I have window handle and I need get pixel color.
#include "Globals.h"
void MainHamsterDlg::OnTimer(UINT nIDEvent)
{
Sleep(4000);
HDC hDC = ::GetDC(tempHWND);
COLORREF rgb = GetPixel(hDC,351,515);
if(GetPixel(hDC,351,515) == RGB(33,30,28))
AfxMessageBox(L"Please select or write correct name!");
::ReleaseDC(tempHWND, hDC);
CDialog::OnTimer(nIDEvent);
}
Debuging says that the COLORREF rgb = GetPixel(hDC,351,515); gets the value 3225917 do i need convert to rgb to check for compare?
I dont uderstund what wrong there because i'm new in mfc.
#include "Globals.h"
void WaitProcessDlg::OnTimer(UINT nIDEvent)
{
if(::FindWindow(NULL, str)){
tempHWND = ::FindWindow(NULL, str);
::SetWindowText(tempHWND, L"Weather");
EndDialog( 0 );
KillTimer(IDC_PROGRESS1);
}
CDialog::OnTimer(nIDEvent);
}
Here window handle and its handles window. I checked with changing title.
I'm using Globals to transfer window handle from one dialog box to another.
Globals.h
-------------------
#pragma once
extern HWND tempHWND;
--------------------
So my question is do I need convert to RGB to check for compare? and how?
I use different code to make that and its work!
HDC hDC = CreateDC(L"DISPLAY",0,0,0);
COLORREF rgb5 = GetPixel(hDC,24,507);
Related
I am having issues in getting my .bmp image displayed to change to another one on user input. The image can be successfully printed at the start (title.bmp), but is supposed to change when pressing 1 or 2 followed by enter (to introduction.bmp & start.bmp). I must be missing something!
Where this happens is around the bottom of the code from while (running == 1) { so skip down to there.
I am using loadImage("title.bmp"); to print my images (I change the filename appropriately of course), and cin >> menuSelection; to pause the program and wait until the user presses one or two followed by enter.
I've searched many, many pages on how to print and change images in WinAPI, and this is the closest I can get. If there is any other information I have missed please tell me and I will comment it. Thanks in advance for helping!
//These are the libraries (external files) to include at the start.
#include <cstdio>
#include <windows.h>
#include <iostream>
#include <stdlib.h>
#include <time.h>
#include <string>
using namespace std;
//Defining the [global] variables that will be used throughout the program
int running = 1;
int menuSelection = 0;
int userInput;
int userInputDummy;
int intPointer;
//Starter variables used in creating a window and printing images. These are global.
HDC imageDC; // the DC to hold our image
HBITMAP imageBmp; // the actual bitmap which contains the image (will be put in the DC)
HBITMAP imageBmpOld; // the DC's old bitmap (for cleanup)
const int screenSize_X = 640;
const int screenSize_Y = 480;
//Functions! Sections of code to re-used in the program
// Function to load the image into our DC so we can draw it to the screen
void loadImage(const char* pathname)
{
imageDC = CreateCompatibleDC(NULL); // create an offscreen DC
imageBmp = (HBITMAP)LoadImageA( // load the bitmap from a file
NULL, // not loading from a module, so this is NULL
pathname, // the path we're loading from
IMAGE_BITMAP, // we are loading a bitmap
0, 0, // don't need to specify width/height
LR_DEFAULTSIZE | LR_LOADFROMFILE// use the default bitmap size (whatever the file is), and load it from a file
);
imageBmpOld = (HBITMAP)SelectObject(imageDC, imageBmp); // put the loaded image into our DC
}
// Function to clean up
void cleanUpImage()
{
SelectObject(imageDC, imageBmpOld); // put the old bmp back in our DC
DeleteObject(imageBmp); // delete the bmp we loaded
DeleteDC(imageDC); // delete the DC we created
}
// The function to draw our image to the display (the given DC is the screen DC)
void drawImage(HDC screen)
{
BitBlt(
screen, // tell it we want to draw to the screen
0, 0, // as position 0,0 (upper-left corner)
screenSize_X, // width of the rect to draw
screenSize_Y, // height of the rect
imageDC, // the DC to get the rect from (our image DC)
0, 0, // take it from position 0,0 in the image DC
SRCCOPY // tell it to do a pixel-by-pixel copy
);
}
// A callback to handle Windows messages as they happen
LRESULT CALLBACK wndProc(HWND wnd, UINT msg, WPARAM w, LPARAM l)
{
// what kind of message is this?
switch (msg)
{
// we are interested in WM_PAINT, as that is how we draw
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC screen = BeginPaint(wnd, &ps); // Get the screen DC
drawImage(screen); // draw our image to our screen DC
EndPaint(wnd, &ps); // clean up
}break;
// we are also interested in the WM_DESTROY message, as that lets us know when to close the window
case WM_DESTROY:
PostQuitMessage(0);
break;
}
// for everything else, let the default window message handler do its thing
return DefWindowProc(wnd, msg, w, l);
}
// A function to create the window and get it set up
HWND createWindow(HINSTANCE inst)
{
WNDCLASSEX wc = { 0 }; // create a WNDCLASSEX struct and zero it
wc.cbSize = sizeof(WNDCLASSEX); // tell windows the size of this struct
wc.hCursor = LoadCursor(NULL, MAKEINTRESOURCE(IDC_ARROW)); // tell it to use the normal arrow cursor for this window
wc.hInstance = inst; // give it our program instance
wc.lpfnWndProc = wndProc; // tell it to use our wndProc function to handle messages
wc.lpszClassName = TEXT("DisplayImage"); // give this window class a name.
RegisterClassEx(&wc); // register our window class with Windows
// the style of the window we want... we want a normal window but do not want it resizable.
int style = WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU; // normal overlapped window with a caption and a system menu (the X to close)
// Figure out how big we need to make the window so that the CLIENT area (the part we will be drawing to) is
// the desired size
RECT rc = { 0,0,screenSize_X,screenSize_Y }; // desired rect
AdjustWindowRect(&rc, style, FALSE); // adjust the rect with the given style, FALSE because there is no menu
return CreateWindow( // create the window
TEXT("DisplayImage"), // the name of the window class to use for this window (the one we just registered)
TEXT("Display an Image"), // the text to appear on the title of the window
style | WS_VISIBLE, // the style of this window (OR it with WS_VISIBLE so it actually becomes visible immediately)
100, 100, // create it at position 100,100
rc.right - rc.left, // width of the window we want
rc.bottom - rc.top, // height of the window
NULL, NULL, // no parent window, no menu
inst, // our program instance
NULL); // no extra parameter
}
//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
// _________________________________________________________________________________________
// The actual entry point for the program!
// This is Windows' version of the 'main' function:
int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmd, int show)
{
// load our image
loadImage("title.bmp");
// create our window
HWND wnd = createWindow(inst);
// Do the message pump! keep polling for messages (and respond to them)
// until the user closes the window.
MSG msg;
while (GetMessage(&msg, wnd, 0, 0)) // while we are getting non-WM_QUIT messages...
TranslateMessage(&msg); // translate them
DispatchMessage(&msg); // and dispatch them (our wndProc will process them)
{
while (running == 1) {
//Welcoming the user to the program, and asking them what they want to do (starts functions)
cin >> menuSelection;
//Selecting the introduction option
if (menuSelection == 1) {
loadImage("introduction.bmp");
cin >> userInputDummy;
menuSelection = 0;
}
//Selecting the start option
else if (menuSelection == 2) {
loadImage("start");
cin >> userInputDummy;
menuSelection = 0;
}
//Selecting the exit option
else if (menuSelection == 3) {
menuSelection = 0;
running = 0;
}
}
// once the user quits....
cleanUpImage();
return 0;
return EXIT_SUCCESS;
}
}
you cannot use cin in win32 use an editbox then get the user's input from it as character string then if you want convert it to an integer value otherwise use the API:
GetDlgItemInt(...);
you are also handling only GetMessage in while-loop while you only handle dispatchmessage outside the loop which means you handle it only once, when getmessage fails (the end of program) so the result is a freezing windows as long as there's no one who takes messages from getmessage to the target windo.
the solution: make DispatchMessage inside while loop:
another thing: you pass hwnd to getmessage the result destroying the window won't make the application exit.
take a look at GetMessage() when passing a non-null value:
link text
the correct thing in your case:
while (GetMessage(&msg, 0, 0, 0) > 0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
* don't load image inside loop just load at the time wanted:
make an edit box with style ES_NUMBER and another button names for example change image so when clicked take the content of edit box convert it to integer, check whether it is 1 or 2 then load imaged depending the value.
you may ask "why I can't use iostream input and output streams in win32" because I ask you "where is console windows?" and if it is here what is the role of while-loop (blocking waiting for messages)?
I wanna draw some pixels with mouse and i wanna do it in C++ just like in Paint but so far i couldnt get it working.
What i have done:
// NewPaint.cpp : main project file.
#include "stdafx.h"
#include <windows.h>
#include <iostream>
#include <conio.h>
#include <dos.h>
#include <Winuser.h>
int main()
{
SetConsoleTitle(L"PaintER"); // Set text of the console so you can find the window
HWND hWnd = GetConsoleWindow(); // Get the HWND
HDC hdc = GetDC(hWnd); // Get the DC from that HWND
textbackgroundcolor(WHITE); // Background color
textcolor(BLACK); // Text color
POINT p; // Pointer
while(1) // Smt like mouse button 1
{
if (ScreenToClient(hWnd, &p)) // Mouse position
{
SetPixel(hdc, p.x, p.y, RGB(0,0,0)); // Draw black pixels
}
}
ReleaseDC(hWnd, hdc); // Release the DC
DeleteDC(hdc); // Delete the DC
system("pause");
return 0;
}
I am using Visual Studio 2010 for this and using Windows 7. I heard these could be inportant infos..
I dont have i only got GDI+ references so if you know a way to use it for this please let me know.
I need coding examples and explanations with it as i've given in my code.
In C++ using Code::Blocks v10.05, how do I draw a single pixel on the console screen? Is this easy at all, or would it be easier to just draw a rectangle? How do I color it?
I'm sorry, but I just can't get any code from SOF, HF, or even cplusplus.com to work. This is for a Super Mario World figure on the screen. The game I think is 16-bit, and is for the SNES system. C::B says I need SDK for C::B. It says "afxwin.h" doesn't exist. Download maybe?
This is what I'm trying to make:
It depends on your OS. I suppose you are programming in a Windows platform, therefore you can use SetPixel but you have to use "windows.h" to get a console handle, so here an example for drawing the cos() function:
#include<windows.h>
#include<iostream>
#include <cmath>
using namespace std;
#define PI 3.14
int main()
{
//Get a console handle
HWND myconsole = GetConsoleWindow();
//Get a handle to device context
HDC mydc = GetDC(myconsole);
int pixel =0;
//Choose any color
COLORREF COLOR= RGB(255,255,255);
//Draw pixels
for(double i = 0; i < PI * 4; i += 0.05)
{
SetPixel(mydc,pixel,(int)(50+25*cos(i)),COLOR);
pixel+=1;
}
ReleaseDC(myconsole, mydc);
cin.ignore();
return 0;
}
You can also use some others libraries like: conio.h allegro.h sdl, etc.
If you're willing to have the image look blocky, you could take advantage of the block characters from the console code page.
█ = '\xDB' = U+2588 FULL BLOCK
▄ = '\xDC' = U+2584 LOWER HALF BLOCK
▀ = '\xDF' = U+2580 UPPER HALF BLOCK
and space
By using the half-blocks in combination with colored text, you can turn an 80×25 console window into an 80×50 16-color display. (This was the approach used by the QBasic version of Nibbles.)
Then, you just need to convert your image to the 16-color palette and a reasonably small size.
windows.h provides a function SetPixel() to print a pixel at specified location of a window. The general form of the function is
SetPixel(HDC hdc, int x, int y, COLORREF& color);
where, x and y are coordinates of pixel to be display and color is the color of pixel.
Important: to print the pixel in your machine with Code::blocks IDE, add a link library libgdi32.a (it is usually inside MinGW\lib ) in linker setting.
Console is a text device, so in general you don't write to individual pixels. You can create a special font and select it as a font for console, but it will be monochromatic. There are libraries which simplify writing console UI (e.g. Curses), but I believe that you also have more gamelike functionality in mind besides just showing a sprite.
if you want to write a game, I suggest taking a look at some of the graphics/game frameworks/libs, e.g. SDL
I have drawn the straight line using windows.h in code::blocks. I can't explain it in details, but I can provide you a code and procedure to compile it in code::blocks.
go to setting menu and select compiler and debugger.
Click on linker tab and add a link library libgdi32.a which is at C:\Program Files\CodeBlocks\MinGW\lib directory.
Now compile this program
#include <windows.h>
#include <cmath>
#define ROUND(a) ((int) (a + 0.5))
/* set window handle */
static HWND sHwnd;
static COLORREF redColor=RGB(255,0,0);
static COLORREF blueColor=RGB(0,0,255);
static COLORREF greenColor=RGB(0,255,0);
void SetWindowHandle(HWND hwnd){
sHwnd=hwnd;
}
/* SetPixel */
void setPixel(int x,int y,COLORREF& color=redColor){
if(sHwnd==NULL){
MessageBox(NULL,"sHwnd was not initialized !","Error",MB_OK|MB_ICONERROR);
exit(0);
}
HDC hdc=GetDC(sHwnd);
SetPixel(hdc,x,y,color);
ReleaseDC(sHwnd,hdc);
return;
// NEVERREACH //
}
void drawLineDDA(int xa, int ya, int xb, int yb){
int dx = xb - xa, dy = yb - ya, steps, k;
float xIncrement, yIncrement, x = xa, y = ya;
if(abs(dx) > abs(dy)) steps = abs(dx);
else steps = abs(dy);
xIncrement = dx / (float) steps;
yIncrement = dy / (float) steps;
setPixel(ROUND(x), ROUND(y));
for(int k = 0; k < steps; k++){
x += xIncrement;
y += yIncrement;
setPixel(x, y);
}
}
/* Window Procedure WndProc */
LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam){
switch(message){
case WM_PAINT:
SetWindowHandle(hwnd);
drawLineDDA(10, 20, 250, 300);
break;
case WM_CLOSE: // FAIL THROUGH to call DefWindowProc
break;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
break; // FAIL to call DefWindowProc //
}
return DefWindowProc(hwnd,message,wParam,lParam);
}
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int iCmdShow){
static TCHAR szAppName[] = TEXT("Straight Line");
WNDCLASS wndclass;
wndclass.style = CS_HREDRAW|CS_VREDRAW ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;
// Register the window //
if(!RegisterClass(&wndclass)){
MessageBox(NULL,"Registering the class failled","Error",MB_OK|MB_ICONERROR);
exit(0);
}
// CreateWindow //
HWND hwnd=CreateWindow(szAppName,"DDA - Programming Techniques",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL);
if(!hwnd){
MessageBox(NULL,"Window Creation Failed!","Error",MB_OK);
exit(0);
}
// ShowWindow and UpdateWindow //
ShowWindow(hwnd,iCmdShow);
UpdateWindow(hwnd);
// Message Loop //
MSG msg;
while(GetMessage(&msg,NULL,0,0)){
TranslateMessage(&msg);
DispatchMessage(&msg);
}
/* return no error to the operating system */
return 0;
}
In this program I have used DDA line drawing algorithm. Pixel drawing tasks is done by setPixel(ROUND(x), ROUND(y)) function.
This is windows programing which you can learn details here
To use in CodeBlocks I found this (you have to add a linker option -lgdi32):
//Code Blocks: Project Build Options Linker settings Othoer linker options: add -lgdi32
I forgot: You have to put this before including windows.h:
#define _WIN32_WINNT 0x0500
The whole cosine code again. Ready to compile:
//Code Blocks: Project Build Options Linker settings Othoer linker options: add -lgdi32
#define _WIN32_WINNT 0x0500
#include "windows.h"
#include <iostream>
#include <cmath>
using namespace std;
#define PI 3.14
int main(){
HWND myconsole = GetConsoleWindow();
HDC mydc = GetDC(myconsole);
int pixel =0;
COLORREF COLOR= RGB(255,255,255);
//Draw pixels
for(double i = 0; i < PI * 4; i += 0.05)
{
SetPixel(mydc,pixel,(int)(50+25*cos(i)),COLOR);
pixel+=1;
}
ReleaseDC(myconsole, mydc);
cin.ignore();
return 0;
}
I would like to get the RGB values of a pixel at different x, y coordinates on the screen.
How would I go about this in C++?
I'm trying to create my own gaussian blur effect.
This would be in Windows 7.
Edit
What libraries need to be included for this to run?
What I have going:
#include <iostream>
using namespace std ;
int main(){
HDC dc = GetDC(NULL);
COLORREF color = GetPixel(dc, 0, 0);
ReleaseDC(NULL, dc);
cout << color;
}
You can use GetDC on the NULL window to get a device context for the whole screen, and can follow that up with a call to GetPixel:
HDC dc = GetDC(NULL);
COLORREF color = GetPixel(dc, x, y);
ReleaseDC(NULL, dc);
Of course, you'd want to only acquire and release the device context once while doing all the pixel-reading for efficiency.
As mentioned in a previous post, you want the GetPixel function from the Win32 API.
GetPixel sits inside gdi32.dll, so if you have a proper environment setup, you should be able to include windows.h (which includes wingdi.h) and you should be golden.
If you have a minimal environment setup for whatever reason, you could also use LoadLibrary on gdi32.dll directly.
The first parameter to GetPixel is a handle to the device context, which can be retrieved by calling the GetDC function(which is also available via <windows.h>).
A basic example that loads GetPixel from the dll and prints out the color of the pixel at your current cursor position is as follows.
#include<windows.h>
#include<stdio.h>
typedef WINAPI COLORREF (*GETPIXEL)(HDC, int, int);
int main(int argc, char** argv)
{
HINSTANCE _hGDI = LoadLibrary("gdi32.dll");
if(_hGDI)
{
while(true) {
GETPIXEL pGetPixel = (GETPIXEL)GetProcAddress(_hGDI, "GetPixel");
HDC _hdc = GetDC(NULL);
if(_hdc)
{
POINT _cursor;
GetCursorPos(&_cursor);
COLORREF _color = (*pGetPixel) (_hdc, _cursor.x, _cursor.y);
int _red = GetRValue(_color);
int _green = GetGValue(_color);
int _blue = GetBValue(_color);
printf("Red: 0x%02x\n", _red);
printf("Green: 0x%02x\n", _green);
printf("Blue: 0x%02x\n", _blue);
}
FreeLibrary(_hGDI);
}
}
return 0;
}
I added a icon at the system context menu(the popped up menu when we right mouse click on any file/foler). But the icon is not transparent(in xp its not notice able, but in vista/win7 it is clearly visible) there is a white background beneath the icon. But WinRAR or TortoiseSVN icons don't have any white background, they are transparent.
I tried the following C++ code:
#define BITMAP_MAIN 201 //in resource.h
BITMAP_MAIN BITMAP "main.bmp" // in .rc file
// showing icon in menu...
HBITMAP imgMain = LoadBitmap( aHinstance, MAKEINTRESOURCE(BITMAP_MAIN) );
SetMenuItemBitmaps ( hSubmenu, uMenuIndex, MF_BYPOSITION, imgMain, imgMain);
[main.bmp is 16X16]
Also the icon(.bmp) is not shown fully in non-english OS.
So is there be any special technique to make the icon in the system context menu transparent like WinRAR?
You need a special mechanism for loading icons in Vista and later, since they don't seem to process (by default) transparencies in BMP files. You need to detect the operating system:
// Necessary for getting icons in the proper manner.
bool isVistaOrMore() {
OSVERSIONINFOEX inf;
SecureZeroMemory(&inf, sizeof(OSVERSIONINFOEX));
inf.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
WORD fullver = GetVersionEx((OSVERSIONINFO *)&inf);
return (fullver >= 0x0600);
}
If it returns false then do what you're doing right now, if it returns true, perform something analog to what's described in:
http://msdn.microsoft.com/en-us/library/bb757020.aspx
I think TortoiseSVN uses owner-draw menus.
Don't know about winrar, but this code might work even on win98 where TransparentBlt has memory leak.
Bitmap must have color table (8-bit).
Use like this (this code formatting can mangle text, so check for errors!)
//we replace magenta with menu color
ReplaceDIBColor(m_hMenuBmp, RGB(255,0,255), GetSysColor(COLOR_MENU));
//function
inline BOOL ReplaceDIBColor(HBITMAP &hDIB, COLORREF oldColor, COLORREF newColor)
{
BOOL bRet=FALSE;
//get color information
DIBSECTION ds;
if (!GetObject(hDIB, sizeof(DIBSECTION), &ds)) return FALSE;
if (ds.dsBmih.biBitCount>8) return FALSE; //must be 8 bpp max
HDC hDC=CreateCompatibleDC(NULL);
if (!hDC) return FALSE;
HBITMAP hbmpOld=(HBITMAP)::SelectObject(hDC, hDIB);
//allocate color table
UINT nColors = ds.dsBmih.biClrUsed ? ds.dsBmih.biClrUsed : 1<<ds.dsBmih.biBitCount; //bpp to UINT
RGBQUAD* ptbl=(RGBQUAD*)CoTaskMemAlloc(nColors*sizeof(RGBQUAD));
if (ptbl)
{
if (GetDIBColorTable(hDC, 0, nColors, ptbl))
{
//replace color table entries
UINT i;
for (i=0; i<nColors ; i++)
{
if (oldColor==RGB(ptbl[i].rgbRed, ptbl[i].rgbGreen, ptbl[i].rgbBlue))
{
ptbl[i].rgbRed=GetRValue(newColor);
ptbl[i].rgbGreen=GetGValue(newColor);
ptbl[i].rgbBlue=GetBValue(newColor);
bRet=TRUE;
}
}
//set new table
if (bRet)
if (!SetDIBColorTable(hDC, 0, nColors, ptbl)) bRet=FALSE;
}
//cleanup
CoTaskMemFree(ptbl);
ptbl=NULL;
bRet=TRUE;
}
else bRet=FALSE;
hDIB=(HBITMAP)::SelectObject(hDC, hbmpOld);
DeleteDC(hDC); return bRet; }