Visual C++ :: Draw Buffer With Raw Data?
Nov 19, 2012Got buffer with raw data. How to display it in MFC dialog and refresh it?
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Visual C++ :: How To Draw 2D Array Of Data In MFC
Jun 3, 2013I have a circle of data that is represented as:
vector<vector <unsigned char> >* data;
The first dimension of this vector is the angle of the data so there are 360 angles, and the second dimension is the bins of the data in which there are 512 bins per angle. Each bin has a value from 0 to 15 to determine the intensity of the bin. So basically, when this is all display, there will be a circle of data, with varying colors of intensity at each bin.
What is the best approach to doing this in MFC? How to draw this on the screen?
Visual C++ :: Serial Communication In Windows - ClearCommError Finds No Data In Read Buffer
Dec 13, 2013I want to send data from a laptop (windows 7, processor 2.60GHz) to a desktop (windows xp, processor 3.10GHz) using serial communication (using a USB to RS232 convertor). The WriteFile function is able to send the data from the laptop (NumberOfBytesWritten is correct). But on the desktop side, ClearCommError detects no data in the read buffer.
This is the relevant code in my desktop:
while(1) {
ClearCommError(hPort,&dwErrors,&commStatus);
if (commStatus.cbInQue != 0) ReadFile(hPort,&data,1,&dwBytesRead,NULL);
Sleep(10);
}
The if condition is never satisfied. The baudrate and other parameters in the DCB struct are the same on both sides.
The same code works when I write and read in the same system by shorting the RX and TX pins in the RS232 connector.
C++ :: Data Buffer With Memory Mapped Files?
Jan 27, 2014I have a data buffer project in Windows 7 x64 embedded OS (using Visual Studio 2008), that would work simply like that:
One writer application will send data (no network protocols, just procedure call on the same machine) to my app like 20 packages per second, each data packages will be approximately 3 MB size and comes with a timestamp tag.
My application will store each data item for 100 minutes and then remove. (So I can calculate the total size from beginnig no need for dynamic allocation etc...)
Meanwhile there will be up to 5 reader applications which will query data from my app via Timestamp tag and retreive data (no updates or deletitions on data by reader apps).
So since the data in my buffer app can grow over 50GB I don't think that shared memory is going to work for my case.
I'm thinking about using Boost Memory Mapped Files or Windows API Memory Mapped Files.
So theoratically I will crate a fixed size File on harddisk (lets say 50GB) and then map some portion to RAM write the data to this portion, if the reader applications wants to use the data which is mapped currently on memory, then they will use directly, otherwise they will map some other potion of the file to their address spaces and use from there...
My problem is I haven't use Map File concept at all and I'm not a C++ developer so I'm not very familiar with the language fundementals. I've searched tutorials of boost and msdn for windows as well but there is not too much code example.
So I don't know how to map some portion of the data to memory and manage it, also how to search data in file or memory according to the timestamp tag. Yes there are codes for creating files and mapping the whole file to memory but none for dividing it into regions, aligning or padding the data which I need for my case.
Visual C++ :: Draw Image Using 2D Byte Array?
Feb 8, 2013I like to Draw an Image Using two dimensional byte array[512][256].
I used SetPixelV method to plot the image.
But Its very slow & hidden some buttons(Controls) at run time in the same dialog.
For reference i send some code,
Code:
for(row = 0; row <512; row ++)
{
for(col = 0; col < 256; col++)
{
Data[row][col] = y;
SetPixelV(d, 10+row, 10+col, RGB(Data[row][col],Data[row][col],Data[row][col]));
}
}
Visual C++ :: Draw Grid Over Bitmap In Scrollview
Jul 5, 2013I have a CScrollView that displays a bitmap and I'm trying to draw a grid that I can turn off and on by check box and when the mouse is over a section of the grid that square highlights... I do all the drawing in the ondraw function... But when I have many grid squares it becomes slow to scroll and to highlight the square the mouse is over... I'm not sure the best way to go about this and where to place code to speed it up... The bitmap is only loaded once... But in ondraw the grid has to redraw every time scrolled and when mouse moved over a square.. In onmousemove I call invalidate so the square under mouse changes...
View 5 Replies View RelatedVisual C++ :: Draw Multiple Lines And Move Them On Screen
Jul 28, 2013I am writing a pure C based win32 applications. I have drawn line. Now i want to translate that line, move the line whereved user wants to move on screen. Then again I drawn another line, I am drawing multiple lines.
I have created rectangle region for each line and trying to move the line.
When I move the 2nd line over the 1st line on screen the 1st line is getting wiped out. Because I am InvalidateRect() of the rect for the line being moved, so when that rectangle is crossing the other line then the other line is getting removed from the screen.
How can I rectify it. How can I have all the lined being on the screen and moved according to the user's wish. The code should be pure C and win32 no MFC.
C :: Parsing Binary Data File By Casting A Buffer - Accessing Double From Struct
Jan 4, 2014I am parsing a binary data file by casting a buffer to a struct. It seems to work really well apart from this one double which is always being accessed two bytes off, despite being in the correct place.
Code:
typedef struct InvoiceRow {
uint INVOICE_NUMBER;
...
double GROSS;
...
char VAT_NUMBER[31];
} InvoiceRow;
If I attempt to print GROSS using printf("%f", row->GROSS) I get 0.0000. However, if I change the type of GROSS to char[8] and then use the following code, I am presented with the correct number...
Code:
typedef struct example {
double d;
}
example;
example *blah = (example*)row->GROSS;
printf("%f", blah->d);
Visual C++ :: How To Create Image Buffer In MFC
Jan 27, 2013how to create, initialize, and maintain a memory device context that works as a local buffer for images? The idea is to maintain some large images in local DCs and bitmaps, and only bitblt them to screen in OnDraw().
What I did so far was was to define CDC and CBitmap objects as members of my View class, and then tried to initialize them with the sequence that begins at "// Initialize buffer". I placed that sequence in either OnInitialUpdate, or PreCreateWindow, or OnPrepareDC, or the view constructor, to no avail. The code always crashes in OnDraw, and I've noticed that the m_hDC member of myDevice is zero at that point.
Obviously, the initialization is wrong and MFC does (too many) things in the background which I'm not aware of.... My question was where can I read about that?
Code:
class CMyView : public CScrollView {
// ...
CDC myDevice;
CBitmap bmp;
CBitmap *oldbmp;
[Code] .....
Visual C++ :: How To Determine If A Buffer Is Freed Or Not
Dec 9, 2014I use new to allocate a buffer, as follows:
BYTE *p;
p = new BYTE[20];
...
delete p;
After p is deleted, if I do NOT assign NULL to p, is there a way to determine whether it has already been freed?
Visual C++ :: How To Draw Pixel-level Color Gradients In CScrollView
Oct 6, 2012i wish to plot a mathematical function on a 2-dimensional grid. The function will be represented by 3 sets of floats, x-values, y-values, and z-values. Obviously, it is impossible to plot 3 such data sets on a 2D grid, so one approach is to use pixel coloration to represent the z-values.
Those examples (and there are many to be found) show something like the function of the complex variable z, f(z) = exp(z). I have attached a exp(z).jpg example of the imaginary part of the plot exp(z).
My question is: How to accomplish such a gradient colorization, assuming one already has the data?
I have experimented with Gdiplus SetPixel, but I have not figured out how to produce a smooth gradient.
Here's my attempt to create a simple gradient:
Code:
CDC * pDC = GetDC();
Graphics graphics(pDC->m_hDC);
CRect r;
GetWindowRect(&r);
ScreenToClient(&r);
[Code] ....
Visual C++ :: Draw A Shape Or Font On Dialog And Then Fill The Outline?
Jul 8, 2013I am trying to draw a shape or font on dialog and then fill the outline. I have 2 buttons on this 2 buttons I have the following code
Code:
case IDC_BUTTON1:
MessageBox(hDlg, L"Start Drawing!!", L"ButtonPressed", MB_OK | MB_ICONEXCLAMATION);
hDC = GetDC(hDlg);
brush = CreateSolidBrush(RGB(128, 128, 128));
SelectObject(hDC, brush);
[code].....
When I remove the BeginPath() and EndPath() functions my lines are being drawn. But when I insert this BeginPath() and EndPath() and StrokeAndFillPath(hDC); the nothing is being drawn.
Why it is not doing as per the expectations. I want to draw a shape for example A with a outline. And i want it to be closed when drawing is ended and filled the hollow portion.
What am I doing wrong in this ?I am not implementing it in WM_PAINT but drawing is done in WM_LBUTTONUP.
Visual C++ :: How To Determine Size Of Allocated Buffer
Dec 9, 2014I use new to allocate a buffer, as follows:
BYTE *p;
p = new BYTE[20];
If I do NOT store the size of the allocated buffer, how to determine the buffer size via p only?
Visual C++ :: Bitmap Display From Buffer Received By TCP Socket
Feb 6, 2013I want to display my image on window without saving it.
When data is received window size changes but there is no display on window.
My Code is:
Code:
int iBufferLength;
int iEnd;
int iSpaceRemaining;
int i;
iBufferLength = iSpaceRemaining = sizeof(chIncomingDataBuffer);
iEnd = 0;
iSpaceRemaining -= iEnd;
[code].....
where I'm doing wrong?
Visual C++ :: Playing Video Using Windows Media Player From A Buffer?
Oct 25, 2013I am developing a VC++ application with windows media player component. play video from a video buffer data which i have?
View 2 Replies View RelatedVisual C++ :: How New / Delete Store Internal Info About Allocated Buffer
Dec 9, 2014I am using C++ new/delete operators to allocate/deallocate the buffers. I think for each allocated buffer, there should be an additional info block stores the size and other info about the buffer. How to know more details about this info block? I need to override these two operators and find such an info block is useful to my implementation.
View 3 Replies View RelatedVisual C++ :: Circular Buffer - No Instance Of Overload Function Matches Argument List
Nov 25, 2014I'm having some issues with my code. For the produce function i am getting an error saying 'no instance of overload function produce() matches the argument list' and also for the lines buffer[head].data = message; buffer[head].time = current_time i get an error saying 'expression must have pointer to object type.
In the code i'm not sure if i passed the variables to the function correctly. I have attached the code .....
code produce.txt
C/C++ :: Unable To Read Data From Buffer Line By Line
Jun 27, 2014I'm reading strings one after another and trying to split it using strtok_r. This doesnot seem to be working
I have a .gz file from which I'm reading the data into the buffer in chunks.
The below code works fine only for the first chunk on data. Later it just breaks out.
while(1) {
char buffer[SIZE];
int bytes_read = gzread (f, buffer, SIZE - 1);
[Code] .....
Visual C++ :: Retrieving Size Of Each String In Order To Produce A New Buffer For Concatenated String
Feb 25, 2013What is the efficiency of the two assignments (line 1 and 2), i.e. (function calls, number of copies made, etc), also the Big O notation. I know there are function calls for retrieving the size of each string in order to produce a new buffer for the concatenated string...any difference between line 1 and 2 in terms of efficiency?
String s("Hello");
String t("There");
1. s = s + t;
2. s += t;
Visual C++ :: Reverse String Sequence In String Buffer
Apr 27, 2013I made a simple little program that takes text from the clipboard, and spits out all the lines I've copied one at a time (so my program can analyze it).
everything works perfectly, except, it spits it own in the wrong order, I want it to spit out from bottom to top. but currently it spits out the data from top to bottom. here is my code :
Code:
#include <iostream>
#include <Windows.h>
#include <string>
#include <sstream>
using namespace std;
int main() {
HANDLE clip; // assigns the var. clip to hold a handle ID.
[Code] .....
I want this loop to run backwards! Like it say's what I want to work backwards. Where as I know how to flip a while loop like this: while(x < 5), how to flip a loop like the one I'm using. how I can do this?
Visual C++ :: Finding Value In Data File Closest To Calculated Data?
Jan 11, 2014I'm reading from a file the middle column of data (Volts) where my test file "AP.txt" is opened by my program. Here is a segment of the data:
time Volts dV
49552 -66.20183 -0.01556807
49553 -67.76025 -0.01556495
49554 -69.30704 -0.01533247
49555 -70.81799 -0.0148486
49556 -72.26774 -0.0141133
49557 -73.63226 -0.01315276
49558 -74.89141 -0.01201764
Since the calculation I performed gives me -71.77 Volts, I need to match this value to the time that this occurs closest to using my program, and output the time that this occurs at.
Here is my program so far:
int main()
{
std::ifstream inFile;
inFile.open("AP.txt");
ofstream results_file ("maxvaluewithinput.txt");
float TimeAtdVMax = 0;
float VoltsAtdVmax = 0;
[Code]...
If you're curious, this program isn't for homework. It's part of the independent learning on C++ I'm doing for a Master's Thesis; the program will eventually model the APD90 of a ventricular action potential.
Visual C++ :: Reading In Data And Displaying Out All Data In Linked List?
Feb 6, 2014I am wanting to be able to add as many different instances of data, while the user has not stated 'n', but then it only ever writes back to the screen the input for the last set of data. Where as I want to display back to the screen all the data that has been entered.
Code:
#include <iostream>
#include <string>
/*Function Declaration*/
void createItem();
void returnItem();
//Items structure
[code]...
C++ :: How To Draw A Polygon
Nov 16, 2013I am fairly new to c++, and I want to be able to draw a polygon. When I have searched for how to draw one, the only thing i can find is scripts doing things like this:
*
**
***
****
*****
I doubt that c++ is that primitive, and I'm looking for something like the c++ equivalent of this python script:
Syntax: draw.polygon((20,20)(30,30)(50,30)(20,40)(20,20), fill(green))
I am using a mac os 10.9
C :: Draw A Grid Using The Characters?
Aug 20, 2013I'm trying to create a grid using the following characters: !, @, #, $, &.
It's an 8 x 8 grid, and should contain the characters in no particular order (trying to create a Bejeweled-like game).
I already defined the width and length to be 8, so:
#define WIDTH 8
#define LENGTH 8
Code:
void makegrid(char grid[])
{
int j;
int k;
for ( j = -1; j < LENGTH; j++ )
{
for ( k = -1; k < WIDTH; k++ )
{
/* I don't know what to type here anymore :( */
}
} }
C++ :: OpenGL - Draw On Top Of Image
Jun 22, 2014This is my first time using opengl and I am experimenting with adding/drawing polygons/points/etc. on top of a PPM image. The image is already loaded when the application runs. My attempt to draw a square is from lines 30 - 35. The program runs but the square is not present. Just the image.
#include<windows.h>
#include <stdio.h>
#include <stdlib.h>
#include<Gl/gl.h>
#include<GL/glut.h>
int n;
int m;
int *image;
[Code] ....
C++ :: How To Draw A 3D Snake In OpenGL
Jan 3, 2014i want to draw a 3D snake in opengl.. i can't get nothing out of my search to make a start.. how it is made
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