inside's Graphics and Mobile Programming Notes

Add non-admin users to Developer Tools group on Mac

2011-07-01T12:13:00.000-07:00

[Source: http://idtechnology.blogspot.com/2010/10/add-user-to-developer-tools-group.html]

To add a user to “Developer Tools” group:
dseditgroup -o edit -u {admin_user} -t user -a {user_name} _developer

Ray Traced Games in the Cloud using MIC

2011-06-07T14:54:00.000-07:00

Ray Traced Games in the Cloud using MIC

Steve Jobs talks iOS 5 at WWDC 2011

2011-06-07T06:22:00.001-07:00

WWDC 2011 liveblog: Steve Jobs talks iOS 5, OS X Lion, iCloud and more

Bit Operation #9

2011-01-08T22:59:00.000-08:00

Print out odd numbers from 1 to 100


void printOddNumber()
{
    for (int i = 1; i <= 100; ++i)
    {
        if (i & 0x01)
            cout << i << \n;
    }
}

Bit Operation #8

2011-01-08T22:28:00.001-08:00


100000
100000
------
011111

000000
000000
------
000000

100000
000000
------
000000

000100
000100
------
111011

100100
100100
------
011011

100100
000100
------
111011

010101
101010
------
000000

111111
111111
------
000000

// A function using bitwise operators for above results. 
unsigned int f(unsigned int a, unsigned int b)
{
    if (a & b)
    {
        return ~(a & b); 
    }
    return 0;
}

Bit Operation #7

2011-01-08T22:12:00.000-08:00

Find the largest possible integer


int largestInt()
{
    return ~0;
}

Bit Operation #6

2011-01-08T00:14:00.000-08:00

Extract a single bit from a character.


int extractBit(char byte, unsigned int pos) 
{
    assert(pos < 8);

    return ((byte >> pos) & 1);
}

Extract a range of bits from a character.


char extractBitRange(char byte, unsigned int startPos, unsigned int offset) 
{
   assert((startPos + offset) < 8);
   return (byte >> startPos) & ~(0xfe << offset);
}

Bit Operation #5

2011-01-07T23:35:00.000-08:00

How can we check whether a particular bit is ON (1) or OFF (0)?


bool checkBitOn(unsigned int num, unsigned int i)
{
   return (num & (1 << i));
}

How can we turn OFF a particular bit in a number?


unsigned int turnBitOff(unsigned int num, unsigned int i)
{
    return (num & (~(1 << i)));
}

For example, num = 00010111 and i = 4. (1<<4)==00010000 and ~(1<<4)==11101111. Hence, num&(~(1<<4))==00010111 & 11101111==00000111.

Then, how can we turn ON a particular bit in a number?


unsigned int turnBitOn(unsigned int num, unsigned int i)
{
    return (num | (1 << i));
}

Bit Operation #4

2011-01-07T23:14:00.000-08:00

Let's think about how we can count the bit set to 1 in an integer?

 

int bitCount(unsigned int a)
{
    int count = 0;
    while (a != 0)
    {
        count += a & 0x01;
        a >>= 1;
    }
    return count;
}

Then, how can we optimize the process to work with several integers?

Bit Operation #3

2011-01-06T21:30:00.000-08:00

Input parameter a is a 4 bits integer (e.g., "1100" or "1000").


int f(int a)
{
    int b = 0;
    while (a >>= 1)
    {
       b++;
    }
    return b;
}

case1> 1100 (b==0)->0110 (b==1)->0011 (b==2)->0001 (b==3)->0000 : return 3
case 2> 1000 (b==0)->0100 (b==1)->0010 (b==2)->0001 (b==3)->0000 : return 3

This function returns the position of the leftmost '1' bit in input a.

Now, let's consider when 'while' statement can be infinite. Zero, with no non-zero bit, returns 0. A negative number throws the computer into an infinite loop. See below.

Signed 4bits integer
+7 : 0111
+6 : 0110
+5 : 0101
+4 : 0100
+3 : 0011
+2: 0010
+1 : 0001
+0: 0000
0 : n/a
-0 : 1111
-1 : 1000
-2 : 1001
-3 : 1011
-4 : 1100
-5 : 1101
-6 : 1110
-7 : 1111

Unsigned 4 bits integer
+15 : 1111
:
+7 : 0111
:
+1 : 0001
+0 : n/a
0 : 0000

Bit Operation #2

2011-01-06T20:52:00.000-08:00

Let's think about simple examples again.

Input: 4 bits integer x (e.g., 1010)


int f(unsigned int x)
{
    return !(x & (x-1));
}

We know that (x & (x-1)) operation erases the rightmost 1 bit in x. Now, consider an integer that is a power of two has exactly one bit that is '1'. Hence, if x contains only one bit that is '1', (x & (x-1)) will be zero (0000). After applying 'logical not' operation (!), a value of 0 becomes 1 and a value other than 0 becomes 0.

Therefore, this function returns whether an integer is a power of two. Consider one case where the input x is zero (0000). Then, this function returns 1 saying x is a power of two although zero is not a power of two. Hence, we have to modify this function as below.


int f(unsigned int x)
{
    return x && !(x & (x-1));
    // same to (x != 0) && !(x & (x-1));
}

Bit Operation #1

2011-01-06T20:03:00.000-08:00

Bit operation is very often asked in job interviews and can be very tricky. Here, I am going to brush up bit operation problems that can be expected in my future job interviews.

Input: 4 bits integer x (e.g., 1010)


int f(unsigned int x)
{
    int a = 0;
    while (x != 0)
    {
        x = x & (x-1);
        ++a;
    }
    return a;
}

Let's think of what (x-1) is in the case of x = 1010. (x-1) is 1001 because the rightmost bit of 1 in x is changed to 0 and all 0 bits to the right are changed to 1. Look at this details.
1 0 1 0
      |  |
      v  v
1 0 0 1

We can easily get the result after applying & operation for x and (x-1).
    1 0 1 0
& 1 0 0 1
-----------
    1 0 0 0

Hence, the result of & operation in while statement shows that the rightmost 1 bit of x turns to 0. Finally, if we do this operation until x become zero (0000), the variable 'a' will count the number of 1 bit in x.

Converting iPhone apps to iPad

2010-08-26T07:38:00.000-07:00

OpenGL and OpenGL ES Tessellator

2010-07-01T17:53:00.000-07:00

Tessellators and Quadrics
Polygon Tessellation In OpenGL
OpenGL Tessellation

GLU ES for OpenGL ES 1.x (for Win32)

iGLU: GLU for OpenGL ES 1.1 (for iPhone)
gluTessellator on iPhone

Anti-aliased line with Texture

2010-07-01T17:44:00.000-07:00

How to Render Anti-Aliased Lines with Textures in iOS 4

Sharing custom data between two iPhone applications

2010-05-05T08:21:00.001-07:00

In my iPhone application work, recently one issue came up. It is separating an iPhone application that I am developing into two applications while sharing custom data (i.e., images and text files) between two applications. So, I googled several forums with this issue. Here is my findings.

1) Using a server as a storage
2) Using a URL scheme
3) Using the pasteborad (UIPasteboard)
3) Using an "Address book" area

None of these was appropriate for my project where I need to share several images (1600x1200) and text files on a device without connection to a server. So, at this moment, I conclude that there is no way to share custom data between two iPhone applications.

[Reference 1] [Reference 2] [Reference 3] [Reference 4]

Code Sign Error after reinstalling provisioning profile

2010-04-29T08:44:00.000-07:00

Sometimes Xcode project file easily gets messed up. For example, when I try to rebuild my application that worked well with my previous provisioning file yesterday, however I reinstall my provisioning file today. In this case, following error message can be show up;

"Code Sign Error: Provisioning Profile (long string) can't be found."

Here is an easy solution.

1) Open the project file in a text editor:
The .xcodeproj file is actually not a file but a directory, like an application bundle. So, you can right click it in Finder to open. Then, select "package contents". Now, you will see several files. The actual project file is "project.pbxproj". Open it in a text editor.

2) Search provisioning profile setting and manually erase the lines. Save the project file:
They will look like these;
PROVISIONING_PROFILE = "xxxxxx.....xxxxx";
"PROVISIONING_PROFILE[sdk=iphoneos*]" = "xxxxxx.....xxxxx";

3) Reopen the project in Xcode and go to the settings to reselect your new provisioning profile.

Android on the iPhone

2010-04-22T17:46:00.000-07:00

Refer this blog

Using camera in your iPhone Application

2010-04-19T11:14:00.000-07:00

Here are some of cool stuffs that can be referred for iPhone application development using build-in camera.

1. iPhone Camera Overlay App With Custom Button Example
2. Custom camera applications development using iPhone SDK
3. Custom UIImagePickerController camera view

Using 3D models on iPhone

2010-04-07T09:43:00.000-07:00

iPhone SDK mesh COLLADA import

OSG new release supporting OpenGL ES

OSG on iPhone
OSG for iPhone support isn't still released (by Robert Osfield, Mar 1st 2010). But, we can try to use above changes by Thomas Holgarth.

3D Game Engines for iPhone

2010-04-06T14:01:00.000-07:00

Oolong Engine2.0
1) Oolong Engine for the iPhone: A First Look
2) Xcode Workspace Setup for Oolong

SIO2

Review of iphone 3d engines

ARM processor

2010-04-06T13:18:00.000-07:00

ARM instruction Set Architecture

iPhone App's Performance

2010-04-06T13:16:00.000-07:00

Break That Thumb For Best iPhone Performance

GDC Austin 2009: Squeezing Every Drop Of Performance Out Of The iPhone

vfp math library for iPhone

Augmented Reality (AR) brings Dibidogs alive in 3D

2010-04-02T13:21:00.000-07:00

Dibidogs alive in 3D

Public vs. Private vs. Protected

2010-02-24T11:46:00.000-08:00

Public members can be accessed by any function in the program.

Private members can only be accessed by other functions within the class.

Protected members is accessible to members of classes that inherit from the class in addition to the class itself and any friends

Overloading vs. Overriding

2010-02-24T11:42:00.000-08:00

Overloading is when you define two methods with the same name, in the same class, distinguished by their parameters.
-> Overloading is resolved at compile time.

Overriding is when you redefine a method that has already been defined in a parent class (using the exact same parameters).
-> Overriding is resolved at runtime (based on the type of the implicit first parameter).

Google developing a translator

2010-02-18T22:40:00.000-08:00

Wow! It will be very useful if it can really instantly translate during phone calls.

Google developing a translator for smartphones

OpenGL Tutorials

2010-02-17T21:24:00.000-08:00

1. Opengl Tutorial

2. OpenGL Vertex Buffer Object (VBO): Simple Tutorial

C++ Static Functions

2010-02-17T11:51:00.001-08:00

C++ Static Functions

Static member functions have a class scope and they do not have access to the 'this' pointer of the class. When a member is declared as static, a static member of class, it has only one data for the entire class even though there are many objects created forthe class. The main usage of static function is when the programmer wants to have a function which is accessible even when the class is not instantiated.

Development environment setup for Maemo 5.0

2010-02-15T20:29:00.000-08:00

Documentation/Maemo 5 Final SDK Installation

Gallery of Computation

2010-02-15T10:49:00.000-08:00

Gallery of Computation

Using UITouch in iPhone programming

2010-02-05T17:00:00.000-08:00

Using UITouch to drag an image on screen...

Universal C/C++ Static Library for iPhone simulator and device by GCC compiling

2010-01-20T13:10:00.000-08:00

This shows how to create universal static library to use c/c++ code for iPhone applications. Here, my cpp code is MathFuncsLib.cpp and MathFuncsLib.h.

I created following script file and run it to get "libMathFuncsLib-fat.a".

#!/bin/bash

/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator3.1.2.sdk -mmacosx-version-min=10.5 -D__IPHONE_OS_VERSION_MIN_REQUIRED=30000 -arch i386 -c -o MathFuncsLib_i386.o MathFuncsLib.cpp
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/gcc-4.2 -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.1.2.sdk -miphoneos-version-min=3.0 -arch armv6 -c -o MathFuncsLib_armv6.o MathFuncsLib.cpp

/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/ar rc MathFuncsLib_i386.a MathFuncsLib_i386.o
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/ar rc MathFuncsLib_armv6.a MathFuncsLib_armv6.o

/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/ranlib MathFuncsLib_i386.a
/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/ranlib MathFuncsLib_armv6.a

lipo MathFuncsLib_i386.a MathFuncsLib_armv6.a -create -output libMathFuncsLib-fat.a

Universal C/C++ Static Library for iPhone simulator and device using Xcode

2010-01-20T09:19:00.001-08:00

In my previous post, I googled many articles to create universal static library by using shell script. However, here is a simple and easy way to create universal static library that can be used for both iPhone Simulator and device.

How to create universal C/C++ static library using Xcode
1. Create a new project using Xcode: iPhone OS->Application->OpenGL ES Application using Xcode (e.g., MathFuncsLib)
2. Delete all files from Classes
3. Delete "main.m" from Other Sources
4. Delete the current target "MathFuncsLib"
5. Create new static library target "MathFuncsLib"
6. Add your header (e.g., MathFuncsLib.h) and source (e.g., MathFuncsLib.cpp) files for MathFuncsLib into in Classes
7. Select active SDK: Simulator - your SDK version and Build (library file for x86 architecture)
8. Select active SDK: Device - your SDK version and Build (library file for arm architecture)
9. Find library files for each architecture under a build folder and change their file name appropriately. For example "MathFuncsLib-x86.a" and "MathFuncsLib-arm.a"
10. Copy them into any same folder
11. Create universal static library by running "lipo MathFuncsLib-x86.a MathFuncsLib-arm.a -create -output libMathFuncsLib-fat.a" in Terminal

How to use universal C/C++ static library in your iPhone application
1. Create your iPhone application
2. Open Info for Target, and on Build tab, add your library name for Linking->Other Linker Flags (you should use this format: -l[your library name]. In my case, -lMathFuncsLib-fat)
3. If you create separate folders for library such as "Include" for header files and "Lib" for library file, add them for Search Paths->Header Search Paths and Library Search Paths on the Build tab
4. Import header file for library in your application (e.g., #import "MathFuncsLib/MathFuncsLib.h")
5. Build and Go application
6. If you want to look at your application on iPhone device, you also need to follow the instruction to install your application on device by using "Apple Developer Program"

Static library for iPhone Application

2010-01-15T10:19:00.000-08:00

[1] Stormy Productions Blog: Building Objective-C static library for iPhone SDK
[2] Cross-compiling for iPhone development
[3] iPhone Programming Tips: building Unix software

How to copy iPhone Application Data to Mac computer

2010-01-14T09:47:00.001-08:00

1) Navigate to the app on your phone via the XCode Organizer.

2) Click the triangle on the left of your app's name to show the "Application Data" field.

3) Press the down arrow on the right side of that to download it.

4) Save the application data into your local folder.
--> "Document", "Library", and "tmp" folders will be saved.

Motorola will release Android based smartphone, ST800 in 2010

2009-12-21T11:07:00.000-08:00

Recently, Motorola introduced new Android based smartphone, ST800.

It supports GSM & CDMA networks and uses two SIM cards so that two phone numbers can be used on a device.

Main features: 3G/WiFi/WAPI, 3.7" FWVGA Display, 854X480 resolution, Bluetooth 2.1, LED Flash 500M pixel camera, GPS, 3.5mm earphone jack

Real Time Rendering Book

2009-09-27T13:53:00.000-07:00

3rd Edition

OpenCL: Parallel programmers' new best friend

2009-08-31T15:21:00.000-07:00

OpenCL: Parallel programmers' new best friend

Job Search Tips: How to Address Job Hopping on a Resume

2009-08-19T08:04:00.001-07:00

Job Search Tips: How to Address Job Hopping on a Resume

Finding iPhone Application's memory leaks

2009-08-19T07:58:00.000-07:00

I found these useful guides by Googling.

1. Finding iPhone Memory Leaks: A “Leaks” Tool Tutorial: This explains with an iPhone device, but I am also sure we can use this tool, "Instruments" with an iPhone simulator. We can do it by choosing "iPhone Simulator" instead of "iPhone" and your own application by "Attach to process" drop down menu.

2. Memory Usage Performance Guide by Apple

Starting with Objective-C for iPhone Apps

2009-07-12T13:32:00.000-07:00

Recently, I need to start iPhone App programming in the project I am working.

Here are some useful references for beginners.

[Books]
1) Dave Mark and Jeff LaMarche, "Beginning iPhong Development", Apress, 2009.
2) Erica Sadun, "The iPhone Developer's Cookbook", Addison-Wesley, 2008.
3) "Learn Objective-C on the Mac", 2009.

[e-Books]
1) Bert Altenberg, Alex Clarke and Philippe Mougin, "Becom an Xcoder", 2008.
2) "Learn Objective-C 2.0 Language"

[Webpages]
1) Apple's iPhone Dev Center
2) Stanford University, CS 193P "iPhone Application Programming"
3) CocoaLab
4) Jeff LaMarche's iPhone Programming Blog

Profiler for Windows Mobile Applications

2009-06-02T15:31:00.000-07:00

EQATECT profiler

Highlighting CUDA syntax in VS2005

2009-04-21T16:30:00.000-07:00

How to enable syntax highlighting for CUDA files in VS2005

GPU programming using CUDA: Study #1

2009-04-21T12:59:00.000-07:00

Study material source
CUDA U [Education] Exercise

Methods : See CUDA Reference Manual for details.

1. Allocate host memory and device memory
cudaMalloc(void **devPtr, size_t count): allocate memory on the GPU
cudaMallocHost(void **hostPtr, size_t size): allocate page-locked memory on the host

2. Copy memory host to device, device to device, and device to host
cudaMemcpy(void *dst, const void *src, size_t count, enum cudaMemcpyKind kind): copies data between GPU and host
cudaMemcpyKind: cudaMemcpyHostToDevice, cudaMemcpyDeviceToDevice, cudaMemcpyDeviceToHost

3. Free host and device memory
cudaFree(void *devPtr): frees memory on the GPU

4. Block until all threads in the block have written their data to shared memory
__syncthreads(); // called on the GPU

5. Block until the device has completed
cudaThreadSynchronize(); // called on the host

Kernel configuration and Launch
dim3 dimGrid(1024);
dim3 dimBlock(256);
kernel_name <<< dimGrid, dimBlock>>>(kernel_arguments);

1D Indexing
single block:
int idx = threadIdx.x;
int reversed_idx = blockDim.x - 1 - threadIdx.x;

multi blocks:
int offset = blockIdx.x * blockDim.x;
int idx = offset + threadIdx.x;
int reversed_offset = blockDim.x * (gridDim.x - 1 - blockIdx.x);
int reversed_threadIdx = blockDim.x - 1 - threadIdx.x;
int reversed_idx = reversed_offset + reversed_threadIdx;

Using shared memory
Declaration:
extern __shared__ int s_data[];

Terminology
1. Host: CPU
2. Device: GPU
3. Kernel: a function that runs on the GPU, executed by an array of threads
4. Grid: a set of blocks (dimension of grid == # blocks a grid)
5. Block: a set of threads (dimension of block == # threads in a block)
6. Thread: one thread runs kernel
7. Shared memory:

Declarations on functions
__host__: host only
__global__: interface
__device__: device only
__shared__: shared memory
__local__:

GPU programming using CUDA

2009-04-21T12:46:00.000-07:00

Starting GPU programming using CUDA

1. CUDA U
[Education]
[University Courses]

Useful tool for the presentation of your mobile application

2009-03-30T12:53:00.000-07:00

"Real-Time Remote Control" and "Presentation Tools" will be very useful.

Pocket Controller Pro

Random Number Generator in C++

2009-03-11T08:57:00.000-07:00

Random Number Generator in C++

See here

Samsung I7410 Pico Projector Phone

2009-03-10T19:36:00.000-07:00

See this video clip

Read this news

How to run windows mobile application as a background process?

2009-03-01T12:16:00.000-08:00

To send your application to the background, you can use Hide() function.

For example, when you have a form (myForm) to hide, call this, myForm.Hide(). This results in that myForm.visible is set with "false".

To check that your application is really running on background, let's go to the "Settings -> System tab -> Memory -> Running programs tab".

Unfortunately, you cannot find your application on the list. (But, actually your application is running as a backroung process.)

Now, let's check with "Remote Process Viewer". Click "Microsoft Visual Studio 2005 -> Visual Studio Remote Tools -> Remote Process Viewer". (You need to connect your mobile device to your computer.)

You can surely find your application's name on the Process list. To kill it, click "X" icon on toolbar menu.

This is a drawback when you use Hide() function to send your application to the background.

Here is another way to overcome this problem.

It is to use the Native function "ShowWindow()" with the ‘Minimized’ property:


[DllImport("coredll.dll")]
        static extern int ShowWindow(IntPtr hWnd, int nCmdShow);
        const int SW_MINIMIZE = 6;
        public void Hide()
        {
            ShowWindow(myForm.Handle, SW_MINIMIZE);
        }

Reference:
1. http://www.go4expert.com/forums/showthread.php?t=973
2. http://jajahdevblog.com/jasmine/?p=41

How to capture screenshots of mobile device or emulator

2009-03-01T11:28:00.000-08:00

Here is a procedure to follow to take a screenshot.

1. Open "Microsoft Visual Studio 2005 -> Visual Studio Remote Tools -> Remote Zoom In".

2. Select one on a "Select a Windows CE Device" dialog, which is the thing you want to connect. Make sure a device connected to your computer.

3. You will see the screenshot. If you want to take another screenshot, click "Target -> Refresh" on the menu of the Remote Zoom In, or press F5 key.

4. Now, you can save the screenshot as an image (BMP). Select "File -> Save As".

Reset StreamReader in C#

2009-02-27T18:36:00.000-08:00

Hello,

This is a little bit weired, but it works.

During reading a file, I wanted to reset file pointer to start from the begining of a file. I used FileStream and StreamReader in C#.

My initial ideal was to call these two functions;

FileStream fs;
StreamReader sr;
:
:
:
fs.Seek(0, SeekOrigin.Begin);
sr.BaseStream.Seek(0, SeekOrigin.Begin);

However, this didn't work although I checked fs.Position == 0 and sr.BaseStream.Position == 0.

Finally, I solved this problem as follows;

FileStream fs;
StreamReader sr;
:
:
:
fs.Seek(0, SeekOrigin.Begin);
sr.DiscardBufferedData();
sr.BaseStream.Seek(0, SeekOrigin.Begin);
sr.BaseStream.Position = 0;

Frankly, I can't understand why I need to use these three lines for resetting StreamReader. But, anyway it works well, and I can start to read from the begining of a file.

IEEE 754 floating point format

2009-02-24T19:09:00.001-08:00

IEEE single precision format

2009-02-24T19:07:00.000-08:00

Toggle bulbs and switches

2009-02-24T19:01:00.000-08:00

room lighting.. room with 100 bulbs and switches..

100 people goes in one by one.

1st person toggles all switches.

2nd person toggles all switeches which are multiles of 2 (2,4,6..)

and so on ( till 100th person toggling only 100th switch)

once finished with all, ==> which all bulbs are ON.

1th: all switches are ON
2nd: 2, 4, 6, 8, ... switches are OFF
3rd: 3, 9,... OFF
3rd: 6 12 ... ON
:
:
:
100th: only toggle 100th switch

sizeof operator

2009-02-24T17:54:00.000-08:00

sizeof
In the programming languages C and C++, the unary operator 'sizeof' is used to calculate the sizes of datatypes. sizeof can be applied to all datatypes, be they primitive types such as the integer and floating-point types defined in the language, pointers to memory addresses, or the compound datatypes (unions, structs, or C++ classes) defined by the programmer. sizeof is a compile-time operator that returns the size in bytes of the variable or parenthesized type-specifier that it precedes. -- http://en.wikipedia.org/wiki/Sizeof --

Here is an interesting test for the size of several types by myself.



#include "stdio.h"

#define mySizeOf(x) ((char*)(&(x)+1)-(char*)(&x))

struct myType { // This is a structure containing four variables of different types
 char a;
 int b;
 float c;
 double d;
};

struct blankType {  // This is a structure with no variable
};

class CBlankClass {  // This is a class with no member variable
public:
public:
 CBlankClass() {};
 ~CBlankClass() {};

 void function1() {};
 void function2() {};
};

class CMyClass {  // This is a class with a int type member variable
public:
 int memberVar1;

public:
 CMyClass() {};
 ~CMyClass() {};

 void function1() {};
 void function2() {};
};

void main()
{
 char var1;
 printf("Size of char type = %d\n", mySizeOf(var1));

 int var2;
 printf("Size of int type = %d\n", mySizeOf(var2));

 float var3;
 printf("Size of float type = %d\n", mySizeOf(var3));

 double var4;
 printf("Size of double type = %d\n", mySizeOf(var4));

 char var5[] = "AB";
 printf("Size of char array ""AB"" = %d\n", mySizeOf(var5));

 struct myType var6;
 printf("Size of struct myType = %d\n", mySizeOf(var6));

 struct blankType var7;
 printf("Size of struct blankType = %d\n", mySizeOf(var7));

 CBlankClass var8;
 printf("Size of class CBlankClass = %d\n", mySizeOf(var8));

 CMyClass var9;
 printf("Size of class CMyClass = %d\n", mySizeOf(var9));
}

Output:
Size of char type = 1
Size of int type = 4
Size of float type = 4
Size of double type = 8
Size of char array AB = 3
Size of struct myType = 24
Size of struct blankType = 1
Size of class CBlankClass = 1
Size of class CMyClass = 4

From this result, interesting things are these,
Size of struct myType = 24
--> For a struct myType, if it has only "char a", its size is 1. But, if it has "char a" and "int b", its size becomes not 5 but 8. If it has "char a", "int b", and "float c", its size becomes 12.
Size of struct blankType = 1
Size of class CBlankClass = 1
--> Both black structure and class (no member variable) have its size 1.
--> For class, member functions don't affect on the size.
Size of class CMyClass = 4
--> If a class has member variables, its size will be the same to the situation of structre above.

memcpy() vs. memmove() in C

2009-02-24T17:42:00.000-08:00

Here is the difference between memcpy() and memmove().

Example:
str = "strings are good";
memmove(str + 8, str + 11, 4);
This returns --> strings are are good
memcpy(str + 8, str + 11, 4);
This returns --> strings are ared

Example:



/* memcpy example */
#include 
#include 

int main ()
{
  char str1[]="Sample string";
  char str2[40];
  char str3[40];
  memcpy (str2,str1,strlen(str1)+1);
  memcpy (str3,"copy successful",16);
  printf ("str1: %s\nstr2: %s\nstr3: %s\n",str1,str2,str3);
  return 0;
}

Output:
str1: Sample string
str2: Sample string
str3: copy successful

Example:



/* memmove example */
#include 
#include 

int main ()
{
  char str[] = "memmove can be very useful......";
  memmove (str+20,str+15,11);
  puts (str);
  return 0;
}

Output:
memmove can be very very useful.

How to connect a server from mobile client in C#

2009-02-12T12:36:00.000-08:00

I need to know this.

Get "unique device ID" of a mobile device

2009-02-12T12:34:00.001-08:00

I searched Internet a lot to find how to get "unique device id" for mobile devices, which is not dependent on any application data.

I am developing on Windows Mobile 6 with HTC phone.

There are severay ways to do it.

1) Use GetDeviceUniqueID(): GetDeviceUniqueID() requires at least 8 bytes of data to generate a hash. Furthermore, you should not expect GetDeviceUniqueID() to return the UUID string as HAL_GET_DEVICEID does. It will return application-specific hash that is unique for this particular device. You should treat it as a sequence of bytes.

2) Use HAL_GET_DEVICEID: This does not work on Smartphone unless your code is signed with a privleged certificate.

3) Get IMEI(International Mobile Equipment Identity) number: The IMEI number is a unique 15-digit code used to identify an individual GSM mobile phone in a GSM network. The IMEI number can be displayed on most phones by dialing the code *#06#. Every phone has a unique IMEI number, which is usually printed under the battery on the phone. The IMEI number is used in many mobile applications since the unique number makes it possible to lock software to a particular phone. This effectively prevents unauthorized copying of an application.
--> Use Tapi dll
--> Make your code (See, References (2))
: References
1) Getting the IMEI number: a UIQ 3 code example

2) IMEI in C#




using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

// Reference: http://groups.google.com/group/microsoft.public.dotnet.framework.compactframework/browse_thread/thread/280299812d7b171c
public class clsDeviceInfo 
{ 
    private string _manufacture; 
    private string _model; 
    private string _revision; 
    private string _serialNumber; // IMEI 
    private string _subscriberID; // IMSI 
    
    public string Manufacture 
    { 
        get { return _manufacture; } 
    } 
    
    public string Model 
    { 
        get { return _model; } 
    } 
    
    public string Revision 
    { 
        get { return _revision; } 
    } 
    
    public string SerialNumber 
    { 
        get { return _serialNumber; } 
    } 
    
    public string SubscriberID 
    { 
        get { return _subscriberID; } 
    } 
    
    public clsDeviceInfo() 
    { 
        GetDeviceInfo(); 
    } 
    
    private void GetDeviceInfo() 
    { 
        IntPtr hLine; 
        int dwNumDev; 
        int num1 = 0x20000; 
        
        LINEINITIALIZEEXPARAMS lineInitializeParams = new LINEINITIALIZEEXPARAMS(); 
        lineInitializeParams.dwTotalSize = (uint)Marshal.SizeOf(lineInitializeParams); 
        lineInitializeParams.dwNeededSize = lineInitializeParams.dwTotalSize; 
        lineInitializeParams.dwUsedSize = lineInitializeParams.dwUsedSize; 
        lineInitializeParams.dwOptions = 2; 
        lineInitializeParams.hEvent = IntPtr.Zero; 
        lineInitializeParams.hCompletionPort = IntPtr.Zero; 
        
        // lineInitializeEx 
        int result = NativeTapi.lineInitializeEx(out hLine, IntPtr.Zero, IntPtr.Zero, null, out dwNumDev, ref num1, ref lineInitializeParams); 
        if (result != 0) 
        { 
            return; 
        } 

        // lineNegotiateAPIVerison 
        int version; 
        int dwAPIVersionLow = 0x10004; 
        int dwAPIVersionHigh = 0x20000; 
        LINEEXTENSIONID lineExtensionID; 
        result = NativeTapi.lineNegotiateAPIVersion(hLine, 0, dwAPIVersionLow, dwAPIVersionHigh, out version, out lineExtensionID); 
        if (result != 0) 
        { 
            return; 
        } 
        
        // lineOpen 
        IntPtr hLine2 = IntPtr.Zero; 
        result = NativeTapi.lineOpen(hLine, 0, out hLine2, version, 0, IntPtr.Zero, 0x00000002, 0x00000004, IntPtr.Zero); 
        if (result != 0) 
        { 
            return; 
        } 
        
        // lineGetGeneralInfo 
        int structSize = Marshal.SizeOf(new LINEGENERALINFO()); 
        byte[] bytes = new byte[structSize]; 
        byte[] tmpBytes = BitConverter.GetBytes(structSize); 
        
        for (int index = 0; index < tmpBytes.Length; index++) 
        { 
            bytes[index] = tmpBytes[index]; 
        } 
        
        // make initial query to retrieve necessary size 
        result = NativeTapi.lineGetGeneralInfo(hLine2, bytes); 
        
        // get the needed size 
        int neededSize = BitConverter.ToInt32(bytes, 4); 
        
        // resize the array 
        bytes = new byte[neededSize]; 
        
        // write out the new allocated size to the byte stream 
        tmpBytes = BitConverter.GetBytes(neededSize); 
        for (int index = 0; index < tmpBytes.Length; index++) 
        { 
            bytes[index] = tmpBytes[index]; 
        } 
        
        // fetch the information with properly size buffer 
        result = NativeTapi.lineGetGeneralInfo(hLine2, bytes); 
        if (result != 0) 
        { 
            //LogManager.GetLogger("DeviceInfo").Error(Marshal.GetLastWin32Error().ToString()); 
            return; 
        } 
        
        int size; 
        int offset; 
        
        size = BitConverter.ToInt32(bytes, 12); 
        offset = BitConverter.ToInt32(bytes, 16); 
        
        // manufacture 
        if (size > 0 && offset > 0) 
        { 
            _manufacture = Encoding.Unicode.GetString(bytes, offset, size); 
            _manufacture = _manufacture.Substring(0, _manufacture.IndexOf('\0')); 
        } 
        
        size = BitConverter.ToInt32(bytes, 20); 
        offset = BitConverter.ToInt32(bytes, 24); 
        
        // model 
        if (size > 0 && offset > 0) 
        { 
            _model = Encoding.Unicode.GetString(bytes, offset, size); 
            _model = _model.Substring(0, _model.IndexOf('\0')); 
        } 
        
        size = BitConverter.ToInt32(bytes, 28); 
        offset = BitConverter.ToInt32(bytes, 32); 
        
        // revision 
        if (size > 0 && offset > 0) 
        { 
            _revision = Encoding.Unicode.GetString(bytes, offset, size); 
            _revision = _revision.Substring(0, _revision.IndexOf('\0')); 
        } 
        
        size = BitConverter.ToInt32(bytes, 36); 
        offset = BitConverter.ToInt32(bytes, 40); 
        
        // serial number (IMEI) 
        if (size > 0 && offset > 0) 
        { 
            _serialNumber = Encoding.Unicode.GetString(bytes, offset, size); 
            _serialNumber = _serialNumber.Substring(0, _serialNumber.IndexOf('\0')); 
        } 
        
        size = BitConverter.ToInt32(bytes, 44); 
        offset = BitConverter.ToInt32(bytes, 48); 
        
        // subscriber id (IMSI) 
        if (size > 0 && offset > 0) 
        { 
            _subscriberID = Encoding.Unicode.GetString(bytes, offset, size); 
            _subscriberID = _subscriberID.Substring(0, _subscriberID.IndexOf('\0')); 
        } 
        
        // lineClose for hLine2 
        NativeTapi.lineClose(hLine2); 
        
        // lineShutdown for hLine 
        NativeTapi.lineShutdown(hLine); 
    } 
    
    [StructLayout(LayoutKind.Sequential)] 
    private struct LINEEXTENSIONID 
    { 
        public IntPtr dwExtensionID0; 
        public IntPtr dwExtensionID1; 
        public IntPtr dwExtensionID2; 
        public IntPtr dwExtensionID3; 
    } 
    
    [StructLayout(LayoutKind.Sequential)] 
    private struct LINEINITIALIZEEXPARAMS 
    { 
        public uint dwTotalSize; 
        public uint dwNeededSize; 
        public uint dwUsedSize; 
        public uint dwOptions; 
        public System.IntPtr hEvent; 
        public System.IntPtr hCompletionPort; 
        public uint dwCompletionKey; 
    } 
    
    [StructLayout(LayoutKind.Sequential)] 
    private struct LINEGENERALINFO 
    { 
        public int dwTotalSize; 
        public int dwNeededSize; 
        public int dwUsedSize; 
        public int dwManufacturerSize; 
        public int dwManufacturerOffset; 
        public int dwModelSize; 
        public int dwModelOffset; 
        public int dwRevisionSize; 
        public int dwRevisionOffset; 
        public int dwSerialNumberSize; 
        public int dwSerialNumberOffset; 
        public int dwSubscriberNumberSize; 
        public int dwSubscriberNumberOffset; 
    } 
    
    private class NativeTapi 
    { 
        [DllImport("coredll")] 
        public static extern int lineClose(IntPtr hLine); 

        [DllImport("cellcore")] 
        public static extern int lineGetGeneralInfo(IntPtr hLine, byte[] bytes); 

        [DllImport("coredll")] 
        public static extern int lineGetAddressCaps(IntPtr hLineApp, int dwDeviceID, int dwAddressID, int dwAPIVersion, int dwExtVersion, byte[] lpAddressCaps); 

        [DllImport("coredll")] 
        public static extern int lineInitializeEx(out IntPtr lpm_hLineApp, IntPtr hInstance, IntPtr lpfnCallback, string lpszFriendlyAppName, out int lpdwNumDevs, ref int lpdwAPIVersion, ref LINEINITIALIZEEXPARAMS lpLineInitializeExParams); 

        [DllImport("coredll")] 
        public static extern int lineNegotiateAPIVersion(IntPtr m_hLineApp, int dwDeviceID, int dwAPILowVersion, int dwAPIHighVersion, out int lpdwAPIVersion, out LINEEXTENSIONID lpExtensionID); 

        [DllImport("coredll")] 
        public static extern int lineOpen(IntPtr m_hLineApp, int dwDeviceID, out IntPtr lphLine, int dwAPIVersion, int dwExtVersion, IntPtr dwCallbackInstance, int dwPrivileges, int dwMediaModes, IntPtr lpCallParams); 

        [DllImport("coredll")] 
        public static extern int lineShutdown(IntPtr m_hLineApp); 
    } 
}

Add remider function in Windows Mobile application

2009-02-12T12:32:00.000-08:00

I need to do this.

Sorting 2D string list in C#

2009-02-11T17:21:00.000-08:00




/*
 * In application code
 */
// Declare a variable for data
public static List recordList = new List(); 

// Set a list
// For example,
//    2/11/2009, apple, 20
//    2/10/2009, banana, 5
//    1/30/2009, pineapple, 3
recodeList.Add(new clsDataRecord(DateTimeVar1, TextVar1, IntVar1));
recodeList.Add(new clsDataRecord(DateTimeVar2, TextVar2, IntVar2));
recodeList.Add(new clsDataRecord(DateTimeVar3, TextVar3, IntVar3));

// Call sorting by date
clsDataRecord.CompType = clsDataRecord.ComparisonType.Date;
Program.altRecordList.Sort();
// Sorted result will be
//    1/30/2009, pineapple, 3
//    2/10/2009, banana, 5
//    2/11/2009, apple, 20

// Call sorting by text
clsDataRecord.CompType = clsDataRecord.ComparisonType.Text;
Program.altRecordList.Sort();
// Sorted result will be
//    2/11/2009, apple, 20
//    2/10/2009, banana, 5
//    1/30/2009, pineapple, 3

// Call sorting by number
clsDataRecord.CompType = clsDataRecord.ComparisonType.Number;
Program.altRecordList.Sort();
// Sorted result will be
//    1/30/2009, pineapple, 3
//    2/10/2009, banana, 5
//    2/11/2009, apple, 20



/*
 * Class for clsDataRecord
 */
using System;
using System.Collections;

class clsDataRecord : IComparable
{
    public enum ComparisonType
    {
        Date = 1,
        Text = 2,
        Number = 3
    };

    // This class has three different members.
    // You can customize these with your own data.
    private DateTime _date;
    private string   _text;
    private int      _number;

    private static ComparisonType _compType;

    public clsDataRecord(DateTime date, string text, int number)
    {
        _date = date;
        _text = text;
        _number = number;
    }

    public DateTime Date
    {
        get { return _date; }
        set { _date = value; }
    }

    public string Text
    {
        get { return _text; }
        set { _text = value; }
    }

    public int Number
    {
        get { return _number; }
        set { _number = value; }
    }

    public static ComparisonType CompType
    {
        get { return _compType; }
        set { _compType = value; }
    }

    public override string ToString()
    {
        return String.Format("{0} - {1} - {2}", _date.ToShortDateString(), _text, _number.ToString());
    }

    public int CompareTo(object obj)
    {
        if (obj is clsDataRecord)
        {
            clsDataRecord r2 = (clsDataRecord)obj;

            switch (_compType)
            {
                case ComparisonType.Date:
                    return _date.CompareTo(r2.Date);
                case ComparisonType.Text:
                    return _text.CompareTo(r2.Text);
                case ComparisonType.Number:
                default:
                    return _number.CompareTo(r2.Number);
            }
        }
        else
            throw new ArgumentException("Object is not an clsDataRecord.");
    }
}

Rectangular Array vs. Jagged Array in C#

2009-02-11T11:40:00.000-08:00

Reference: http://en.csharp-online.net/All_about_Arrays_in_CSharp%E2%80%94Comparing_Rectangular_and_Jagged_Arrays

Set DateTimePicker in C# with specific date

2009-02-06T14:06:00.000-08:00

string example = "2/6/09";
char[] delimiter = {'/'};
string[] dateInfo = example.Split(delimiter);

private System.Windows.Forms.DateTimePicker myDateTimePicker;

myDateTimePicker.Value = new DateTime(int.Parse(dateInfo[2]) + 2000, int.Parse(dateInfo[0]), int.Parse(dateInfo[1]));

string to integer in C#

2009-02-06T14:04:00.000-08:00

Example

string str = "09";
int year = int.Parse(str) + 2000;

Output
year == 2009

Split string in C#

2009-02-06T13:24:00.000-08:00

Example code

class TestStringSplit
{
static void Main()
{
char[] delimiterChars = { ' ', ',', '.', ':', '\t' };
string text = "one\ttwo three:four,five six seven";
System.Console.WriteLine("Original text: '{0}'", text);
string[] words = text.Split(delimiterChars);
System.Console.WriteLine("{0} words in text:", words.Length);
foreach (string s in words)
{
System.Console.WriteLine(s);
}
}
}

Output

Original text: 'one two three:four,five six seven'
7 words in text:
one
two
three
four
five
six
seven

Reference: http://msdn.microsoft.com/en-us/library/ms228388(VS.80).aspx

Related work searching

2009-02-06T12:09:00.000-08:00

"http://www.scitopia.org/" provides an interesting related work searching facility supoorted by a large number of professonal societies - led by IEEE.

How to access the file system on Windows Mobile 5 Smartphone emulator

2009-02-06T07:06:00.000-08:00

Here is the short description about how to access the file system on Windows Mobile emulator.

If your application is using data files or images, you need to copy them in a memory for the emulator.

I assume that you use Visual Studio 2005, you didn't connect any mobile device to your desktop, and you have already installed ActiveSync.

Here is simple procedure.
1. Under "Tools" in Visual Studio 2005, select "Device Emulator Manager".
2. Scroll down the list of emulated devices until you see what you want to use.
(i.e., I selected "Windows Mobile 5.0 Smartphone Emulator".)
3. Under "Actions" in the emulator manager, select "Connect". Then, an emulator will pop up.
4. Under "Actions" in the emulator manager, select "Cradle".
5. Now open ActiveSync. Under "File" in ActiveSync, select "Connection Settings". Check "Allow connections to one of the following" and select "DMA". You only need to do this once. When you click “Connect” in ActiveSync, it connects to the emulator and give you some setup screens. After the first time, the connection happens automatically when you “cradle” the emulator via the Device Emulator manager.
6. Now you can browse the file system on the emulator by selecting “Explore” on ActiveSync (or
selecting “Mobile Device” from My Computer). By default, your application is deployed to
“Program Files\[your application name]”.

Reference: http://inst.eecs.berkeley.edu/~cs160/sp06/section/vstutorial.pdf

The first post

2008-09-06T10:38:00.000-07:00

I created this new blog to write some meno and information for myself and people who want to be a graphics software engineer. I got master degree in computer graphics in 2000, and worked as a graphcis softwre engineer in Korea for six years. Now, I am a Ph.D. student at Purdue University. I also hope to continue to work as a graphics software engineer after getting Ph.D. degree.