# include <iostream.h> # include <graphics.h> # include <conio.h> # include <math.h> # define f 0.3 # define projection_angle 45 void show_screen( ); void apply_rotation_along_z_axis(const int [5][3],const int); void multiply_matrices(const float[4],const float[4][4],float[4]); void draw_pyramid(int [5][3]); void get_projected_point(int&,int&,int&); void Line(const int,const int,const int,const int); int main( ) { int driver=VGA; int mode=VGAHI; initgraph(&driver,&mode,\"..\\\\Bgi\"); show_screen( ); int pyramid[5][3]={ {20,120,50}, // base front left {80,120,50}, // base front right {80,120,-50}, // base back right {20,120,-50}, // base back left {50,20,0} // top }; setcolor(15); draw_pyramid(pyramid); setcolor(15); settextstyle(0,0,1); outtextxy(50,415,\"*** Use + & - Keys to apply Rotation along z-axis.\"); int angle=0; int key_code=0; char Key=NULL; do { Key=NULL; key_code=0; Key=getch( ); key_code=int(Key); if(key_code==0) { Key=getch( ); key_code=int(Key); } if(key_code==27) break; else if(key_code==43) angle-=5; else if(key_code==45) angle+=5; setfillstyle(1,0); bar(40,70,600,410); apply_rotation_along_z_axis(pyramid,angle); } while(1); return 0; } //------------------- apply_rotation_along_z_axis( ) ------------------// void apply_rotation_along_z_axis(const int control_points[5][3], const int theta) { int edge_points[5][3]={0}; float angle=(theta*(M_PI/180)); for(int count=0;count<5;count++) { edge_points[count][0]=control_points[count][0]; edge_points[count][1]=control_points[count][1]; edge_points[count][2]=control_points[count][2]; float matrix_a[4]={edge_points[count][0],edge_points[count][1], edge_points[count][2],1}; float matrix_b[4][4]={ { cos(angle),sin(angle),0,0 } , { -sin(angle),cos(angle),0,0 } , { 0,0,1,0 } , { 0,0,0,1 } }; float matrix_c[4]={0}; multiply_matrices(matrix_a,matrix_b,matrix_c); edge_points[count][0]=(int)(matrix_c[0]+0.5); edge_points[count][1]=(int)(matrix_c[1]+0.5); edge_points[count][2]=(int)(matrix_c[2]+0.5); } setcolor(10); draw_pyramid(edge_points); } /************************************************************************/ //---------------------- multiply_matrices( ) ------------------------// /************************************************************************/ void multiply_matrices(const float matrix_1[4], const float matrix_2[4][4],float matrix_3[4]) { for(int count_1=0;count_1<4;count_1++) { for(int count_2=0;count_2<4;count_2++) matrix_3[count_1]+= (matrix_1[count_2]*matrix_2[count_2][count_1]); } } /************************************************************************/ //-------------------------- draw_pyramid( ) -------------------------// /************************************************************************/ void draw_pyramid(int points[5][3]) { int edge_points[5][3]; for(int i=0;i<5;i++) { edge_points[i][0]=points[i][0]; edge_points[i][1]=points[i][1]; edge_points[i][2]=points[i][2]; get_projected_point(edge_points[i][0], edge_points[i][1],edge_points[i][2]); edge_points[i][0]+=320; edge_points[i][1]+=240; } Line(edge_points[0][0],edge_points[0][1], edge_points[1][0],edge_points[1][1]); Line(edge_points[1][0],edge_points[1][1], edge_points[2][0],edge_points[2][1]); Line(edge_points[2][0],edge_points[2][1], edge_points[3][0],edge_points[3][1]); Line(edge_points[3][0],edge_points[3][1], edge_points[0][0],edge_points[0][1]); Line(edge_points[0][0],edge_points[0][1], edge_points[4][0],edge_points[4][1]); Line(edge_points[1][0],edge_points[1][1], edge_points[4][0],edge_points[4][1]); Line(edge_points[2][0],edge_points[2][1], edge_points[4][0],edge_points[4][1]); Line(edge_points[3][0],edge_points[3][1], edge_points[4][0],edge_points[4][1]); } /************************************************************************/ //--------------------- get_projected_point( ) -----------------------// /************************************************************************/ void get_projected_point(int& x,int& y,int& z) { float fcos0=(f*cos(projection_angle*(M_PI/180))); float fsin0=(f*sin(projection_angle*(M_PI/180))); float Par_v[4][4]={ {1,0,0,0}, {0,1,0,0}, {fcos0,fsin0,0,0}, {0,0,0,1} }; float xy[4]={x,y,z,1}; float new_xy[4]={0}; multiply_matrices(xy,Par_v,new_xy); x=(int)(new_xy[0]+0.5); y=(int)(new_xy[1]+0.5); z=(int)(new_xy[2]+0.5); } //------------------------------- Line( ) -----------------------------// void Line(const int x_1,const int y_1,const int x_2,const int y_2) { int color=getcolor( ); int x1=x_1; int y1=y_1; int x2=x_2; int y2=y_2; if(x_1>x_2) { x1=x_2; y1=y_2; x2=x_1; y2=y_1; } int dx=abs(x2-x1); int dy=abs(y2-y1); int inc_dec=((y2>=y1)?1:-1); if(dx>dy) { int two_dy=(2*dy); int two_dy_dx=(2*(dy-dx)); int p=((2*dy)-dx); int x=x1; int y=y1; putpixel(x,y,color); while(x<x2) { x++; if(p<0) p+=two_dy; else { y+=inc_dec; p+=two_dy_dx; } putpixel(x,y,color); } } else { int two_dx=(2*dx); int two_dx_dy=(2*(dx-dy)); int p=((2*dx)-dy); int x=x1; int y=y1; putpixel(x,y,color); while(y!=y2) { y+=inc_dec; if(p<0) p+=two_dx; else { x++; p+=two_dx_dy; } putpixel(x,y,color); } } } //-------------------------- show_screen( ) ---------------------------// void show_screen( ) { setfillstyle(1,1); bar(210,26,420,38); settextstyle(0,0,1); setcolor(15); outtextxy(5,5,\"******************************************************************************\"); outtextxy(5,17,\"*-**************************************************************************-*\"); outtextxy(5,29,\"*----------------------- ------------------------*\"); outtextxy(5,41,\"*-**************************************************************************-*\"); outtextxy(5,53,\"*-**************************************************************************-*\"); setcolor(11); outtextxy(218,29,\"3D Rotation along Z-axis\"); setcolor(15); for(int count=0;count<=30;count++) outtextxy(5,(65+(count*12)),\"*-* *-*\"); outtextxy(5,438,\"*-**************************************************************************-*\"); outtextxy(5,450,\"*------------------------- -------------------------*\"); outtextxy(5,462,\"******************************************************************************\"); setcolor(12); outtextxy(229,450,\"Press any Key to exit.\"); }