N
Hallo,
es kommt oft vor, dass man Pixelfarbe irgendwo auslesen will.
Ich hab einfach ein Tool geschrieben, das die Pixelfarbe unter der Mausposition auslesen und als RGB Wert darstellen kann(auch als Farbvisualisierung).
Das Program ist in C/C++ geschrieben und läuft nur unter Windows, da ich WinAPI verwende.
Sourcecode ist sehr klein und Kommentare sind auch enthalten:
Download(src+exe): http://badworld-crew.com/dev/getpixel/
Sourcecode(benötigt gdi32.lib):
#include <windows.h>
#include <stdio.h>
//process the window messages
LRESULT CALLBACK windowProc(HWND, UINT, WPARAM, LPARAM);
//extract RGB values from COLORREF
void toRGB(COLORREF color, unsigned char *rgb);
//handle to the screen
HDC screen;
//timer id
unsigned int timer = 100;
//interval in ms to get the color
unsigned int interval = 100;
//color of the pixel under mouse pointer
//colorref has form: 0x00bbggrr
COLORREF pixelColor = 0;
COLORREF pixelColorLast = 0;
//color rectangle for visualization
RECT colorRect;
//main function
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
//program and class name
const char *progName = "getPixel";
//create window class
WNDCLASS windowClass;
//message function
windowClass.lpfnWndProc = windowProc;
//enable redrawing
windowClass.style = CS_HREDRAW | CS_VREDRAW;
//program instance
windowClass.hInstance = hInstance;
//standard cursor
windowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
//standard icon
windowClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
//gray background
windowClass.hbrBackground = static_cast<HBRUSH>(GetStockObject(GRAY_BRUSH));
//extra buffer
windowClass.cbClsExtra = 0;
windowClass.cbWndExtra = 0;
//name to represent our window class
windowClass.lpszClassName = progName;
//we don't need menu
windowClass.lpszMenuName = NULL;
//register our class to windows
if(!RegisterClass(&windowClass))
return 0;
//create window
HWND window;
window = CreateWindowEx(WS_EX_TOPMOST, //allways on top of others
progName, //name of window class
progName, //text in the titlebar
//no resizable window without minimize option
WS_OVERLAPPEDWINDOW^WS_MAXIMIZEBOX^WS_THICKFRAME,
//default window position
CW_USEDEFAULT, CW_USEDEFAULT,
//window width and height
300, 185,
//no parent window
NULL,
//no menu
NULL,
hInstance,
//no extra parameters
NULL);
//quit if we can't create a window
if(!window)
return 0;
//show
ShowWindow(window, nCmdShow);
UpdateWindow(window);
//process messages
MSG message;
while(GetMessage(&message, NULL, 0, 0))
{
TranslateMessage(&message);
DispatchMessage(&message);
}
return message.wParam;
}
LRESULT CALLBACK windowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch(message)
{
//window creation
case WM_CREATE:
{
//get the whole display context
screen = CreateDC("DISPLAY",NULL,NULL,NULL);
if(!screen)
return 0;
//set timer to get the pixel color
if(!SetTimer(hwnd, timer, interval, NULL))
return 0;
//rectangle for color visualisation
colorRect.left = 180;
colorRect.top = 15;
colorRect.right = 280;
colorRect.bottom = 126;
}break;
//timer
case WM_TIMER:
{
//get the current mouse position
POINT mousePos;
GetCursorPos(&mousePos);
//get the color under the mouse position
pixelColor = GetPixel(screen, mousePos.x, mousePos.y);
//if the color doesn't change, then don't redraw
if(pixelColor!=pixelColorLast)
InvalidateRect(hwnd, NULL, true);
//save color for comparisson
pixelColorLast = pixelColor;
}break;
//repaint
case WM_PAINT:
{
//get the window device context for drawing
PAINTSTRUCT ps;
HDC windowDC;
windowDC = BeginPaint(hwnd, &ps);
//background color for text
SetBkColor(windowDC, 0x848284);
//draw rectangular frame around our rectangle
Rectangle(windowDC, colorRect.left-1, colorRect.top-1,
colorRect.right+1, colorRect.bottom+1);
//draw the rectangle in pixel color for more visuualization
HBRUSH color = CreateSolidBrush(pixelColor);
FillRect(windowDC, &colorRect, color);
char text[50] = " ";
//saves rgb values
unsigned char rgbColors[3];
//extract RGB values from COLORREF
toRGB(pixelColor, rgbColors);
//Output of information
sprintf(text, "Red : 0x%02X %d", rgbColors[0], rgbColors[0]);
TextOut(windowDC, 10, 15, text, strlen(text));
sprintf(text, "Green: 0x%02X %d", rgbColors[1], rgbColors[1]);
TextOut(windowDC, 10, 45, text, strlen(text));
sprintf(text, "Blue : 0x%02X %d", rgbColors[2], rgbColors[2]);
TextOut(windowDC, 10, 75, text, strlen(text));
sprintf(text, "RGB Color: 0x%02X%02X%02X", rgbColors[0], rgbColors[1], rgbColors[2]);
TextOut(windowDC, 10, 115, text, strlen(text));
EndPaint(hwnd, &ps);
}break;
case WM_DESTROY:
{
//clean up
DeleteDC(screen);
KillTimer(hwnd, timer);
PostQuitMessage(0);
return 0;
}break;
}
return DefWindowProc(hwnd, message, wParam, lParam);
}
//rgb[0] = red
//rgb[1] = green
//rgb[2] = blue
void toRGB(COLORREF color, unsigned char *rgb)
{
rgb[0] = (color & 0x000000FF);
rgb[1] = (color & 0x0000FF00)>>8;
rgb[2] = (color & 0x00FF0000)>>16;
}
Screenshot:
http://badworld-crew.com/dev/getpixel/getpixel.PNG
