84 lines
1.9 KiB
C++
84 lines
1.9 KiB
C++
/*
|
|
* This file is part of the DXX-Rebirth project <http://www.dxx-rebirth.com/>.
|
|
* It is copyright by its individual contributors, as recorded in the
|
|
* project's Git history. See COPYING.txt at the top level for license
|
|
* terms and a link to the Git history.
|
|
*/
|
|
/*
|
|
*
|
|
* Instancing routines
|
|
*
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include "dxxerror.h"
|
|
|
|
#include "3d.h"
|
|
#include "globvars.h"
|
|
|
|
#define MAX_INSTANCE_DEPTH 5
|
|
|
|
namespace {
|
|
|
|
struct instance_context {
|
|
vms_matrix m;
|
|
vms_vector p;
|
|
};
|
|
|
|
}
|
|
|
|
static array<instance_context, MAX_INSTANCE_DEPTH> instance_stack;
|
|
|
|
int instance_depth = 0;
|
|
|
|
//instance at specified point with specified orientation
|
|
//if matrix==NULL, don't modify matrix. This will be like doing an offset
|
|
void g3_start_instance_matrix(const vms_vector &pos,const vms_matrix *orient)
|
|
{
|
|
Assert(instance_depth<MAX_INSTANCE_DEPTH);
|
|
|
|
instance_stack[instance_depth].m = View_matrix;
|
|
instance_stack[instance_depth].p = View_position;
|
|
instance_depth++;
|
|
|
|
//step 1: subtract object position from view position
|
|
|
|
if (orient) {
|
|
const auto tempv = vm_vec_sub(View_position, pos);
|
|
//step 2: rotate view vector through object matrix
|
|
|
|
vm_vec_rotate(View_position,tempv,*orient);
|
|
|
|
//step 3: rotate object matrix through view_matrix (vm = ob * vm)
|
|
|
|
View_matrix = vm_matrix_x_matrix(vm_transposed_matrix(*orient),View_matrix);
|
|
}
|
|
}
|
|
|
|
|
|
//instance at specified point with specified orientation
|
|
//if angles==NULL, don't modify matrix. This will be like doing an offset
|
|
void g3_start_instance_angles(const vms_vector &pos,const vms_angvec *angles)
|
|
{
|
|
if (angles==NULL) {
|
|
g3_start_instance_matrix(pos,NULL);
|
|
return;
|
|
}
|
|
const auto tm = vm_angles_2_matrix(*angles);
|
|
g3_start_instance_matrix(pos,&tm);
|
|
}
|
|
|
|
|
|
//pops the old context
|
|
void g3_done_instance()
|
|
{
|
|
instance_depth--;
|
|
|
|
Assert(instance_depth >= 0);
|
|
|
|
View_position = instance_stack[instance_depth].p;
|
|
View_matrix = instance_stack[instance_depth].m;
|
|
}
|
|
|
|
|