Printing a float in a grx20.h

[jonnis2206]

Firstly, my compiler is dev-C++, and I'm writing the program in C, using stdio.h, stdlib.h, math.h and grx20.h.

I have a value for velocity defined as a float (v[i]) which changes over time, which in my program has already been calculated for the various different i values. I want to print the value of v[i] for i=0 in the grx20.h window, then the program pauses using the sleep function, and then as i is increased (affecting lots of different variables) I want the velocity value to change. This display will effectively serve as a digital speedometer.

I've looked into a number of options. I can't imagine it would make any difference, but I'm currently using GrTextXY to plot the text.

As far as I can see I need to convert the velocity float to a character string that is memorised for different values of i, but I'm not sure if this is possible.

I have tried using the gcvt function, and think I need to combine it with memset? Can anyone help?

I've devised a simple example to help me try to work this out, by working off this I'll be able to implement the code into my program:

 #include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <grx20.h>
 
int i,j;
float v[100];
char *buffer[80];
 
main()
{
for (i=0 ; i<80 ; i++)
{
v[i]=2*i;
printf("%d %f\n", i, v[i]);
gcvt(v[i], 3, buffer);
memset(buffer; );
}
printf("%c", buffer);
system("PAUSE");
graphics();
}
 
graphics()
{
           GrSetMode(GR_default_graphics);
           GrClearScreen(15);
           while (j<80)
           {
           GrTextXY(30,30,"??????",0,15);
           j++;
           }
 
 
 
           GrKeyRead();
} 

I may be completely wrong here, what I'm really struggling with is how to store all those float values as characters, so that I'm able to print them in the graphics window. Then I need to understand how to print the right float value based on my integer.

[johny10151981]

you can use sprintf function to create your required string.