xash3d-fwgs/ref/soft/r_sprite.c

/*
gl_sprite.c - sprite rendering
Copyright (C) 2010 Uncle Mike

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 3 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.
*/

#include "r_local.h"
#include "pm_local.h"
#include "sprite.h"
#include "studio.h"
#include "entity_types.h"

#define GLARE_FALLOFF 19000.0f

char        sprite_name[MAX_QPATH];
char        group_suffix[8];
static uint r_texFlags = 0;
static int  sprite_version;
float       sprite_radius;

/*
====================
R_SpriteInit

====================
*/
void R_SpriteInit( void )
{
}

/*
====================
R_SpriteLoadFrame

upload a single frame
====================
*/
static const byte *R_SpriteLoadFrame( model_t *mod, const void *pin, mspriteframe_t **ppframe, int num )
{
	dspriteframe_t pinframe;
	mspriteframe_t *pspriteframe;
	int gl_texturenum = 0;
	char           texname[128];
	int bytes = 1;

	memcpy( &pinframe, pin, sizeof( dspriteframe_t ));

	if( sprite_version == SPRITE_VERSION_32 )
		bytes = 4;

	// build uinque frame name
	if( FBitSet( mod->flags, MODEL_CLIENT )) // it's a HUD sprite
	{
		Q_snprintf( texname, sizeof( texname ), "#HUD/%s(%s:%i%i).spr", sprite_name, group_suffix, num / 10, num % 10 );
		gl_texturenum = GL_LoadTexture( texname, pin, pinframe.width * pinframe.height * bytes, r_texFlags );
	}
	else
	{
		Q_snprintf( texname, sizeof( texname ), "#%s(%s:%i%i).spr", sprite_name, group_suffix, num / 10, num % 10 );
		gl_texturenum = GL_LoadTexture( texname, pin, pinframe.width * pinframe.height * bytes, r_texFlags );
	}

	// setup frame description
	pspriteframe = Mem_Malloc( mod->mempool, sizeof( mspriteframe_t ));
	pspriteframe->width = pinframe.width;
	pspriteframe->height = pinframe.height;
	pspriteframe->up = pinframe.origin[1];
	pspriteframe->left = pinframe.origin[0];
	pspriteframe->down = pinframe.origin[1] - pinframe.height;
	pspriteframe->right = pinframe.width + pinframe.origin[0];
	pspriteframe->gl_texturenum = gl_texturenum;
	*ppframe = pspriteframe;

	return (const byte *)((const byte *)pin + sizeof( dspriteframe_t ) + pinframe.width * pinframe.height * bytes );
}

/*
====================
R_SpriteLoadGroup

upload a group frames
====================
*/
static const void *R_SpriteLoadGroup( model_t *mod, const void *pin, mspriteframe_t **ppframe, int framenum )
{
	const dspritegroup_t    *pingroup;
	mspritegroup_t          *pspritegroup;
	const dspriteinterval_t *pin_intervals;
	float      *poutintervals;
	int        i, groupsize, numframes;
	const void *ptemp;

	pingroup = (const dspritegroup_t *)pin;
	numframes = pingroup->numframes;

	groupsize = sizeof( mspritegroup_t ) + ( numframes - 1 ) * sizeof( pspritegroup->frames[0] );
	pspritegroup = Mem_Calloc( mod->mempool, groupsize );
	pspritegroup->numframes = numframes;

	*ppframe = (mspriteframe_t *)pspritegroup;
	pin_intervals = (const dspriteinterval_t *)( pingroup + 1 );
	poutintervals = Mem_Calloc( mod->mempool, numframes * sizeof( float ));
	pspritegroup->intervals = poutintervals;

	for( i = 0; i < numframes; i++ )
	{
		*poutintervals = pin_intervals->interval;
		if( *poutintervals <= 0.0f )
			*poutintervals = 1.0f; // set error value
		poutintervals++;
		pin_intervals++;
	}

	ptemp = (const void *)pin_intervals;
	for( i = 0; i < numframes; i++ )
	{
		ptemp = R_SpriteLoadFrame( mod, ptemp, &pspritegroup->frames[i], framenum * 10 + i );
	}

	return ptemp;
}

/*
====================
Mod_LoadSpriteModel

load sprite model
====================
*/
void Mod_LoadSpriteModel( model_t *mod, const void *buffer, qboolean *loaded, uint texFlags )
{
	const dsprite_t *pin;
	const short     *numi = NULL;
	const byte      *pframetype;
	msprite_t       *psprite;
	int i;

	pin = buffer;
	psprite = mod->cache.data;

	if( pin->version == SPRITE_VERSION_Q1 || pin->version == SPRITE_VERSION_32 )
		numi = NULL;
	else if( pin->version == SPRITE_VERSION_HL )
		numi = (const short *)((const byte *)buffer + sizeof( dsprite_hl_t ));

	r_texFlags = texFlags;
	sprite_version = pin->version;
	Q_strncpy( sprite_name, mod->name, sizeof( sprite_name ));
	COM_StripExtension( sprite_name );

	if( numi == NULL )
	{
		rgbdata_t *pal;

		pal = gEngfuncs.FS_LoadImage( "#id.pal", (byte *)&i, 768 );
		pframetype = ((const byte *)buffer + sizeof( dsprite_q1_t )); // pinq1 + 1
		gEngfuncs.FS_FreeImage( pal );                                // palette installed, no reason to keep this data
	}
	else if( *numi == 256 )
	{
		const byte *src = (const byte *)( numi + 1 );
		rgbdata_t  *pal;

		// install palette
		switch( psprite->texFormat )
		{
		case SPR_INDEXALPHA:
			pal = gEngfuncs.FS_LoadImage( "#gradient.pal", src, 768 );
			break;
		case SPR_ALPHTEST:
			pal = gEngfuncs.FS_LoadImage( "#masked.pal", src, 768 );
			break;
		default:
			pal = gEngfuncs.FS_LoadImage( "#normal.pal", src, 768 );
			break;
		}

		pframetype = (const byte *)( src + 768 );
		gEngfuncs.FS_FreeImage( pal ); // palette installed, no reason to keep this data
	}
	else
	{
		gEngfuncs.Con_DPrintf( S_ERROR "%s has wrong number of palette colors %i (should be 256)\n", mod->name, *numi );
		return;
	}

	if( mod->numframes < 1 )
		return;

	for( i = 0; i < mod->numframes; i++ )
	{
		frametype_t  frametype;
		dframetype_t dframetype;

		memcpy( &dframetype, pframetype, sizeof( dframetype ));
		frametype = dframetype.type;
		psprite->frames[i].type = (spriteframetype_t)frametype;

		switch( frametype )
		{
		case FRAME_SINGLE:
			Q_strncpy( group_suffix, "frame", sizeof( group_suffix ));
			pframetype = R_SpriteLoadFrame( mod, pframetype + sizeof( dframetype_t ), &psprite->frames[i].frameptr, i );
			break;
		case FRAME_GROUP:
			Q_strncpy( group_suffix, "group", sizeof( group_suffix ));
			pframetype = R_SpriteLoadGroup( mod, pframetype + sizeof( dframetype_t ), &psprite->frames[i].frameptr, i );
			break;
		case FRAME_ANGLED:
			Q_strncpy( group_suffix, "angle", sizeof( group_suffix ));
			pframetype = R_SpriteLoadGroup( mod, pframetype + sizeof( dframetype_t ), &psprite->frames[i].frameptr, i );
			break;
		}
		if( pframetype == NULL )
			break;                  // technically an error
	}

	if( loaded )
		*loaded = true;         // done
}

/*
====================
Mod_UnloadSpriteModel

release sprite model and frames
====================
*/
void Mod_SpriteUnloadTextures( void *data )
{
	msprite_t      *psprite;
	mspritegroup_t *pspritegroup;
	mspriteframe_t *pspriteframe;
	int i, j;

	psprite = data;

	if( psprite )
	{
		// release all textures
		for( i = 0; i < psprite->numframes; i++ )
		{
			if( psprite->frames[i].type == SPR_SINGLE )
			{
				pspriteframe = psprite->frames[i].frameptr;
				GL_FreeTexture( pspriteframe->gl_texturenum );
			}
			else
			{
				pspritegroup = (mspritegroup_t *)psprite->frames[i].frameptr;

				for( j = 0; j < pspritegroup->numframes; j++ )
				{
					pspriteframe = pspritegroup->frames[i];
					GL_FreeTexture( pspriteframe->gl_texturenum );
				}
			}
		}
	}
}

/*
================
R_GetSpriteFrame

assume pModel is valid
================
*/
mspriteframe_t *R_GetSpriteFrame( const model_t *pModel, int frame, float yaw )
{
	msprite_t      *psprite;
	mspritegroup_t *pspritegroup;
	mspriteframe_t *pspriteframe = NULL;
	float          *pintervals, fullinterval;
	int i, numframes;
	float          targettime;

	Assert( pModel != NULL );
	psprite = pModel->cache.data;

	if( frame < 0 )
	{
		frame = 0;
	}
	else if( frame >= psprite->numframes )
	{
		if( frame > psprite->numframes )
			gEngfuncs.Con_Printf( S_WARN "%s: no such frame %d (%s)\n", __func__, frame, pModel->name );
		frame = psprite->numframes - 1;
	}

	if( psprite->frames[frame].type == SPR_SINGLE )
	{
		pspriteframe = psprite->frames[frame].frameptr;
	}
	else if( psprite->frames[frame].type == SPR_GROUP )
	{
		pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
		pintervals = pspritegroup->intervals;
		numframes = pspritegroup->numframes;
		fullinterval = pintervals[numframes - 1];

		// when loading in Mod_LoadSpriteGroup, we guaranteed all interval values
		// are positive, so we don't have to worry about division by zero
		targettime = gp_cl->time - ((int)( gp_cl->time / fullinterval )) * fullinterval;

		for( i = 0; i < ( numframes - 1 ); i++ )
		{
			if( pintervals[i] > targettime )
				break;
		}
		pspriteframe = pspritegroup->frames[i];
	}
	else if( psprite->frames[frame].type == FRAME_ANGLED )
	{
		int angleframe = (int)( Q_rint(( RI.viewangles[1] - yaw + 45.0f ) / 360 * 8 ) - 4 ) & 7;

		// e.g. doom-style sprite monsters
		pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
		pspriteframe = pspritegroup->frames[angleframe];
	}

	return pspriteframe;
}

/*
================
R_GetSpriteFrameInterpolant

NOTE: we using prevblending[0] and [1] for holds interval
between frames where are we lerping
================
*/
static float R_GetSpriteFrameInterpolant( cl_entity_t *ent, mspriteframe_t **oldframe, mspriteframe_t **curframe )
{
	msprite_t      *psprite;
	mspritegroup_t *pspritegroup;
	int i, j, numframes, frame;
	float          lerpFrac, time, jtime, jinterval;
	float          *pintervals, fullinterval, targettime;
	int m_fDoInterp;

	psprite = ent->model->cache.data;
	frame = (int)ent->curstate.frame;
	lerpFrac = 1.0f;

	// misc info
	m_fDoInterp = ( ent->curstate.effects & EF_NOINTERP ) ? false : true;

	if( frame < 0 )
	{
		frame = 0;
	}
	else if( frame >= psprite->numframes )
	{
		gEngfuncs.Con_Reportf( S_WARN "%s: no such frame %d (%s)\n", __func__, frame, ent->model->name );
		frame = psprite->numframes - 1;
	}

	if( psprite->frames[frame].type == FRAME_SINGLE )
	{
		if( m_fDoInterp )
		{
			if( ent->latched.prevblending[0] >= psprite->numframes || psprite->frames[ent->latched.prevblending[0]].type != FRAME_SINGLE )
			{
				// this can be happens when rendering switched between single and angled frames
				// or change model on replace delta-entity
				ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
				ent->latched.sequencetime = gp_cl->time;
				lerpFrac = 1.0f;
			}

			if( ent->latched.sequencetime < gp_cl->time )
			{
				if( frame != ent->latched.prevblending[1] )
				{
					ent->latched.prevblending[0] = ent->latched.prevblending[1];
					ent->latched.prevblending[1] = frame;
					ent->latched.sequencetime = gp_cl->time;
					lerpFrac = 0.0f;
				}
				else
					lerpFrac = ( gp_cl->time - ent->latched.sequencetime ) * 11.0f;
			}
			else
			{
				ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
				ent->latched.sequencetime = gp_cl->time;
				lerpFrac = 0.0f;
			}
		}
		else
		{
			ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
			lerpFrac = 1.0f;
		}

		if( ent->latched.prevblending[0] >= psprite->numframes )
		{
			// reset interpolation on change model
			ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
			ent->latched.sequencetime = gp_cl->time;
			lerpFrac = 0.0f;
		}

		// get the interpolated frames
		if( oldframe )
			*oldframe = psprite->frames[ent->latched.prevblending[0]].frameptr;
		if( curframe )
			*curframe = psprite->frames[frame].frameptr;
	}
	else if( psprite->frames[frame].type == FRAME_GROUP )
	{
		pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
		pintervals = pspritegroup->intervals;
		numframes = pspritegroup->numframes;
		fullinterval = pintervals[numframes - 1];
		jinterval = pintervals[1] - pintervals[0];
		time = gp_cl->time;
		jtime = 0.0f;

		// when loading in Mod_LoadSpriteGroup, we guaranteed all interval values
		// are positive, so we don't have to worry about division by zero
		targettime = time - ((int)( time / fullinterval )) * fullinterval;

		// LordHavoc: since I can't measure the time properly when it loops from numframes - 1 to 0,
		// i instead measure the time of the first frame, hoping it is consistent
		for( i = 0, j = numframes - 1; i < ( numframes - 1 ); i++ )
		{
			if( pintervals[i] > targettime )
				break;
			j = i;
			jinterval = pintervals[i] - jtime;
			jtime = pintervals[i];
		}

		if( m_fDoInterp )
			lerpFrac = ( targettime - jtime ) / jinterval;
		else
			j = i; // no lerping

		// get the interpolated frames
		if( oldframe )
			*oldframe = pspritegroup->frames[j];
		if( curframe )
			*curframe = pspritegroup->frames[i];
	}
	else if( psprite->frames[frame].type == FRAME_ANGLED )
	{
		// e.g. doom-style sprite monsters
		float yaw = ent->angles[YAW];
		int   angleframe = (int)( Q_rint(( RI.viewangles[1] - yaw + 45.0f ) / 360 * 8 ) - 4 ) & 7;

		if( m_fDoInterp )
		{
			if( ent->latched.prevblending[0] >= psprite->numframes || psprite->frames[ent->latched.prevblending[0]].type != FRAME_ANGLED )
			{
				// this can be happens when rendering switched between single and angled frames
				// or change model on replace delta-entity
				ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
				ent->latched.sequencetime = gp_cl->time;
				lerpFrac = 1.0f;
			}

			if( ent->latched.sequencetime < gp_cl->time )
			{
				if( frame != ent->latched.prevblending[1] )
				{
					ent->latched.prevblending[0] = ent->latched.prevblending[1];
					ent->latched.prevblending[1] = frame;
					ent->latched.sequencetime = gp_cl->time;
					lerpFrac = 0.0f;
				}
				else
					lerpFrac = ( gp_cl->time - ent->latched.sequencetime ) * ent->curstate.framerate;
			}
			else
			{
				ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
				ent->latched.sequencetime = gp_cl->time;
				lerpFrac = 0.0f;
			}
		}
		else
		{
			ent->latched.prevblending[0] = ent->latched.prevblending[1] = frame;
			lerpFrac = 1.0f;
		}

		pspritegroup = (mspritegroup_t *)psprite->frames[ent->latched.prevblending[0]].frameptr;
		if( oldframe )
			*oldframe = pspritegroup->frames[angleframe];

		pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
		if( curframe )
			*curframe = pspritegroup->frames[angleframe];
	}

	return lerpFrac;
}

/*
================
R_CullSpriteModel

Cull sprite model by bbox
================
*/
static qboolean R_CullSpriteModel( cl_entity_t *e, vec3_t origin )
{
	vec3_t sprite_mins, sprite_maxs;
	float  scale = 1.0f;

	if( !e->model->cache.data )
		return true;

	if( e->curstate.scale > 0.0f )
		scale = e->curstate.scale;

	// scale original bbox (no rotation for sprites)
	VectorScale( e->model->mins, scale, sprite_mins );
	VectorScale( e->model->maxs, scale, sprite_maxs );

	sprite_radius = RadiusFromBounds( sprite_mins, sprite_maxs );

	VectorAdd( sprite_mins, origin, sprite_mins );
	VectorAdd( sprite_maxs, origin, sprite_maxs );

	return R_CullModel( e, sprite_mins, sprite_maxs );
}

/*
================
R_GlowSightDistance

Set sprite brightness factor
================
*/
static float R_SpriteGlowBlend( vec3_t origin, int rendermode, int renderfx, float *pscale )
{
	float     dist, brightness;
	vec3_t    glowDist;
	pmtrace_t *tr;

	VectorSubtract( origin, RI.vieworg, glowDist );
	dist = VectorLength( glowDist );

	if( RP_NORMALPASS( ))
	{
		tr = gEngfuncs.EV_VisTraceLine( RI.vieworg, origin, r_traceglow.value ? PM_GLASS_IGNORE : ( PM_GLASS_IGNORE | PM_STUDIO_IGNORE ));

		if(( 1.0f - tr->fraction ) * dist > 8.0f )
			return 0.0f;
	}

	if( renderfx == kRenderFxNoDissipation )
		return 1.0f;

	brightness = GLARE_FALLOFF / ( dist * dist );
	brightness = bound( 0.05f, brightness, 1.0f );
	*pscale *= dist * ( 1.0f / 200.0f );

	return brightness;
}

/*
================
R_SpriteOccluded

Do occlusion test for glow-sprites
================
*/
static qboolean R_SpriteOccluded( cl_entity_t *e, vec3_t origin, float *pscale )
{
	if( e->curstate.rendermode == kRenderGlow )
	{
		float  blend;
		vec3_t v;

		TriWorldToScreen( origin, v );

		if( v[0] < RI.viewport[0] || v[0] > RI.viewport[0] + RI.viewport[2] )
			return true; // do scissor
		if( v[1] < RI.viewport[1] || v[1] > RI.viewport[1] + RI.viewport[3] )
			return true; // do scissor

		blend = R_SpriteGlowBlend( origin, e->curstate.rendermode, e->curstate.renderfx, pscale );
		tr.blend *= blend;

		if( blend <= 0.01f )
			return true; // faded
	}
	else
	{
		if( R_CullSpriteModel( e, origin ))
			return true;
	}

	return false;
}

/*
=================
R_DrawSpriteQuad
=================
*/
static void R_DrawSpriteQuad( mspriteframe_t *frame, vec3_t org, vec3_t v_right, vec3_t v_up, float scale )
{
	vec3_t  point;
	image_t *image;

	r_stats.c_sprite_polys++;
	/*image = R_GetTexture(frame->gl_texturenum);
	r_affinetridesc.pskin = image->pixels[0];
	r_affinetridesc.skinwidth = image->width;
	r_affinetridesc.skinheight = image->height;*/

	TriBegin( TRI_QUADS );
	TriTexCoord2f( 0.0f, 1.0f );
	VectorMA( org, frame->down * scale, v_up, point );
	VectorMA( point, frame->left * scale, v_right, point );
	TriVertex3fv( point );
	TriTexCoord2f( 0.0f, 0.0f );
	VectorMA( org, frame->up * scale, v_up, point );
	VectorMA( point, frame->left * scale, v_right, point );
	TriVertex3fv( point );
	TriTexCoord2f( 1.0f, 0.0f );
	VectorMA( org, frame->up * scale, v_up, point );
	VectorMA( point, frame->right * scale, v_right, point );
	TriVertex3fv( point );
	TriTexCoord2f( 1.0f, 1.0f );
	VectorMA( org, frame->down * scale, v_up, point );
	VectorMA( point, frame->right * scale, v_right, point );
	TriVertex3fv( point );
	TriEnd();
}

static qboolean R_SpriteHasLightmap( cl_entity_t *e, int texFormat )
{
	if( !r_sprite_lighting->value )
		return false;

	if( texFormat != SPR_ALPHTEST )
		return false;

	if( e->curstate.effects & EF_FULLBRIGHT )
		return false;

	if( e->curstate.renderamt <= 127 )
		return false;

	switch( e->curstate.rendermode )
	{
	case kRenderNormal:
	case kRenderTransAlpha:
	case kRenderTransTexture:
		break;
	default:
		return false;
	}

	return true;
}

/*
=================
R_SpriteAllowLerping
=================
*/
static qboolean R_SpriteAllowLerping( cl_entity_t *e, msprite_t *psprite )
{
	if( !r_sprite_lerping->value )
		return false;

	if( psprite->numframes <= 1 )
		return false;

	if( psprite->texFormat != SPR_ADDITIVE )
		return false;

	if( e->curstate.rendermode == kRenderNormal || e->curstate.rendermode == kRenderTransAlpha )
		return false;

	return true;
}

/*
=================
R_DrawSpriteModel
=================
*/
void R_DrawSpriteModel( cl_entity_t *e )
{
	mspriteframe_t *frame, *oldframe;
	msprite_t      *psprite;
	model_t        *model;
	int i, type;
	float          angle, dot, sr, cr;
	float          lerp = 1.0f, ilerp, scale;
	vec3_t         v_forward, v_right, v_up;
	vec3_t         origin, color, color2;

	if( RI.params & RP_ENVVIEW )
		return;

	model = e->model;
	psprite = (msprite_t *)model->cache.data;
	VectorCopy( e->origin, origin ); // set render origin

	// do movewith
	if( e->curstate.aiment > 0 && e->curstate.movetype == MOVETYPE_FOLLOW )
	{
		cl_entity_t *parent;

		parent = CL_GetEntityByIndex( e->curstate.aiment );

		if( parent && parent->model )
		{
			if( parent->model->type == mod_studio && e->curstate.body > 0 )
			{
				int num = bound( 1, e->curstate.body, MAXSTUDIOATTACHMENTS );
				VectorCopy( parent->attachment[num - 1], origin );
			}
			else
				VectorCopy( parent->origin, origin );
		}
	}

	scale = e->curstate.scale;
	if( !scale )
		scale = 1.0f;

	if( R_SpriteOccluded( e, origin, &scale ))
		return; // sprite culled

	r_stats.c_sprite_models_drawn++;

	if( e->curstate.rendermode == kRenderGlow || e->curstate.rendermode == kRenderTransAdd )
		R_AllowFog( false );

	GL_SetRenderMode( e->curstate.rendermode );

	// NOTE: never pass sprites with rendercolor '0 0 0' it's a stupid Valve Hammer Editor bug
	if( e->curstate.rendercolor.r || e->curstate.rendercolor.g || e->curstate.rendercolor.b )
	{
		color[0] = (float)e->curstate.rendercolor.r * ( 1.0f / 255.0f );
		color[1] = (float)e->curstate.rendercolor.g * ( 1.0f / 255.0f );
		color[2] = (float)e->curstate.rendercolor.b * ( 1.0f / 255.0f );
	}
	else
	{
		color[0] = 1.0f;
		color[1] = 1.0f;
		color[2] = 1.0f;
	}

	if( R_SpriteHasLightmap( e, psprite->texFormat ))
	{
		colorVec lightColor = R_LightPoint( origin );
		// FIXME: collect light from dlights?
		color2[0] = (float)lightColor.r * ( 1.0f / 255.0f );
		color2[1] = (float)lightColor.g * ( 1.0f / 255.0f );
		color2[2] = (float)lightColor.b * ( 1.0f / 255.0f );
		// NOTE: sprites with 'lightmap' looks ugly when alpha func is GL_GREATER 0.0
		//	pglAlphaFunc( GL_GREATER, 0.5f );
	}

	if( R_SpriteAllowLerping( e, psprite ))
		lerp = R_GetSpriteFrameInterpolant( e, &oldframe, &frame );
	else
		frame = oldframe = R_GetSpriteFrame( model, e->curstate.frame, e->angles[YAW] );

	type = psprite->type;

	// automatically roll parallel sprites if requested
	if( e->angles[ROLL] != 0.0f && type == SPR_FWD_PARALLEL )
		type = SPR_FWD_PARALLEL_ORIENTED;

	switch( type )
	{
	case SPR_ORIENTED:
		AngleVectors( e->angles, v_forward, v_right, v_up );
		VectorScale( v_forward, 0.01f, v_forward ); // to avoid z-fighting
		VectorSubtract( origin, v_forward, origin );
		break;
	case SPR_FACING_UPRIGHT:
		VectorSet( v_right, origin[1] - RI.vieworg[1], -( origin[0] - RI.vieworg[0] ), 0.0f );
		VectorSet( v_up, 0.0f, 0.0f, 1.0f );
		VectorNormalize( v_right );
		break;
	case SPR_FWD_PARALLEL_UPRIGHT:
		dot = RI.vforward[2];
		if(( dot > 0.999848f ) || ( dot < -0.999848f )) // cos(1 degree) = 0.999848
			return; // invisible
		VectorSet( v_up, 0.0f, 0.0f, 1.0f );
		VectorSet( v_right, RI.vforward[1], -RI.vforward[0], 0.0f );
		VectorNormalize( v_right );
		break;
	case SPR_FWD_PARALLEL_ORIENTED:
		angle = e->angles[ROLL] * ( M_PI2 / 360.0f );
		SinCos( angle, &sr, &cr );
		for( i = 0; i < 3; i++ )
		{
			v_right[i] = ( RI.vright[i] * cr + RI.vup[i] * sr );
			v_up[i] = RI.vright[i] * -sr + RI.vup[i] * cr;
		}
		break;
	case SPR_FWD_PARALLEL: // normal sprite
	default:
		VectorCopy( RI.vright, v_right );
		VectorCopy( RI.vup, v_up );
		break;
	}

	// if( psprite->facecull == SPR_CULL_NONE )
	// GL_Cull( GL_NONE );

	if( oldframe == frame )
	{
		// draw the single non-lerped frame
		_TriColor4f( color[0], color[1], color[2], tr.blend );
		GL_Bind( XASH_TEXTURE0, frame->gl_texturenum );
		R_DrawSpriteQuad( frame, origin, v_right, v_up, scale );
	}
	else
	{
		// draw two combined lerped frames
		lerp = bound( 0.0f, lerp, 1.0f );
		ilerp = 1.0f - lerp;

		if( ilerp != 0.0f )
		{
			_TriColor4f( color[0], color[1], color[2], tr.blend * ilerp );
			GL_Bind( XASH_TEXTURE0, oldframe->gl_texturenum );
			R_DrawSpriteQuad( oldframe, origin, v_right, v_up, scale );
		}

		if( lerp != 0.0f )
		{
			_TriColor4f( color[0], color[1], color[2], tr.blend * lerp );
			GL_Bind( XASH_TEXTURE0, frame->gl_texturenum );
			R_DrawSpriteQuad( frame, origin, v_right, v_up, scale );
		}
	}
}