Updated glGenerateMipmap to accept the GL_TEXTURE_3D target.

TRAC #22705

Signed-off-by: Jamie Madill
Signed-off-by: Shannon Woods
Author: Geoff Lang

git-svn-id: https://angleproject.googlecode.com/svn/branches/es3proto@2173 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/libGLESv2/libGLESv2.cpp b/src/libGLESv2/libGLESv2.cpp
index 77a0855..34130a8 100644
--- a/src/libGLESv2/libGLESv2.cpp
+++ b/src/libGLESv2/libGLESv2.cpp
@@ -3155,6 +3155,23 @@
                     break;
                 }
 
+              case GL_TEXTURE_3D:
+                {
+                    if (context->getClientVersion() < 3)
+                    {
+                        return gl::error(GL_INVALID_ENUM);
+                    }
+
+                    gl::Texture3D *tex3D = context->getTexture3D();
+                    if (tex3D->isCompressed(0))
+                    {
+                        return gl::error(GL_INVALID_OPERATION);
+                    }
+
+                    tex3D->generateMipmaps();
+                    break;
+                }
+
               default:
                 return gl::error(GL_INVALID_ENUM);
             }