xash3d-fwgs/ref_soft/r_aclip.c
Gleb Mazovetskiy 5e0a0765ce Trim all trailing whitespace
The `.editorconfig` file in this repo is configured to trim all trailing
whitespace regardless of whether the line is modified.

Trims all trailing whitespace in the repository to make the codebase easier
to work with in editors that respect `.editorconfig`.

`git blame` becomes less useful on these lines but it already isn't very useful.

Commands:

```
find . -type f -name '*.h' -exec sed --in-place 's/[[:space:]]\+$//' {} \+
find . -type f -name '*.c' -exec sed --in-place 's/[[:space:]]\+$//' {} \+
```
2021-01-04 20:55:10 +03:00

324 lines
8.7 KiB
C

/*
Copyright (C) 1997-2001 Id Software, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
// r_aclip.c: clip routines for drawing Alias models directly to the screen
#include "r_local.h"
static finalvert_t fv[2][8];
void R_AliasProjectAndClipTestFinalVert (finalvert_t *fv);
void R_Alias_clip_top (finalvert_t *pfv0, finalvert_t *pfv1,
finalvert_t *out);
void R_Alias_clip_bottom (finalvert_t *pfv0, finalvert_t *pfv1,
finalvert_t *out);
void R_Alias_clip_left (finalvert_t *pfv0, finalvert_t *pfv1,
finalvert_t *out);
void R_Alias_clip_right (finalvert_t *pfv0, finalvert_t *pfv1,
finalvert_t *out);
/*
================
R_Alias_clip_z
pfv0 is the unclipped vertex, pfv1 is the z-clipped vertex
================
*/
void R_Alias_clip_z (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out)
{
float scale;
scale = (ALIAS_Z_CLIP_PLANE - pfv0->xyz[2]) /
(pfv1->xyz[2] - pfv0->xyz[2]);
out->xyz[0] = pfv0->xyz[0] + (pfv1->xyz[0] - pfv0->xyz[0]) * scale;
out->xyz[1] = pfv0->xyz[1] + (pfv1->xyz[1] - pfv0->xyz[1]) * scale;
out->xyz[2] = ALIAS_Z_CLIP_PLANE;
out->s = pfv0->s + (pfv1->s - pfv0->s) * scale;
out->t = pfv0->t + (pfv1->t - pfv0->t) * scale;
out->l = pfv0->l + (pfv1->l - pfv0->l) * scale;
R_AliasProjectAndClipTestFinalVert (out);
}
#if !id386
void R_Alias_clip_left (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out)
{
float scale;
if (pfv0->v >= pfv1->v )
{
scale = (float)(RI.aliasvrect.x - pfv0->u) /
(pfv1->u - pfv0->u);
out->u = pfv0->u + ( pfv1->u - pfv0->u ) * scale + 0.5f;
out->v = pfv0->v + ( pfv1->v - pfv0->v ) * scale + 0.5f;
out->s = pfv0->s + ( pfv1->s - pfv0->s ) * scale + 0.5f;
out->t = pfv0->t + ( pfv1->t - pfv0->t ) * scale + 0.5f;
out->l = pfv0->l + ( pfv1->l - pfv0->l ) * scale + 0.5f;
out->zi = pfv0->zi + ( pfv1->zi - pfv0->zi) * scale + 0.5f;
}
else
{
scale = (float)(RI.aliasvrect.x - pfv1->u) /
(pfv0->u - pfv1->u);
out->u = pfv1->u + ( pfv0->u - pfv1->u ) * scale + 0.5f;
out->v = pfv1->v + ( pfv0->v - pfv1->v ) * scale + 0.5f;
out->s = pfv1->s + ( pfv0->s - pfv1->s ) * scale + 0.5f;
out->t = pfv1->t + ( pfv0->t - pfv1->t ) * scale + 0.5f;
out->l = pfv1->l + ( pfv0->l - pfv1->l ) * scale + 0.5f;
out->zi = pfv1->zi + ( pfv0->zi - pfv1->zi) * scale + 0.5f;
}
}
void R_Alias_clip_right (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out)
{
float scale;
if ( pfv0->v >= pfv1->v )
{
scale = (float)(RI.aliasvrectright - pfv0->u ) /
(pfv1->u - pfv0->u );
out->u = pfv0->u + ( pfv1->u - pfv0->u ) * scale + 0.5f;
out->v = pfv0->v + ( pfv1->v - pfv0->v ) * scale + 0.5f;
out->s = pfv0->s + ( pfv1->s - pfv0->s ) * scale + 0.5f;
out->t = pfv0->t + ( pfv1->t - pfv0->t ) * scale + 0.5f;
out->l = pfv0->l + ( pfv1->l - pfv0->l ) * scale + 0.5f;
out->zi = pfv0->zi + ( pfv1->zi - pfv0->zi) * scale + 0.5f;
}
else
{
scale = (float)(RI.aliasvrectright - pfv1->u ) /
(pfv0->u - pfv1->u );
out->u = pfv1->u + ( pfv0->u - pfv1->u ) * scale + 0.5f;
out->v = pfv1->v + ( pfv0->v - pfv1->v ) * scale + 0.5f;
out->s = pfv1->s + ( pfv0->s - pfv1->s ) * scale + 0.5f;
out->t = pfv1->t + ( pfv0->t - pfv1->t ) * scale + 0.5f;
out->l = pfv1->l + ( pfv0->l - pfv1->l ) * scale + 0.5f;
out->zi = pfv1->zi + ( pfv0->zi - pfv1->zi) * scale + 0.5f;
}
}
void R_Alias_clip_top (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out)
{
float scale;
if (pfv0->v >= pfv1->v)
{
scale = (float)(RI.aliasvrect.y - pfv0->v) /
(pfv1->v - pfv0->v);
out->u = pfv0->u + ( pfv1->u - pfv0->u ) * scale + 0.5f;
out->v = pfv0->v + ( pfv1->v - pfv0->v ) * scale + 0.5f;
out->s = pfv0->s + ( pfv1->s - pfv0->s ) * scale + 0.5f;
out->t = pfv0->t + ( pfv1->t - pfv0->t ) * scale + 0.5f;
out->l = pfv0->l + ( pfv1->l - pfv0->l ) * scale + 0.5f;
out->zi = pfv0->zi + ( pfv1->zi - pfv0->zi) * scale + 0.5f;
}
else
{
scale = (float)(RI.aliasvrect.y - pfv1->v) /
(pfv0->v - pfv1->v);
out->u = pfv1->u + ( pfv0->u - pfv1->u ) * scale + 0.5f;
out->v = pfv1->v + ( pfv0->v - pfv1->v ) * scale + 0.5f;
out->s = pfv1->s + ( pfv0->s - pfv1->s ) * scale + 0.5f;
out->t = pfv1->t + ( pfv0->t - pfv1->t ) * scale + 0.5f;
out->l = pfv1->l + ( pfv0->l - pfv1->l ) * scale + 0.5f;
out->zi = pfv1->zi + ( pfv0->zi - pfv1->zi) * scale + 0.5f;
}
}
void R_Alias_clip_bottom (finalvert_t *pfv0, finalvert_t *pfv1,
finalvert_t *out)
{
float scale;
if (pfv0->v >= pfv1->v)
{
scale = (float)(RI.aliasvrectbottom - pfv0->v) /
(pfv1->v - pfv0->v);
out->u = pfv0->u + ( pfv1->u - pfv0->u ) * scale + 0.5f;
out->v = pfv0->v + ( pfv1->v - pfv0->v ) * scale + 0.5f;
out->s = pfv0->s + ( pfv1->s - pfv0->s ) * scale + 0.5f;
out->t = pfv0->t + ( pfv1->t - pfv0->t ) * scale + 0.5f;
out->l = pfv0->l + ( pfv1->l - pfv0->l ) * scale + 0.5f;
out->zi = pfv0->zi + ( pfv1->zi - pfv0->zi) * scale + 0.5f;
}
else
{
scale = (float)(RI.aliasvrectbottom - pfv1->v) /
(pfv0->v - pfv1->v);
out->u = pfv1->u + ( pfv0->u - pfv1->u ) * scale + 0.5f;
out->v = pfv1->v + ( pfv0->v - pfv1->v ) * scale + 0.5f;
out->s = pfv1->s + ( pfv0->s - pfv1->s ) * scale + 0.5f;
out->t = pfv1->t + ( pfv0->t - pfv1->t ) * scale + 0.5f;
out->l = pfv1->l + ( pfv0->l - pfv1->l ) * scale + 0.5f;
out->zi = pfv1->zi + ( pfv0->zi - pfv1->zi) * scale + 0.5f;
}
}
#endif
int R_AliasClip (finalvert_t *in, finalvert_t *out, int flag, int count,
void(*clip)(finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out) )
{
int i,j,k;
int flags, oldflags;
j = count-1;
k = 0;
for (i=0 ; i<count ; j = i, i++)
{
oldflags = in[j].flags & flag;
flags = in[i].flags & flag;
if (flags && oldflags)
continue;
if (oldflags ^ flags)
{
clip (&in[j], &in[i], &out[k]);
out[k].flags = 0;
if (out[k].u < RI.aliasvrect.x)
out[k].flags |= ALIAS_LEFT_CLIP;
if (out[k].v < RI.aliasvrect.y)
out[k].flags |= ALIAS_TOP_CLIP;
if (out[k].u > RI.aliasvrectright)
out[k].flags |= ALIAS_RIGHT_CLIP;
if (out[k].v > RI.aliasvrectbottom)
out[k].flags |= ALIAS_BOTTOM_CLIP;
k++;
}
if (!flags)
{
out[k] = in[i];
k++;
}
}
return k;
}
/*
================
R_AliasClipTriangle
================
*/
void R_AliasClipTriangle (finalvert_t *index0, finalvert_t *index1, finalvert_t *index2)
{
int i, k, pingpong;
unsigned clipflags;
// copy vertexes and fix seam texture coordinates
fv[0][0] = *index0;
fv[0][1] = *index1;
fv[0][2] = *index2;
// clip
clipflags = fv[0][0].flags | fv[0][1].flags | fv[0][2].flags;
if (clipflags & ALIAS_Z_CLIP)
{
k = R_AliasClip (fv[0], fv[1], ALIAS_Z_CLIP, 3, R_Alias_clip_z);
if (k == 0)
return;
pingpong = 1;
clipflags = fv[1][0].flags | fv[1][1].flags | fv[1][2].flags;
}
else
{
pingpong = 0;
k = 3;
}
if (clipflags & ALIAS_LEFT_CLIP)
{
k = R_AliasClip (fv[pingpong], fv[pingpong ^ 1],
ALIAS_LEFT_CLIP, k, R_Alias_clip_left);
if (k == 0)
return;
pingpong ^= 1;
}
if (clipflags & ALIAS_RIGHT_CLIP)
{
k = R_AliasClip (fv[pingpong], fv[pingpong ^ 1],
ALIAS_RIGHT_CLIP, k, R_Alias_clip_right);
if (k == 0)
return;
pingpong ^= 1;
}
if (clipflags & ALIAS_BOTTOM_CLIP)
{
k = R_AliasClip (fv[pingpong], fv[pingpong ^ 1],
ALIAS_BOTTOM_CLIP, k, R_Alias_clip_bottom);
if (k == 0)
return;
pingpong ^= 1;
}
if (clipflags & ALIAS_TOP_CLIP)
{
k = R_AliasClip (fv[pingpong], fv[pingpong ^ 1],
ALIAS_TOP_CLIP, k, R_Alias_clip_top);
if (k == 0)
return;
pingpong ^= 1;
}
for (i=0 ; i<k ; i++)
{
if (fv[pingpong][i].u < RI.aliasvrect.x)
fv[pingpong][i].u = RI.aliasvrect.x;
else if (fv[pingpong][i].u > RI.aliasvrectright)
fv[pingpong][i].u = RI.aliasvrectright;
if (fv[pingpong][i].v < RI.aliasvrect.y)
fv[pingpong][i].v = RI.aliasvrect.y;
else if (fv[pingpong][i].v > RI.aliasvrectbottom)
fv[pingpong][i].v = RI.aliasvrectbottom;
fv[pingpong][i].flags = 0;
}
// draw triangles
for (i=1 ; i<k-1 ; i++)
{
aliastriangleparms.a = &fv[pingpong][0];
aliastriangleparms.b = &fv[pingpong][i];
aliastriangleparms.c = &fv[pingpong][i+1];
R_DrawTriangle();
}
}