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Diffstat (limited to 'source/sw_part.c')
| -rw-r--r-- | source/sw_part.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/source/sw_part.c b/source/sw_part.c new file mode 100644 index 0000000..c3fb2ce --- /dev/null +++ b/source/sw_part.c @@ -0,0 +1,191 @@ +/* +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. + +*/ +#include "sw_local.h" + +vec3_t r_pright, r_pup, r_ppn; + +#define PARTICLE_33 0 +#define PARTICLE_66 1 +#define PARTICLE_OPAQUE 2 + +typedef struct +{ + particle_t *particle; + int level; + int color; +} partparms_t; + +static partparms_t partparms; + +/* +** R_DrawParticle +** +** Yes, this is amazingly slow, but it's the C reference +** implementation and should be both robust and vaguely +** understandable. The only time this path should be +** executed is if we're debugging on x86 or if we're +** recompiling and deploying on a non-x86 platform. +** +** To minimize error and improve readability I went the +** function pointer route. This exacts some overhead, but +** it pays off in clean and easy to understand code. +*/ +static void R_DrawParticle( void ) +{ + particle_t *pparticle = partparms.particle; + int level = partparms.level; + vec3_t local, transformed; + float zi; + byte *pdest; + short *pz; + int color = pparticle->color; + int i, izi, pix, count, u, v; + + /* + ** transform the particle + */ + VectorSubtract (pparticle->origin, r_origin, local); + + transformed[0] = DotProduct(local, r_pright); + transformed[1] = DotProduct(local, r_pup); + transformed[2] = DotProduct(local, r_ppn); + + if (transformed[2] < PARTICLE_Z_CLIP) + return; + + /* + ** project the point + */ + // FIXME: preadjust xcenter and ycenter + zi = 1.0 / transformed[2]; + u = (int)(xcenter + zi * transformed[0] + 0.5); + v = (int)(ycenter - zi * transformed[1] + 0.5); + + if ((v > d_vrectbottom_particle) || + (u > d_vrectright_particle) || + (v < d_vrecty) || + (u < d_vrectx)) + { + return; + } + + /* + ** compute addresses of zbuffer, framebuffer, and + ** compute the Z-buffer reference value. + */ + pz = d_pzbuffer + (d_zwidth * v) + u; + pdest = d_viewbuffer + d_scantable[v] + u; + izi = (int)(zi * 0x8000); + + /* + ** determine the screen area covered by the particle, + ** which also means clamping to a min and max + */ + pix = izi >> d_pix_shift; + if (pix < d_pix_min) + pix = d_pix_min; + else if (pix > d_pix_max) + pix = d_pix_max; + + /* + ** render the appropriate pixels + */ + count = pix; + + switch (level) { + case PARTICLE_33 : + for ( ; count ; count--, pz += d_zwidth, pdest += r_screenwidth) + { +//FIXME--do it in blocks of 8? + for (i=0 ; i<pix ; i++) + { + if (pz[i] <= izi) + { + pz[i] = izi; + pdest[i] = vid.alphamap[color + ((int)pdest[i]<<8)]; + } + } + } + break; + + case PARTICLE_66 : + for ( ; count ; count--, pz += d_zwidth, pdest += r_screenwidth) + { + for (i=0 ; i<pix ; i++) + { + if (pz[i] <= izi) + { + pz[i] = izi; + pdest[i] = vid.alphamap[(color<<8) + (int)pdest[i]]; + } + } + } + break; + + default: //100 + for ( ; count ; count--, pz += d_zwidth, pdest += r_screenwidth) + { + for (i=0 ; i<pix ; i++) + { + if (pz[i] <= izi) + { + pz[i] = izi; + pdest[i] = color; + } + } + } + break; + } +} + +/* +** R_DrawParticles +** +** Responsible for drawing all of the particles in the particle list +** throughout the world. Doesn't care if we're using the C path or +** if we're using the asm path, it simply assigns a function pointer +** and goes. +*/ +void R_DrawParticles (void) +{ + particle_t *p; + int i; + + VectorScale( vright, xscaleshrink, r_pright ); + VectorScale( vup, yscaleshrink, r_pup ); + VectorCopy( vpn, r_ppn ); + + for (p=r_newrefdef.particles, i=0 ; i<r_newrefdef.num_particles ; i++,p++) + { + + if ( p->alpha > 0.66 ) + partparms.level = PARTICLE_OPAQUE; + else if ( p->alpha > 0.33 ) + partparms.level = PARTICLE_66; + else + partparms.level = PARTICLE_33; + + partparms.particle = p; + partparms.color = p->color; + + R_DrawParticle(); + } +} + |