commit ambient occlusion for terrain

panda/src/grutil/geoMipTerrain.I

@@ -1,7 +1,5 @@
 // Filename: geoMipTerrain.I
-// Created by:  pro-rsoft (29jun07)
+// Created by:  rdb (29Jun07)
-// Modified by: CMU ETC Summer 2010 team (03aug10) (added getters
-//   for _auto_flatten, _near, _far).
 //
 ////////////////////////////////////////////////////////////////////
 //
@@ -520,7 +518,7 @@ set_color_map(const string &path) {
 //  Description: Returns whether a color map has been set.
 ////////////////////////////////////////////////////////////////////
 INLINE bool GeoMipTerrain::
-has_color_map() {
+has_color_map() const {
   return _has_color_map;
 }
 

panda/src/grutil/geoMipTerrain.cxx

@@ -1,5 +1,5 @@
 // Filename: geoMipTerrain.cxx
-// Created by:  pro-rsoft (29jun07)
+// Created by:  rdb (29Jun07)
 //
 ////////////////////////////////////////////////////////////////////
 //
@@ -73,7 +73,7 @@ generate_block(unsigned short mx,
   vdata->unclean_set_num_rows((_block_size + 1) * (_block_size + 1));
   GeomVertexWriter cwriter;
   if (_has_color_map) {
-    cwriter=GeomVertexWriter(vdata, "color"  );
+    cwriter = GeomVertexWriter(vdata, "color");
   }
   GeomVertexWriter vwriter (vdata, "vertex"  );
   GeomVertexWriter twriter (vdata, "texcoord");
@@ -355,12 +355,46 @@ make_slope_image() {
                  normal.get_y() / _root.get_sy(),
                  normal.get_z() / _root.get_sz());
       normal.normalize();
-      result.set_gray(x, y, normal.angle_deg(LVector3f::up()) / 90.0);
+      result.set_xel(x, y, normal.angle_deg(LVector3f::up()) / 90.0);
     }
   }
   return result;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: GeoMipTerrain::calc_ambient_occlusion
+//       Access: Published
+//  Description: Calculates an approximate for the ambient occlusion
+//               and stores it in the color map, so that it will be
+//               written to the vertex colors. Any existing color
+//               map will be discarded.
+//               You need to call this before generating the geometry.
+////////////////////////////////////////////////////////////////////
+void GeoMipTerrain::
+calc_ambient_occlusion(float radius, float contrast, float brightness) {
+  _color_map = PNMImage(_xsize, _ysize);
+  _color_map.make_grayscale();
+  _color_map.set_maxval(_heightfield.get_maxval());
+
+  for (unsigned int x = 0; x < _xsize; ++x) {
+    for (unsigned int y = 0; y < _ysize; ++y) {
+      _color_map.set_xel(x, _ysize - y - 1, get_pixel_value(x, y));
+    }
+  }
+
+  // We use the cheap old method of subtracting a blurred version
+  // of the heightmap from the heightmap, and using that as lightmap.
+  _color_map.gaussian_filter(radius);
+
+  for (unsigned int x = 0; x < _xsize; ++x) {
+    for (unsigned int y = 0; y < _ysize; ++y) {
+      _color_map.set_xel(x, y, (get_pixel_value(x, _ysize - y - 1) - _color_map.get_gray(x, y)) * contrast + brightness);
+    }
+  }
+
+  _has_color_map = true;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: GeoMipTerrain::generate
 //       Access: Published

panda/src/grutil/geoMipTerrain.h

@@ -1,7 +1,5 @@
 // Filename: geoMipTerrain.h
-// Created by:  pro-rsoft (29jun07)
+// Created by:  rdb (29Jun07)
-// Modified by: CMU ETC Summer 2010 team (03aug10) (added
-//   get_flatten_mode(), get_near(), get_far() ).
 //
 ////////////////////////////////////////////////////////////////////
 //
@@ -54,8 +52,9 @@ PUBLISHED:
   INLINE bool set_color_map(const PNMImage &image);
   INLINE bool set_color_map(const Texture *image);
   INLINE bool set_color_map(const string &path);
-  INLINE bool has_color_map();
+  INLINE bool has_color_map() const;
   INLINE void clear_color_map();
+  void calc_ambient_occlusion(float radius = 32, float contrast = 2.0f, float brightness = 0.75f);
   double get_elevation(double x, double y);
   LVector3f get_normal(int x, int y);
   INLINE LVector3f get_normal(unsigned short mx, unsigned short my,