Descent3/renderer/HardwareClipper.cpp
2024-04-15 21:43:29 -06:00

436 lines
9.4 KiB
C++

#include "RendererConfig.h"
#ifndef USE_SOFTWARE_TNL
#include "pserror.h"
#include "3d.h"
#include "HardwareInternal.h"
static int free_point_num = -1;
static g3Point temp_points[MAX_POINTS_IN_POLY];
static g3Point *free_points[MAX_POINTS_IN_POLY];
vector Clip_plane_point;
void InitFreePoints(void)
{
int i;
for( i = 0; i < MAX_POINTS_IN_POLY; i++ )
{
free_points[i] = &temp_points[i];
}
free_point_num = 0;
}
g3Point *GetTempPoint(void)
{
ASSERT(free_point_num < MAX_POINTS_IN_POLY);
g3Point *p = free_points[ free_point_num++ ];
p->p3_flags = PF_TEMP_POINT;
return p;
}
void FreeTempPoint(g3Point *p)
{
if( free_point_num < 1 )
{
mprintf((1,"clipper: no temp points to free\n"));
free_point_num = 1;
Int3();
}
ASSERT( p->p3_flags & PF_TEMP_POINT );
free_points[ --free_point_num ] = p;
p->p3_flags &= ~PF_TEMP_POINT;
}
//Verify that all the temp points are free, and free them it they are not.
#ifdef _DEBUG
void CheckTempPoints(void)
{
if( free_point_num )
{
Int3();
InitFreePoints();
}
}
#endif
//Free up any temp points (created by the clipper) in the given pointlist
//Parameters: pointlist - pointer to list of pointers to points, returned by g3_ClipPolygon()
// nv - the number of points in pointlist
void g3_FreeTempPoints( g3Point **pointlist, int nv )
{
// Go through list
int i;
for( i = 0; i < nv; i++ )
{
if( pointlist[i]->p3_flags & PF_TEMP_POINT )
{
FreeTempPoint( pointlist[i] );
}
}
// Make sure all temp points are freed
CheckTempPoints();
}
// Clips an edge against the far plane
g3Point *ClipFarEdge( g3Point *on_pnt, g3Point *off_pnt )
{
float z_on = on_pnt->p3_z;
float z_off = off_pnt->p3_z;
float k = 1.0f - ((z_off-Far_clip_z) / (z_off-z_on));
g3Point *tmp = GetTempPoint();
tmp->p3_z = on_pnt->p3_z + ((off_pnt->p3_z-on_pnt->p3_z) * k);
tmp->p3_x = on_pnt->p3_x + ((off_pnt->p3_x-on_pnt->p3_x) * k);
tmp->p3_y = on_pnt->p3_y + ((off_pnt->p3_y-on_pnt->p3_y) * k);
if (on_pnt->p3_flags & PF_UV)
{
tmp->p3_u = on_pnt->p3_u + ((off_pnt->p3_u-on_pnt->p3_u) * k);
tmp->p3_v = on_pnt->p3_v + ((off_pnt->p3_v-on_pnt->p3_v) * k);
tmp->p3_flags |= PF_UV;
}
if (on_pnt->p3_flags & PF_UV2)
{
tmp->p3_u2 = on_pnt->p3_u2 + ((off_pnt->p3_u2-on_pnt->p3_u2) * k);
tmp->p3_v2 = on_pnt->p3_v2 + ((off_pnt->p3_v2-on_pnt->p3_v2) * k);
tmp->p3_flags |= PF_UV2;
}
if (on_pnt->p3_flags & PF_L)
{
tmp->p3_l = on_pnt->p3_l + ((off_pnt->p3_l-on_pnt->p3_l) * k);
tmp->p3_flags |= PF_L;
}
if (on_pnt->p3_flags & PF_RGBA)
{
tmp->p3_r = on_pnt->p3_r + ((off_pnt->p3_r-on_pnt->p3_r) * k);
tmp->p3_g = on_pnt->p3_g + ((off_pnt->p3_g-on_pnt->p3_g) * k);
tmp->p3_b = on_pnt->p3_b + ((off_pnt->p3_b-on_pnt->p3_b) * k);
tmp->p3_a = on_pnt->p3_a + ((off_pnt->p3_a-on_pnt->p3_a) * k);
tmp->p3_flags |= PF_RGBA;
}
g3_CodePoint(tmp);
return tmp;
}
// Clips an edge against the far plane
g3Point *ClipCustomEdge( g3Point *on_pnt, g3Point *off_pnt )
{
g3Point *tmp = GetTempPoint();
vector ray_direction = off_pnt->p3_vec - on_pnt->p3_vec;
ray_direction.x /= Matrix_scale.x;
ray_direction.y /= Matrix_scale.y;
ray_direction.z /= Matrix_scale.z;
vector w = on_pnt->p3_vec - Clip_plane_point;
w.x /= Matrix_scale.x;
w.y /= Matrix_scale.y;
w.z /= Matrix_scale.z;
float k, den = -(Clip_plane * ray_direction);
if( den == 0.0f )
{
k = 1.0f;
}
else
{
float num = Clip_plane * w;
k = num / den;
}
tmp->p3_vec = on_pnt->p3_vec + ((off_pnt->p3_vec-on_pnt->p3_vec) * k);
if (on_pnt->p3_flags & PF_UV)
{
tmp->p3_u = on_pnt->p3_u + ((off_pnt->p3_u-on_pnt->p3_u) * k);
tmp->p3_v = on_pnt->p3_v + ((off_pnt->p3_v-on_pnt->p3_v) * k);
tmp->p3_flags |= PF_UV;
}
if (on_pnt->p3_flags & PF_UV2)
{
tmp->p3_u2 = on_pnt->p3_u2 + ((off_pnt->p3_u2-on_pnt->p3_u2) * k);
tmp->p3_v2 = on_pnt->p3_v2 + ((off_pnt->p3_v2-on_pnt->p3_v2) * k);
tmp->p3_flags |= PF_UV2;
}
if (on_pnt->p3_flags & PF_L)
{
tmp->p3_l = on_pnt->p3_l + ((off_pnt->p3_l-on_pnt->p3_l) * k);
tmp->p3_flags |= PF_L;
}
if (on_pnt->p3_flags & PF_RGBA)
{
tmp->p3_r = on_pnt->p3_r + ((off_pnt->p3_r-on_pnt->p3_r) * k);
tmp->p3_g = on_pnt->p3_g + ((off_pnt->p3_g-on_pnt->p3_g) * k);
tmp->p3_b = on_pnt->p3_b + ((off_pnt->p3_b-on_pnt->p3_b) * k);
tmp->p3_a = on_pnt->p3_a + ((off_pnt->p3_a-on_pnt->p3_a) * k);
tmp->p3_flags |= PF_RGBA;
}
g3_CodePoint(tmp);
return tmp;
}
//clips an edge against one plane.
g3Point *ClipEdge( int plane_flag, g3Point *on_pnt, g3Point *off_pnt )
{
float a,b,k;
g3Point *tmp;
//compute clipping value k = (xs-zs) / (xs-xe-zs+ze)
//use x or y as appropriate, and negate x/y value as appropriate
if (plane_flag & CC_OFF_FAR)
{
return ClipFarEdge (on_pnt,off_pnt);
}
if ((plane_flag & CC_OFF_CUSTOM) && Clip_custom)
{
return ClipCustomEdge (on_pnt,off_pnt);
}
if (plane_flag & (CC_OFF_RIGHT | CC_OFF_LEFT))
{
a = on_pnt->p3_x;
b = off_pnt->p3_x;
}
else
{
a = on_pnt->p3_y;
b = off_pnt->p3_y;
}
if (plane_flag & (CC_OFF_LEFT | CC_OFF_BOT))
{
a = -a;
b = -b;
}
k = (a - on_pnt->p3_z) / ((a - on_pnt->p3_z) - b + off_pnt->p3_z); //(xs-zs) / (xs-zs-xe+ze)
tmp = GetTempPoint();
tmp->p3_x = on_pnt->p3_x + ((off_pnt->p3_x-on_pnt->p3_x) * k);
tmp->p3_y = on_pnt->p3_y + ((off_pnt->p3_y-on_pnt->p3_y) * k);
if (plane_flag & (CC_OFF_TOP|CC_OFF_BOT))
{
tmp->p3_z = tmp->p3_y;
}
else
{
tmp->p3_z = tmp->p3_x;
}
if (plane_flag & (CC_OFF_LEFT|CC_OFF_BOT))
{
tmp->p3_z = -tmp->p3_z;
}
if (on_pnt->p3_flags & PF_UV)
{
tmp->p3_u = on_pnt->p3_u + ((off_pnt->p3_u-on_pnt->p3_u) * k);
tmp->p3_v = on_pnt->p3_v + ((off_pnt->p3_v-on_pnt->p3_v) * k);
tmp->p3_flags |= PF_UV;
}
if (on_pnt->p3_flags & PF_UV2)
{
tmp->p3_u2 = on_pnt->p3_u2 + ((off_pnt->p3_u2-on_pnt->p3_u2) * k);
tmp->p3_v2 = on_pnt->p3_v2 + ((off_pnt->p3_v2-on_pnt->p3_v2) * k);
tmp->p3_flags |= PF_UV2;
}
if (on_pnt->p3_flags & PF_L)
{
tmp->p3_l = on_pnt->p3_l + ((off_pnt->p3_l-on_pnt->p3_l) * k);
tmp->p3_flags |= PF_L;
}
if (on_pnt->p3_flags & PF_RGBA)
{
tmp->p3_r = on_pnt->p3_r + ((off_pnt->p3_r-on_pnt->p3_r) * k);
tmp->p3_g = on_pnt->p3_g + ((off_pnt->p3_g-on_pnt->p3_g) * k);
tmp->p3_b = on_pnt->p3_b + ((off_pnt->p3_b-on_pnt->p3_b) * k);
tmp->p3_a = on_pnt->p3_a + ((off_pnt->p3_a-on_pnt->p3_a) * k);
tmp->p3_flags |= PF_RGBA;
}
g3_CodePoint(tmp);
return tmp;
}
//clips a line to the viewing pyramid.
void ClipLine(g3Point **p0,g3Point **p1,ubyte codes_or)
{
int plane_flag;
g3Point *old_p1;
//might have these left over
//(*p0)->p3_flags &= ~(PF_UV|PF_L|PF_RGBA|PF_UV2);
//(*p1)->p3_flags &= ~(PF_UV|PF_L|PF_RGBA|PF_UV2);
for (plane_flag=1;plane_flag<=32;plane_flag<<=1)
{
if (codes_or & plane_flag)
{
if ((*p0)->p3_codes & plane_flag)
{
//swap!
g3Point *t=*p0;
*p0=*p1;
*p1=t;
}
old_p1 = *p1;
*p1 = ClipEdge(plane_flag,*p0,*p1);
codes_or = (*p0)->p3_codes | (*p1)->p3_codes; //get new codes
if (old_p1->p3_flags & PF_TEMP_POINT)
{
FreeTempPoint(old_p1);
}
}
}
}
int ClipPlane(int plane_flag,g3Point **src,g3Point **dest,int *nv,g3Codes *cc)
{
int i,prev,next;
g3Point **save_dest=dest;
//Init codes
cc->cc_and = 0xff; cc->cc_or = 0;
for (i=0,prev=*nv-1,next=1;i<*nv;i++)
{
if (src[i]->p3_codes & plane_flag)
{
//cur point off?
if (! (src[prev]->p3_codes & plane_flag))
{
//prev not off?
*dest = ClipEdge(plane_flag,src[prev],src[i]);
cc->cc_or |= (*dest)->p3_codes;
cc->cc_and &= (*dest)->p3_codes;
dest++;
}
if (! (src[next]->p3_codes & plane_flag))
{
*dest = ClipEdge(plane_flag,src[next],src[i]);
cc->cc_or |= (*dest)->p3_codes;
cc->cc_and &= (*dest)->p3_codes;
dest++;
}
//see if must free discarded point
if (src[i]->p3_flags & PF_TEMP_POINT)
{
FreeTempPoint(src[i]);
}
}
else
{
//cur not off, copy to dest buffer
*dest++ = src[i];
cc->cc_or |= src[i]->p3_codes;
cc->cc_and &= src[i]->p3_codes;
}
prev = i;
if (++next == *nv)
{
next = 0;
}
}
return (dest-save_dest);
}
//temp buffers for clipping
static g3Point *Vbuf0[MAX_POINTS_IN_POLY];
static g3Point *Vbuf1[MAX_POINTS_IN_POLY];
//Clips a polygon
//Parameters: pointlist - pointer to a list of pointers to points
// nv - the number of points in the polygon
// cc - the clip codes for this polygon
//Returns: a pointer to a list of pointer of points in the clipped polygon
//NOTE: You MUST call g3_FreeTempPoints() when you're done with the clipped polygon
g3Point **g3_ClipPolygon(g3Point **pointlist,int *nv,g3Codes *cc)
{
int plane_flag;
g3Point **dest;
dest = Vbuf0;
//& ASSERT(free_point_num == 0); //DAJ UTB CMO
if(free_point_num!=0){
mprintf((1,"clipper: leftover temp point\n"));
free_point_num = 0;
Int3();
}
for (plane_flag=1;plane_flag<=32;plane_flag<<=1)
{
if (cc->cc_or & plane_flag)
{
*nv = ClipPlane(plane_flag,pointlist,dest,nv,cc);
if (cc->cc_and) //clipped away
return dest;
pointlist = dest;
dest = (pointlist == Vbuf0) ? Vbuf1 : Vbuf0;
}
}
return pointlist; //we swapped after we copied
}
// sets the z distance of the far clipping plane
void g3_SetFarClipZ(float z)
{
Far_clip_z = z;
}
// Sets up a custom clipping plane - g3_StartFrame must be called before this is called
void g3_SetCustomClipPlane(ubyte state,vector *pnt,vector *normal)
{
Clip_custom=state;
if (state)
{
vector tempv;
vector norm=*normal;
tempv = *pnt - View_position;
Clip_plane_point = tempv * View_matrix;
Clip_plane=norm * Unscaled_matrix;//View_matrix;
vm_NormalizeVector(&Clip_plane);
}
}
#endif