add egg-flat-colors

panda/src/egg2pg/config_egg2pg.cxx

@@ -93,6 +93,18 @@ ConfigVariableBool egg_flat_shading
           "to set it true if your scene largely or entirely consists of "
           "flat-shaded polygons."));
 
+ConfigVariableBool egg_flat_colors
+("egg-flat-colors", true,
+ PRC_DESC("Set this true to allow the egg loader to create geometry with the "
+          "ColorAttrib::T_flat attribute set: that is, geometry that uses "
+          "the scene graph color instead of per-vertex color.  Normally Panda "
+          "will do this as an optimization for Geoms whose vertices are all "
+          "the same color, or all white.  This allows the removal of the "
+          "color attribute from the vertices where it is not necessary to "
+          "specify colors per-vertex.  If this is false, the color attribute "
+          "will always be specified per-vertex, even if all vertices have the "
+          "same value."));
+
 ConfigVariableBool egg_load_old_curves
 ("egg-load-old-curves", true,
  PRC_DESC("When this is true, a <NurbsCurve> entry appearing in an egg file "

panda/src/egg2pg/config_egg2pg.h

@@ -42,6 +42,7 @@ extern EXPCL_PANDAEGG ConfigVariableDouble egg_flatten_radius;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_combine_geoms;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_rigid_geometry;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_flat_shading;
+extern EXPCL_PANDAEGG ConfigVariableBool egg_flat_colors;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_load_old_curves;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_load_classic_nurbs_curves;
 extern EXPCL_PANDAEGG ConfigVariableBool egg_accept_errors;

panda/src/egg2pg/eggLoader.cxx

@@ -371,6 +371,12 @@ make_polyset(EggBin *egg_bin, PandaNode *parent, const LMatrix4d *transform,
     bool has_overall_color;
     Colorf overall_color;
     vertex_pool->check_overall_color(has_overall_color, overall_color);
+    if (!egg_flat_colors) {
+      // If flat colors aren't allowed, then we don't care whether
+      // there is an overall color.  In that case, treat all vertex
+      // pools as if they contain a combination of multiple colors.
+      has_overall_color = false;
+    }
     
     // Create a handful of GeomPrimitives corresponding to the various
     // types of primitives that reference this vertex pool.