//projects a point
void g3_project_point(g3s_point *p)
{
#ifndef __powerc
fix tx,ty;
if (p->p3_flags & PF_PROJECTED || p->p3_codes & CC_BEHIND)
return;
if (checkmuldiv(&tx,p->p3_x,Canv_w2,p->p3_z) && checkmuldiv(&ty,p->p3_y,Canv_h2,p->p3_z)) {
p->p3_sx = Canv_w2 + tx;
p->p3_sy = Canv_h2 - ty;
p->p3_flags |= PF_PROJECTED;
}
else
p->p3_flags |= PF_OVERFLOW;
#else
double fz;
if ((p->p3_flags & PF_PROJECTED) || (p->p3_codes & CC_BEHIND))
return;
if ( p->p3_z <= 0 ) {
p->p3_flags |= PF_OVERFLOW;
return;
}
fz = f2fl(p->p3_z);
p->p3_sx = fl2f(fCanv_w2 + (f2fl(p->p3_x)*fCanv_w2 / fz));
p->p3_sy = fl2f(fCanv_h2 - (f2fl(p->p3_y)*fCanv_h2 / fz));
p->p3_flags |= PF_PROJECTED;
#endif
}
//draws a bitmap with the specified 3d width & height
//returns 1 if off screen, 0 if drew
void g3_draw_bitmap(const vms_vector &pos,fix width,fix height,grs_bitmap &bm)
{
g3s_point pnt;
fix w,h;
if (g3_rotate_point(pnt,pos) & CC_BEHIND)
return;
g3_project_point(pnt);
if (pnt.p3_flags & PF_OVERFLOW)
return;
#ifndef __powerc
fix t;
if (checkmuldiv(&t,width,Canv_w2,pnt.p3_z))
w = fixmul(t,Matrix_scale.x);
else
return;
if (checkmuldiv(&t,height,Canv_h2,pnt.p3_z))
h = fixmul(t,Matrix_scale.y);
else
return;
#else
if (pnt.p3_z == 0)
return;
double fz = f2fl(pnt.p3_z);
w = fixmul(fl2f(((f2fl(width)*fCanv_w2) / fz)), Matrix_scale.x);
h = fixmul(fl2f(((f2fl(height)*fCanv_h2) / fz)), Matrix_scale.y);
#endif
const fix blob0y = pnt.p3_sy - h, blob1x = pnt.p3_sx + w;
const array<grs_point, 3> blob_vertices{{
{pnt.p3_sx - w, blob0y},
{blob1x, blob0y},
{blob1x, pnt.p3_sy + h},
}};
scale_bitmap(bm, blob_vertices, 0);
}
//draw a sortof sphere - i.e., the 2d radius is proportional to the 3d
//radius, but not to the distance from the eye
int g3_draw_sphere(g3s_point *pnt,fix rad)
{
if (! (pnt->p3_codes & CC_BEHIND)) {
if (! (pnt->p3_flags & PF_PROJECTED))
g3_project_point(pnt);
if (! (pnt->p3_codes & PF_OVERFLOW)) {
fix r2,t;
r2 = fixmul(rad,Matrix_scale.x);
#ifndef __powerc
if (checkmuldiv(&t,r2,Canv_w2,pnt->p3_z))
return gr_disk(pnt->p3_sx,pnt->p3_sy,t);
#else
if (pnt->p3_z == 0)
return 0;
return gr_disk(pnt->p3_sx, pnt->p3_sy, fl2f(((f2fl(r2) * fCanv_w2) / f2fl(pnt->p3_z))));
#endif
}
}
return 0;
}
//draws a bitmap with the specified 3d width & height
//returns 1 if off screen, 0 if drew
bool g3_draw_bitmap(vms_vector *pos,fix width,fix height,grs_bitmap *bm)
{
#ifndef __powerc
g3s_point pnt;
fix t,w,h;
if (g3_rotate_point(&pnt,pos) & CC_BEHIND)
return 1;
g3_project_point(&pnt);
if (pnt.p3_flags & PF_OVERFLOW)
return 1;
if (checkmuldiv(&t,width,Canv_w2,pnt.p3_z))
w = fixmul(t,Matrix_scale.x);
else
return 1;
if (checkmuldiv(&t,height,Canv_h2,pnt.p3_z))
h = fixmul(t,Matrix_scale.y);
else
return 1;
blob_vertices[0].x = pnt.p3_sx - w;
blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h;
blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w;
blob_vertices[2].y = pnt.p3_sy + h;
scale_bitmap(bm,blob_vertices,0);
return 0;
#else
g3s_point pnt;
fix w,h;
double fz;
if (g3_rotate_point(&pnt,pos) & CC_BEHIND)
return 1;
g3_project_point(&pnt);
if (pnt.p3_flags & PF_OVERFLOW)
return 1;
if (pnt.p3_z == 0)
return 1;
fz = f2fl(pnt.p3_z);
w = fixmul(fl2f(((f2fl(width)*fCanv_w2) / fz)), Matrix_scale.x);
h = fixmul(fl2f(((f2fl(height)*fCanv_h2) / fz)), Matrix_scale.y);
blob_vertices[0].x = pnt.p3_sx - w;
blob_vertices[0].y = blob_vertices[1].y = pnt.p3_sy - h;
blob_vertices[1].x = blob_vertices[2].x = pnt.p3_sx + w;
blob_vertices[2].y = pnt.p3_sy + h;
scale_bitmap(bm, blob_vertices, 0);
return 0;
#endif
}
