| /* | |
| Copyright (C) 1996-1997 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 "quakedef.h" | |
| #include "r_local.h" | |
| #include "d_local.h" | |
| static finalvert_t fv[2][8]; | |
| static auxvert_t av[8]; | |
| void R_AliasProjectFinalVert (finalvert_t *fv, auxvert_t *av); | |
| 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; | |
| auxvert_t *pav0, *pav1, avout; | |
| pav0 = &av[pfv0 - &fv[0][0]]; | |
| pav1 = &av[pfv1 - &fv[0][0]]; | |
| if (pfv0->v[1] >= pfv1->v[1]) | |
| { | |
| scale = (ALIAS_Z_CLIP_PLANE - pav0->fv[2]) / | |
| (pav1->fv[2] - pav0->fv[2]); | |
| avout.fv[0] = pav0->fv[0] + (pav1->fv[0] - pav0->fv[0]) * scale; | |
| avout.fv[1] = pav0->fv[1] + (pav1->fv[1] - pav0->fv[1]) * scale; | |
| avout.fv[2] = ALIAS_Z_CLIP_PLANE; | |
| out->v[2] = pfv0->v[2] + (pfv1->v[2] - pfv0->v[2]) * scale; | |
| out->v[3] = pfv0->v[3] + (pfv1->v[3] - pfv0->v[3]) * scale; | |
| out->v[4] = pfv0->v[4] + (pfv1->v[4] - pfv0->v[4]) * scale; | |
| } | |
| else | |
| { | |
| scale = (ALIAS_Z_CLIP_PLANE - pav1->fv[2]) / | |
| (pav0->fv[2] - pav1->fv[2]); | |
| avout.fv[0] = pav1->fv[0] + (pav0->fv[0] - pav1->fv[0]) * scale; | |
| avout.fv[1] = pav1->fv[1] + (pav0->fv[1] - pav1->fv[1]) * scale; | |
| avout.fv[2] = ALIAS_Z_CLIP_PLANE; | |
| out->v[2] = pfv1->v[2] + (pfv0->v[2] - pfv1->v[2]) * scale; | |
| out->v[3] = pfv1->v[3] + (pfv0->v[3] - pfv1->v[3]) * scale; | |
| out->v[4] = pfv1->v[4] + (pfv0->v[4] - pfv1->v[4]) * scale; | |
| } | |
| R_AliasProjectFinalVert (out, &avout); | |
| if (out->v[0] < r_refdef.aliasvrect.x) | |
| out->flags |= ALIAS_LEFT_CLIP; | |
| if (out->v[1] < r_refdef.aliasvrect.y) | |
| out->flags |= ALIAS_TOP_CLIP; | |
| if (out->v[0] > r_refdef.aliasvrectright) | |
| out->flags |= ALIAS_RIGHT_CLIP; | |
| if (out->v[1] > r_refdef.aliasvrectbottom) | |
| out->flags |= ALIAS_BOTTOM_CLIP; | |
| } | |
| #if !id386 | |
| void R_Alias_clip_left (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out) | |
| { | |
| float scale; | |
| int i; | |
| if (pfv0->v[1] >= pfv1->v[1]) | |
| { | |
| scale = (float)(r_refdef.aliasvrect.x - pfv0->v[0]) / | |
| (pfv1->v[0] - pfv0->v[0]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv0->v[i] + (pfv1->v[i] - pfv0->v[i])*scale + 0.5; | |
| } | |
| else | |
| { | |
| scale = (float)(r_refdef.aliasvrect.x - pfv1->v[0]) / | |
| (pfv0->v[0] - pfv1->v[0]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv1->v[i] + (pfv0->v[i] - pfv1->v[i])*scale + 0.5; | |
| } | |
| } | |
| void R_Alias_clip_right (finalvert_t *pfv0, finalvert_t *pfv1, | |
| finalvert_t *out) | |
| { | |
| float scale; | |
| int i; | |
| if (pfv0->v[1] >= pfv1->v[1]) | |
| { | |
| scale = (float)(r_refdef.aliasvrectright - pfv0->v[0]) / | |
| (pfv1->v[0] - pfv0->v[0]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv0->v[i] + (pfv1->v[i] - pfv0->v[i])*scale + 0.5; | |
| } | |
| else | |
| { | |
| scale = (float)(r_refdef.aliasvrectright - pfv1->v[0]) / | |
| (pfv0->v[0] - pfv1->v[0]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv1->v[i] + (pfv0->v[i] - pfv1->v[i])*scale + 0.5; | |
| } | |
| } | |
| void R_Alias_clip_top (finalvert_t *pfv0, finalvert_t *pfv1, finalvert_t *out) | |
| { | |
| float scale; | |
| int i; | |
| if (pfv0->v[1] >= pfv1->v[1]) | |
| { | |
| scale = (float)(r_refdef.aliasvrect.y - pfv0->v[1]) / | |
| (pfv1->v[1] - pfv0->v[1]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv0->v[i] + (pfv1->v[i] - pfv0->v[i])*scale + 0.5; | |
| } | |
| else | |
| { | |
| scale = (float)(r_refdef.aliasvrect.y - pfv1->v[1]) / | |
| (pfv0->v[1] - pfv1->v[1]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv1->v[i] + (pfv0->v[i] - pfv1->v[i])*scale + 0.5; | |
| } | |
| } | |
| void R_Alias_clip_bottom (finalvert_t *pfv0, finalvert_t *pfv1, | |
| finalvert_t *out) | |
| { | |
| float scale; | |
| int i; | |
| if (pfv0->v[1] >= pfv1->v[1]) | |
| { | |
| scale = (float)(r_refdef.aliasvrectbottom - pfv0->v[1]) / | |
| (pfv1->v[1] - pfv0->v[1]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv0->v[i] + (pfv1->v[i] - pfv0->v[i])*scale + 0.5; | |
| } | |
| else | |
| { | |
| scale = (float)(r_refdef.aliasvrectbottom - pfv1->v[1]) / | |
| (pfv0->v[1] - pfv1->v[1]); | |
| for (i=0 ; i<6 ; i++) | |
| out->v[i] = pfv1->v[i] + (pfv0->v[i] - pfv1->v[i])*scale + 0.5; | |
| } | |
| } | |
| #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].v[0] < r_refdef.aliasvrect.x) | |
| out[k].flags |= ALIAS_LEFT_CLIP; | |
| if (out[k].v[1] < r_refdef.aliasvrect.y) | |
| out[k].flags |= ALIAS_TOP_CLIP; | |
| if (out[k].v[0] > r_refdef.aliasvrectright) | |
| out[k].flags |= ALIAS_RIGHT_CLIP; | |
| if (out[k].v[1] > r_refdef.aliasvrectbottom) | |
| out[k].flags |= ALIAS_BOTTOM_CLIP; | |
| k++; | |
| } | |
| if (!flags) | |
| { | |
| out[k] = in[i]; | |
| k++; | |
| } | |
| } | |
| return k; | |
| } | |
| /* | |
| ================ | |
| R_AliasClipTriangle | |
| ================ | |
| */ | |
| void R_AliasClipTriangle (mtriangle_t *ptri) | |
| { | |
| int i, k, pingpong; | |
| mtriangle_t mtri; | |
| unsigned clipflags; | |
| // copy vertexes and fix seam texture coordinates | |
| if (ptri->facesfront) | |
| { | |
| fv[0][0] = pfinalverts[ptri->vertindex[0]]; | |
| fv[0][1] = pfinalverts[ptri->vertindex[1]]; | |
| fv[0][2] = pfinalverts[ptri->vertindex[2]]; | |
| } | |
| else | |
| { | |
| for (i=0 ; i<3 ; i++) | |
| { | |
| fv[0][i] = pfinalverts[ptri->vertindex[i]]; | |
| if (!ptri->facesfront && (fv[0][i].flags & ALIAS_ONSEAM) ) | |
| fv[0][i].v[2] += r_affinetridesc.seamfixupX16; | |
| } | |
| } | |
| // clip | |
| clipflags = fv[0][0].flags | fv[0][1].flags | fv[0][2].flags; | |
| if (clipflags & ALIAS_Z_CLIP) | |
| { | |
| for (i=0 ; i<3 ; i++) | |
| av[i] = pauxverts[ptri->vertindex[i]]; | |
| 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].v[0] < r_refdef.aliasvrect.x) | |
| fv[pingpong][i].v[0] = r_refdef.aliasvrect.x; | |
| else if (fv[pingpong][i].v[0] > r_refdef.aliasvrectright) | |
| fv[pingpong][i].v[0] = r_refdef.aliasvrectright; | |
| if (fv[pingpong][i].v[1] < r_refdef.aliasvrect.y) | |
| fv[pingpong][i].v[1] = r_refdef.aliasvrect.y; | |
| else if (fv[pingpong][i].v[1] > r_refdef.aliasvrectbottom) | |
| fv[pingpong][i].v[1] = r_refdef.aliasvrectbottom; | |
| fv[pingpong][i].flags = 0; | |
| } | |
| // draw triangles | |
| mtri.facesfront = ptri->facesfront; | |
| r_affinetridesc.ptriangles = &mtri; | |
| r_affinetridesc.pfinalverts = fv[pingpong]; | |
| // FIXME: do all at once as trifan? | |
| mtri.vertindex[0] = 0; | |
| for (i=1 ; i<k-1 ; i++) | |
| { | |
| mtri.vertindex[1] = i; | |
| mtri.vertindex[2] = i+1; | |
| D_PolysetDraw (); | |
| } | |
| } | |