Displaying numbers as text on the prizm
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I am trying to compare the speed of two pixel plotting functions, but I cant seem to get the speeds to print out:


Code:

int main(void) {
   int t1,t2,t3,t4;
   int i,j;
   
   t1 = RTC_GetTicks();
   for(i=0;i<1000;i++)
   {   
      plot(0,0,COLOR_WHITE);
   }
   t2 = RTC_GetTicks();
   
   t3 = RTC_GetTicks();
   for(j=0;j<1000;j++)
   {
      plot_asm(1,1,COLOR_WHITE);
   }
   t4 = RTC_GetTicks();
   
   t1 = (t2-t1)/128;
   t3 = (t4-t3)/128;
   
   unsigned char time1[sizeof(t1)+3];
   char time2[sizeof(t3)+3];
   
   time1[0] = 'X';
   time1[1] = 'X';
   time2[0] = 'X';
   time2[1] = 'X';
   time1[2] = 'X';
   time2[2] = 'X';
   
   memcpy(&time1[3],&t1,sizeof(t1));
   memcpy(&time2[3],&t3,sizeof(t3));
   
   unsigned char * time1loc = &time1[0];
   char * time2loc = &time2[0];
   
   PrintXY(1, 1, "XXResults:", TEXT_MODE_NORMAL, TEXT_COLOR_BLACK);
   int x = 0;
   int y = 50;
   PrintMini( &x, &y, time1loc, 0x02, 350, 0, 0, TEXT_COLOR_BLACK, TEXT_COLOR_WHITE, 1, 0);
   PrintXY(1, 4, time2loc, TEXT_MODE_NORMAL, TEXT_COLOR_BLACK);
   
   while(!keydownlast(KEY_PRGM_MENU))
   {
      Bdisp_PutDisp_DD();
      keyupdate();
   }
   
   return 0;
}


PrintMini prints out three Xs, and PrintXY displays one X, but neither have any numbers following them. Am I using memcpy correctly here?
t1 and t3 are numbers, not strings. You'll want to convert them to strings first using itoa and then copy it or concat or w/e. In Minesweeper I do something like:

Code:
      unsigned char out[3];
      itoa(numMines-numFlags, out);
      DefineStatusMessage(concat("  Minesweeper!    Mines: ", (char*)out), 1, 0, 0);
Shaun
Your attempt won't work at all, because the machine representation of numbers is not a string.

itoa is reasonable I guess, but is rather less portable than sprintf (it's not part of any C standard).

The usual way to handle this is with some variant on sprintf:
Code:
#include <stdio.h>

void display_uint(int x, int y, unsigned value) {
    char buf[13];
    sprintf(buf + 2, "%u", value);
    PrintXY(x, y, buf, TEXT_MODE_NORMAL, TEXT_COLOR_BLACK);
}
The necessary size of buf is derived from the valid range of unsigned int (32 bits): ⌈log10(232-1)⌉ plus two ignored bytes for PrintXY and one for a null terminator.
タリ ·· Ask questions the smart way ·· digipres.club
While I do see your argument for using sprintf you do have to remember that the program expands in size as sprintf must now be linked into your program.
I think sprintf should only be used if you are doing lots of diverse string manipulation.
However if you just want to display a number use itoa.
I understand that the size savings is not that much as we have 16mb of memory and are saving around 2kb.
  
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