putimage puts the bit image previously saved with getimage back onto the
screen, with the upper left corner of the image placed at (left,top).
bitmap points to the area in memory where the source image is stored.
The op parameter to putimage specifies a combination operator that
controls how the color for each destination pixel onscreen is computed,
based on the pixel already onscreen and the corresponding source pixel in
memory. The enumeration putimage_ops, as defined in graphics.h, gives
names to these operators.
Name Value  ==== Description of putimage ====
<code c>
COPY_PUTÂ Â 0 Copy
XOR_PUT 1 Exclusive or
OR_PUT2 Inclusive or
AND_PUT 3 And
NOT_PUT 4 Copy the inverse of the source
In other words, COPY_PUT copies the source bitmap image onto the screen,
XOR_PUT XORs the source image with the image already onscreen, OR_PUT ORs
the source image with that onscreen, and so on.
/* putimage example */
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#define ARROW_SIZE 10
void draw_arrow(int x, int y);
int main()
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
void *arrow;
int x, y, maxx;
unsigned int size;
/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* terminate with an error code */
}
maxx = getmaxx();
x = 0;
y = getmaxy() / 2;
draw_arrow(x, y);
/* calculate the size of the image and allocate space for it */
size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE);
arrow = malloc(size);
/* grab the image */
getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE, arrow);
/* repeat until a key is pressed */
while (!kbhit()) {
/* erase old image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
x += ARROW_SIZE;
if (x >= maxx)
x = 0;
/* plot new image */
putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
}
free(arrow);
closegraph();
return 0;
}
void draw_arrow(int x, int y) {
moveto(x, y);
linerel(4*ARROW_SIZE, 0);
linerel(-2*ARROW_SIZE, -1*ARROW_SIZE);
linerel(0, 2*ARROW_SIZE);
linerel(2*ARROW_SIZE, -1*ARROW_SIZE);
}