C++ :: Rotating A Circular Disk?
Aug 30, 2013Any algorithm or function to rotate a displayed circle. To turn it 360 degrees like a car-tire. (It's needed to turn a turn-table in a model-railrod control program) .....
View 14 Replies
ADVERTISEMENT
C++ :: Quaternion For Rotating Vectors
Dec 28, 2013I try to use quaternion to rotate one(and later more!) 3d-vectors in a general manner.
i read in wikipedia, that the general calculation goes with:
vector_rot = quaternion * vector * quaternion_compl.conj.
I used the class of irrlicht [URL] .... to do the calculations.
there is no premade function in this class to rotate vectors through this quaternions, so i just tried to it this way:
irr::core::vector3df v1(1,0,0);
irr::core::quaternion a1(2,3,4,6);
a1.normalize();
irr::core::vector3df result2(a1.X*v1.X*(-a1.X),a1.Y*v1.Y*(- a1.Y),a1.Z*v1.Z*(-a1.Z));
result2 should then be the rotated vector, but it does not work. i dont know how to explicitely write down the rotation specification in this topic.
C++ :: Rotating Pixel Field
Apr 21, 2014I wrote a script that generates n random pixel positions and draws them to the screen. Works well. Now i tried to rotate them. Rotating does work too. But it does not work as i planned it.
paramters 'angle' and 'timestep' work somehow, but not as they should do. the function 'move' is supposed to rotate the pixelfield 'angle' degrees in a given direction, addicted to the 'timestep' parameter. 'timestep' is needed time for drawing in one single game loop.
angle_step = timestep * angle
// x
ppdPoint[i]->x =
pRotationPoint->x + cos(angel_step) * (ppdPoint[i]->x - pRotationPoint->x) - sin(angel_step) * (ppdPoint[i]->y - pRotationPoint->y);
// y
ppdPoint[i]->y =
pRotationPoint->y + sin(angel_step) * (ppdPoint[i]->x - pRotationPoint->x) + cos(angel_step) * (ppdPoint[i]->y - pRotationPoint->y);
rotation point is the middle of the screen. when i set angle to 10 it should rotate 10 degrees / second. Instead it's rotating very very fast and all stars are moving nearer to the center of the screen, so after x rounds there is just 1 pixel left in the middle of the screen. there is a kind of gravition.I'm working with SDL2. What I did find out:
FPS is <= 60, 'cause of the 'SDL_RENDERER_PRESENTVSYNC' flag. When i skip that flag, for any reason the 'gravition' would take more time. FPS is <= 1400 then, 'though i got a natural game loop (i hope):
while(pBuild->getExecuteFlag())
{
pBuild->draw();
pBuild->update(time_dif, pTimeWindow->TimeStampB);
time_dif = (pTimeWindow->TimeStampB - pTimeWindow->TimeStampA);
time_dif *= 0.001;
pTimeWindow->TimeStampA = pTimeWindow->TimeStampB;
pTimeWindow->TimeStampB = SDL_GetTicks();
pBuild->count_fps(pTimeWindow->TimeStampB);
}
So maybe (timestep * angle) isn't the right way?
C++ :: SDL Rotating Images Function
Jun 9, 2013Since SDL doesn't have it's own function for rotating images and I'm tired of storing multiple angles of the same sprite in a file, I created my own function for doing so:
//XY Class
class XY {
public:
XY(){}
XY(float x, float y);
[Code] ....
The problem is while Spin does spin the surface correctly, some pixels are rotated to the same new position so gaps appear in the returned surface. I need a way of filling in the gaps so the returned image looks better. A link to a program I made that uses this function is below so you can see the problem that I'm talking about. [URL] ....
I currently use SDL 1.2. Could my problem be fixed if I used 2.0? For example, does SDL 2.0 have a built in function for rotating surfaces?
C :: Rotating Array And Assigning It To Different Variables
Feb 3, 2013I have a problem with rotating an array and assigning it to different variables. This is wat i have done.
Code:
#include<stdio.h>#include<stdlib.h>
#include<conio.h>
#include<math.h>
int n[16],a[16],n1[16],n2[16],n3[16],n4[16],n5[16],n6[16],n7[16],n8[16],n9[16],n10[16],n11[16],n12[16],n13[16],n14[16],n15[16],n16[16], c=0;
int x[16],i,j,k;
int rotate();
[code]....
C++ :: How To Write Bits To A Disk
Mar 30, 2014I'm trying to write a program that writes data to a disk in C++ without caring about it's file system. Here is what I can do so far:
#include <iostream>
#include <unistd.h>
#include <fcntl.h>
using namespace std;
char buffer[] = "Wow! I'm writing this data to a disk without puttting it into a file!";
int main(){
int Disk=open("/dev/sdb",O_RDWR);
write(Disk,buffer,sizeof(buffer));
close(Disk);
return 0;}
But this program can only write ASCII characters to the disk. But what if I want to mainipulate bits on the disk, how would I do that?
C :: How To Save Char Arrays To Disk
Dec 29, 2013lets say I have a char array with four elements but only one char is used, does it write four elements or just one?
View 3 Replies View RelatedC++ :: RAM Disk And Pointer To Content In File
Mar 3, 2014When we are using RAM DISK - the files are stored on the RAM. From what I understand (and saw many examples) in order to read data from file (the file which locate on the RAM) - I need to use the read function.
Is there a chance to get char* (or any pointer) to the content of the file without using the read function ?
If the file locate on the RAM, it seem that it is like I have a buffer on the RAM (like an array which was dynamic allocated) and in the case of a buffer on the ram -> we can use pointers to the data without reading all the data.
example:
class CDATA {
int nValue1;
int nValue2;
double dValue3;
double dValue4;
char achBuf[10];
[Code] .....
C++ :: Implementing Class To Simulate A Disk
Oct 1, 2013So this code compiles without any problem but it is not producing the correct output. I know there's a problem in either my getBlock or putBlock functions but I can't see it.
Currently the output is "Should be 32 1s: "
"Should be 32 2s: "
There should be 32 1s and 32 2s and nothing is coming out.
#include <iostream>
#include <fstream>
using namespace std;
class Sdisk {
public :
Sdisk(string diskname);
[Code] .....
Visual C++ :: Storing Some Variables In Disk?
Feb 9, 2014I am using Visual C++ to write an app. One problem is that the application will allocate a lot of object instances of a specific class CMyObject, maybe 400, 000. This will cause "Out of memory" error when total allocated CMyObject reaches 400,000.
To solve this problem, I just wonder when a new CMyObject instance is created, is it possible to specify so that the instance will allocate on a disk cache, or file mapping instead of the memory space?
C :: How To Get Memory Address Of A File In Hard Disk
Sep 12, 2013I made a text file. I can do all File I/O functions in c. no problem! except that "I want to get the memory address of the beginning of that File", so that I can access each character of the file by incrementing memory address.
View 1 Replies View RelatedC++ :: Writing Image Data To Disk In Parallel?
Apr 21, 2012Basically, I want to write an image to disk in parallel with an algorithm that is processing that same image. The code is really simple:
Code:
string ProcessImage(System::Drawing::Bitmap ^bmp, System::String^ targetFile) {
bmp->Save(targetFile);
System::Drawing::Bitmap^ bmp8 = BitmapConvertPixelFormat(bmp, 8); //<-- a function I wrote which converts the 32bpp I am passed into an 8bpp one
string results = Analyze(bmp8); //<--- takes a good bit of time
return results;
}
What would be the fastest way to do this? Any libraries with a code sample. I would prefer one that is within .NET or native C++ just to avoid having to link into many different libraries.
Visual C++ :: Getting Free Disk Space Of Certain Directory?
Nov 23, 2014Code:
_int64 free_space_64bit;
PULARGE_INTEGER lpFreeBytesAvailable, lpTotalNumberOfBytes,lpTotalNumberOfFreeBytes;
//char currentPath[MAX_PATH];
//GetCurrentDirectoryA(MAX_PATH, currentPath);
GetDiskFreeSpaceExA("H:C", lpFreeBytesAvailable, lpTotalNumberOfBytes,lpTotalNumberOfFreeBytes);
free_space_64bit = lpFreeBytesAvailable->HighPart << 32 | lpFreeBytesAvailable->LowPart;
This directory "H:C" does exist, if I comment out the GetDiskFreeSpaceExA line, the program doesn't crash, but it leads to some peculiar results (some uninitialized and random value, but at least it doesn't crash)
C++ :: Call Only Those Functions Whose Names Are Written In Disk File
May 26, 2013Here is a working C++ program and its output that reads the names of a certain number of functions whose names are written in a disk file that provides the control parameters in a near-real time fashion. Based on this information, the program calls those functions whose names were given in this text file as parameters. The method I have used is to build a map of functions that connects the names of the functions to the actual functions. Once this map is created, then it is very easy to iterate in such a way that only those selected functions are called.
So far this is working well, and it makes the logic of the code easier because ultimately there will be a large inventory of functions (probably hundreds of functions), and this way of pre-building a map of functions avoids writing hundreds of if statements in the code. Of course, pre-building this reusable map in the background is still equivalent to writing that many if statements, but at least it makes the code very compact and much more automatic, since it is done only once.
But I now have a related question: In this case (when the selected subset of functions to call is given as incoming data as in this example), does C++ make it possible to avoid using maps of functions, by directly applying the string variable that holds the name of the function in order to call the original function immediately For instance, if a string variable s = "MyFunction", then is there a more direct way of using this string as if it were the actual function whose name is spelled exactly in that way? This would make the code even more compact.
Here is the sample test code for the map of functions, and its output:
First of all here is the text file "FileForNamesOfFunctions.TXT" that contains the part of the "data", which is the set of functions select from from the inventory and only call these:
Code:
function2
function3
function5 And here is the C++ code that uses this "data":
Code:
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
[Code] ....
Visual C++ :: Open Large Files - Save Video As Long As Users Have Space In Hard Disk
Jan 15, 2013Opening large files in c++. In my application, i am trying to save video as long as users have space in harddisk. What I am trying to do is when user is recording video i am trying to append the video data in to the file. The problem is that every time file size reach over 2GB my software crashes.
View 5 Replies View RelatedC++ :: Circular Right Shift A Cstring
Jan 29, 2013I need to circular right shift a cstring in C++
Let's say I have unsigned char test[10] = "HELLO!!!"; How would I go about circularly shifting this to the right? Inline assembly instructions would be ok too
C++ :: Circular Reference Not Working?
Mar 15, 2013It's compiling but it's not working, it enters in stack overflow. It's a Doubly Linked List I'm compiling in Visual Studio. I think there's nothing wrong with this declaration, but there's just might be it:
class ListItem;
class List {
public:
ListItem *firstItemRef;
[Code] .....
C/C++ :: Circular Permutation Through Function
Jan 17, 2015I need to create such a function that the content of the first is put into the second, the content of the second into the third and the content of the third into the first.
For example, output should be like this
3
2
1
But the code below prints out:
1
2
2
Where am I making a mistake?
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <ctype.h>
[Code]....
C# :: Circular Progress Bar In WPF (Not Silverlight)
Jul 30, 2014Is there a way to make a circular progress bar in WPF without using another library or NuGet Package?
Like a tutorial on how to make it from scratch?
Right now, I'm using the existing ProgressBar UserControl but it looks horrible especially after I change the Foreground color from Green to DarkBlue.
C/C++ :: How To Remove Circular Dependency
Jan 23, 2014I have ran into some sort of Circular dependency between two classes.
Forward declaration doesn't work as I'm allocating the memory for pointer array of Student and it requires the default constructor.
P.S I'm aware I haven't written the BIG 3, it's an incomplete code. Just want to know how to resolve this dependency.
class Student;
class Course {
char *name;
Student *s[3];
[Code].....
C :: Circular Queue Based On Struct
Oct 6, 2013I am stuck with how to make a circular queue that are based on a struct. Have been reading about the implementation but cant really understand it fully. Here is what i got so far.
Code:
#define SIZE 10
typedef struct {
char reg;
char brand;
int modelyear;
int mileage;
[Code] .....
C++ :: Circular Dependency In Template Arguments
Nov 7, 2013Today I faced a problem where I had circular dependency in my template arguments. I was trying to make a class hierarchy similar to:
template<class BType>
class A_base {
public:
BType* getB();
};
[Code] .....
Basically I had objects that were of type A<B<A<B<...
Basically I have a tree like structure of heterogeneous types that must facilitate two-way interactions where A's can call B's and B's can call A's. This structure is useful in many contexts the difference is the methods A and B provide are different in each of these contexts. Instead of adding the getA and getB and all the other connectivity methods in every version of A and every version of B, I wanted to create a base class that managed this automatically.
Another piece of advice was break up your code so there is a forward-only and backwards-only dependent types. This is not a complete solution because the two cannot know about the other and this does not really facilitate arbitrary two-way communication (where A calls B then B calls A back). It also makes the code more complicated in that I have two sets of objects and interfaces.
So the solution was to make the template arguments specific to the things I wanted to be flexible. The connectivity interface of A_base and B_base should be constant. Hence that cannot be in the template parameter. It was merely the traits that I wanted to make flexible so... I came up with this solution:
#include <iostream>
template<class aTraitType,class bTraitType>
class A;
template<class aTraitType,class bTraitType>
class B;
[Code] ....
Now this compiles and works great. The problem is that aObj and bObj cannot call their opposite within a trait method because print() does not know anything about the connectivity. So the solution there was to make traits an abstract base class. Then magically everything works!
#include <iostream>
template<class aTraitType,class bTraitType>
class A_base;
template<class aTraitType,class bTraitType>
class B_base;
[Code] .....
So this outputs the following. Clearly there is two-way communication!
Class A is not connected to B
Class B is not connected to A
Class A at 0x7fff25d1aa10 reporting for duty
Class B at 0x7fff25d1aa00 reporting for duty
Class B at 0x7fff25d1aa00 reporting for duty
Class A at 0x7fff25d1aa10 reporting for duty
Class A at 0x7fff25d1aa10 reporting for duty
Class B at 0x7fff25d1aa00 reporting for duty
C++ :: Fixing Circular Dependencies With Pointers
Dec 18, 2012I've been making a project that requires different files to have access to objects declared in other files such that circular dependencies are created. I've done some research and discovered that pointers and forward declarations should be able to fix this.
Example:
File 1 declares variable x, must edit x and y
File 2 must edit x and y, declares variable y
I know this isn't the best example, as you could probably declare x and y in the same file, but please suffice it to say that I'm unable to do that in my project.
C++ :: Creating Circular Linked List
Jan 30, 2015I've been making a circular linked list and I'm trying to assign each list a "name" and its next "link" but when I run my code it crashes.
Soldier *Head;
Head = NULL;
string names[] = {"Arman","Bogut","Castro","Damascus","Elene"};
for (int i = 0; i < 5; ++i) {
[Code] .....
C/C++ :: Make Circular List And Print It
Apr 28, 2015I have this program. I am trying to do this Circular List but i think something going wrong. The first of all is the list.The second is if my code for delete and select function are correct and the third i would like my program getting a "n" number of names and then make the circural list then print it and then when i select a number delete every node until give us the only one left.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SIZE 10
#define NUM_PER_LINE 6
typedef struct node {
char name[SIZE];
struct node * next;
[Code] .....
C :: Access A FIFO (Circular Queue) Between Two Cores
Oct 31, 2014I want to write a program where one core (core 0) will fill the FIFO and other core (core 1 ) will delete the data from FIFO.
Core 0:
I create a fifo
Code:
struct node
{
int info;
struct node *ptr;
}*front,*rear,*temp,*front1;
And my en-queue function is in core 0 and writing to specific memory location..(which works perfectly)
Code:
void enq(int data)
{
if (rear == NULL)
{
rear = (struct node *)malloc(1*sizeof(struct node));
rear->ptr = NULL;
rear->info = data;
front = rear;
[Code] ....
Now the problem is in the core 1. Here I am unable to read the values from the specific memory location. I am getting garbage value. Where I am doing some stupid error.. I did not understand
Code:
(front->ptr) = (unsigned int *) memory_location;
When I print the (front->ptr) it shows correct memory address but inside the De-queue function in core 1, I am getting wrong value..
Code:
int deq(int buf[n]) {
front1 = front;
printf("Val %d ", front->info); // showing wrong value
if (front1 == NULL) {
printf("
Error: Trying to display elements from empty queue");
return 0;
[Code] ...
