From c277d802a00c5f49e8286fa3b384f619e0a30392 Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Thu, 6 Jun 2013 02:05:35 +0000
Subject: [PATCH] pull_spot()

---
 panda/src/pnmimage/pfmFile.cxx | 37 ++++++++++++++++++++++++++++++++++
 panda/src/pnmimage/pfmFile.h   |  3 +++
 2 files changed, 40 insertions(+)

diff --git a/panda/src/pnmimage/pfmFile.cxx b/panda/src/pnmimage/pfmFile.cxx
index 8475e29c3e..3591b72795 100644
--- a/panda/src/pnmimage/pfmFile.cxx
+++ b/panda/src/pnmimage/pfmFile.cxx
@@ -1529,6 +1529,43 @@ clear_to_texcoords(int x_size, int y_size) {
   }
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: PfmFile::pull_spot
+//       Access: Published
+//  Description: Applies delta * t to the point values within radius
+//               distance of (xc, yc).  The t value is scaled from 1.0
+//               at the center to 0.0 at radius, and this scale
+//               follows the specified exponent.  Returns the number
+//               of points affected.
+////////////////////////////////////////////////////////////////////
+int PfmFile::
+pull_spot(const LPoint4f &delta, double xc, double yc, 
+          double radius, double exponent) {
+  int minx = max((int)cceil(xc - radius), 0);
+  int maxx = min((int)cfloor(xc + radius), _x_size - 1);
+  int miny = max((int)cceil(yc - radius), 0);
+  int maxy = min((int)cfloor(yc + radius), _y_size - 1);
+
+  int count = 0;
+  for (int yi = miny; yi <= maxy; ++yi) {
+    for (int xi = minx; xi <= maxx; ++xi) {
+      double r2 = (xi - xc) * (xi - xc) + (yi - yc) * (yi - yc);
+      if (r2 >= 1.0) {
+        continue;
+      }
+      PN_float32 t = (PN_float32)pow(1.0 - sqrt(r2), exponent);
+
+      PN_float32 *f = &_table[(yi * _x_size + xi) * _num_channels];
+      for (int ci = 0; ci < _num_channels; ++ci) {
+        f[ci] += delta[ci] * t;
+      }
+      ++count;
+    }
+  }
+
+  return count;
+}
+  
 ////////////////////////////////////////////////////////////////////
 //     Function: PfmFile::calc_tight_bounds
 //       Access: Published
diff --git a/panda/src/pnmimage/pfmFile.h b/panda/src/pnmimage/pfmFile.h
index b1697481ec..608cac0c56 100644
--- a/panda/src/pnmimage/pfmFile.h
+++ b/panda/src/pnmimage/pfmFile.h
@@ -124,6 +124,9 @@ PUBLISHED:
   BLOCKING void apply_crop(int x_begin, int x_end, int y_begin, int y_end);
   BLOCKING void clear_to_texcoords(int x_size, int y_size);
 
+  BLOCKING int pull_spot(const LPoint4f &delta, double xc, double yc, 
+                         double radius, double exponent);
+
   bool calc_tight_bounds(LPoint3f &min_point, LPoint3f &max_point) const;
   BLOCKING PT(BoundingHexahedron) compute_planar_bounds(const LPoint2f &center, PN_float32 point_dist, PN_float32 sample_radius, bool points_only) const;
   INLINE BLOCKING PT(BoundingHexahedron) compute_planar_bounds(const LPoint2d &center, PN_float32 point_dist, PN_float32 sample_radius, bool points_only) const;