/* trilinear interpolation */
static void vol_get_precached_scattering(Render *re, ShadeInput *shi, float scatter_col[3], const float co[3])
{
VolumePrecache *vp = shi->obi->volume_precache;
float bbmin[3], bbmax[3], dim[3];
float world_co[3], sample_co[3];
if (!vp) return;
/* find sample point in global space bounding box 0.0-1.0 */
global_bounds_obi(re, shi->obi, bbmin, bbmax);
sub_v3_v3v3(dim, bbmax, bbmin);
mul_v3_m4v3(world_co, re->viewinv, co);
/* sample_co in 0.0-1.0 */
sample_co[0] = (world_co[0] - bbmin[0]) / dim[0];
sample_co[1] = (world_co[1] - bbmin[1]) / dim[1];
sample_co[2] = (world_co[2] - bbmin[2]) / dim[2];
scatter_col[0] = BLI_voxel_sample_triquadratic(vp->data_r, vp->res, sample_co);
scatter_col[1] = BLI_voxel_sample_triquadratic(vp->data_g, vp->res, sample_co);
scatter_col[2] = BLI_voxel_sample_triquadratic(vp->data_b, vp->res, sample_co);
}
int voxeldatatex(struct Tex *tex, const float texvec[3], struct TexResult *texres)
{
VoxelData *vd = tex->vd;
float co[3], offset[3] = {0.5, 0.5, 0.5}, a;
int retval = (vd->data_type == TEX_VD_RGBA_PREMUL) ? TEX_RGB : TEX_INT;
int depth = (vd->data_type == TEX_VD_RGBA_PREMUL) ? 4 : 1;
int ch;
if (vd->dataset == NULL) {
texres->tin = 0.0f;
return 0;
}
/* scale lookup from 0.0-1.0 (original location) to -1.0, 1.0, consistent with image texture tex coords */
/* in implementation this works backwards, bringing sample locations from -1.0, 1.0
* to the range 0.0, 1.0, before looking up in the voxel structure. */
copy_v3_v3(co, texvec);
mul_v3_fl(co, 0.5f);
add_v3_v3(co, offset);
/* co is now in the range 0.0, 1.0 */
switch (vd->extend) {
case TEX_CLIP:
{
if ((co[0] < 0.f || co[0] > 1.f) || (co[1] < 0.f || co[1] > 1.f) || (co[2] < 0.f || co[2] > 1.f)) {
texres->tin = 0.f;
return retval;
}
break;
}
case TEX_REPEAT:
{
co[0] = co[0] - floorf(co[0]);
co[1] = co[1] - floorf(co[1]);
co[2] = co[2] - floorf(co[2]);
break;
}
case TEX_EXTEND:
{
CLAMP(co[0], 0.f, 1.f);
CLAMP(co[1], 0.f, 1.f);
CLAMP(co[2], 0.f, 1.f);
break;
}
}
for (ch = 0; ch < depth; ch++) {
float *dataset = vd->dataset + ch*vd->resol[0]*vd->resol[1]*vd->resol[2];
float *result = &texres->tin;
if (vd->data_type == TEX_VD_RGBA_PREMUL) {
switch (ch) {
case 0:
result = &texres->tr;
break;
case 1:
result = &texres->tg;
break;
case 2:
result = &texres->tb;
break;
}
}
switch (vd->interp_type) {
case TEX_VD_NEARESTNEIGHBOR:
*result = BLI_voxel_sample_nearest(dataset, vd->resol, co);
break;
case TEX_VD_LINEAR:
*result = BLI_voxel_sample_trilinear(dataset, vd->resol, co);
break;
case TEX_VD_QUADRATIC:
*result = BLI_voxel_sample_triquadratic(dataset, vd->resol, co);
break;
case TEX_VD_TRICUBIC_CATROM:
case TEX_VD_TRICUBIC_BSPLINE:
*result = BLI_voxel_sample_tricubic(dataset, vd->resol, co, (vd->interp_type == TEX_VD_TRICUBIC_BSPLINE));
break;
}
}
a = texres->tin;
texres->tin *= vd->int_multiplier;
BRICONT;
if (vd->data_type == TEX_VD_RGBA_PREMUL) {
/* unmultiply */
if (a>0.001f) {
texres->tr /= a;
texres->tg /= a;
texres->tb /= a;
}
texres->talpha = 1;
}
else {
texres->tr = texres->tin;
texres->tg = texres->tin;
texres->tb = texres->tin;
}
texres->ta = texres->tin;
BRICONTRGB;
return retval;
}