void R_DrawLightningBeams(void)
{
int i;
beam_t *b;
if (!cl_beams_polygons.integer)
return;
beamrepeatscale = 1.0f / r_lightningbeam_repeatdistance.value;
for (i = 0, b = cl.beams;i < cl.num_beams;i++, b++)
{
if (b->model && b->lightning)
{
vec3_t org, start, end, dir;
vec_t dist;
CL_Beam_CalculatePositions(b, start, end);
// calculate the nearest point on the line (beam) for depth sorting
VectorSubtract(end, start, dir);
dist = (DotProduct(r_refdef.view.origin, dir) - DotProduct(start, dir)) / (DotProduct(end, dir) - DotProduct(start, dir));
dist = bound(0, dist, 1);
VectorLerp(start, dist, end, org);
// now we have the nearest point on the line, so sort with it
R_MeshQueue_AddTransparent(TRANSPARENTSORT_DISTANCE, org, R_DrawLightningBeam_TransparentCallback, NULL, i, NULL);
}
}
}
static void R_DrawLightningBeam_TransparentCallback(const entity_render_t *ent, const rtlight_t *rtlight, int numsurfaces, int *surfacelist)
{
int surfacelistindex;
float vertex3f[12*3];
float texcoord2f[12*2];
RSurf_ActiveCustomEntity(&identitymatrix, &identitymatrix, 0, 0, r_lightningbeam_color_red.value, r_lightningbeam_color_green.value, r_lightningbeam_color_blue.value, 1, 12, vertex3f, texcoord2f, NULL, NULL, NULL, NULL, 6, r_lightningbeamelement3i, r_lightningbeamelement3s, false, false);
if (r_lightningbeam_qmbtexture.integer && r_lightningbeamqmbtexture == NULL)
r_lightningbeams_setupqmbtexture();
if (!r_lightningbeam_qmbtexture.integer && r_lightningbeamtexture == NULL)
r_lightningbeams_setuptexture();
for (surfacelistindex = 0;surfacelistindex < numsurfaces;surfacelistindex++)
{
const beam_t *b = cl.beams + surfacelist[surfacelistindex];
vec3_t beamdir, right, up, offset, start, end;
float length, t1, t2;
CL_Beam_CalculatePositions(b, start, end);
// calculate beam direction (beamdir) vector and beam length
// get difference vector
VectorSubtract(end, start, beamdir);
// find length of difference vector
length = sqrt(DotProduct(beamdir, beamdir));
// calculate scale to make beamdir a unit vector (normalized)
t1 = 1.0f / length;
// scale beamdir so it is now normalized
VectorScale(beamdir, t1, beamdir);
// calculate up vector such that it points toward viewer, and rotates around the beamdir
// get direction from start of beam to viewer
VectorSubtract(r_refdef.view.origin, start, up);
// remove the portion of the vector that moves along the beam
// (this leaves only a vector pointing directly away from the beam)
t1 = -DotProduct(up, beamdir);
VectorMA(up, t1, beamdir, up);
// generate right vector from forward and up, the result is unnormalized
CrossProduct(beamdir, up, right);
// now normalize the right vector and up vector
VectorNormalize(right);
VectorNormalize(up);
// calculate T coordinate scrolling (start and end texcoord along the beam)
t1 = r_refdef.scene.time * -r_lightningbeam_scroll.value;// + beamrepeatscale * DotProduct(start, beamdir);
t1 = t1 - (int) t1;
t2 = t1 + beamrepeatscale * length;
// the beam is 3 polygons in this configuration:
// * 2
// * *
// 1******
// * *
// * 3
// they are showing different portions of the beam texture, creating an
// illusion of a beam that appears to curl around in 3D space
// (and realize that the whole polygon assembly orients itself to face
// the viewer)
// polygon 1, verts 0-3
VectorScale(right, r_lightningbeam_thickness.value, offset);
R_CalcLightningBeamPolygonVertex3f(vertex3f + 0, start, end, offset);
// polygon 2, verts 4-7
VectorAdd(right, up, offset);
VectorScale(offset, r_lightningbeam_thickness.value * 0.70710681f, offset);
R_CalcLightningBeamPolygonVertex3f(vertex3f + 12, start, end, offset);
// polygon 3, verts 8-11
VectorSubtract(right, up, offset);
VectorScale(offset, r_lightningbeam_thickness.value * 0.70710681f, offset);
R_CalcLightningBeamPolygonVertex3f(vertex3f + 24, start, end, offset);
R_CalcLightningBeamPolygonTexCoord2f(texcoord2f + 0, t1, t2);
R_CalcLightningBeamPolygonTexCoord2f(texcoord2f + 8, t1 + 0.33, t2 + 0.33);
R_CalcLightningBeamPolygonTexCoord2f(texcoord2f + 16, t1 + 0.66, t2 + 0.66);
// draw the 3 polygons as one batch of 6 triangles using the 12 vertices
R_DrawCustomSurface(r_lightningbeam_qmbtexture.integer ? r_lightningbeamqmbtexture : r_lightningbeamtexture, &identitymatrix, MATERIALFLAG_ADD | MATERIALFLAG_BLENDED | MATERIALFLAG_FULLBRIGHT | MATERIALFLAG_NOCULLFACE, 0, 12, 0, 6, false, false);
}
}
void CL_Beam_AddPolygons(const beam_t *b)
{
vec3_t beamdir, right, up, offset, start, end;
vec_t beamscroll = r_refdef.scene.time * -r_lightningbeam_scroll.value;
vec_t beamrepeatscale = 1.0f / r_lightningbeam_repeatdistance.value;
float length, t1, t2;
dp_model_t *mod;
msurface_t *surf;
if (r_lightningbeam_qmbtexture.integer && cl_beams_externaltexture.currentskinframe == NULL)
CL_Beams_SetupExternalTexture();
if (!r_lightningbeam_qmbtexture.integer && cl_beams_builtintexture.currentskinframe == NULL)
CL_Beams_SetupBuiltinTexture();
// calculate beam direction (beamdir) vector and beam length
// get difference vector
CL_Beam_CalculatePositions(b, start, end);
VectorSubtract(end, start, beamdir);
// find length of difference vector
length = sqrt(DotProduct(beamdir, beamdir));
// calculate scale to make beamdir a unit vector (normalized)
t1 = 1.0f / length;
// scale beamdir so it is now normalized
VectorScale(beamdir, t1, beamdir);
// calculate up vector such that it points toward viewer, and rotates around the beamdir
// get direction from start of beam to viewer
VectorSubtract(r_refdef.view.origin, start, up);
// remove the portion of the vector that moves along the beam
// (this leaves only a vector pointing directly away from the beam)
t1 = -DotProduct(up, beamdir);
VectorMA(up, t1, beamdir, up);
// generate right vector from forward and up, the result is unnormalized
CrossProduct(beamdir, up, right);
// now normalize the right vector and up vector
VectorNormalize(right);
VectorNormalize(up);
// calculate T coordinate scrolling (start and end texcoord along the beam)
t1 = beamscroll;
t1 = t1 - (int)t1;
t2 = t1 + beamrepeatscale * length;
// the beam is 3 polygons in this configuration:
// * 2
// * *
// 1*****
// * *
// * 3
// they are showing different portions of the beam texture, creating an
// illusion of a beam that appears to curl around in 3D space
// (and realize that the whole polygon assembly orients itself to face
// the viewer)
mod = &cl_meshentitymodels[MESH_PARTICLES];
surf = Mod_Mesh_AddSurface(mod, r_lightningbeam_qmbtexture.integer ? &cl_beams_externaltexture : &cl_beams_builtintexture, false);
// polygon 1
VectorM(r_lightningbeam_thickness.value, right, offset);
CL_Beam_AddQuad(mod, surf, start, end, offset, t1, t2);
// polygon 2
VectorMAM(r_lightningbeam_thickness.value * 0.70710681f, right, r_lightningbeam_thickness.value * 0.70710681f, up, offset);
CL_Beam_AddQuad(mod, surf, start, end, offset, t1 + 0.33f, t2 + 0.33f);
// polygon 3
VectorMAM(r_lightningbeam_thickness.value * 0.70710681f, right, r_lightningbeam_thickness.value * -0.70710681f, up, offset);
CL_Beam_AddQuad(mod, surf, start, end, offset, t1 + 0.66f, t2 + 0.66f);
}