r_alias.c

quake1 dos源代码最新版本

/*
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_alias.c: routines for setting up to draw alias models

#include "quakedef.h"
#include "r_local.h"
#include "d_local.h"	// FIXME: shouldn't be needed (is needed for patch
						// right now, but that should move)

#define LIGHT_MIN	5		// lowest light value we'll allow, to avoid the
							//  need for inner-loop light clamping

mtriangle_t		*ptriangles;
affinetridesc_t	r_affinetridesc;

void *			acolormap;	// FIXME: should go away

trivertx_t		*r_apverts;

// TODO: these probably will go away with optimized rasterization
mdl_t				*pmdl;
vec3_t				r_plightvec;
int					r_ambientlight;
float				r_shadelight;
aliashdr_t			*paliashdr;
finalvert_t			*pfinalverts;
auxvert_t			*pauxverts;
static float		ziscale;
static model_t		*pmodel;

static vec3_t		alias_forward, alias_right, alias_up;

static maliasskindesc_t	*pskindesc;

int				r_amodels_drawn;
int				a_skinwidth;
int				r_anumverts;

float	aliastransform[3][4];

typedef struct {
	int	index0;
	int	index1;
} aedge_t;

static aedge_t	aedges[12] = {
{0, 1}, {1, 2}, {2, 3}, {3, 0},
{4, 5}, {5, 6}, {6, 7}, {7, 4},
{0, 5}, {1, 4}, {2, 7}, {3, 6}
};

#define NUMVERTEXNORMALS	162

float	r_avertexnormals[NUMVERTEXNORMALS][3] = {
#include "anorms.h"
};

void R_AliasTransformAndProjectFinalVerts (finalvert_t *fv,
	stvert_t *pstverts);
void R_AliasSetUpTransform (int trivial_accept);
void R_AliasTransformVector (vec3_t in, vec3_t out);
void R_AliasTransformFinalVert (finalvert_t *fv, auxvert_t *av,
	trivertx_t *pverts, stvert_t *pstverts);
void R_AliasProjectFinalVert (finalvert_t *fv, auxvert_t *av);


/*
================
R_AliasCheckBBox
================
*/
qboolean R_AliasCheckBBox (void)
{
	int					i, flags, frame, numv;
	aliashdr_t			*pahdr;
	float				zi, basepts[8][3], v0, v1, frac;
	finalvert_t			*pv0, *pv1, viewpts[16];
	auxvert_t			*pa0, *pa1, viewaux[16];
	maliasframedesc_t	*pframedesc;
	qboolean			zclipped, zfullyclipped;
	unsigned			anyclip, allclip;
	int					minz;

// expand, rotate, and translate points into worldspace

	currententity->trivial_accept = 0;
	pmodel = currententity->model;
	pahdr = Mod_Extradata (pmodel);
	pmdl = (mdl_t *)((byte *)pahdr + pahdr->model);

	R_AliasSetUpTransform (0);

// construct the base bounding box for this frame
	frame = currententity->frame;
// TODO: don't repeat this check when drawing?
	if ((frame >= pmdl->numframes) || (frame < 0))
	{
		Con_DPrintf ("No such frame %d %s\n", frame,
				pmodel->name);
		frame = 0;
	}

	pframedesc = &pahdr->frames[frame];

// x worldspace coordinates
	basepts[0][0] = basepts[1][0] = basepts[2][0] = basepts[3][0] =
			(float)pframedesc->bboxmin.v[0];
	basepts[4][0] = basepts[5][0] = basepts[6][0] = basepts[7][0] =
			(float)pframedesc->bboxmax.v[0];

// y worldspace coordinates
	basepts[0][1] = basepts[3][1] = basepts[5][1] = basepts[6][1] =
			(float)pframedesc->bboxmin.v[1];
	basepts[1][1] = basepts[2][1] = basepts[4][1] = basepts[7][1] =
			(float)pframedesc->bboxmax.v[1];

// z worldspace coordinates
	basepts[0][2] = basepts[1][2] = basepts[4][2] = basepts[5][2] =
			(float)pframedesc->bboxmin.v[2];
	basepts[2][2] = basepts[3][2] = basepts[6][2] = basepts[7][2] =
			(float)pframedesc->bboxmax.v[2];

	zclipped = false;
	zfullyclipped = true;

	minz = 9999;
	for (i=0; i<8 ; i++)
	{
		R_AliasTransformVector  (&basepts[i][0], &viewaux[i].fv[0]);

		if (viewaux[i].fv[2] < ALIAS_Z_CLIP_PLANE)
		{
		// we must clip points that are closer than the near clip plane
			viewpts[i].flags = ALIAS_Z_CLIP;
			zclipped = true;
		}
		else
		{
			if (viewaux[i].fv[2] < minz)
				minz = viewaux[i].fv[2];
			viewpts[i].flags = 0;
			zfullyclipped = false;
		}
	}


	if (zfullyclipped)
	{
		return false;	// everything was near-z-clipped
	}

	numv = 8;

	if (zclipped)
	{
	// organize points by edges, use edges to get new points (possible trivial
	// reject)
		for (i=0 ; i<12 ; i++)
		{
		// edge endpoints
			pv0 = &viewpts[aedges[i].index0];
			pv1 = &viewpts[aedges[i].index1];
			pa0 = &viewaux[aedges[i].index0];
			pa1 = &viewaux[aedges[i].index1];

		// if one end is clipped and the other isn't, make a new point
			if (pv0->flags ^ pv1->flags)
			{
				frac = (ALIAS_Z_CLIP_PLANE - pa0->fv[2]) /
					   (pa1->fv[2] - pa0->fv[2]);
				viewaux[numv].fv[0] = pa0->fv[0] +
						(pa1->fv[0] - pa0->fv[0]) * frac;
				viewaux[numv].fv[1] = pa0->fv[1] +
						(pa1->fv[1] - pa0->fv[1]) * frac;
				viewaux[numv].fv[2] = ALIAS_Z_CLIP_PLANE;
				viewpts[numv].flags = 0;
				numv++;
			}
		}
	}

// project the vertices that remain after clipping
	anyclip = 0;
	allclip = ALIAS_XY_CLIP_MASK;

// TODO: probably should do this loop in ASM, especially if we use floats
	for (i=0 ; i<numv ; i++)
	{
	// we don't need to bother with vertices that were z-clipped
		if (viewpts[i].flags & ALIAS_Z_CLIP)
			continue;

		zi = 1.0 / viewaux[i].fv[2];

	// FIXME: do with chop mode in ASM, or convert to float
		v0 = (viewaux[i].fv[0] * xscale * zi) + xcenter;
		v1 = (viewaux[i].fv[1] * yscale * zi) + ycenter;

		flags = 0;

		if (v0 < r_refdef.fvrectx)
			flags |= ALIAS_LEFT_CLIP;
		if (v1 < r_refdef.fvrecty)
			flags |= ALIAS_TOP_CLIP;
		if (v0 > r_refdef.fvrectright)
			flags |= ALIAS_RIGHT_CLIP;
		if (v1 > r_refdef.fvrectbottom)
			flags |= ALIAS_BOTTOM_CLIP;

		anyclip |= flags;
		allclip &= flags;
	}

	if (allclip)
		return false;	// trivial reject off one side

	currententity->trivial_accept = !anyclip & !zclipped;

	if (currententity->trivial_accept)
	{
		if (minz > (r_aliastransition + (pmdl->size * r_resfudge)))
		{
			currententity->trivial_accept |= 2;
		}
	}

	return true;
}


/*
================
R_AliasTransformVector
================
*/
void R_AliasTransformVector (vec3_t in, vec3_t out)
{
	out[0] = DotProduct(in, aliastransform[0]) + aliastransform[0][3];
	out[1] = DotProduct(in, aliastransform[1]) + aliastransform[1][3];
	out[2] = DotProduct(in, aliastransform[2]) + aliastransform[2][3];
}


/*
================
R_AliasPreparePoints

General clipped case
================
*/
void R_AliasPreparePoints (void)
{
	int			i;
	stvert_t	*pstverts;
	finalvert_t	*fv;
	auxvert_t	*av;
	mtriangle_t	*ptri;
	finalvert_t	*pfv[3];

	pstverts = (stvert_t *)((byte *)paliashdr + paliashdr->stverts);
	r_anumverts = pmdl->numverts;
 	fv = pfinalverts;
	av = pauxverts;

	for (i=0 ; i<r_anumverts ; i++, fv++, av++, r_apverts++, pstverts++)
	{
		R_AliasTransformFinalVert (fv, av, r_apverts, pstverts);
		if (av->fv[2] < ALIAS_Z_CLIP_PLANE)
			fv->flags |= ALIAS_Z_CLIP;
		else
		{
			 R_AliasProjectFinalVert (fv, av);

			if (fv->v[0] < r_refdef.aliasvrect.x)
				fv->flags |= ALIAS_LEFT_CLIP;
			if (fv->v[1] < r_refdef.aliasvrect.y)
				fv->flags |= ALIAS_TOP_CLIP;
			if (fv->v[0] > r_refdef.aliasvrectright)
				fv->flags |= ALIAS_RIGHT_CLIP;
			if (fv->v[1] > r_refdef.aliasvrectbottom)
				fv->flags |= ALIAS_BOTTOM_CLIP;
		}
	}

//
// clip and draw all triangles
//
	r_affinetridesc.numtriangles = 1;

	ptri = (mtriangle_t *)((byte *)paliashdr + paliashdr->triangles);
	for (i=0 ; i<pmdl->numtris ; i++, ptri++)
	{
		pfv[0] = &pfinalverts[ptri->vertindex[0]];
		pfv[1] = &pfinalverts[ptri->vertindex[1]];
		pfv[2] = &pfinalverts[ptri->vertindex[2]];

		if ( pfv[0]->flags & pfv[1]->flags & pfv[2]->flags & (ALIAS_XY_CLIP_MASK | ALIAS_Z_CLIP) )
			continue;		// completely clipped

		if ( ! ( (pfv[0]->flags | pfv[1]->flags | pfv[2]->flags) &
			(ALIAS_XY_CLIP_MASK | ALIAS_Z_CLIP) ) )
		{	// totally unclipped
			r_affinetridesc.pfinalverts = pfinalverts;
			r_affinetridesc.ptriangles = ptri;
			D_PolysetDraw ();
		}
		else
		{	// partially clipped
			R_AliasClipTriangle (ptri);
		}
	}
}


/*
================
R_AliasSetUpTransform
================
*/
void R_AliasSetUpTransform (int trivial_accept)
{
	int				i;
	float			rotationmatrix[3][4], t2matrix[3][4];
	static float	tmatrix[3][4];
	static float	viewmatrix[3][4];
	vec3_t			angles;

// TODO: should really be stored with the entity instead of being reconstructed
// TODO: should use a look-up table
// TODO: could cache lazily, stored in the entity

	angles[ROLL] = currententity->angles[ROLL];
	angles[PITCH] = -currententity->angles[PITCH];
	angles[YAW] = currententity->angles[YAW];
	AngleVectors (angles, alias_forward, alias_right, alias_up);

	tmatrix[0][0] = pmdl->scale[0];
	tmatrix[1][1] = pmdl->scale[1];
	tmatrix[2][2] = pmdl->scale[2];

	tmatrix[0][3] = pmdl->scale_origin[0];
	tmatrix[1][3] = pmdl->scale_origin[1];
	tmatrix[2][3] = pmdl->scale_origin[2];

// TODO: can do this with simple matrix rearrangement

	for (i=0 ; i<3 ; i++)
	{
		t2matrix[i][0] = alias_forward[i];
		t2matrix[i][1] = -alias_right[i];
		t2matrix[i][2] = alias_up[i];
	}

	t2matrix[0][3] = -modelorg[0];
	t2matrix[1][3] = -modelorg[1];
	t2matrix[2][3] = -modelorg[2];

// FIXME: can do more efficiently than full concatenation
	R_ConcatTransforms (t2matrix, tmatrix, rotationmatrix);