This fixes a number of things that are warnings in the Mac compiler....

core/cross/gl/param_cache_gl.cc

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 308 matching lines @@
     }
   }
   virtual void ResetEffectParam(RendererGL* renderer, CGparameter cg_param) {
     ParamArray* param = param_->value();
     if (param) {
       int size = cgGetArraySize(cg_param, 0);
       if (size == static_cast<int>(param->size())) {
         for (int i = 0; i < size; ++i) {
           Param* untyped_element = param->GetUntypedParam(i);
           if (untyped_element->IsA(ParamSampler::GetApparentClass())) {
-            CGparameter cg_element = cgGetArrayParameter(cg_param, i);
             ParamSampler* element = down_cast<ParamSampler*>(untyped_element);
             SamplerGL* sampler_gl = down_cast<SamplerGL*>(element->value());
             if (!sampler_gl) {
               sampler_gl = down_cast<SamplerGL*>(renderer->error_sampler());
             }
             sampler_gl->ResetTexture(cg_param);
           }
         }
       }
     }
@@ skipping 111 matching lines @@
             new EffectParamArrayHandlerGL<ParamBoolean>(param_param_array));
         break;
       case CG_SAMPLER:
       case CG_SAMPLER1D:
       case CG_SAMPLER2D:
       case CG_SAMPLER3D:
       case CG_SAMPLERCUBE:
         handler = EffectParamHandlerGL::Ref(
             new EffectParamArraySamplerHandlerGL(param_param_array));
         break;
+      default:
+        break;
     }
   } else if (param->IsA(ParamMatrix4::GetApparentClass())) {
     if (cg_type == CG_FLOAT4x4) {
       if (effect_gl->matrix_load_order() == Effect::COLUMN_MAJOR) {
         // set the data as floats in column major order.
         handler = EffectParamHandlerGL::Ref(
             new EffectParamHandlerGLMatrixColumns(
                 down_cast<ParamMatrix4*>(param)));
       } else {
         // set the data as floats in row major order.
@@ skipping 281 matching lines @@
   DoScanCgEffectParameters(semantic_manager_,
                            renderer_,
                            this,
                            cg_vertex,
                            cg_fragment,
                            effect_gl,
                            param_object_list);
 }
 
 }  // namespace o3d