r_alias.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

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

/*
** use a real variable to control lerping
*/
#include "r_local.h"

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

//PGM
extern byte iractive;
//PGM

int				r_amodels_drawn;

affinetridesc_t	r_affinetridesc;

vec3_t			r_plightvec;
vec3_t          r_lerped[1024];
vec3_t          r_lerp_frontv, r_lerp_backv, r_lerp_move;

int				r_ambientlight;
int				r_aliasblendcolor;
float			r_shadelight;


daliasframe_t	*r_thisframe, *r_lastframe;
dmdl_t			*s_pmdl;

float	aliastransform[3][4];
float   aliasworldtransform[3][4];
float   aliasoldworldtransform[3][4];

static float	s_ziscale;
static vec3_t	s_alias_forward, s_alias_right, s_alias_up;


#define NUMVERTEXNORMALS	162

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


void R_AliasSetUpLerpData( dmdl_t *pmdl, float backlerp );
void R_AliasSetUpTransform (void);
void R_AliasTransformVector (vec3_t in, vec3_t out, float m[3][4] );
void R_AliasProjectAndClipTestFinalVert (finalvert_t *fv);

void R_AliasTransformFinalVerts( int numpoints, finalvert_t *fv, dtrivertx_t *oldv, dtrivertx_t *newv );

void R_AliasLerpFrames( dmdl_t *paliashdr, float backlerp );

/*
================
R_AliasCheckBBox
================
*/
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 BBOX_TRIVIAL_ACCEPT 0
#define BBOX_MUST_CLIP_XY   1
#define BBOX_MUST_CLIP_Z    2
#define BBOX_TRIVIAL_REJECT 8

/*
** R_AliasCheckFrameBBox
**
** Checks a specific alias frame bounding box
*/
unsigned long R_AliasCheckFrameBBox( daliasframe_t *frame, float worldxf[3][4] )
{
	unsigned long aggregate_and_clipcode = ~0U, 
		          aggregate_or_clipcode = 0;
	int           i;
	vec3_t        mins, maxs;
	vec3_t        transformed_min, transformed_max;
	qboolean      zclipped = false, zfullyclipped = true;
	float         minz = 9999.0F;

	/*
	** get the exact frame bounding box
	*/
	for (i=0 ; i<3 ; i++)
	{
		mins[i] = frame->translate[i];
		maxs[i] = mins[i] + frame->scale[i]*255;
	}

	/*
	** transform the min and max values into view space
	*/
	R_AliasTransformVector( mins, transformed_min, aliastransform );
	R_AliasTransformVector( maxs, transformed_max, aliastransform );

	if ( transformed_min[2] >= ALIAS_Z_CLIP_PLANE )
		zfullyclipped = false;
	if ( transformed_max[2] >= ALIAS_Z_CLIP_PLANE )
		zfullyclipped = false;

	if ( zfullyclipped )
	{
		return BBOX_TRIVIAL_REJECT;
	}
	if ( zclipped )
	{
		return ( BBOX_MUST_CLIP_XY | BBOX_MUST_CLIP_Z );
	}

	/*
	** build a transformed bounding box from the given min and max
	*/
	for ( i = 0; i < 8; i++ )
	{
		int      j;
		vec3_t   tmp, transformed;
		unsigned long clipcode = 0;

		if ( i & 1 )
			tmp[0] = mins[0];
		else
			tmp[0] = maxs[0];

		if ( i & 2 )
			tmp[1] = mins[1];
		else
			tmp[1] = maxs[1];

		if ( i & 4 )
			tmp[2] = mins[2];
		else
			tmp[2] = maxs[2];

		R_AliasTransformVector( tmp, transformed, worldxf );

		for ( j = 0; j < 4; j++ )
		{
			float dp = DotProduct( transformed, view_clipplanes[j].normal );

			if ( ( dp - view_clipplanes[j].dist ) < 0.0F )
				clipcode |= 1 << j;
		}

		aggregate_and_clipcode &= clipcode;
		aggregate_or_clipcode  |= clipcode;
	}

	if ( aggregate_and_clipcode )
	{
		return BBOX_TRIVIAL_REJECT;
	}
	if ( !aggregate_or_clipcode )
	{
		return BBOX_TRIVIAL_ACCEPT;
	}

	return BBOX_MUST_CLIP_XY;
}

qboolean R_AliasCheckBBox (void)
{
	unsigned long ccodes[2] = { 0, 0 };

	ccodes[0] = R_AliasCheckFrameBBox( r_thisframe, aliasworldtransform );

	/*
	** non-lerping model
	*/
	if ( currententity->backlerp == 0 )
	{
		if ( ccodes[0] == BBOX_TRIVIAL_ACCEPT )
			return BBOX_TRIVIAL_ACCEPT;
		else if ( ccodes[0] & BBOX_TRIVIAL_REJECT )
			return BBOX_TRIVIAL_REJECT;
		else
			return ( ccodes[0] & ~BBOX_TRIVIAL_REJECT );
	}

	ccodes[1] = R_AliasCheckFrameBBox( r_lastframe, aliasoldworldtransform );

	if ( ( ccodes[0] | ccodes[1] ) == BBOX_TRIVIAL_ACCEPT )
		return BBOX_TRIVIAL_ACCEPT;
	else if ( ( ccodes[0] & ccodes[1] ) & BBOX_TRIVIAL_REJECT )
		return BBOX_TRIVIAL_REJECT;
	else
		return ( ccodes[0] | ccodes[1] ) & ~BBOX_TRIVIAL_REJECT;
}


/*
================
R_AliasTransformVector
================
*/
void R_AliasTransformVector(vec3_t in, vec3_t out, float xf[3][4] )
{
	out[0] = DotProduct(in, xf[0]) + xf[0][3];
	out[1] = DotProduct(in, xf[1]) + xf[1][3];
	out[2] = DotProduct(in, xf[2]) + xf[2][3];
}


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

General clipped case
================
*/
typedef struct
{
	int          num_points;
	dtrivertx_t *last_verts;   // verts from the last frame
	dtrivertx_t *this_verts;   // verts from this frame
	finalvert_t *dest_verts;   // destination for transformed verts
} aliasbatchedtransformdata_t;

aliasbatchedtransformdata_t aliasbatchedtransformdata;

void R_AliasPreparePoints (void)
{
	int			i;
	dstvert_t	*pstverts;
	dtriangle_t	*ptri;
	finalvert_t	*pfv[3];
	finalvert_t	finalverts[MAXALIASVERTS +
						((CACHE_SIZE - 1) / sizeof(finalvert_t)) + 3];
	finalvert_t	*pfinalverts;

//PGM
	iractive = (r_newrefdef.rdflags & RDF_IRGOGGLES && currententity->flags & RF_IR_VISIBLE);
//	iractive = 0;
//	if(r_newrefdef.rdflags & RDF_IRGOGGLES && currententity->flags & RF_IR_VISIBLE)
//		iractive = 1;
//PGM

	// put work vertexes on stack, cache aligned
	pfinalverts = (finalvert_t *)
			(((long)&finalverts[0] + CACHE_SIZE - 1) & ~(CACHE_SIZE - 1));

	aliasbatchedtransformdata.num_points = s_pmdl->num_xyz;
	aliasbatchedtransformdata.last_verts = r_lastframe->verts;
	aliasbatchedtransformdata.this_verts = r_thisframe->verts;
	aliasbatchedtransformdata.dest_verts = pfinalverts;

	R_AliasTransformFinalVerts( aliasbatchedtransformdata.num_points,
		                        aliasbatchedtransformdata.dest_verts,
								aliasbatchedtransformdata.last_verts,
								aliasbatchedtransformdata.this_verts );

// clip and draw all triangles
//
	pstverts = (dstvert_t *)((byte *)s_pmdl + s_pmdl->ofs_st);
	ptri = (dtriangle_t *)((byte *)s_pmdl + s_pmdl->ofs_tris);

	if ( ( currententity->flags & RF_WEAPONMODEL ) && ( r_lefthand->value == 1.0F ) )
	{
		for (i=0 ; i<s_pmdl->num_tris ; i++, ptri++)
		{
			pfv[0] = &pfinalverts[ptri->index_xyz[0]];
			pfv[1] = &pfinalverts[ptri->index_xyz[1]];
			pfv[2] = &pfinalverts[ptri->index_xyz[2]];

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

			// insert s/t coordinates
			pfv[0]->s = pstverts[ptri->index_st[0]].s << 16;
			pfv[0]->t = pstverts[ptri->index_st[0]].t << 16;

			pfv[1]->s = pstverts[ptri->index_st[1]].s << 16;
			pfv[1]->t = pstverts[ptri->index_st[1]].t << 16;

			pfv[2]->s = pstverts[ptri->index_st[2]].s << 16;
			pfv[2]->t = pstverts[ptri->index_st[2]].t << 16;

			if ( ! (pfv[0]->flags | pfv[1]->flags | pfv[2]->flags) )
			{	// totally unclipped
				aliastriangleparms.a = pfv[2];
				aliastriangleparms.b = pfv[1];
				aliastriangleparms.c = pfv[0];

				R_DrawTriangle();
			}
			else
			{
				R_AliasClipTriangle (pfv[2], pfv[1], pfv[0]);
			}
		}
	}
	else
	{
		for (i=0 ; i<s_pmdl->num_tris ; i++, ptri++)
		{
			pfv[0] = &pfinalverts[ptri->index_xyz[0]];
			pfv[1] = &pfinalverts[ptri->index_xyz[1]];
			pfv[2] = &pfinalverts[ptri->index_xyz[2]];

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

			// insert s/t coordinates
			pfv[0]->s = pstverts[ptri->index_st[0]].s << 16;
			pfv[0]->t = pstverts[ptri->index_st[0]].t << 16;

			pfv[1]->s = pstverts[ptri->index_st[1]].s << 16;
			pfv[1]->t = pstverts[ptri->index_st[1]].t << 16;

			pfv[2]->s = pstverts[ptri->index_st[2]].s << 16;
			pfv[2]->t = pstverts[ptri->index_st[2]].t << 16;

			if ( ! (pfv[0]->flags | pfv[1]->flags | pfv[2]->flags) )
			{	// totally unclipped
				aliastriangleparms.a = pfv[0];
				aliastriangleparms.b = pfv[1];
				aliastriangleparms.c = pfv[2];

				R_DrawTriangle();
			}
			else		
			{	// partially clipped
				R_AliasClipTriangle (pfv[0], pfv[1], pfv[2]);
			}
		}
	}
}


/*
================
R_AliasSetUpTransform
================
*/
void R_AliasSetUpTransform (void)
{
	int				i;
	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, s_alias_forward, s_alias_right, s_alias_up );

// TODO: can do this with simple matrix rearrangement

	memset( aliasworldtransform, 0, sizeof( aliasworldtransform ) );
	memset( aliasoldworldtransform, 0, sizeof( aliasworldtransform ) );

	for (i=0 ; i<3 ; i++)
	{
		aliasoldworldtransform[i][0] = aliasworldtransform[i][0] =  s_alias_forward[i];
		aliasoldworldtransform[i][0] = aliasworldtransform[i][1] = -s_alias_right[i];
		aliasoldworldtransform[i][0] = aliasworldtransform[i][2] =  s_alias_up[i];
	}

	aliasworldtransform[0][3] = currententity->origin[0]-r_origin[0];
	aliasworldtransform[1][3] = currententity->origin[1]-r_origin[1];
	aliasworldtransform[2][3] = currententity->origin[2]-r_origin[2];

	aliasoldworldtransform[0][3] = currententity->oldorigin[0]-r_origin[0];
	aliasoldworldtransform[1][3] = currententity->oldorigin[1]-r_origin[1];
	aliasoldworldtransform[2][3] = currententity->oldorigin[2]-r_origin[2];

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