Puzzle T26

TriangleMod Constructor

A constructor for a TriangleMod struct allocates memory for the main struct and the structs it points to (of type Point and Color). Non-pointer members are initialized to zero. Write a newTriangleMod() function in the following:

#include <stdio.h>
#include <stdlib.h>

typedef struct
{
  int x, y;
} Point;

void printPoint( Point *p )
{
  printf("(%d, %d) ", p->x, p->y );
}

Point *newPoint()
{
  Point *p = (Point *)malloc( sizeof( Point ) );
  p->x=0;
  p->y=0;
  return p;
}

void setPoint( Point *p, int x, int y )
{
  p->x = x; p->y = y;
}

typedef struct
{
  int red, green, blue;
} Color;

Color *newColor()
{
  Color *c = (Color *)malloc( sizeof( Color ) );
  c->red=0;
  c->green=0;
  c->blue=0;
  return c;
}

/* function to set a Color */
void setColor( Color *c, int r, int g, int b )
{
  if ( r<0 || r>255 ) r = 0;
  if ( g<0 || g>255 ) g = 0;
  if ( b<0 || b>255 ) b = 0;

  c->red   = r;
  c->green = g;
  c->blue  = b;
}

void printColor( Color *c )
{
  printf("%3d red, %3d grn, %3d blu", c->red, c->green, c->blue );
}

/* Write this function */
/* Use newColor() and newPoint()  (above) */

TriangleMod *newTriangleMod()
{
}

int main()
{
  TriangleMod *trimod = newTriangleMod();
  
  /* Initialize trimod here */

  /* Print out trimod here */
  printTriangleMod( trimod );
  
  /* Free memory here */

}

The next puzzle has you write a destructor for TriangleMod. You can write it and include it in this program if you want.