r_sprite.c

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/*
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_sprite.c
#include "r_local.h"
 
extern polydesc_t r_polydesc;
 
void R_BuildPolygonFromSurface(msurface_t *fa);
void R_PolygonCalculateGradients (void);
 
extern void R_PolyChooseSpanletRoutine( float alpha, qboolean isturbulent );
 
extern vec5_t r_clip_verts[2][MAXWORKINGVERTS+2];
 
extern void R_ClipAndDrawPoly( float alpha, qboolean isturbulent, qboolean textured );
 
/*
** R_DrawSprite
**
** Draw currententity / currentmodel as a single texture
** mapped polygon
*/
void R_DrawSprite (void)
{
    vec5_t      *pverts;
    vec3_t      left, up, right, down;
    dsprite_t   *s_psprite;
    dsprframe_t *s_psprframe;
 
 
    s_psprite = (dsprite_t *)currentmodel->extradata;
#if 0
    if (currententity->frame >= s_psprite->numframes
        || currententity->frame < 0)
    {
        ri.Con_Printf (PRINT_ALL, "No such sprite frame %i\n", 
            currententity->frame);
        currententity->frame = 0;
    }
#endif
    currententity->frame %= s_psprite->numframes;
 
    s_psprframe = &s_psprite->frames[currententity->frame];
 
    r_polydesc.pixels       = currentmodel->skins[currententity->frame]->pixels[0];
    r_polydesc.pixel_width  = s_psprframe->width;
    r_polydesc.pixel_height = s_psprframe->height;
    r_polydesc.dist         = 0;
 
    // generate the sprite's axes, completely parallel to the viewplane.
    VectorCopy (vup, r_polydesc.vup);
    VectorCopy (vright, r_polydesc.vright);
    VectorCopy (vpn, r_polydesc.vpn);
 
// build the sprite poster in worldspace
    VectorScale (r_polydesc.vright, 
        s_psprframe->width - s_psprframe->origin_x, right);
    VectorScale (r_polydesc.vup, 
        s_psprframe->height - s_psprframe->origin_y, up);
    VectorScale (r_polydesc.vright,
        -s_psprframe->origin_x, left);
    VectorScale (r_polydesc.vup,
        -s_psprframe->origin_y, down);
 
    // invert UP vector for sprites
    VectorInverse( r_polydesc.vup );
 
    pverts = r_clip_verts[0];
 
    pverts[0][0] = r_entorigin[0] + up[0] + left[0];
    pverts[0][1] = r_entorigin[1] + up[1] + left[1];
    pverts[0][2] = r_entorigin[2] + up[2] + left[2];
    pverts[0][3] = 0;
    pverts[0][4] = 0;
 
    pverts[1][0] = r_entorigin[0] + up[0] + right[0];
    pverts[1][1] = r_entorigin[1] + up[1] + right[1];
    pverts[1][2] = r_entorigin[2] + up[2] + right[2];
    pverts[1][3] = s_psprframe->width;
    pverts[1][4] = 0;
 
    pverts[2][0] = r_entorigin[0] + down[0] + right[0];
    pverts[2][1] = r_entorigin[1] + down[1] + right[1];
    pverts[2][2] = r_entorigin[2] + down[2] + right[2];
    pverts[2][3] = s_psprframe->width;
    pverts[2][4] = s_psprframe->height;
 
    pverts[3][0] = r_entorigin[0] + down[0] + left[0];
    pverts[3][1] = r_entorigin[1] + down[1] + left[1];
    pverts[3][2] = r_entorigin[2] + down[2] + left[2];
    pverts[3][3] = 0;
    pverts[3][4] = s_psprframe->height;
 
    r_polydesc.nump = 4;
    r_polydesc.s_offset = ( r_polydesc.pixel_width  >> 1);
    r_polydesc.t_offset = ( r_polydesc.pixel_height >> 1);
    VectorCopy( modelorg, r_polydesc.viewer_position );
 
    r_polydesc.stipple_parity = 1;
    if ( currententity->flags & RF_TRANSLUCENT )
        R_ClipAndDrawPoly ( currententity->alpha, false, true );
    else
        R_ClipAndDrawPoly ( 1.0F, false, true );
    r_polydesc.stipple_parity = 0;
}