Add WCSData::calculateBounds

imageinfo.cpp

@@ -79,9 +79,10 @@ WCSData::~WCSData()
         freeWCS();
 }
 
-SkyPoint WCSData::pixelToWorld(QPointF pixel) const
+bool WCSData::pixelToWorld(const QPointF &pixel, SkyPoint &point) const
 {
-    if(wcs == nullptr)return SkyPoint();
+    if(!valid())return false;
+
     double pixcrd[2] = {pixel.x(), pixel.y()};
     double imgcrd[8] = {0};
     double phi = 0;
@@ -91,27 +92,80 @@ SkyPoint WCSData::pixelToWorld(QPointF pixel) const
     int status = wcsp2s(wcs, 1, 2, pixcrd, imgcrd, &phi, &theta, world, stat);
     if(status == 0)
     {
-        return SkyPoint(world[0], world[1]);
+        point = SkyPoint(world[0], world[1]);
+        return true;
     }
-    return SkyPoint();
+    return false;
 }
 
-QPointF WCSData::worldToPixel(SkyPoint point) const
+bool WCSData::worldToPixel(const SkyPoint &point, QPointF &pixel) const
 {
-    return QPointF();
+    if(!valid())return false;
+
+    double world[2] = {point.RA(), point.DEC()};
+    double phi = 0;
+    double theta = 0;
+    double imgcrd[8] = {0};
+    double pixcrd[8] = {0};
+    int stat[NWCSFIX] = {0};
+    int status = wcss2p(wcs, 1, 2, world, &phi, &theta, imgcrd, pixcrd, stat);
+    if(status == 0)
+    {
+        pixel = QPointF(pixcrd[0], pixcrd[1]);
+        return true;
+    }
+    return false;
 }
 
-void WCSData::calculateBounds(double &minRa, double &maxRa, double &minDec, double &maxDec)
+void WCSData::calculateBounds(int w, int h, double &minRa, double &maxRa, double &minDec, double &maxDec)
 {
-    minRa = -1000;
-    maxRa = 1000;
-    minDec = -1000;
-    maxDec = 1000;
+    if(wcs == nullptr)return;
+
+    minRa = 1000;
+    maxRa = -1000;
+    minDec = 1000;
+    maxDec = -1000;
+
+    auto update = [&](const QPointF &pixel)
+    {
+        SkyPoint point;
+        pixelToWorld(pixel, point);
+        minRa = std::min(minRa, point.RA());
+        maxRa = std::max(maxRa, point.RA());
+        minDec = std::min(minDec, point.DEC());
+        maxDec = std::max(maxDec, point.DEC());
+    };
+
+    for(int x=0; x<w; x++)
+    {
+        update(QPointF(x, 0));
+        update(QPointF(x, h - 1));
+    }
+
+    for(int y=0; y<h; y++)
+    {
+        update(QPointF(0, y));
+        update(QPointF(w - 1, y));
+    }
+
+    QPointF ncp;
+    QPointF scp;
+    QRectF s(0, 0, w - 1, h - 1);
+    if(worldToPixel(SkyPoint(0, 90), ncp))
+    {
+        if(s.contains(ncp))
+            maxDec = 90;
+    }
+
+    if(worldToPixel(SkyPoint(0, -90), scp))
+    {
+        if(s.contains(scp))
+            minDec = -90;
+    }
 }
 
 SkyPoint::SkyPoint() : ra(NAN), dec(NAN)
 {
-
 }
 
 SkyPoint::SkyPoint(double ra, double dec) : ra(ra), dec(dec)