Changeset 16228 for trunk/Ohana/src/kapa2/src/CreateZoom32.c

Timestamp:

Jan 24, 2008, 5:45:18 PM (18 years ago)

Author:

eugene

Message:

cleaning up the image/screen relationships and remap functions

File:

• trunk/Ohana/src/kapa2/src/CreateZoom32.c (modified) (3 diffs)

trunk/Ohana/src/kapa2/src/CreateZoom32.c

@@ -8 +8 @@
   int dropback;  /* this is a bit of a kludge... */
   int dx, dy, DX, DY;
-  double expand, zoomscale, Rx, Ry;
+  double expand, zoomscale, Ix, Iy;
   int expand_in, expand_out;
   unsigned int *out_pix, *out_pix2;
@@ -40 +40 @@
   DY = image[0].image[0].matrix.Naxis[1];
   
-  /* Rx,Ry are the screen coordinates of the first image pixel */
-  Rx = x - expand*(int)(0.5*(dx + 1)) + 1;
-  Ry = y - expand*(int)(0.5*(dy + 1)) + 1;
+  /* Ix,Iy are the image coordinates of the first image pixel */
+  // x,y is the image coordinate of the zoombox center
+  Ix = x - expand*(int)(0.5*(dx + 1)) + 1;
+  Iy = y - expand*(int)(0.5*(dy + 1)) + 1;
 
-  i_start = MIN (MAX (-Rx / expand, (1 - FRAC(Rx)) / expand), dx - expand_out + 1);
-  j_start = MIN (MAX (-Ry / expand, (1 - FRAC(Ry)) / expand), dy - expand_out + 1);
-  i_end   = MAX (MIN ((DX-Rx) / expand, dx - expand_out + 1), 0);
-  j_end   = MAX (MIN ((DY-Ry) / expand, dy - expand_out + 1), 0);
+  i_start = MIN (MAX (-Ix / expand, (1 - FRAC(Ix)) / expand), dx - expand_out + 1);
+  j_start = MIN (MAX (-Iy / expand, (1 - FRAC(Iy)) / expand), dy - expand_out + 1);
+  i_end   = MAX (MIN ((DX-Ix) / expand, dx - expand_out + 1), 0);
+  j_end   = MAX (MIN ((DY-Iy) / expand, dy - expand_out + 1), 0);
 
   dropback = expand_out - (i_end - i_start) % expand_out;
@@ -53 +54 @@
 
   out_pix = (unsigned int *) image[0].zoom.data;
-  in_pix  = &image[0].pixmap[DX*(int)MAX(Ry,0) + (int)MAX(Rx,0)];
+  in_pix  = &image[0].pixmap[DX*(int)MAX(Iy,0) + (int)MAX(Ix,0)];
 
   /********** below we do the mapping from buffer pixels (in) to picture pixels (out) **********/