ref: 47eca22c0a296502f838d1b3676b0cd8f5ba57b9
dir: /r_sprite.c/
#include <u.h>
#include <libc.h>
#include "quakedef.h"
#include "r_local.h"
static int clip_current;
static vec5_t clip_verts[2][MAXWORKINGVERTS];
static int sprite_width, sprite_height;
spritedesc_t r_spritedesc;
/*
================
R_RotateSprite
================
*/
void R_RotateSprite (float beamlength)
{
vec3_t vec;
if (beamlength == 0.0)
return;
VectorScale (r_spritedesc.vpn, -beamlength, vec);
VectorAdd (r_entorigin, vec, r_entorigin);
VectorSubtract (modelorg, vec, modelorg);
}
/*
=============
R_ClipSpriteFace
Clips the winding at clip_verts[clip_current] and changes clip_current
Throws out the back side
==============
*/
int R_ClipSpriteFace (int nump, clipplane_t *pclipplane)
{
int i, outcount;
float dists[MAXWORKINGVERTS+1];
float frac, clipdist, *pclipnormal;
float *in, *instep, *outstep, *vert2;
clipdist = pclipplane->dist;
pclipnormal = pclipplane->normal;
// calc dists
if (clip_current)
{
in = clip_verts[1][0];
outstep = clip_verts[0][0];
clip_current = 0;
}
else
{
in = clip_verts[0][0];
outstep = clip_verts[1][0];
clip_current = 1;
}
instep = in;
for (i=0 ; i<nump ; i++, instep += sizeof (vec5_t) / sizeof (float))
{
dists[i] = DotProduct (instep, pclipnormal) - clipdist;
}
// handle wraparound case
dists[nump] = dists[0];
Q_memcpy (instep, in, sizeof (vec5_t));
// clip the winding
instep = in;
outcount = 0;
for (i=0 ; i<nump ; i++, instep += sizeof (vec5_t) / sizeof (float))
{
if (dists[i] >= 0)
{
Q_memcpy (outstep, instep, sizeof (vec5_t));
outstep += sizeof (vec5_t) / sizeof (float);
outcount++;
}
if (dists[i] == 0 || dists[i+1] == 0)
continue;
if ( (dists[i] > 0) == (dists[i+1] > 0) )
continue;
// split it into a new vertex
frac = dists[i] / (dists[i] - dists[i+1]);
vert2 = instep + sizeof (vec5_t) / sizeof (float);
outstep[0] = instep[0] + frac*(vert2[0] - instep[0]);
outstep[1] = instep[1] + frac*(vert2[1] - instep[1]);
outstep[2] = instep[2] + frac*(vert2[2] - instep[2]);
outstep[3] = instep[3] + frac*(vert2[3] - instep[3]);
outstep[4] = instep[4] + frac*(vert2[4] - instep[4]);
outstep += sizeof (vec5_t) / sizeof (float);
outcount++;
}
return outcount;
}
/*
================
R_SetupAndDrawSprite
================
*/
void R_SetupAndDrawSprite ()
{
int i, nump;
float dot, scale, *pv;
vec5_t *pverts;
vec3_t left, up, right, down, transformed, local;
emitpoint_t outverts[MAXWORKINGVERTS+1], *pout;
dot = DotProduct (r_spritedesc.vpn, modelorg);
// backface cull
if (dot >= 0)
return;
// build the sprite poster in worldspace
VectorScale (r_spritedesc.vright, r_spritedesc.pspriteframe->right, right);
VectorScale (r_spritedesc.vup, r_spritedesc.pspriteframe->up, up);
VectorScale (r_spritedesc.vright, r_spritedesc.pspriteframe->left, left);
VectorScale (r_spritedesc.vup, r_spritedesc.pspriteframe->down, down);
pverts = 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] = sprite_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] = sprite_width;
pverts[2][4] = sprite_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] = sprite_height;
// clip to the frustum in worldspace
nump = 4;
clip_current = 0;
for (i=0 ; i<4 ; i++)
{
nump = R_ClipSpriteFace (nump, &view_clipplanes[i]);
if (nump < 3)
return;
if (nump >= MAXWORKINGVERTS)
Sys_Error("R_SetupAndDrawSprite: too many points");
}
// transform vertices into viewspace and project
pv = &clip_verts[clip_current][0][0];
r_spritedesc.nearzi = -999999;
for (i=0 ; i<nump ; i++)
{
VectorSubtract (pv, r_origin, local);
TransformVector (local, transformed);
if (transformed[2] < NEAR_CLIP)
transformed[2] = NEAR_CLIP;
pout = &outverts[i];
pout->zi = 1.0 / transformed[2];
if (pout->zi > r_spritedesc.nearzi)
r_spritedesc.nearzi = pout->zi;
pout->s = pv[3];
pout->t = pv[4];
scale = xscale * pout->zi;
pout->u = (xcenter + scale * transformed[0]);
scale = yscale * pout->zi;
pout->v = (ycenter - scale * transformed[1]);
pv += sizeof (vec5_t) / sizeof (*pv);
}
// draw it
r_spritedesc.nump = nump;
r_spritedesc.pverts = outverts;
D_DrawSprite ();
}
/*
================
R_GetSpriteframe
================
*/
mspriteframe_t *R_GetSpriteframe (msprite_t *psprite)
{
mspritegroup_t *pspritegroup;
mspriteframe_t *pspriteframe;
int i, numframes, frame;
float *pintervals, fullinterval, targettime, time;
frame = currententity->frame;
if ((frame >= psprite->numframes) || (frame < 0))
{
Con_Printf ("R_DrawSprite: no such frame %d\n", frame);
frame = 0;
}
if (psprite->frames[frame].type == SPR_SINGLE)
{
pspriteframe = psprite->frames[frame].frameptr;
}
else
{
pspritegroup = (mspritegroup_t *)psprite->frames[frame].frameptr;
pintervals = pspritegroup->intervals;
numframes = pspritegroup->numframes;
fullinterval = pintervals[numframes-1];
time = cl.time + currententity->syncbase;
// when loading in Mod_LoadSpriteGroup, we guaranteed all interval values
// are positive, so we don't have to worry about division by 0
targettime = time - ((int)(time / fullinterval)) * fullinterval;
for (i=0 ; i<(numframes-1) ; i++)
{
if (pintervals[i] > targettime)
break;
}
pspriteframe = pspritegroup->frames[i];
}
return pspriteframe;
}
/*
================
R_DrawSprite
================
*/
void R_DrawSprite (void)
{
int i;
msprite_t *psprite;
vec3_t tvec;
float dot, angle, sr, cr;
psprite = currententity->model->cache.data;
r_spritedesc.pspriteframe = R_GetSpriteframe (psprite);
sprite_width = r_spritedesc.pspriteframe->width;
sprite_height = r_spritedesc.pspriteframe->height;
// TODO: make this caller-selectable
if (psprite->type == SPR_FACING_UPRIGHT)
{
// generate the sprite's axes, with vup straight up in worldspace, and
// r_spritedesc.vright perpendicular to modelorg.
// This will not work if the view direction is very close to straight up or
// down, because the cross product will be between two nearly parallel
// vectors and starts to approach an undefined state, so we don't draw if
// the two vectors are less than 1 degree apart
tvec[0] = -modelorg[0];
tvec[1] = -modelorg[1];
tvec[2] = -modelorg[2];
VectorNormalize (tvec);
dot = tvec[2]; // same as DotProduct (tvec, r_spritedesc.vup) because
// r_spritedesc.vup is 0, 0, 1
if ((dot > 0.999848) || (dot < -0.999848)) // cos(1 degree) = 0.999848
return;
r_spritedesc.vup[0] = 0;
r_spritedesc.vup[1] = 0;
r_spritedesc.vup[2] = 1;
r_spritedesc.vright[0] = tvec[1];
// CrossProduct(r_spritedesc.vup, -modelorg,
r_spritedesc.vright[1] = -tvec[0];
// r_spritedesc.vright)
r_spritedesc.vright[2] = 0;
VectorNormalize (r_spritedesc.vright);
r_spritedesc.vpn[0] = -r_spritedesc.vright[1];
r_spritedesc.vpn[1] = r_spritedesc.vright[0];
r_spritedesc.vpn[2] = 0;
// CrossProduct (r_spritedesc.vright, r_spritedesc.vup,
// r_spritedesc.vpn)
}
else if (psprite->type == SPR_VP_PARALLEL)
{
// generate the sprite's axes, completely parallel to the viewplane. There
// are no problem situations, because the sprite is always in the same
// position relative to the viewer
for (i=0 ; i<3 ; i++)
{
r_spritedesc.vup[i] = vup[i];
r_spritedesc.vright[i] = vright[i];
r_spritedesc.vpn[i] = vpn[i];
}
}
else if (psprite->type == SPR_VP_PARALLEL_UPRIGHT)
{
// generate the sprite's axes, with vup straight up in worldspace, and
// r_spritedesc.vright parallel to the viewplane.
// This will not work if the view direction is very close to straight up or
// down, because the cross product will be between two nearly parallel
// vectors and starts to approach an undefined state, so we don't draw if
// the two vectors are less than 1 degree apart
dot = vpn[2]; // same as DotProduct (vpn, r_spritedesc.vup) because
// r_spritedesc.vup is 0, 0, 1
if ((dot > 0.999848) || (dot < -0.999848)) // cos(1 degree) = 0.999848
return;
r_spritedesc.vup[0] = 0;
r_spritedesc.vup[1] = 0;
r_spritedesc.vup[2] = 1;
r_spritedesc.vright[0] = vpn[1];
// CrossProduct (r_spritedesc.vup, vpn,
r_spritedesc.vright[1] = -vpn[0]; // r_spritedesc.vright)
r_spritedesc.vright[2] = 0;
VectorNormalize (r_spritedesc.vright);
r_spritedesc.vpn[0] = -r_spritedesc.vright[1];
r_spritedesc.vpn[1] = r_spritedesc.vright[0];
r_spritedesc.vpn[2] = 0;
// CrossProduct (r_spritedesc.vright, r_spritedesc.vup,
// r_spritedesc.vpn)
}
else if (psprite->type == SPR_ORIENTED)
{
// generate the sprite's axes, according to the sprite's world orientation
AngleVectors (currententity->angles, r_spritedesc.vpn,
r_spritedesc.vright, r_spritedesc.vup);
}
else if (psprite->type == SPR_VP_PARALLEL_ORIENTED)
{
// generate the sprite's axes, parallel to the viewplane, but rotated in
// that plane around the center according to the sprite entity's roll
// angle. So vpn stays the same, but vright and vup rotate
angle = currententity->angles[ROLL] * (M_PI*2 / 360);
sr = sin(angle);
cr = cos(angle);
for (i=0 ; i<3 ; i++)
{
r_spritedesc.vpn[i] = vpn[i];
r_spritedesc.vright[i] = vright[i] * cr + vup[i] * sr;
r_spritedesc.vup[i] = vright[i] * -sr + vup[i] * cr;
}
}
else
{
Sys_Error ("R_DrawSprite: Bad sprite type %d", psprite->type);
}
R_RotateSprite (psprite->beamlength);
R_SetupAndDrawSprite ();
}