ScreenRead

#include <windows.h>
#include <iostream>
#define Winver 0x500
#include <tlhelp32.h>
#include <stdio.h>
#include <winable.h>
#include <fstream>
#include <istream>
#include <string>

using namespace std;

int ScreenWidth;
int ScreenHeight;

void get_bitmap_ava(HWND ava_hwnd, int size_x, int size_y, bool get_pixel_color = false)
{
    int pos_x, pos_y; //position of the mouse
    POINT p;
    GetCursorPos(&p); //get the current mouse position
    pos_x = p.x; //set pos_x to the mouse x coordinate
    pos_y = p.y; //set pos_y to the mouse y coordinate

    int radius = 25; //size of the box to record

    HDC ava_dc = GetDC(ava_hwnd); //get the device context of the window handle
    HDC ava_dc_cap = CreateCompatibleDC(ava_dc); //create a compatible DC for BitBlt to use
    HBITMAP hCaptureBitmap = CreateCompatibleBitmap(ava_dc, size_x, size_y); //create a bitmap of the DC
    SelectObject(ava_dc_cap, hCaptureBitmap); //select the bitmap/ dc in memory
    BitBlt(ava_dc_cap,0,0,size_x,size_y, ava_dc, 0, 0, SRCCOPY); //call BitBlt on the object

    //getting the size of the picture
    BITMAP bm;
    GetObject(hCaptureBitmap, sizeof(bm), &bm); //get the object from memory and place it in bm
    int width(bm.bmWidth), height(bm.bmHeight); //set the width and height of the bitmap for the header info

    //creating a bitmapheader for getting the dibits
    BITMAPINFOHEADER bminfoheader;
    ::ZeroMemory(&bminfoheader, sizeof(BITMAPINFOHEADER));
    bminfoheader.biSize        = sizeof(BITMAPINFOHEADER); //set the size of the header
    bminfoheader.biWidth       = width; //set the width
    bminfoheader.biHeight      = -height; //and height
    bminfoheader.biPlanes      = 1; //must be set to 1
    bminfoheader.biBitCount    = 32; //32 bits per pixel
    bminfoheader.biCompression = BI_RGB; //easiest way to get the RGB of a pixel

    bminfoheader.biSizeImage = width * 4 * height; //set the size of the image
    bminfoheader.biClrUsed = 0; //require all colors
    bminfoheader.biClrImportant = 0; //reference http://msdn.microsoft.com/en-us/library/windows/desktop/dd183376(v=vs.85).aspx for a better explanation


    //create a buffer and let the GetDIBits fill in the buffer
    unsigned char* pPixels = new unsigned char[(width * 4 * height)];
    if( !GetDIBits(CreateCompatibleDC(0), hCaptureBitmap, 0, height, pPixels, (BITMAPINFO*) &bminfoheader, DIB_RGB_COLORS)) // load pixel info
    {
        //return if fails but first delete the resources
        DeleteObject(hCaptureBitmap);
        delete [] pPixels; // delete the array of objects
        cout << "fail" << endl;

        return;
    }

    int x, y; // fill the x and y coordinate for grabbing pixels
    x = 0;
    y = 0;

    for(int iter = 0; iter < (size_x * size_y); iter++){
        if(x < size_x){ //go from left to right across the screen
            x++;
        }
        else{
            x = 0;
            y++; //and top to bottom
        }
        unsigned int r = pPixels[(width*y+x) * 4 + 2]; //get the pixel colors
        unsigned int g = pPixels[(width*y+x) * 4 + 1];
        unsigned int b = pPixels[(width*y+x) * 4 + 0];
        if(get_pixel_color){ //for grabbing one area
            if(x - pos_x < radius && x - pos_x > -1*radius && y - pos_y < radius && y - pos_y > -1*radius ){ //creates a box
                cout << "RED: " << r << "   GREEN: " << g << "   BLUE: " << b << "\n"; //print the values
            }
        }
    }
    //clean up the bitmap and buffer unless you still need it
    DeleteObject(hCaptureBitmap);
    delete [] pPixels; // delete the array of objects

    ReleaseDC(ava_hwnd, ava_dc);
    DeleteDC(ava_dc_cap);
    DeleteObject(hCaptureBitmap);
}