C / C++ / MFC Discussion Boards

Re: Scrolling is not working ScrollView

Cedric Moonen22-Jul-10 23:11

Cedric Moonen

22-Jul-10 23:11

What are you doing with the iHIndex later ?
You have to take that offset into account when you redraw your view.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Re: Scrolling is not working ScrollView

Anu_Bala22-Jul-10 23:44

Anu_Bala

22-Jul-10 23:44

Im using iHIndex in OnDraw() function

iHIndex = HScroll.GetScrollPos();

and assinging in SCROLLINFO
SCROLLINFO infoH;
infoH.cbSize = sizeof(SCROLLINFO);
infoH.fMask = SIF_ALL;
infoH.nMin = 0;
infoH.nMax = PageCount;
infoH.nPage = 1;
infoH.nPos = iHIndex;
infoH.nTrackPos = 1;
HScroll.SetScrollInfo(&infoH);

Im plotting some dynamic values as trend in a Rect and im using this scroolbar to scroll and see the previous trend.
THis scrollbar is working properly.
Problem in Window scrollbar,when i move that it,it again move to previous position.

Anu

32 bitmap and gdi+ problem

rjkg22-Jul-10 23:01

rjkg

22-Jul-10 23:01

I have a 32bit bitmap with alpha channnel . I am drawing it using gdi+ . but I am not getting the transparency . How to get the transparency usnig gdi+

Rajesh

Re: 32 bitmap and gdi+ problem

Niklas L22-Jul-10 23:14

Niklas L

22-Jul-10 23:14

How are you drawing it? Do you have any code you can share? (small piece)

home

Re: 32 bitmap and gdi+ problem

rjkg22-Jul-10 23:37

rjkg

22-Jul-10 23:37

Graphics graphics(hdc);//Handle to the device context
//Load the image from a file
Image image(L"test.bmp",FALSE); // test.bmp is 32bit with alpha channels for transparency
graphics.DrawImage(&image,0,0,image.GetWidth(),image.GetHeight());

Rajesh

Re: 32 bitmap and gdi+ problem

S p k 52123-Jul-10 0:28

S p k 521

23-Jul-10 0:28

You have to specify Colormatrix and load it via ImageAttributes'
SetColorMatrix() before using DrawImage()

Regards,
Spk

Re: 32 bitmap and gdi+ problem

rjkg23-Jul-10 0:40

rjkg

23-Jul-10 0:40

What will be color matrix values ???

Rajesh

Re: 32 bitmap and gdi+ problem

S p k 52123-Jul-10 0:51

S p k 521

23-Jul-10 0:51

Thats based upon your requirement... if you need to convert 80% of the bitmap alpha values use this sample one...

ColorMatrix colorMatrix = {1.0f, 0.0f, 0.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 0.0f, 0.8f, 0.0f,
0.0f, 0.0f, 0.0f, 0.0f, 1.0f};

ImageAttributes imageAtt;
imageAtt.SetColorMatrix(&colorMatrix, ColorMatrixFlagsDefault,
ColorAdjustTypeBitmap);

Regards,
Spk

Re: 32 bitmap and gdi+ problem [modified]

rjkg23-Jul-10 0:59

rjkg

23-Jul-10 0:59

you understand wrong . I have 32bit bmp and talking about the alpha channel tranparency . not opacity of image .

Rajesh

modified on Friday, July 23, 2010 7:50 AM

Re: 32 bitmap and gdi+ problem

Joe Woodbury23-Jul-10 7:02

Joe Woodbury

23-Jul-10 7:02

If you call GetPixelFormat() on a 32-bit bitmap (.bmp) loaded with Image, it will return PixelFormat32bppRGB.

I've found that using PNG images works.

Re: 32 bitmap and gdi+ problem

rjkg24-Jul-10 0:01

rjkg

24-Jul-10 0:01

Can you share with some piece of code for help me

Rajesh

Re: 32 bitmap and gdi+ problem

Joe Woodbury24-Jul-10 8:14

Joe Woodbury

24-Jul-10 8:14

It's exactly the same, just load a .PNG file that has an alpha channel.

AddPrinterDriver returning ERROR_IO_PENDING, what should I do?

sashoalm22-Jul-10 22:44

sashoalm

22-Jul-10 22:44

bResult = AddPrinterDriver(NULL, 3, (LPBYTE) &di3);
TRACE("%d", (int) GetLastError());
if (!bResult)
    return FALSE;

The call to AddPrinterDriver fails returning FALSE, and GetLastError() returns ERROR_IO_PENDING. The Error Lookup tool shows for this error "Overlapped I/O operation is in progress."

What does this mean, and what should I do to work around this problem?

There is sufficient light for those who desire to see, and there is sufficient darkness for those of a contrary disposition.
Blaise Pascal

Re: AddPrinterDriver returning ERROR_IO_PENDING, what should I do?

Code-o-mat22-Jul-10 23:47

Code-o-mat

22-Jul-10 23:47

If i check out the documentation of AddPrinterFriver[^], it doesn't mention anywhere that it sets the last error code in case of an error, are you sure you are not getting the error code of something called before AddPrinterDriver OR maybe something that was called inside AddPrinterDriver but doesn't really contain much of information about the problem?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> "It doesn't work, fix it" does not qualify as a bug report. <
> Amazing what new features none of the programmers working on the project ever heard of you can learn about when reading what the marketing guys wrote about it. <

Re: AddPrinterDriver returning ERROR_IO_PENDING, what should I do?

David Crow23-Jul-10 3:17

David Crow

23-Jul-10 3:17

Strange, it used to say:

If the function fails, the return value is zero. To get extended error information, call GetLastError().

"One man's wage rise is another man's price increase." - Harold Wilson

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

"Man who follows car will be exhausted." - Confucius

Processing speed becomes slow if i do not use FILE_FLAG_OVERLAPPED parameter in my CreateFile Function

learningvisualc22-Jul-10 20:50

learningvisualc

22-Jul-10 20:50

Hi all,

I am trying to read a file from a device connected to a serial port. I am using CreateFile() and ReadFile() methods to read the file. But my problem is when i am not using FILE_FLAG_OVERLAPPED parameter my processing becomes slow. I wanted to know why this is happening??

Can anybody help me in this?

Thanks in advance

Re: Processing speed becomes slow if i do not use FILE_FLAG_OVERLAPPED parameter in my CreateFile Function

Code-o-mat22-Jul-10 22:45

Code-o-mat

22-Jul-10 22:45

I think that is quite hard to guess without actually seeing what you do and how you do it. My guess is that without overlapping your program blocks on the read operatin until there's data available to be read so the processing becomes "blocky". Do you know the difference between overlapped and non-overlapped IO?

Re: Processing speed becomes slow if i do not use FILE_FLAG_OVERLAPPED parameter in my CreateFile Function

Iain Clarke, Warrior Programmer23-Jul-10 11:19

Iain Clarke, Warrior Programmer

23-Jul-10 11:19

If you have not read it before you MUST read: http://www.flounder.com/serial.htm[^]

You'd think working with a serial port be easy, but it's far from.

Good luck,

Iain.

I am one of "those foreigners coming over here and stealing our jobs". Yay me!

Memory Bits To Bitfield Definition

Trevor Johansen22-Jul-10 20:48

Trevor Johansen

22-Jul-10 20:48

I would like to address several bytes of memory but different bits from different locations. The program I am using is on an embedded system and I need access to different pieces of the peripherals. Specifically when dealing with ports where something connected crosses multiple ports and I need a modular way to access them through a simple 'maskport = value' and you only need to modify some macros or a enum to change things instead of each functions code.

IS this even allowed or am I out to lunch? (I am using GCC)

For example: (this doesn't work btw but it was my attempt)

struct bits {
  uint8_t b0:1;
  uint8_t b1:1;
  uint8_t b2:1;
  uint8_t b3:1;
  uint8_t b4:1;
  uint8_t b5:1;
  uint8_t b6:1;
  uint8_t b7:1;
} __attribute__((__packed__));

#define SBIT(port,pin) ((*(volatile struct bits*)&amp;port).b##pin)

struct FIELD {
  uint8_t b0:1;
  uint8_t b1:1;
  uint8_t b2:1;
  uint8_t b3:1;
  uint8_t b4:1;
  uint8_t b5:1;
  uint8_t b6:1;
  uint8_t b7:1;
};

struct FIELD test;

test.b0 = SBIT(0xE2, 0);
test.b1 = SBIT(0xE2, 4);
test.b2 = SBIT(0xE2, 7);
test.b3 = SBIT(0xEF, 2);
test.b4 = SBIT(0xEF, 3);
test.b5 = SBIT(0x07, 1);
test.b6 = SBIT(0x07, 5);
test.b7 = SBIT(0x07, 6);

test = 0x7A; // 0111 1010

That way by assigning a value to test:

<br />
test = 0x7A; // 0111 1010<br />

0xE2:

<br />
0001 0000<br />

0xEF:

<br />
0000 1100<br />

0x07:

<br />
0010 0010<br />

Re: Memory Bits To Bitfield Definition

Member 392263923-Jul-10 2:50

Member 3922639

23-Jul-10 2:50

If I understood, you can try with a union:

union FIELDEX
{
struct FIELD
{
uint8_t b0:1;
uint8_t b1:1;
uint8_t b2:1;
uint8_t b3:1;
uint8_t b4:1;
uint8_t b5:1;
uint8_t b6:1;
uint8_t b7:1;
} fld;
uint8_t val;
};
FIELDEX test;
test.val = 0x7A; // 0111 1010
test.fld.b0 = 1; // set bit 0

Re: Memory Bits To Bitfield Definition

Trevor Johansen23-Jul-10 6:55

Trevor Johansen

23-Jul-10 6:55

I would still have the problem of setting separate address bits, however your example would make a good compact bitfield definition.

I am trying to take bits from separate registers and create my own 'masked register' so when I write to my register it sends each bit to its specified bits in other registers.

test.b0 = SBIT(0xE2, 0); // 0xE2: 0000000x
test.b1 = SBIT(0xE2, 4); // 0xE2: 000x0000
test.b2 = SBIT(0xE2, 7); // 0xE2: x0000000

test.b3 = SBIT(0xEF, 2); // 0xEF: 000000x0
test.b4 = SBIT(0xEF, 3); // 0xEF: 00000x00

test.b5 = SBIT(0x07, 1); // 0x07: 000000x0
test.b6 = SBIT(0x07, 5); // 0x07: 00x00000
test.b7 = SBIT(0x07, 6); // 0x07: 0x000000

Hopefully this will show more clearly what I am after:

test = 0x7A; // 0111 1010

// 0xE2 gets bits xxxxx010
 // xx0 = 0xE2 bit 0
 // x1x = 0xE2 bit 4
 // 0xx = 0xE2 bit 7
 // 0xE2 = 00010000

// 0xEF gets bits xxx11xxx
 // x1 = 0xEF bit 2
 // 1x = 0xEF bit 3
 // 0xEF = 00001100

// 0x07 gets bits 011xxxxx
 // xx1 = 0x07 bit 1
 // x1x = 0x07 bit 5
 // 0xx = 0x07 bit 6
 // 0x07 = 00100010

How to delete a memory on Heap if it is holded by a reference

pandit8422-Jul-10 20:43

pandit84

22-Jul-10 20:43

Hi All
If I can delete a memory using delete keyword for memory allocated on heap using new keyword.

class A
{
} ;
A &a1 = * (new A ) ;

How to release memory which is holded by a reference.

Re: How to delete a memory on Heap if it is holded by a reference

Cedric Moonen22-Jul-10 20:45

Cedric Moonen

22-Jul-10 20:45

This looks very ugly. Why do you need to have something like that ? I guess you need to revise your design a bit.

Anyway, did you try to delete the address of the reference: delete &a1; ? I never done this myself so I don't know if this works but it looks like the obvious solution.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Re: How to delete a memory on Heap if it is holded by a reference

Emilio Garavaglia22-Jul-10 21:28

Emilio Garavaglia

22-Jul-10 21:28

delete &a1 is exactly what he has to do. It works perfectly.
It may sound unorthodox, but depends how a1 is used: if a1 participate into arithmetic expression of overloaded operators inside generic code, it cannot be a pointer, and *a1 may be not suitable for template function expecting references.

Generic programming changes a lot the "traditional rules".
(Note: you can also have a nullable reference as *(A*)0 that can be checked as !&a).

2 bugs found.
> recompile ...
65534 bugs found.
D'Oh! | :doh:

Re: How to delete a memory on Heap if it is holded by a reference

pandit8422-Jul-10 21:31

pandit84

22-Jul-10 21:31

Thanks a lot ...!!!

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