#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <math.h>

float matrix[4][4] =
{{1, 0, 0, 0},
{0, 0, 0, 0},
{0, 0, 1, 0},
{0, 0, 0, 1}};

void vertex( float x, float y, float z ){
float n[4],r[4]={0, 0, 0, 0};
n[0]=x; n[1]=y; n[2]=z; n[3]=1;

for(int i=0; i<4; i++)
for(int j=0; j<4; j++)
r[i]+=n[j]*matrix[j][i];

putpixel(r[0]+(getmaxx()/2),r[1]+(getmaxx()/2),YELLOW);
}

int main(void)
{
int gdriver = DETECT, gmode, errorcode;
initgraph(&gdriver, &gmode, "");
errorcode = graphresult();
if (errorcode != grOk) {
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1);
}

int angle = 40;

do{

cleardevice();

//isometric projection
matrix[2][0] = -0.5 * sin( angle * M_PI / 180 );
matrix[2][1] = -0.5 * cos( angle * M_PI / 180 );


for(int i=-100; i< 100; i+=1)
for(int j=-100; j< 100; j+=1)
vertex(i,0,j);

angle+=10;
if(angle>=360) angle=0;

}while(!kbhit());

getch();
closegraph();
return 0;
}