ref: c909a88a89b43d5555f3090c0a54de31b067fe7c
dir: /ref/r_part.c/
/*
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 "r_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;
#if id386 && !defined __linux__
static unsigned s_prefetch_address;
/*
** BlendParticleXX
**
** Inputs:
** EAX = color
** EDI = pdest
**
** Scratch:
** EBX = scratch (dstcolor)
** EBP = scratch
**
** Outputs:
** none
*/
__declspec(naked) void BlendParticle33( void )
{
// return vid.alphamap[color + dstcolor*256];
__asm mov ebp, vid.alphamap
__asm xor ebx, ebx
__asm mov bl, byte ptr [edi]
__asm shl ebx, 8
__asm add ebp, ebx
__asm add ebp, eax
__asm mov al, byte ptr [ebp]
__asm mov byte ptr [edi], al
__asm ret
}
__declspec(naked) void BlendParticle66( void )
{
// return vid.alphamap[pcolor*256 + dstcolor];
__asm mov ebp, vid.alphamap
__asm xor ebx, ebx
__asm shl eax, 8
__asm mov bl, byte ptr [edi]
__asm add ebp, ebx
__asm add ebp, eax
__asm mov al, byte ptr [ebp]
__asm mov byte ptr [edi], al
__asm ret
}
__declspec(naked) void BlendParticle100( void )
{
__asm mov byte ptr [edi], al
__asm ret
}
/*
** R_DrawParticle (asm version)
**
** Since we use __declspec( naked ) we don't have a stack frame
** that we can use. Since I want to reserve EBP anyway, I tossed
** all the important variables into statics. This routine isn't
** meant to be re-entrant, so this shouldn't cause any problems
** other than a slightly higher global memory footprint.
**
*/
__declspec(naked) void R_DrawParticle( void )
{
static vec3_t local, transformed;
static float zi;
static int u, v, tmp;
static short izi;
static int ebpsave;
static byte (*blendfunc)(void);
/*
** must be memvars since x86 can't load constants
** directly. I guess I could use fld1, but that
** actually costs one more clock than fld [one]!
*/
static float particle_z_clip = PARTICLE_Z_CLIP;
static float one = 1.0F;
static float point_five = 0.5F;
static float eight_thousand_hex = 0x8000;
/*
** save trashed variables
*/
__asm mov ebpsave, ebp
__asm push esi
__asm push edi
/*
** transform the particle
*/
// VectorSubtract (pparticle->origin, r_origin, local);
__asm mov esi, partparms.particle
__asm fld dword ptr [esi+0] ; p_o.x
__asm fsub dword ptr [r_origin+0] ; p_o.x-r_o.x
__asm fld dword ptr [esi+4] ; p_o.y | p_o.x-r_o.x
__asm fsub dword ptr [r_origin+4] ; p_o.y-r_o.y | p_o.x-r_o.x
__asm fld dword ptr [esi+8] ; p_o.z | p_o.y-r_o.y | p_o.x-r_o.x
__asm fsub dword ptr [r_origin+8] ; p_o.z-r_o.z | p_o.y-r_o.y | p_o.x-r_o.x
__asm fxch st(2) ; p_o.x-r_o.x | p_o.y-r_o.y | p_o.z-r_o.z
__asm fstp dword ptr [local+0] ; p_o.y-r_o.y | p_o.z-r_o.z
__asm fstp dword ptr [local+4] ; p_o.z-r_o.z
__asm fstp dword ptr [local+8] ; (empty)
// transformed[0] = DotProduct(local, r_pright);
// transformed[1] = DotProduct(local, r_pup);
// transformed[2] = DotProduct(local, r_ppn);
__asm fld dword ptr [local+0] ; l.x
__asm fmul dword ptr [r_pright+0] ; l.x*pr.x
__asm fld dword ptr [local+4] ; l.y | l.x*pr.x
__asm fmul dword ptr [r_pright+4] ; l.y*pr.y | l.x*pr.x
__asm fld dword ptr [local+8] ; l.z | l.y*pr.y | l.x*pr.x
__asm fmul dword ptr [r_pright+8] ; l.z*pr.z | l.y*pr.y | l.x*pr.x
__asm fxch st(2) ; l.x*pr.x | l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y + l.z*pr.z
__asm fstp dword ptr [transformed+0] ; (empty)
__asm fld dword ptr [local+0] ; l.x
__asm fmul dword ptr [r_pup+0] ; l.x*pr.x
__asm fld dword ptr [local+4] ; l.y | l.x*pr.x
__asm fmul dword ptr [r_pup+4] ; l.y*pr.y | l.x*pr.x
__asm fld dword ptr [local+8] ; l.z | l.y*pr.y | l.x*pr.x
__asm fmul dword ptr [r_pup+8] ; l.z*pr.z | l.y*pr.y | l.x*pr.x
__asm fxch st(2) ; l.x*pr.x | l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y + l.z*pr.z
__asm fstp dword ptr [transformed+4] ; (empty)
__asm fld dword ptr [local+0] ; l.x
__asm fmul dword ptr [r_ppn+0] ; l.x*pr.x
__asm fld dword ptr [local+4] ; l.y | l.x*pr.x
__asm fmul dword ptr [r_ppn+4] ; l.y*pr.y | l.x*pr.x
__asm fld dword ptr [local+8] ; l.z | l.y*pr.y | l.x*pr.x
__asm fmul dword ptr [r_ppn+8] ; l.z*pr.z | l.y*pr.y | l.x*pr.x
__asm fxch st(2) ; l.x*pr.x | l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y | l.z*pr.z
__asm faddp st(1), st ; l.x*pr.x + l.y*pr.y + l.z*pr.z
__asm fstp dword ptr [transformed+8] ; (empty)
/*
** make sure that the transformed particle is not in front of
** the particle Z clip plane. We can do the comparison in
** integer space since we know the sign of one of the inputs
** and can figure out the sign of the other easily enough.
*/
// if (transformed[2] < PARTICLE_Z_CLIP)
// return;
__asm mov eax, dword ptr [transformed+8]
__asm and eax, eax
__asm js end
__asm cmp eax, particle_z_clip
__asm jl end
/*
** project the point by initiating the 1/z calc
*/
// zi = 1.0 / transformed[2];
__asm fld one
__asm fdiv dword ptr [transformed+8]
/*
** bind the blend function pointer to the appropriate blender
** while we're dividing
*/
//if ( level == PARTICLE_33 )
// blendparticle = BlendParticle33;
//else if ( level == PARTICLE_66 )
// blendparticle = BlendParticle66;
//else
// blendparticle = BlendParticle100;
__asm cmp partparms.level, PARTICLE_66
__asm je blendfunc_66
__asm jl blendfunc_33
__asm lea ebx, BlendParticle100
__asm jmp done_selecting_blend_func
blendfunc_33:
__asm lea ebx, BlendParticle33
__asm jmp done_selecting_blend_func
blendfunc_66:
__asm lea ebx, BlendParticle66
done_selecting_blend_func:
__asm mov blendfunc, ebx
// prefetch the next particle
__asm mov ebp, s_prefetch_address
__asm mov ebp, [ebp]
// finish the above divide
__asm fstp zi
// u = (int)(xcenter + zi * transformed[0] + 0.5);
// v = (int)(ycenter - zi * transformed[1] + 0.5);
__asm fld zi ; zi
__asm fmul dword ptr [transformed+0] ; zi * transformed[0]
__asm fld zi ; zi | zi * transformed[0]
__asm fmul dword ptr [transformed+4] ; zi * transformed[1] | zi * transformed[0]
__asm fxch st(1) ; zi * transformed[0] | zi * transformed[1]
__asm fadd xcenter ; xcenter + zi * transformed[0] | zi * transformed[1]
__asm fxch st(1) ; zi * transformed[1] | xcenter + zi * transformed[0]
__asm fld ycenter ; ycenter | zi * transformed[1] | xcenter + zi * transformed[0]
__asm fsubrp st(1), st(0) ; ycenter - zi * transformed[1] | xcenter + zi * transformed[0]
__asm fxch st(1) ; xcenter + zi * transformed[0] | ycenter + zi * transformed[1]
__asm fadd point_five ; xcenter + zi * transformed[0] + 0.5 | ycenter - zi * transformed[1]
__asm fxch st(1) ; ycenter - zi * transformed[1] | xcenter + zi * transformed[0] + 0.5
__asm fadd point_five ; ycenter - zi * transformed[1] + 0.5 | xcenter + zi * transformed[0] + 0.5
__asm fxch st(1) ; u | v
__asm fistp dword ptr [u] ; v
__asm fistp dword ptr [v] ; (empty)
/*
** clip out the particle
*/
// if ((v > d_vrectbottom_particle) ||
// (u > d_vrectright_particle) ||
// (v < d_vrecty) ||
// (u < d_vrectx))
// {
// return;
// }
__asm mov ebx, u
__asm mov ecx, v
__asm cmp ecx, d_vrectbottom_particle
__asm jg end
__asm cmp ecx, d_vrecty
__asm jl end
__asm cmp ebx, d_vrectright_particle
__asm jg end
__asm cmp ebx, d_vrectx
__asm jl end
/*
** compute addresses of zbuffer, framebuffer, and
** compute the Z-buffer reference value.
**
** EBX = U
** ECX = V
**
** Outputs:
** ESI = Z-buffer address
** EDI = framebuffer address
*/
// ESI = d_pzbuffer + (d_zwidth * v) + u;
__asm mov esi, d_pzbuffer ; esi = d_pzbuffer
__asm mov eax, d_zwidth ; eax = d_zwidth
__asm mul ecx ; eax = d_zwidth*v
__asm add eax, ebx ; eax = d_zwidth*v+u
__asm shl eax, 1 ; eax = 2*(d_zwidth*v+u)
__asm add esi, eax ; esi = ( short * ) ( d_pzbuffer + ( d_zwidth * v ) + u )
// initiate
// izi = (int)(zi * 0x8000);
__asm fld zi
__asm fmul eight_thousand_hex
// EDI = pdest = d_viewbuffer + d_scantable[v] + u;
__asm lea edi, [d_scantable+ecx*4]
__asm mov edi, [edi]
__asm add edi, d_viewbuffer
__asm add edi, ebx
// complete
// izi = (int)(zi * 0x8000);
__asm fistp tmp
__asm mov eax, tmp
__asm mov izi, ax
/*
** determine the screen area covered by the particle,
** which also means clamping to a min and max
*/
// pix = izi >> d_pix_shift;
__asm xor edx, edx
__asm mov dx, izi
__asm mov ecx, d_pix_shift
__asm shr dx, cl
// if (pix < d_pix_min)
// pix = d_pix_min;
__asm cmp edx, d_pix_min
__asm jge check_pix_max
__asm mov edx, d_pix_min
__asm jmp skip_pix_clamp
// else if (pix > d_pix_max)
// pix = d_pix_max;
check_pix_max:
__asm cmp edx, d_pix_max
__asm jle skip_pix_clamp
__asm mov edx, d_pix_max
skip_pix_clamp:
/*
** render the appropriate pixels
**
** ECX = count (used for inner loop)
** EDX = count (used for outer loop)
** ESI = zbuffer
** EDI = framebuffer
*/
__asm mov ecx, edx
__asm cmp ecx, 1
__asm ja over
over:
/*
** at this point:
**
** ECX = count
*/
__asm push ecx
__asm push edi
__asm push esi
top_of_pix_vert_loop:
top_of_pix_horiz_loop:
// for ( ; count ; count--, pz += d_zwidth, pdest += screenwidth)
// {
// for (i=0 ; i<pix ; i++)
// {
// if (pz[i] <= izi)
// {
// pdest[i] = blendparticle( color, pdest[i] );
// }
// }
// }
__asm xor eax, eax
__asm mov ax, word ptr [esi]
__asm cmp ax, izi
__asm jg end_of_horiz_loop
#if ENABLE_ZWRITES_FOR_PARTICLES
__asm mov bp, izi
__asm mov word ptr [esi], bp
#endif
__asm mov eax, partparms.color
__asm call [blendfunc]
__asm add edi, 1
__asm add esi, 2
end_of_horiz_loop:
__asm dec ecx
__asm jnz top_of_pix_horiz_loop
__asm pop esi
__asm pop edi
__asm mov ebp, d_zwidth
__asm shl ebp, 1
__asm add esi, ebp
__asm add edi, [r_screenwidth]
__asm pop ecx
__asm push ecx
__asm push edi
__asm push esi
__asm dec edx
__asm jnz top_of_pix_vert_loop
__asm pop ecx
__asm pop ecx
__asm pop ecx
end:
__asm pop edi
__asm pop esi
__asm mov ebp, ebpsave
__asm ret
}
#else
static byte BlendParticle33( int pcolor, int dstcolor )
{
return vid.alphamap[pcolor + dstcolor*256];
}
static byte BlendParticle66( int pcolor, int dstcolor )
{
return vid.alphamap[pcolor*256+dstcolor];
}
static byte BlendParticle100( int pcolor, int dstcolor )
{
dstcolor = dstcolor;
return pcolor;
}
/*
** 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.
*/
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;
byte (*blendparticle)( int, int );
/*
** 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;
/*
** bind the blend function pointer to the appropriate blender
*/
if ( level == PARTICLE_33 )
blendparticle = BlendParticle33;
else if ( level == PARTICLE_66 )
blendparticle = BlendParticle66;
else
blendparticle = BlendParticle100;
/*
** 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;
}
}
#endif // !id386
/*
** 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;
extern unsigned long fpu_sp24_cw, fpu_chop_cw;
VectorScale( vright, xscaleshrink, r_pright );
VectorScale( vup, yscaleshrink, r_pup );
VectorCopy( vpn, r_ppn );
#if id386 && !defined __linux__
__asm fldcw word ptr [fpu_sp24_cw]
#endif
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;
#if id386 && !defined __linux__
if ( i < r_newrefdef.num_particles-1 )
s_prefetch_address = ( unsigned int ) ( p + 1 );
else
s_prefetch_address = ( unsigned int ) r_newrefdef.particles;
#endif
R_DrawParticle();
}
#if id386 && !defined __linux__
__asm fldcw word ptr [fpu_chop_cw]
#endif
}