Message Passing Extensions Graphics

/*
*Joel Adams, Calvin College 2013.
* Master Task draws a bulls-eye, with worker Tasks drawing concentric rings
* Modified Jerrold Siegel Fall 2016 - As written, there is a bug. Worker tasks are written as infinite loops.
*/
#include <mpi.h>
#include <mpe.h>
#include <stdlib.h> /* getenv() */
#include <string.h> /* strcmp() */
#include <stdio.h>   /* printf(), etc. */

char *mystring="hello";
char* getDisplay() {
    char * display = getenv("DISPLAY");
    if ( strncmp(display, "(null)", 7) == 0 ) {
        fprintf(stderr, "\n*** Fatal: DISPLAY variable not set.\n");
        exit(1);
    }
    return display;
}
int main(int argc, char* argv[]) {
    const int WINDOW_WIDTH = 800;
    const int WINDOW_HEIGHT = 800;
    const int CIRCLE_RADIUS = 5;
    const int MOUSE_RIGHT_BUTTON = 3;
    int        x = 0, y = 0,height=100;
    int        rank = 0, button = 0,i;
    char buffer[2],msg[20];
    MPE_XGraph canvas;
    MPI_Init(&argc,&argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    if ( rank == 0 ) {
        printf("Opening %dx%d window.\n", WINDOW_WIDTH, WINDOW_HEIGHT);
    }
    MPE_Open_graphics( &canvas, MPI_COMM_WORLD,
                       getDisplay(),
                       -1, -1,
                       WINDOW_WIDTH, WINDOW_HEIGHT, 0 );

    MPE_Line_thickness( canvas, 4 );
    if ( rank == 0 ) {
        MPE_Fill_circle( canvas,
                         WINDOW_WIDTH / 2,
                         WINDOW_HEIGHT / 2,
                         8,
                         MPE_BLACK);
        /* int MPE_Draw_string( graph, x, y, color, string )*/
        MPE_Draw_string( canvas,
                         WINDOW_WIDTH / 2,
                         WINDOW_HEIGHT / 2, MPE_BLACK, " Task 0" );

    } else {
        snprintf(buffer, 2, "%d", rank);
        MPE_Fill_circle( canvas,
                         WINDOW_WIDTH / 2+(rank * 55),
                         (WINDOW_HEIGHT /2 ),
                         8,
                         MPE_RED);
        MPE_Draw_circle( canvas,
                         WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2,
                         (rank * 55),
                         MPE_RED);
        MPE_Draw_string( canvas,
                         ((WINDOW_WIDTH/2)+rank*45),
                         ((WINDOW_WIDTH/2)+rank*45), MPE_BLACK, buffer);
        MPE_Update(canvas);
    }
    /*Draw blue circles wherever the user left-clicks */
    if ( rank == 0 ) {
        printf("Click:\n- left mouse button to draw blue circles;\n");
        printf("- right mouse button to quit.\n");
        do {
            MPE_Get_mouse_press( canvas, &x, &y, &button );
            if (button == MOUSE_RIGHT_BUTTON) {
                MPE_Close_graphics( &canvas);
                MPI_Finalize();
                if ( rank == 0 ) {
                    printf("Program complete.\n\n");
                }
                return 0;
            }
            for (i=0;i<5;i++) {
                printf("%i %i %i\n",x,(430+i*45), abs(x-(430+i*45)));
                if (abs(x-(430+i*45))<25) {
                    //printf("%i\n",i);
                    snprintf(buffer, 2, "%d", i);
                    MPI_Send(buffer, 2, MPI_INT, i, i, MPI_COMM_WORLD);
                    MPI_Recv(msg,20, MPI_CHAR, i, i, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
                    MPE_Draw_string( canvas,100, height, MPE_BLACK, msg );
                    height=height+12;
                }
            }
            MPE_Fill_circle( canvas, x, y, CIRCLE_RADIUS, MPE_BLUE );
        } while (button != MOUSE_RIGHT_BUTTON);
    } else {
        snprintf(msg,20,"This is rank %d", rank);
        while (1) {
            MPI_Recv(buffer,2, MPI_INT, 0, rank, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
            MPI_Send(msg, 20, MPI_CHAR, 0, rank, MPI_COMM_WORLD);
        }
    }
    /* clean up */
    MPE_Close_graphics( &canvas);
    MPI_Finalize();
    if ( rank == 0 ) {
        printf("Program complete.\n\n");
    }
    return 0;
}

makempe.sh

mpicc -DMPE_GRAPHICS -Wall $1.c -o $1 -L/usr/X11R6/lib -lmpe -lX11 -lm

Console Output

[siegelj@tc-login mpe]$ mpirun -n 5 mpeGraphics Opening 800x800 window. Click: - left mouse button to draw blue circles; - right mouse button to quit. 625 430 195 625 475 150 625 520 105 625 565 60 625 610 15 566 430 136 566 475 91 566 520 46 566 565 1 566 610 44 514 430 84 514 475 39 514 520 6 514 565 51 514 610 96