void draw_horz_line(int x0, int x1, int y, double z0, double z1, screen s, color c){
int i;
double z = z0;
if(x0 <= x1){
double m = (z1 - z0) / (x1 - x0);
for (i = x0; i <= x1; i++){
plot_z(s,c,i,y,z);
z += m;
}
}else{
double m = (z1 - z0) / (x0 - x1);
for (i = x1; i <= x0; i++){
plot_z(s,c,i,y,z);
z += m;
}
}
}
void draw_line(int x0, int y0, double z0, int x1, int y1, double z1, screen s, color c) {
int x, y, d, dx, dy;
double m,z;
x = x0;
y = y0;
//swap points so we're always draing left to right
if ( x0 > x1 ) {
x = x1;
y = y1;
x1 = x0;
y1 = y0;
}
m = (z1 - z0) / (x1 - x0);
//need to know dx and dy for this version
dx = (x1 - x) * 2;
dy = (y1 - y) * 2;
//positive slope: Octants 1, 2 (5 and 6)
if ( dy > 0 ) {
//slope < 1: Octant 1 (5)
if ( dx > dy ) {
d = dy - ( dx / 2 );
while ( x <= x1 ) {
plot_z(s, c, x, y, z);
if ( d < 0 ) {
x = x + 1;
z += m;
d = d + dy;
}
else {
x = x + 1;
z += m;
y = y + 1;
d = d + dy - dx;
}
}
}
//slope > 1: Octant 2 (6)
else {
d = ( dy / 2 ) - dx;
while ( y <= y1 ) {
plot_z(s, c, x, y, z );
if ( d > 0 ) {
y = y + 1;
d = d - dx;
}
else {
y = y + 1;
x = x + 1;
z += m;
d = d + dy - dx;
}
}
}
}
//negative slope: Octants 7, 8 (3 and 4)
else {
//slope > -1: Octant 8 (4)
if ( dx > abs(dy) ) {
d = dy + ( dx / 2 );
while ( x <= x1 ) {
plot_z(s, c, x, y, z);
if ( d > 0 ) {
x = x + 1;
z += m;
d = d + dy;
}
else {
x = x + 1;
z += m;
y = y - 1;
d = d + dy + dx;
}
}
}
//slope < -1: Octant 7 (3)
else {
d = (dy / 2) + dx;
while ( y >= y1 ) {
plot_z(s, c, x, y, z );
if ( d < 0 ) {
y = y - 1;
d = d + dx;
}
else {
y = y - 1;
x = x + 1;
z += m;
d = d + dy + dx;
}
}
}
}
}
void draw_line_z(int x0, int y0, int z0, int x1, int y1, int z1, screen s, color c) {
double zees[XRES][YRES];
int z_x,z_y;
int x, y, z, d, dx, dy, dz, dd;
x = x0;
y = y0;
z = z0;
//swap points so we're always draing left to right
if ( x0 > x1 ) {
x = x1;
y = y1;
z = z1;
x1 = x0;
y1 = y0;
z1 = z0;
}
//need to know dx and dy for this version
dx = (x1 - x) * 2;
dy = (y1 - y) * 2;
dz = (z1 - z) * 2;
//positive slope: Octants 1, 2 (5 and 6)
if ( dy > 0 ) {
//slope < 1: Octant 1 (5)
if ( dx > dy ) {
d = dy - ( dx / 2 );
if( dz > 0){
dd = dy - ( dz / 2 );
}else{
dd = ( dy / 2 ) - dz;
}
while ( x <= x1 ) {
for(z_x=0;z_x<500;z_x++){
for(z_y=0;z_y<500;z_y++){
zees[z_x][z_y] = z_values[z_x][z_y];
}
}
z_values[x][YRES-1-y] = plot_z(s, c, x, y, z, zees);
if ( d < 0 ) {
x = x + 1;
z = z + 1;
d = d + dy;
}
else {
x = x + 1;
y = y + 1;
z = z + 1;
d = d + dy - dx;
}
if( dd < 0 ){
dd = dd + dy;
}else{
dd = dd + dy - dz;
}
}
}
//slope > 1: Octant 2 (6)
else {
d = ( dy / 2 ) - dx;
if( dz > 0){
dd = dy - ( dz / 2 );
}else{
dd = ( dz / 2 ) - dz;
}
while ( y <= y1 ) {
for(z_x=0;z_x<500;z_x++){
for(z_y=0;z_y<500;z_y++){
zees[z_x][z_y] = z_values[z_x][z_y];
}
}
z_values[x][YRES-1-y] = plot_z(s, c, x, y, z, zees);
if ( d > 0 ) {
y = y + 1;
d = d - dx;
}
else {
y = y + 1;
x = x + 1;
z = z + 1;
d = d + dy - dx;
}
if ( dd > 0 ){
dd = dd - dz;
}else{
dd = dd + dy - dz;
}
}
}
}
//negative slope: Octants 7, 8 (3 and 4)
else {
//slope > -1: Octant 8 (4)
if ( dx > abs(dy) ) {
d = dy + ( dx / 2 );
if( dz > abs(dy) ){
dd = dy + ( dz / 2 );
}else{
dd = (dy / 2) + dz;
}
while ( x <= x1 ) {
for(z_x=0;z_x<500;z_x++){
for(z_y=0;z_y<500;z_y++){
zees[z_x][z_y] = z_values[z_x][z_y];
}
}
z_values[x][YRES-1-y] = plot_z(s, c, x, y, z, zees);
if ( d > 0 ) {
x = x + 1;
z = z + 1;
d = d + dy;
}
else {
x = x + 1;
y = y - 1;
z = z + 1;
d = d + dy + dx;
}
if ( dd > 0 ){
dd = dd + dy;
}else{
dd = dd + dy + dz;
}
}
}
//slope < -1: Octant 7 (3)
else {
d = (dy / 2) + dx;
if( dz > abs(dy) ){
dd = dy + ( dz / 2 );
}else{
dd = (dy / 2) + dz;
}
while ( y >= y1 ) {
for(z_x=0;z_x<500;z_x++){
for(z_y=0;z_y<500;z_y++){
zees[z_x][z_y] = z_values[z_x][z_y];
}
}
z_values[x][YRES-1-y] = plot_z(s, c, x, y, z, zees);
if ( d < 0 ) {
y = y - 1;
d = d + dx;
}
else {
y = y - 1;
x = x + 1;
z = z + 1;
d = d + dy + dx;
}
if ( dd < 0 ){
dd = dd + dz;
}else{
dd = dd + dy + dz;
}
}
}
}
}
