[X]);
dcol = VCOL2DCOL(gs, vcol);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p1[Z]);
dcol = VCOL2DCOL(gs, vcol + 1);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p2[Z]);
alpha = (pt[X] - VCOL2X(gs, vcol)) / VXRES(gs);
pt[Z] = LERP(alpha, p1[Z], p2[Z]);
return (1);
}
else if (pt[X] == 0.0) {
/* bottom left corner */
offset = DRC2OFF(gs, drow, 0);
GET_MAPATT(buf, offset, pt[Z]);
return (1);
}
else {
/* bottom right corner */
dcol = VCOL2DCOL(gs, VCOLS(gs));
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, pt[Z]);
return (1);
}
}
else {
/* on right edge, not bottom corner */
dcol = VCOL2DCOL(gs, VCOLS(gs));
if (pt[Y] < ymax) {
vrow = Y2VROW(gs, pt[Y]);
drow = VROW2DROW(gs, vrow);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p1[Z]);
drow = VROW2DROW(gs, vrow + 1);
offset = DRC2OFF(gs, drow, dcol);
GET_MAPATT(buf, offset, p2[Z]);
alpha = (VROW2Y(gs, vrow) - pt[Y]) / VYRES(gs);
pt[Z] = LERP(alpha, p1[Z], p2[Z]);
return (1);
}
else {
/* top right corner */
GET_MAPATT(buf, dcol, pt[Z]);
return (1);
}
}
return (0);
}
