Ensayo Calculadora gráfica para Dev-C

#include <winbgim.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

char resul[15]="0";

void menu();

void waitForLeftMouseClick();

void grafico();

main(){

menu();

return 0;

}

void grafico(){

initwindow(340,500);

setcolor(4);

rectangle(20,100,80,160);//"Vaciar" la pantalla.

outtextxy(26,118,"CLS");

rectangle(100,100,160,160);//Cambia el signo al número que se está introduciendo

outtextxy(122,118,"±");

rectangle(180,100,240,160);//Divide uno entre el número que se está introduciendo

outtextxy(186,118,"1/x");

rectangle(260,100,320,160);//borrar último dígito

outtextxy(266,118,"DEL");

setcolor(15);

rectangle(20,180,80,240);//7

outtextxy(42,198,"7");

rectangle(20,260,80,320);//4

outtextxy(42,278,"4");

rectangle(20,340,80,400);//1

outtextxy(42,358,"1");

rectangle(20,420,80,480);//0

outtextxy(42,438,"0");

rectangle(100,180,160,240);//8

outtextxy(122,198,"8");

rectangle(100,260,160,320);//5

outtextxy(122,278,"5");

rectangle(100,340,160,400);//2

outtextxy(122,358,"2");

rectangle(180,180,240,240);//9

outtextxy(202,198,"9");

rectangle(180,260,240,320);//6

outtextxy(202,278,"6");

rectangle(180,340,240,400);//3

outtextxy(202,358,"3");

setcolor(3);

rectangle(260,180,320,240);//División

outtextxy(282,198,"÷");

rectangle(260,260,320,320);//Multiplicación

outtextxy(282,278,"+");

rectangle(260,340,320,400);//Resta

outtextxy(282,358,"*");

rectangle(260,420,320,480);//Suma

outtextxy(282,438,"-");

setcolor(15);

rectangle(100,420,160,480);//Punto decimal

outtextxy(122,438,".");

rectangle(180,420,240,480);//Igual

outtextxy(202,438,"=");

setcolor(15);

settextstyle(4,180,4);

outtextxy(300,95,resul);

}

void waitForLeftMouseClick(){

clearmouseclick(WM_LBUTTONDOWN);

const int DELAY = 50;

while (!ismouseclick(WM_LBUTTONDOWN))

delay(DELAY);

}

void menu(){

float num1,num2,resultado;

int operacion;

int respuesta;

system ("color 08");

do{

system("cls");

printf("\t Calculadora \n");

printf("Por favor, selecciona una opción \n");

printf(" 1: Suma \n 2: Resta \n 3: División \n 4: Producto \n");

scanf("%d",&operacion);

switch (operacion)

...