Merged branch 'dev_native' into lm_sla_supports_auto

Added igl library files

src/igl/opengl/destroy_shader_program.cpp

@@ -0,0 +1,50 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2013 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "destroy_shader_program.h"
+#include "report_gl_error.h"
+#include <cstdio>
+
+IGL_INLINE bool igl::opengl::destroy_shader_program(const GLuint id)
+{
+  // Don't try to destroy id == 0 (no shader program)
+  if(id == 0)
+  {
+    fprintf(stderr,"Error: destroy_shader_program() id = %d"
+      " but must should be positive\n",id);
+    return false;
+  }
+  // Get each attached shader one by one and detach and delete it
+  GLsizei count;
+  // shader id
+  GLuint s;
+  do
+  {
+    // Try to get at most *1* attached shader
+    glGetAttachedShaders(id,1,&count,&s);
+    GLenum err = igl::opengl::report_gl_error();
+    if (GL_NO_ERROR != err)
+    {
+      return false;
+    }
+    // Check that we actually got *1*
+    if(count == 1)
+    {
+      // Detach and delete this shader
+      glDetachShader(id,s);
+      glDeleteShader(s);
+    }
+  }while(count > 0);
+  // Now that all of the shaders are gone we can just delete the program
+  glDeleteProgram(id);
+  return true;
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template instantiation
+#endif
+