s_johnson@csc32.enet.dec.com (Scott Johnson) (03/27/91)
Hi,
I have a problem. I am in graphics mode and write a number to the display
device using outtextxy(). I overwrite the number with a string of spaces to
clear it. When this statement gets executed, the number is still there. After
that I write a new number to the same location. The problem is that the space
does not get cleared away before writing the new number. If this is done
enough, then the number becomes a square and is no longer a number.
The following code demonstrates the problem. A message is sent to Display to
initialize and then a series of messages is sent to update the display with a
new value being passed in for fish each time.
I am using dos 3.3 with c++ 1.0. My monitor is vga and it uses a paradise card.
Is this a bug or am I doing something wrong?
Thanks for any and all help.
scott
---------------------------------------------
#include <iostream.h>
#include <graphics.h>
#include <conio.h>
#include <stdlib.h>
#include <string.h>
#define fishx 20
int maxy;
void Display::initialize(void)
{
int i;
int delta;
int gdriver=DETECT,gmode,errorcode;
initgraph(&gdriver, &gmode,"\\tc\\bgi");
errorcode = graphresult();
if (errorcode != grOk){
cout<<"Graphics Error\n";
getch();
}
// Get the maximum coordinates for the display in both the x and y dir.
maxy = getmaxy()-20;
outtextxy(fishx,maxy+10,"Fish:");
};
void Display::update(int fish)
{
char temp[5];
strcpy(temp," ");
outtextxy(fishx+43,maxy+10,temp);
getch();
itoa(fish,temp,10);
outtextxy(fishx+43,maxy+10,temp);
};
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Scott Johnson
Digital Equipment Corporation
Colorado Springs, Co