//-----------------------------------------------------------------------------
// findSelected() -- find the selected graphic from the 'select buffer'.
//
// 1) When item == 0, returns nearest (by depth buffer) entry.
// 2) When item < 0, returns furthest (by depth buffer) entry.
// 3) When item > 0, returns the item'th selected entry or the first entry if
// there are less than 'item' entries
// 4) Returns zero(0) when there are no entries in the select buffer or if the
// Graphic for the select ID is not found.
//-----------------------------------------------------------------------------
BasicGL::Graphic* FoxDisplay::findSelected(const GLuint sbuff[], const int size, const int item)
{
BasicGL::Graphic* sel = nullptr;
GLuint id = 0;
GLuint dmin = 0;
GLuint dmax = 0;
int cnt = 0;
int idx = 0;
while (idx < size && sbuff[idx] > 0) {
int n = sbuff[idx++]; // Number of select names
GLuint xmin = sbuff[idx++]; // Min Depth
GLuint xmax = sbuff[idx++]; // Max Depth
// First select name only
GLuint xId = sbuff[idx++];
for (int i = 1; i < n; i++) { idx++; }
if (cnt == 0) {
// First item
id = xId;
dmin = xmin;
dmax = xmax;
}
else if (item == 0 && xmin < dmin) {
// Nearest --
dmin = xmin;
id = xId;
}
else if (item < 0 && xmax > dmax) {
// Nearest --
dmax = xmax;
id = xId;
}
else if (item == (cnt+1)) {
id = xId;
}
cnt++;
}
// Find the Graphic with this id
if (id > 0) {
//std::cout << "selected id = " << id << std::endl;
Basic::Pair* pair = findBySelectName(id);
if (pair != nullptr) {
sel = dynamic_cast<BasicGL::Graphic*>(pair->object());
if (sel != nullptr) {
return sel;
}
}
}
return sel;
}
//-----------------------------------------------------------------------------
// findSelected() -- find the selected graphic from the 'select buffer'.
//
// 1) When item == 0, returns nearest (by depth buffer) entry.
// 2) When item < 0, returns furthest (by depth buffer) entry.
// 3) When item > 0, returns the item'th selected entry or the first entry if
// there are less than 'item' entries
// 4) Returns zero(0) when there are no entries in the select buffer or if the
// Graphic for the select ID is not found.
//-----------------------------------------------------------------------------
BasicGL::Graphic* GlutDisplay::findSelected(const GLint hits, const GLuint sbuff[], const int item)
{
Graphic* sel = nullptr;
GLuint id = 0;
// ---
// Build a list of hit names with their z values
// ---
static const unsigned int MAX_HITS = 64;
GLuint hitList[MAX_HITS];
GLuint zminList[MAX_HITS];
GLuint zmaxList[MAX_HITS];
unsigned int hitCnt = 0;
unsigned int idx = 0;
for (GLint hit = 1; hit <= hits && hitCnt < MAX_HITS; hit++) {
GLuint n = sbuff[idx++]; // Number of select names
GLuint zmin = sbuff[idx++]; // Min Depth
GLuint zmax = sbuff[idx++]; // Max Depth
if (n > 0) {
hitList[hitCnt] = sbuff[idx];
zminList[hitCnt] = zmin;
zmaxList[hitCnt] = zmax;
hitCnt++;
}
for (GLuint i = 0; i < n; i++) idx++; // move past the stack
}
// ---
// We have at least one hit
// ---
if (hitCnt > 0) {
// Select this item (if it exists)
if (item > 0 && item <= static_cast<int>(hitCnt)) {
id = hitList[item-1];
}
// Or look for the nearest
else if (item == 0) {
// (find the smallest zmin)
GLuint h = hitList[0];
GLuint zmin = zminList[0];
for (unsigned int i = 1; i < hitCnt; i++) {
if (zminList[i] < zmin) {
h = hitList[i];
zmin = zminList[i];
}
}
id = h;
}
// Or look for the furthest
else if (item < 0) {
// (find the largest zmax)
GLuint h = hitList[0];
GLuint zmax = zmaxList[0];
for (unsigned int i = 1; i < hitCnt; i++) {
if (zmaxList[i] > zmax) {
h = hitList[i];
zmax = zmaxList[i];
}
}
id = h;
}
}
// ---
// Find the Graphic with this id
// ---
if (id > 0) {
Basic::Pair* pair = findBySelectName(id);
if (pair != nullptr) {
sel = static_cast<Graphic*>(pair->object());
}
}
return sel;
}
