enum name to string generator

/** based on this solution: http://stackoverflow.com/a/10966395 */

/** Macros to auto-generate enum and to string function */
#define GENERATE_ENUM_LINE(PREFIX, ENUM) PREFIX##_##ENUM,
#define GENERATE_ENUM_CASE_STRING(PREFIX, ENUM) case PREFIX##_##ENUM: return #ENUM;
#define GENERATE_ENUM(NAME, MEMBERS)                                    \
  enum NAME { MEMBERS(NAME, GENERATE_ENUM_LINE) };                      \
  static const char * NAME##String (enum NAME e)                        \
  {                                                                     \
    switch (e) { MEMBERS(NAME, GENERATE_ENUM_CASE_STRING) }             \
    return("Unknown Type");                                             \
  }


/** define enum */
#define FRUIT_ENUM_MEMBERS(NAME, FRUIT)         \
  FRUIT(NAME, apple)                            \
  FRUIT(NAME, orange)                           \
  FRUIT(NAME, grape)                            \
  FRUIT(NAME, banana)

/** and then generate it */
GENERATE_ENUM(fruitEnum, FRUIT_ENUM_MEMBERS)

/** use enum and string converter */
#include <stdio.h>
int main()
{
  enum fruitEnum e;
  e = fruitEnum_apple;
  printf("e = %s\n", fruitEnumString(e));
  e = fruitEnum_apple;
  printf("e = %s\n", fruitEnumString(e));
  e = fruitEnum_orange;
  printf("e = %s\n", fruitEnumString(e));
  e = fruitEnum_grape;
  printf("e = %s\n", fruitEnumString(e));
  e = fruitEnum_banana;
  printf("e = %s\n", fruitEnumString(e));
  e = -1;
  printf("e = %s\n", fruitEnumString(e));
  return 0;
}

ColorBrewer

Color advice for maps: http://colorbrewer2.org/

Choosing the right estimator

Neat flowchart: http://scikit-learn.org/stable/tutorial/machine_learning_map/index.html

Multi-Dimensional Bresenham Line in C++

Implementation of a multi-dimensional Bresenham Line algorithm in C++ using STL.

#include <vector>

/**
  Multi-dimenstional Bresenham line algorithm
*/
std::vector< std::vector <int> >
Bresenham(std::vector<int> &from, std::vector<int> &to)
{
  std::vector<int> current;
  for (size_t i=0; i<from.size(); i++)
    current.push_back(from[i]);

  std::vector<int> diff;
  for (size_t i=0; i<from.size(); i++)
    diff.push_back(to[i] - from[i]);

  int num_steps = 0;
  for (size_t i=0; i<diff.size(); i++)
    num_steps = std::max(num_steps, (int)floor(std::abs(diff[i])));

  std::vector<int> step;
  for (size_t i=0; i<diff.size(); i++)
    step.push_back(diff[i]/num_steps);

  std::vector< std::vector <int> > output;
  for (int i=0; i<num_steps; i++)
  {
    std::vector pt;

    for (size_t j=0; j<current.size(); j++)
      pt.push_back(floor(current[j]));

    output.push_back(pt);

    for (size_t j=0; j<current.size(); j++)
      current[j] = current[j] + step[j];
  }
  return output;
}

					

Fast key repeat rate

On Windows 7:

http://stackoverflow.com/questions/171326/how-can-i-increase-the-key-repeat-rate-beyond-the-oss-limit

On Linux:

xset r rate DELAY RATE

This works for me:

• delay: 150 ms
• rate: 15 ms

On Mac OSX

echo "Set a fast keyboard repeat rate, "
defaults write NSGlobalDomain KeyRepeat -int 1
echo "Set a shorter Delay until key repeat"
defaults write NSGlobalDomain InitialKeyRepeat -int 12

thread debugging

Valgrind has a thread error detector:

http://valgrind.org/docs/manual/drd-manual.html

mutrace measures mutex contention

http://0pointer.de/blog/projects/mutrace.html

LTTng has a lot of cool features too.

http://lttng.org/

System tap looks interesting too:

https://sourceware.org/systemtap/

 

c++ reflection

I just found these 3 links. Haven’t tested them yet.

http://root.cern.ch/drupal/content/reflex

http://www.extreme.indiana.edu/reflcpp/

http://www.ischo.com/xrtti/index.html

 

Cool page about radar

http://www.radartutorial.eu/index.en.html

 

parsing options using libc’s argp

For the longest time I used getopt to parse options in my C/C++ programs. Only today I discovered argp.h (which is a part of GNU libc). argp adds documentation line for each flag in long options as well as formats a help message for you. Below is a link and a quick example

http://www.gnu.org/software/libc/manual/html_node/Argp-Example-3.html#Argp-Example-3

ssh escape sequence

Help sequence is:

ENTER
~?

This will output available options:

user@host:~$ ~?
Supported escape sequences:
  ~.  - terminate connection (and any multiplexed sessions)
  ~B  - send a BREAK to the remote system
  ~C  - open a command line
  ~R  - Request rekey (SSH protocol 2 only)
  ~^Z - suspend ssh
  ~#  - list forwarded connections
  ~&  - background ssh (when waiting for connections to terminate)
  ~?  - this message
  ~~  - send the escape character by typing it twice
(Note that escapes are only recognized immediately after newline.)