getpixel() function in C

The header file graphics.h contains getpixel() function which returns the color of pixel present at location (x, y).

Syntax :

int getpixel(int x, int y);

Note : By default the screen is BLACK, therefore color of pixel at (0,0) is BLACK.

Below is the implementation of getpixel() function.

// C Implementation for getpixel()
#include <graphics.h>
#include <stdio.h>

// driver code
int main()
{
    // gm is Graphics mode which is
    // a computer display mode that
    // generates image using pixels.
    // DETECT is a macro defined in
    // "graphics.h" header file
    int gd = DETECT, gm, color;
    char arr[50];

    // initgraph initializes the
    // graphics system by loading a
    // graphics driver from disk
    initgraph(&gd, &gm, "");

    // getpixel function
    color = getpixel(0, 0);

    // sprintf stands for “String print”.
    // Instead of printing on console,
    // it store output on char buffer
    // which are specified in sprintf
    sprintf(arr, "color of pixel at (0,0) = %d",
                                       color);

    // outtext function displays text
    // at current position.
    outtext(arr);

    getch();

    // closegraph function closes the
    // graphics mode and deallocates
    // all memory allocated by
    // graphics system .
    closegraph();

    return 0;
}

Output :

Explanation : As nothing is drawn anything on screen and by default screen is BLACK, therefore color of pixel at (0, 0) is BLACK as 0 indicates BLACK color.