C Program
#include<conio.h> #include<graphics.h> #include<math.h> void ddaline(int x1, int y1, int x2, int y2) { int s, m, dx, dy; float xi, yi, x, y; dx = x2 - x1; dy = y2 - y1; if (abs(dx) > abs(dy)) s = abs(dx); else s = abs(dy); xi = dx / (float) s; yi = dy / (float) s; x = x1; y = y1; putpixel(x1 + 0.5, y1 + 0.5, 15); for (m = 0; m < s; m++) { x += xi; y += yi; putpixel(x + 0.5, y + 0.5, 15); } } void fill(int x, int y) { int i, j; for (i = x; i < (x + 50); i++) ddaline(i, y, i, y + 50); } void main() { int i, j, c = 0; int gd = DETECT, gm = DETECT; initgraph(&gd, &gm, ""); cleardevice(); ddaline(100, 50, 100, 450); ddaline(100, 50, 500, 50); ddaline(500, 50, 500, 450); ddaline(100, 450, 500, 450); for (i = 100; i < 500; i += 50) { for (j = 50; j < 450; j += 50) { if (c % 2 == 0) fill(i, j); c++; } c++; } getch(); }