shadeinput.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2006 Blender Foundation
 * All rights reserved.
 *
 * Contributors: Hos, Robert Wenzlaff.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdio.h>
#include <math.h>
#include <string.h>


#include "BLI_math.h"
#include "BLI_blenlib.h"
#include "BLI_utildefines.h"

#include "DNA_curve_types.h"
#include "DNA_group_types.h"
#include "DNA_lamp_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_material_types.h"

#include "BKE_colortools.h"

#include "BKE_node.h"

/* local include */
#include "raycounter.h"
#include "renderpipeline.h"
#include "render_types.h"
#include "renderdatabase.h"
#include "rendercore.h"
#include "shadbuf.h"
#include "shading.h"
#include "strand.h"
#include "texture.h"
#include "volumetric.h"
#include "zbuf.h"

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
/* defined in pipeline.c, is hardcopy of active dynamic allocated Render */
/* only to be used here in this file, it's for speed */
extern struct Render R;
/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */


#define VECADDISFAC(v1,v3,fac) {*(v1)+= *(v3)*(fac); *(v1+1)+= *(v3+1)*(fac); *(v1+2)+= *(v3+2)*(fac);}



/* Shade Sample order:

- shade_samples_fill_with_ps()
    - for each sample
        - shade_input_set_triangle()  <- if prev sample-face is same, use shade_input_copy_triangle()
        - if vlr
            - shade_input_set_viewco()    <- not for ray or bake
            - shade_input_set_uv()        <- not for ray or bake
            - shade_input_set_normals()
- shade_samples()
    - if AO
        - shade_samples_do_AO()
    - if shading happens
        - for each sample
            - shade_input_set_shade_texco()
            - shade_samples_do_shade()
- OSA: distribute sample result with filter masking

    */

/* initialise material variables in shadeinput, 
 * doing inverse gamma correction where applicable */
void shade_input_init_material(ShadeInput *shi)
{
    /* note, keep this synced with render_types.h */
    memcpy(&shi->r, &shi->mat->r, 23*sizeof(float));
    shi->har= shi->mat->har;
}

/* also used as callback for nodes */
/* delivers a fully filled in ShadeResult, for all passes */
void shade_material_loop(ShadeInput *shi, ShadeResult *shr)
{

    shade_lamp_loop(shi, shr);  /* clears shr */
    
    if(shi->translucency!=0.0f) {
        ShadeResult shr_t;
        float fac= shi->translucency;
        
        shade_input_init_material(shi);
        negate_v3_v3(shi->vn, shi->vno);
        negate_v3(shi->facenor);
        shi->depth++;   /* hack to get real shadow now */
        shade_lamp_loop(shi, &shr_t);
        shi->depth--;

        /* a couple of passes */
        VECADDISFAC(shr->combined, shr_t.combined, fac);
        if(shi->passflag & SCE_PASS_SPEC)
            VECADDISFAC(shr->spec, shr_t.spec, fac);
        if(shi->passflag & SCE_PASS_DIFFUSE)
            VECADDISFAC(shr->diff, shr_t.diff, fac);
        if(shi->passflag & SCE_PASS_SHADOW)
            VECADDISFAC(shr->shad, shr_t.shad, fac);

        negate_v3(shi->vn);
        negate_v3(shi->facenor);
    }
    
    /* depth >= 1 when ray-shading */
    if(shi->depth==0 || shi->volume_depth > 0) {
        if(R.r.mode & R_RAYTRACE) {
            if(shi->ray_mirror!=0.0f || ((shi->mode & MA_TRANSP) && (shi->mode & MA_RAYTRANSP) && shr->alpha!=1.0f)) {
                /* ray trace works on combined, but gives pass info */
                ray_trace(shi, shr);
            }
        }
        /* disable adding of sky for raytransp */
        if((shi->mode & MA_TRANSP) && (shi->mode & MA_RAYTRANSP))
            if((shi->layflag & SCE_LAY_SKY) && (R.r.alphamode==R_ADDSKY))
                shr->alpha= 1.0f;
    }
    
    if(R.r.mode & R_RAYTRACE) {
        if (R.render_volumes_inside.first)
            shade_volume_inside(shi, shr);
    }
}


/* do a shade, finish up some passes, apply mist */
void shade_input_do_shade(ShadeInput *shi, ShadeResult *shr)
{
    float alpha;
    
    /* ------  main shading loop -------- */
#ifdef RE_RAYCOUNTER
    memset(&shi->raycounter, 0, sizeof(shi->raycounter));
#endif
    
    if(shi->mat->nodetree && shi->mat->use_nodes) {
        ntreeShaderExecTree(shi->mat->nodetree, shi, shr);
    }
    else {
        /* copy all relevant material vars, note, keep this synced with render_types.h */
        shade_input_init_material(shi);
        
        if (shi->mat->material_type == MA_TYPE_VOLUME) {
            if(R.r.mode & R_RAYTRACE) {
                shade_volume_outside(shi, shr);
            }
        } else { /* MA_TYPE_SURFACE, MA_TYPE_WIRE */
            shade_material_loop(shi, shr);
        }
    }
    
    /* copy additional passes */
    if(shi->passflag & (SCE_PASS_VECTOR|SCE_PASS_NORMAL)) {
        copy_v4_v4(shr->winspeed, shi->winspeed);
        copy_v3_v3(shr->nor, shi->vn);
    }
    
    /* MIST */
    if((shi->passflag & SCE_PASS_MIST) || ((R.wrld.mode & WO_MIST) && (shi->mat->mode & MA_NOMIST)==0))  {
        if(R.r.mode & R_ORTHO)
            shr->mist= mistfactor(-shi->co[2], shi->co);
        else
            shr->mist= mistfactor(len_v3(shi->co), shi->co);
    }
    else shr->mist= 0.0f;
    
    if((R.wrld.mode & WO_MIST) && (shi->mat->mode & MA_NOMIST)==0 ) {
        alpha= shr->mist;
    }
    else alpha= 1.0f;
    
    /* add mist and premul color */
    if(shr->alpha!=1.0f || alpha!=1.0f) {
        float fac= alpha*(shr->alpha);
        shr->combined[3]= fac;
        
        if (shi->mat->material_type!= MA_TYPE_VOLUME)
            mul_v3_fl(shr->combined, fac);
    }
    else
        shr->combined[3]= 1.0f;
    
    /* add z */
    shr->z= -shi->co[2];
    
    /* RAYHITS */
/*
    if(1 || shi->passflag & SCE_PASS_RAYHITS)
    {
        shr->rayhits[0] = (float)shi->raycounter.faces.test;
        shr->rayhits[1] = (float)shi->raycounter.bb.hit;
        shr->rayhits[2] = 0.0;
        shr->rayhits[3] = 1.0;
    }
 */
    RE_RC_MERGE(&re_rc_counter[shi->thread], &shi->raycounter);
}

/* **************************************************************************** */
/*                    ShadeInput                                                */
/* **************************************************************************** */


void vlr_set_uv_indices(VlakRen *vlr, int *i1, int *i2, int *i3)
{
    /* to prevent storing new tfaces or vcols, we check a split runtime */
    /*      4---3       4---3 */
    /*      |\ 1|   or  |1 /| */
    /*      |0\ |       |/ 0| */
    /*      1---2       1---2   0 = orig face, 1 = new face */
    
    /* Update vert nums to point to correct verts of original face */
    if(vlr->flag & R_DIVIDE_24) {  
        if(vlr->flag & R_FACE_SPLIT) {
            (*i1)++; (*i2)++; (*i3)++;
        }
        else {
            (*i3)++;
        }
    }
    else if(vlr->flag & R_FACE_SPLIT) {
        (*i2)++; (*i3)++; 
    }
}

/* copy data from face to ShadeInput, general case */
/* indices 0 1 2 3 only */
void shade_input_set_triangle_i(ShadeInput *shi, ObjectInstanceRen *obi, VlakRen *vlr, short i1, short i2, short i3)
{
    VertRen **vpp= &vlr->v1;
    
    shi->vlr= vlr;
    shi->obi= obi;
    shi->obr= obi->obr;

    shi->v1= vpp[i1];
    shi->v2= vpp[i2];
    shi->v3= vpp[i3];
    
    shi->i1= i1;
    shi->i2= i2;
    shi->i3= i3;
    
    /* note, shi->mat is set in node shaders */
    shi->mat= shi->mat_override?shi->mat_override:vlr->mat;
    
    shi->osatex= (shi->mat->texco & TEXCO_OSA);
    shi->mode= shi->mat->mode_l;        /* or-ed result for all nodes */

    /* facenormal copy, can get flipped */
    shi->flippednor= 0;
    RE_vlakren_get_normal(&R, obi, vlr, shi->facenor);
    
    /* calculate vertexnormals */
    if(vlr->flag & R_SMOOTH) {
        copy_v3_v3(shi->n1, shi->v1->n);
        copy_v3_v3(shi->n2, shi->v2->n);
        copy_v3_v3(shi->n3, shi->v3->n);

        if(obi->flag & R_TRANSFORMED) {
            mul_m3_v3(obi->nmat, shi->n1); normalize_v3(shi->n1);
            mul_m3_v3(obi->nmat, shi->n2); normalize_v3(shi->n2);
            mul_m3_v3(obi->nmat, shi->n3); normalize_v3(shi->n3);
        }
    }
}

/* note, facenr declared volatile due to over-eager -O2 optimizations
 * on cygwin (particularly -frerun-cse-after-loop)
 */

/* copy data from face to ShadeInput, scanline case */
void shade_input_set_triangle(ShadeInput *shi, volatile int obi, volatile int facenr, int UNUSED(normal_flip))
{
    if(facenr>0) {
        shi->obi= &R.objectinstance[obi];
        shi->obr= shi->obi->obr;
        shi->facenr= (facenr-1) & RE_QUAD_MASK;
        if( shi->facenr < shi->obr->totvlak ) {
            VlakRen *vlr= RE_findOrAddVlak(shi->obr, shi->facenr);
            
            if(facenr & RE_QUAD_OFFS)
                shade_input_set_triangle_i(shi, shi->obi, vlr, 0, 2, 3);
            else
                shade_input_set_triangle_i(shi, shi->obi, vlr, 0, 1, 2);
        }
        else
            shi->vlr= NULL; /* general signal we got sky */
    }
    else
        shi->vlr= NULL; /* general signal we got sky */
}

/* full osa case: copy static info */
void shade_input_copy_triangle(ShadeInput *shi, ShadeInput *from)
{
    /* not so nice, but works... warning is in RE_shader_ext.h */
    memcpy(shi, from, sizeof(struct ShadeInputCopy));
}

/* copy data from strand to shadeinput */
void shade_input_set_strand(ShadeInput *shi, StrandRen *strand, StrandPoint *spoint)
{
    /* note, shi->mat is set in node shaders */
    shi->mat= shi->mat_override? shi->mat_override: strand->buffer->ma;
    
    shi->osatex= (shi->mat->texco & TEXCO_OSA);
    shi->mode= shi->mat->mode_l;        /* or-ed result for all nodes */

    /* shade_input_set_viewco equivalent */
    copy_v3_v3(shi->co, spoint->co);
    copy_v3_v3(shi->view, shi->co);
    normalize_v3(shi->view);

    shi->xs= (int)spoint->x;
    shi->ys= (int)spoint->y;

    if(shi->osatex || (R.r.mode & R_SHADOW)) {
        copy_v3_v3(shi->dxco, spoint->dtco);
        copy_v3_v3(shi->dyco, spoint->dsco);
    }

    /* dxview, dyview, not supported */

    /* facenormal, simply viewco flipped */
    copy_v3_v3(shi->facenor, spoint->nor);

    /* shade_input_set_normals equivalent */
    if(shi->mat->mode & MA_TANGENT_STR) {
        copy_v3_v3(shi->vn, spoint->tan);
    }
    else {
        float cross[3];

        cross_v3_v3v3(cross, spoint->co, spoint->tan);
        cross_v3_v3v3(shi->vn, cross, spoint->tan);
        normalize_v3(shi->vn);

        if(dot_v3v3(shi->vn, shi->view) < 0.0f)
            negate_v3(shi->vn);
    }

    copy_v3_v3(shi->vno, shi->vn);
}

void shade_input_set_strand_texco(ShadeInput *shi, StrandRen *strand, StrandVert *svert, StrandPoint *spoint)
{
    StrandBuffer *strandbuf= strand->buffer;
    ObjectRen *obr= strandbuf->obr;
    StrandVert *sv;
    int mode= shi->mode;        /* or-ed result for all nodes */
    short texco= shi->mat->texco;

    if((shi->mat->texco & TEXCO_REFL)) {
        /* shi->dxview, shi->dyview, not supported */
    }

    if(shi->osatex && (texco & (TEXCO_NORM|TEXCO_REFL))) {
        /* not supported */
    }

    if(mode & (MA_TANGENT_V|MA_NORMAP_TANG)) {
        copy_v3_v3(shi->tang, spoint->tan);
        copy_v3_v3(shi->nmaptang, spoint->tan);
    }

    if(mode & MA_STR_SURFDIFF) {
        float *surfnor= RE_strandren_get_surfnor(obr, strand, 0);

        if(surfnor)
            copy_v3_v3(shi->surfnor, surfnor);
        else
            copy_v3_v3(shi->surfnor, shi->vn);

        if(shi->mat->strand_surfnor > 0.0f) {
            shi->surfdist= 0.0f;
            for(sv=strand->vert; sv!=svert; sv++)
                shi->surfdist+=len_v3v3(sv->co, (sv+1)->co);
            shi->surfdist += spoint->t*len_v3v3(sv->co, (sv+1)->co);
        }
    }

    if(R.r.mode & R_SPEED) {
        float *speed;
        
        speed= RE_strandren_get_winspeed(shi->obi, strand, 0);
        if(speed)
            copy_v4_v4(shi->winspeed, speed);
        else
            shi->winspeed[0]= shi->winspeed[1]= shi->winspeed[2]= shi->winspeed[3]= 0.0f;
    }

    /* shade_input_set_shade_texco equivalent */
    if(texco & NEED_UV) {
        if(texco & TEXCO_ORCO) {
            copy_v3_v3(shi->lo, strand->orco);
            /* no shi->osatex, orco derivatives are zero */
        }

        if(texco & TEXCO_GLOB) {
            copy_v3_v3(shi->gl, shi->co);
            mul_m4_v3(R.viewinv, shi->gl);
            
            if(shi->osatex) {
                copy_v3_v3(shi->dxgl, shi->dxco);
                mul_mat3_m4_v3(R.viewinv, shi->dxgl); 
                copy_v3_v3(shi->dygl, shi->dyco);
                mul_mat3_m4_v3(R.viewinv, shi->dygl);
            }
        }

        if(texco & TEXCO_STRAND) {
            shi->strandco= spoint->strandco;

            if(shi->osatex) {
                shi->dxstrand= spoint->dtstrandco;
                shi->dystrand= 0.0f;
            }
        }

        if((texco & TEXCO_UV) || (mode & (MA_VERTEXCOL|MA_VERTEXCOLP|MA_FACETEXTURE)))  {
            MCol *mcol;
            float *uv;
            char *name;
            int i;

            shi->totuv= 0;
            shi->totcol= 0;
            shi->actuv= obr->actmtface;
            shi->actcol= obr->actmcol;

            if(mode & (MA_VERTEXCOL|MA_VERTEXCOLP)) {
                for (i=0; (mcol=RE_strandren_get_mcol(obr, strand, i, &name, 0)); i++) {
                    ShadeInputCol *scol= &shi->col[i];
                    char *cp= (char*)mcol;
                    
                    shi->totcol++;
                    scol->name= name;

                    scol->col[0]= cp[3]/255.0f;
                    scol->col[1]= cp[2]/255.0f;
                    scol->col[2]= cp[1]/255.0f;
                    scol->col[3]= cp[0]/255.0f;
                }

                if(shi->totcol) {
                    shi->vcol[0]= shi->col[shi->actcol].col[0];
                    shi->vcol[1]= shi->col[shi->actcol].col[1];
                    shi->vcol[2]= shi->col[shi->actcol].col[2];
                    shi->vcol[3]= shi->col[shi->actcol].col[3];
                }
                else {
                    shi->vcol[0]= 0.0f;
                    shi->vcol[1]= 0.0f;
                    shi->vcol[2]= 0.0f;
                    shi->vcol[3]= 0.0f;
                }
            }

            for (i=0; (uv=RE_strandren_get_uv(obr, strand, i, &name, 0)); i++) {
                ShadeInputUV *suv= &shi->uv[i];

                shi->totuv++;
                suv->name= name;

                if(strandbuf->overrideuv == i) {
                    suv->uv[0]= -1.0f;
                    suv->uv[1]= spoint->strandco;
                    suv->uv[2]= 0.0f;
                }
                else {
                    suv->uv[0]= -1.0f + 2.0f*uv[0];
                    suv->uv[1]= -1.0f + 2.0f*uv[1];
                    suv->uv[2]= 0.0f;   /* texture.c assumes there are 3 coords */
                }

                if(shi->osatex) {
                    suv->dxuv[0]= 0.0f;
                    suv->dxuv[1]= 0.0f;
                    suv->dyuv[0]= 0.0f;
                    suv->dyuv[1]= 0.0f;
                }

                if((mode & MA_FACETEXTURE) && i==obr->actmtface) {
                    if((mode & (MA_VERTEXCOL|MA_VERTEXCOLP))==0) {
                        shi->vcol[0]= 1.0f;
                        shi->vcol[1]= 1.0f;
                        shi->vcol[2]= 1.0f;
                        shi->vcol[3]= 1.0f;
                    }
                }
            }

            if(shi->totuv == 0) {
                ShadeInputUV *suv= &shi->uv[0];

                suv->uv[0]= 0.0f;
                suv->uv[1]= spoint->strandco;
                suv->uv[2]= 0.0f;   /* texture.c assumes there are 3 coords */
                
                if(mode & MA_FACETEXTURE) {
                    /* no tface? set at 1.0f */
                    shi->vcol[0]= 1.0f;
                    shi->vcol[1]= 1.0f;
                    shi->vcol[2]= 1.0f;
                    shi->vcol[3]= 1.0f;
                }
            }

        }

        if(texco & TEXCO_NORM) {
            shi->orn[0]= -shi->vn[0];
            shi->orn[1]= -shi->vn[1];
            shi->orn[2]= -shi->vn[2];
        }

        if(texco & TEXCO_STRESS) {
            /* not supported */
        }

        if(texco & TEXCO_TANGENT) {
            if((mode & MA_TANGENT_V)==0) {
                /* just prevent surprises */
                shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
                shi->nmaptang[0]= shi->nmaptang[1]= shi->nmaptang[2]= 0.0f;
            }
        }
    }

    /* this only avalailable for scanline renders */
    if(shi->depth==0) {
        if(texco & TEXCO_WINDOW) {
            shi->winco[0]= -1.0f + 2.0f*spoint->x/(float)R.winx;
            shi->winco[1]= -1.0f + 2.0f*spoint->y/(float)R.winy;
            shi->winco[2]= 0.0f;

            /* not supported */
            if(shi->osatex) {
                shi->dxwin[0]= 0.0f;
                shi->dywin[1]= 0.0f;
                shi->dxwin[0]= 0.0f;
                shi->dywin[1]= 0.0f;
            }
        }

        if(texco & TEXCO_STICKY) {
            /* not supported */
        }
    }
    
    if (shi->do_manage) {
        if(mode & (MA_VERTEXCOL|MA_VERTEXCOLP|MA_FACETEXTURE)) {
            srgb_to_linearrgb_v3_v3(shi->vcol, shi->vcol);
        }
    }
    
}

/* from scanline pixel coordinates to 3d coordinates, requires set_triangle */
void shade_input_calc_viewco(ShadeInput *shi, float x, float y, float z, float view[3], float dxyview[2], float co[3], float dxco[3], float dyco[3])
{
    /* returns not normalized, so is in viewplane coords */
    calc_view_vector(view, x, y);
    
    if(shi->mat->material_type == MA_TYPE_WIRE) {
        /* wire cannot use normal for calculating shi->co, so
         * we reconstruct the coordinate less accurate */
        if(R.r.mode & R_ORTHO)
            calc_renderco_ortho(co, x, y, z);
        else
            calc_renderco_zbuf(co, view, z);
    }
    else {
        /* for non-wire, intersect with the triangle to get the exact coord */
        float fac, dface, v1[3];
        
        copy_v3_v3(v1, shi->v1->co);
        if(shi->obi->flag & R_TRANSFORMED)
            mul_m4_v3(shi->obi->mat, v1);
        
        dface= v1[0]*shi->facenor[0]+v1[1]*shi->facenor[1]+v1[2]*shi->facenor[2];
        
        /* ortho viewplane cannot intersect using view vector originating in (0,0,0) */
        if(R.r.mode & R_ORTHO) {
            /* x and y 3d coordinate can be derived from pixel coord and winmat */
            float fx= 2.0f/(R.winx*R.winmat[0][0]);
            float fy= 2.0f/(R.winy*R.winmat[1][1]);
            
            co[0]= (x - 0.5f*R.winx)*fx - R.winmat[3][0]/R.winmat[0][0];
            co[1]= (y - 0.5f*R.winy)*fy - R.winmat[3][1]/R.winmat[1][1];
            
            /* using a*x + b*y + c*z = d equation, (a b c) is normal */
            if(shi->facenor[2]!=0.0f)
                co[2]= (dface - shi->facenor[0]*co[0] - shi->facenor[1]*co[1])/shi->facenor[2];
            else
                co[2]= 0.0f;
            
            if(dxco && dyco) {
                dxco[0]= fx;
                dxco[1]= 0.0f;
                if(shi->facenor[2]!=0.0f)
                    dxco[2]= -(shi->facenor[0]*fx)/shi->facenor[2];
                else 
                    dxco[2]= 0.0f;
                
                dyco[0]= 0.0f;
                dyco[1]= fy;
                if(shi->facenor[2]!=0.0f)
                    dyco[2]= -(shi->facenor[1]*fy)/shi->facenor[2];
                else 
                    dyco[2]= 0.0f;
                
                if(dxyview) {
                    if(co[2]!=0.0f) fac= 1.0f/co[2]; else fac= 0.0f;
                    dxyview[0]= -R.viewdx*fac;
                    dxyview[1]= -R.viewdy*fac;
                }
            }
        }
        else {
            float div;
            
            div= shi->facenor[0]*view[0] + shi->facenor[1]*view[1] + shi->facenor[2]*view[2];
            if (div!=0.0f) fac= dface/div;
            else fac= 0.0f;
            
            co[0]= fac*view[0];
            co[1]= fac*view[1];
            co[2]= fac*view[2];
            
            /* pixel dx/dy for render coord */
            if(dxco && dyco) {
                float u= dface/(div - R.viewdx*shi->facenor[0]);
                float v= dface/(div - R.viewdy*shi->facenor[1]);
                
                dxco[0]= co[0]- (view[0]-R.viewdx)*u;
                dxco[1]= co[1]- (view[1])*u;
                dxco[2]= co[2]- (view[2])*u;
                
                dyco[0]= co[0]- (view[0])*v;
                dyco[1]= co[1]- (view[1]-R.viewdy)*v;
                dyco[2]= co[2]- (view[2])*v;
                
                if(dxyview) {
                    if(fac!=0.0f) fac= 1.0f/fac;
                    dxyview[0]= -R.viewdx*fac;
                    dxyview[1]= -R.viewdy*fac;
                }
            }
        }
    }
    
    /* set camera coords - for scanline, it's always 0.0,0.0,0.0 (render is in camera space)
     * however for raytrace it can be different - the position of the last intersection */
    shi->camera_co[0] = shi->camera_co[1] = shi->camera_co[2] = 0.0f;
    
    /* cannot normalize earlier, code above needs it at viewplane level */
    normalize_v3(view);
}

/* from scanline pixel coordinates to 3d coordinates, requires set_triangle */
void shade_input_set_viewco(ShadeInput *shi, float x, float y, float xs, float ys, float z)
{
    float *dxyview= NULL, *dxco= NULL, *dyco= NULL;
    
    /* currently in use for dithering (soft shadow), node preview, irregular shad */
    shi->xs= (int)xs;
    shi->ys= (int)ys;

    /* original scanline coordinate without jitter */
    shi->scanco[0]= x;
    shi->scanco[1]= y;
    shi->scanco[2]= z;

    /* check if we need derivatives */
    if(shi->osatex || (R.r.mode & R_SHADOW)) {
        dxco= shi->dxco;
        dyco= shi->dyco;

        if((shi->mat->texco & TEXCO_REFL))
            dxyview= &shi->dxview;
    }

    shade_input_calc_viewco(shi, xs, ys, z, shi->view, dxyview, shi->co, dxco, dyco);
}

/* calculate U and V, for scanline (silly render face u and v are in range -1 to 0) */
void shade_input_set_uv(ShadeInput *shi)
{
    VlakRen *vlr= shi->vlr;
    
    if((vlr->flag & R_SMOOTH) || (shi->mat->texco & NEED_UV) || (shi->passflag & SCE_PASS_UV)) {
        float v1[3], v2[3], v3[3];

        copy_v3_v3(v1, shi->v1->co);
        copy_v3_v3(v2, shi->v2->co);
        copy_v3_v3(v3, shi->v3->co);

        if(shi->obi->flag & R_TRANSFORMED) {
            mul_m4_v3(shi->obi->mat, v1);
            mul_m4_v3(shi->obi->mat, v2);
            mul_m4_v3(shi->obi->mat, v3);
        }

        /* exception case for wire render of edge */
        if(vlr->v2==vlr->v3) {
            float lend, lenc;
            
            lend= len_v3v3(v2, v1);
            lenc= len_v3v3(shi->co, v1);
            
            if(lend==0.0f) {
                shi->u=shi->v= 0.0f;
            }
            else {
                shi->u= - (1.0f - lenc/lend);
                shi->v= 0.0f;
            }
            
            if(shi->osatex) {
                shi->dx_u=  0.0f;
                shi->dx_v=  0.0f;
                shi->dy_u=  0.0f;
                shi->dy_v=  0.0f;
            }
        }
        else {
            /* most of this could become re-used for faces */
            float detsh, t00, t10, t01, t11;
            int axis1, axis2;

            /* find most stable axis to project */
            axis_dominant_v3(&axis1, &axis2, shi->facenor);

            /* compute u,v and derivatives */
            t00= v3[axis1]-v1[axis1]; t01= v3[axis2]-v1[axis2];
            t10= v3[axis1]-v2[axis1]; t11= v3[axis2]-v2[axis2];

            detsh= (t00*t11-t10*t01);
            detsh= (detsh != 0.0f)? 1.0f/detsh: 0.0f;
            t00*= detsh; t01*=detsh; 
            t10*=detsh; t11*=detsh;

            shi->u= (shi->co[axis1]-v3[axis1])*t11-(shi->co[axis2]-v3[axis2])*t10;
            shi->v= (shi->co[axis2]-v3[axis2])*t00-(shi->co[axis1]-v3[axis1])*t01;
            if(shi->osatex) {
                shi->dx_u=  shi->dxco[axis1]*t11- shi->dxco[axis2]*t10;
                shi->dx_v=  shi->dxco[axis2]*t00- shi->dxco[axis1]*t01;
                shi->dy_u=  shi->dyco[axis1]*t11- shi->dyco[axis2]*t10;
                shi->dy_v=  shi->dyco[axis2]*t00- shi->dyco[axis1]*t01;
            }

            /* u and v are in range -1 to 0, we allow a little bit extra but not too much, screws up speedvectors */
            CLAMP(shi->u, -2.0f, 1.0f);
            CLAMP(shi->v, -2.0f, 1.0f);
        }
    }   
}

void shade_input_set_normals(ShadeInput *shi)
{
    float u= shi->u, v= shi->v;
    float l= 1.0f+u+v;

    shi->flippednor = 0;

    /* test flip normals to viewing direction */
    if(!(shi->vlr->flag & R_TANGENT)) {
        if(dot_v3v3(shi->facenor, shi->view) < 0.0f) {
            negate_v3(shi->facenor);
            shi->flippednor= 1;
        }
    }
    
    /* calculate vertexnormals */
    if(shi->vlr->flag & R_SMOOTH) {
        float *n1= shi->n1, *n2= shi->n2, *n3= shi->n3;

        if(shi->flippednor) {
            negate_v3(n1);
            negate_v3(n2);
            negate_v3(n3);
        }
        
        shi->vn[0]= l*n3[0]-u*n1[0]-v*n2[0];
        shi->vn[1]= l*n3[1]-u*n1[1]-v*n2[1];
        shi->vn[2]= l*n3[2]-u*n1[2]-v*n2[2];

        // use unnormalized normal (closer to games)
        copy_v3_v3(shi->nmapnorm, shi->vn);
        
        normalize_v3(shi->vn);
    }
    else
    {
        copy_v3_v3(shi->vn, shi->facenor);
        copy_v3_v3(shi->nmapnorm, shi->vn);
    }
    
    /* used in nodes */
    copy_v3_v3(shi->vno, shi->vn);

    /* flip normals to viewing direction */
    if(!(shi->vlr->flag & R_TANGENT))
        if(dot_v3v3(shi->facenor, shi->view) < 0.0f)
            shade_input_flip_normals(shi);
}

/* XXX shi->flippednor messes up otherwise */
void shade_input_set_vertex_normals(ShadeInput *shi)
{
    float u= shi->u, v= shi->v;
    float l= 1.0f+u+v;
    
    /* calculate vertexnormals */
    if(shi->vlr->flag & R_SMOOTH) {
        float *n1= shi->n1, *n2= shi->n2, *n3= shi->n3;
        
        shi->vn[0]= l*n3[0]-u*n1[0]-v*n2[0];
        shi->vn[1]= l*n3[1]-u*n1[1]-v*n2[1];
        shi->vn[2]= l*n3[2]-u*n1[2]-v*n2[2];
        
        // use unnormalized normal (closer to games)
        copy_v3_v3(shi->nmapnorm, shi->vn);
        
        normalize_v3(shi->vn);
    }
    else
    {
        copy_v3_v3(shi->vn, shi->facenor);
        copy_v3_v3(shi->nmapnorm, shi->vn);
    }
    
    /* used in nodes */
    copy_v3_v3(shi->vno, shi->vn);
}


/* use by raytrace, sss, bake to flip into the right direction */
void shade_input_flip_normals(ShadeInput *shi)
{
    shi->facenor[0]= -shi->facenor[0];
    shi->facenor[1]= -shi->facenor[1];
    shi->facenor[2]= -shi->facenor[2];

    shi->vn[0]= -shi->vn[0];
    shi->vn[1]= -shi->vn[1];
    shi->vn[2]= -shi->vn[2];

    shi->vno[0]= -shi->vno[0];
    shi->vno[1]= -shi->vno[1];
    shi->vno[2]= -shi->vno[2];

    shi->nmapnorm[0] = -shi->nmapnorm[0];
    shi->nmapnorm[1] = -shi->nmapnorm[1];
    shi->nmapnorm[2] = -shi->nmapnorm[2];

    shi->flippednor= !shi->flippednor;
}

void shade_input_set_shade_texco(ShadeInput *shi)
{
    ObjectInstanceRen *obi= shi->obi;
    ObjectRen *obr= shi->obr;
    VertRen *v1= shi->v1, *v2= shi->v2, *v3= shi->v3;
    float u= shi->u, v= shi->v;
    float l= 1.0f+u+v, dl;
    int mode= shi->mode;        /* or-ed result for all nodes */
    short texco= shi->mat->texco;

    /* calculate dxno */
    if(shi->vlr->flag & R_SMOOTH) {
        
        if(shi->osatex && (texco & (TEXCO_NORM|TEXCO_REFL)) ) {
            float *n1= shi->n1, *n2= shi->n2, *n3= shi->n3;
            
            dl= shi->dx_u+shi->dx_v;
            shi->dxno[0]= dl*n3[0]-shi->dx_u*n1[0]-shi->dx_v*n2[0];
            shi->dxno[1]= dl*n3[1]-shi->dx_u*n1[1]-shi->dx_v*n2[1];
            shi->dxno[2]= dl*n3[2]-shi->dx_u*n1[2]-shi->dx_v*n2[2];
            dl= shi->dy_u+shi->dy_v;
            shi->dyno[0]= dl*n3[0]-shi->dy_u*n1[0]-shi->dy_v*n2[0];
            shi->dyno[1]= dl*n3[1]-shi->dy_u*n1[1]-shi->dy_v*n2[1];
            shi->dyno[2]= dl*n3[2]-shi->dy_u*n1[2]-shi->dy_v*n2[2];
            
        }
    }

    /* calc tangents */
    if (mode & (MA_TANGENT_V|MA_NORMAP_TANG) || R.flag & R_NEED_TANGENT) {
        float *tangent, *s1, *s2, *s3;
        float tl, tu, tv;

        if(shi->vlr->flag & R_SMOOTH) {
            tl= l;
            tu= u;
            tv= v;
        }
        else {
            /* qdn: flat faces have tangents too,
               could pick either one, using average here */
            tl= 1.0f/3.0f;
            tu= -1.0f/3.0f;
            tv= -1.0f/3.0f;
        }

        shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
        shi->nmaptang[0]= shi->nmaptang[1]= shi->nmaptang[2]= 0.0f;

        if(mode & MA_TANGENT_V) {
            s1 = RE_vertren_get_tangent(obr, v1, 0);
            s2 = RE_vertren_get_tangent(obr, v2, 0);
            s3 = RE_vertren_get_tangent(obr, v3, 0);

            if(s1 && s2 && s3) {
                shi->tang[0]= (tl*s3[0] - tu*s1[0] - tv*s2[0]);
                shi->tang[1]= (tl*s3[1] - tu*s1[1] - tv*s2[1]);
                shi->tang[2]= (tl*s3[2] - tu*s1[2] - tv*s2[2]);

                if(obi->flag & R_TRANSFORMED)
                    mul_m3_v3(obi->nmat, shi->tang);

                normalize_v3(shi->tang);
                copy_v3_v3(shi->nmaptang, shi->tang);
            }
        }

        if(mode & MA_NORMAP_TANG || R.flag & R_NEED_TANGENT) {
            tangent= RE_vlakren_get_nmap_tangent(obr, shi->vlr, 0);

            if(tangent) {
                int j1= shi->i1, j2= shi->i2, j3= shi->i3;
                float c0[3], c1[3], c2[3];

                vlr_set_uv_indices(shi->vlr, &j1, &j2, &j3);

                copy_v3_v3(c0, &tangent[j1*4]);
                copy_v3_v3(c1, &tangent[j2*4]);
                copy_v3_v3(c2, &tangent[j3*4]);

                // keeping tangents normalized at vertex level
                // corresponds better to how it's done in game engines
                if(obi->flag & R_TRANSFORMED)
                {
                    mul_mat3_m4_v3(obi->mat, c0); normalize_v3(c0);
                    mul_mat3_m4_v3(obi->mat, c1); normalize_v3(c1);
                    mul_mat3_m4_v3(obi->mat, c2); normalize_v3(c2);
                }
                
                // we don't normalize the interpolated TBN tangent
                // corresponds better to how it's done in game engines
                shi->nmaptang[0]= (tl*c2[0] - tu*c0[0] - tv*c1[0]);
                shi->nmaptang[1]= (tl*c2[1] - tu*c0[1] - tv*c1[1]);
                shi->nmaptang[2]= (tl*c2[2] - tu*c0[2] - tv*c1[2]);

                // the sign is the same for all 3 vertices of any
                // non degenerate triangle.
                shi->nmaptang[3]= tangent[j1*4+3];
            }
        }
    }

    if(mode & MA_STR_SURFDIFF) {
        float *surfnor= RE_vlakren_get_surfnor(obr, shi->vlr, 0);

        if(surfnor) {
            copy_v3_v3(shi->surfnor, surfnor);
            if(obi->flag & R_TRANSFORMED)
                mul_m3_v3(obi->nmat, shi->surfnor);
        }
        else
            copy_v3_v3(shi->surfnor, shi->vn);

        shi->surfdist= 0.0f;
    }
    
    if(R.r.mode & R_SPEED) {
        float *s1, *s2, *s3;
        
        s1= RE_vertren_get_winspeed(obi, v1, 0);
        s2= RE_vertren_get_winspeed(obi, v2, 0);
        s3= RE_vertren_get_winspeed(obi, v3, 0);
        if(s1 && s2 && s3) {
            shi->winspeed[0]= (l*s3[0] - u*s1[0] - v*s2[0]);
            shi->winspeed[1]= (l*s3[1] - u*s1[1] - v*s2[1]);
            shi->winspeed[2]= (l*s3[2] - u*s1[2] - v*s2[2]);
            shi->winspeed[3]= (l*s3[3] - u*s1[3] - v*s2[3]);
        }
        else {
            shi->winspeed[0]= shi->winspeed[1]= shi->winspeed[2]= shi->winspeed[3]= 0.0f;
        }
    }

    /* pass option forces UV calc */
    if(shi->passflag & SCE_PASS_UV)
        texco |= (NEED_UV|TEXCO_UV);
    
    /* texture coordinates. shi->dxuv shi->dyuv have been set */
    if(texco & NEED_UV) {
        
        if(texco & TEXCO_ORCO) {
            if(v1->orco) {
                float *o1, *o2, *o3;
                
                o1= v1->orco;
                o2= v2->orco;
                o3= v3->orco;
                
                shi->lo[0]= l*o3[0]-u*o1[0]-v*o2[0];
                shi->lo[1]= l*o3[1]-u*o1[1]-v*o2[1];
                shi->lo[2]= l*o3[2]-u*o1[2]-v*o2[2];
                
                if(shi->osatex) {
                    dl= shi->dx_u+shi->dx_v;
                    shi->dxlo[0]= dl*o3[0]-shi->dx_u*o1[0]-shi->dx_v*o2[0];
                    shi->dxlo[1]= dl*o3[1]-shi->dx_u*o1[1]-shi->dx_v*o2[1];
                    shi->dxlo[2]= dl*o3[2]-shi->dx_u*o1[2]-shi->dx_v*o2[2];
                    dl= shi->dy_u+shi->dy_v;
                    shi->dylo[0]= dl*o3[0]-shi->dy_u*o1[0]-shi->dy_v*o2[0];
                    shi->dylo[1]= dl*o3[1]-shi->dy_u*o1[1]-shi->dy_v*o2[1];
                    shi->dylo[2]= dl*o3[2]-shi->dy_u*o1[2]-shi->dy_v*o2[2];
                }
            }

            copy_v3_v3(shi->duplilo, obi->dupliorco);
        }
        
        if(texco & TEXCO_GLOB) {
            copy_v3_v3(shi->gl, shi->co);
            mul_m4_v3(R.viewinv, shi->gl);
            if(shi->osatex) {
                copy_v3_v3(shi->dxgl, shi->dxco);
                mul_mat3_m4_v3(R.viewinv, shi->dxgl); 
                copy_v3_v3(shi->dygl, shi->dyco);
                mul_mat3_m4_v3(R.viewinv, shi->dygl);
            }
        }
        
        if(texco & TEXCO_STRAND) {
            shi->strandco= (l*v3->accum - u*v1->accum - v*v2->accum);
            if(shi->osatex) {
                dl= shi->dx_u+shi->dx_v;
                shi->dxstrand= dl*v3->accum-shi->dx_u*v1->accum-shi->dx_v*v2->accum;
                dl= shi->dy_u+shi->dy_v;
                shi->dystrand= dl*v3->accum-shi->dy_u*v1->accum-shi->dy_v*v2->accum;
            }
        }
                
        if((texco & TEXCO_UV) || (mode & (MA_VERTEXCOL|MA_VERTEXCOLP|MA_FACETEXTURE)))  {
            VlakRen *vlr= shi->vlr;
            MTFace *tface;
            MCol *mcol;
            char *name;
            int i, j1=shi->i1, j2=shi->i2, j3=shi->i3;

            /* uv and vcols are not copied on split, so set them according vlr divide flag */
            vlr_set_uv_indices(vlr, &j1, &j2, &j3);

            shi->totuv= 0;
            shi->totcol= 0;
            shi->actuv= obr->actmtface;
            shi->actcol= obr->actmcol;

            if(mode & (MA_VERTEXCOL|MA_VERTEXCOLP)) {
                for (i=0; (mcol=RE_vlakren_get_mcol(obr, vlr, i, &name, 0)); i++) {
                    ShadeInputCol *scol= &shi->col[i];
                    char *cp1, *cp2, *cp3;
                    float a[3];
                    
                    shi->totcol++;
                    scol->name= name;

                    cp1= (char *)(mcol+j1);
                    cp2= (char *)(mcol+j2);
                    cp3= (char *)(mcol+j3);

                    /* alpha values */
                    a[0] = ((float)cp1[0])/255.f;
                    a[1] = ((float)cp2[0])/255.f;
                    a[2] = ((float)cp3[0])/255.f;
                    scol->col[3]= l*a[2] - u*a[0] - v*a[1];

                    /* sample premultiplied color value */
                    scol->col[0]= (l*((float)cp3[3])*a[2] - u*((float)cp1[3])*a[0] - v*((float)cp2[3])*a[1])/255.f;
                    scol->col[1]= (l*((float)cp3[2])*a[2] - u*((float)cp1[2])*a[0] - v*((float)cp2[2])*a[1])/255.f;
                    scol->col[2]= (l*((float)cp3[1])*a[2] - u*((float)cp1[1])*a[0] - v*((float)cp2[1])*a[1])/255.f;

                    /* if not zero alpha, restore non-multiplied color */
                    if (scol->col[3]) {
                        mul_v3_fl(scol->col, 1.0f/scol->col[3]);
                    }
                }

                if(shi->totcol) {
                    shi->vcol[0]= shi->col[shi->actcol].col[0];
                    shi->vcol[1]= shi->col[shi->actcol].col[1];
                    shi->vcol[2]= shi->col[shi->actcol].col[2];
                    shi->vcol[3]= shi->col[shi->actcol].col[3];
                }
                else {
                    shi->vcol[0]= 0.0f;
                    shi->vcol[1]= 0.0f;
                    shi->vcol[2]= 0.0f;
                    shi->vcol[3]= 1.0f;
                }
            }

            for (i=0; (tface=RE_vlakren_get_tface(obr, vlr, i, &name, 0)); i++) {
                ShadeInputUV *suv= &shi->uv[i];
                float *uv1, *uv2, *uv3;

                shi->totuv++;
                suv->name= name;
                
                uv1= tface->uv[j1];
                uv2= tface->uv[j2];
                uv3= tface->uv[j3];
                
                suv->uv[0]= -1.0f + 2.0f*(l*uv3[0]-u*uv1[0]-v*uv2[0]);
                suv->uv[1]= -1.0f + 2.0f*(l*uv3[1]-u*uv1[1]-v*uv2[1]);
                suv->uv[2]= 0.0f;   /* texture.c assumes there are 3 coords */

                if(shi->osatex) {
                    float duv[2];
                    
                    dl= shi->dx_u+shi->dx_v;
                    duv[0]= shi->dx_u; 
                    duv[1]= shi->dx_v;
                    
                    suv->dxuv[0]= 2.0f*(dl*uv3[0]-duv[0]*uv1[0]-duv[1]*uv2[0]);
                    suv->dxuv[1]= 2.0f*(dl*uv3[1]-duv[0]*uv1[1]-duv[1]*uv2[1]);
                    
                    dl= shi->dy_u+shi->dy_v;
                    duv[0]= shi->dy_u; 
                    duv[1]= shi->dy_v;
                    
                    suv->dyuv[0]= 2.0f*(dl*uv3[0]-duv[0]*uv1[0]-duv[1]*uv2[0]);
                    suv->dyuv[1]= 2.0f*(dl*uv3[1]-duv[0]*uv1[1]-duv[1]*uv2[1]);
                }

                if((mode & MA_FACETEXTURE) && i==obr->actmtface) {
                    if((mode & (MA_VERTEXCOL|MA_VERTEXCOLP))==0) {
                        shi->vcol[0]= 1.0f;
                        shi->vcol[1]= 1.0f;
                        shi->vcol[2]= 1.0f;
                        shi->vcol[3]= 1.0f;
                    }
                    if(tface->tpage) {
                        render_realtime_texture(shi, tface->tpage);
                    }
                }


            }

            shi->dupliuv[0]= -1.0f + 2.0f*obi->dupliuv[0];
            shi->dupliuv[1]= -1.0f + 2.0f*obi->dupliuv[1];
            shi->dupliuv[2]= 0.0f;

            if(shi->totuv == 0) {
                ShadeInputUV *suv= &shi->uv[0];

                suv->uv[0]= 2.0f*(u+.5f);
                suv->uv[1]= 2.0f*(v+.5f);
                suv->uv[2]= 0.0f;   /* texture.c assumes there are 3 coords */
                
                if(mode & MA_FACETEXTURE) {
                    /* no tface? set at 1.0f */
                    shi->vcol[0]= 1.0f;
                    shi->vcol[1]= 1.0f;
                    shi->vcol[2]= 1.0f;
                    shi->vcol[3]= 1.0f;
                }
            }
        }
        
        if(texco & TEXCO_NORM) {
            shi->orn[0]= -shi->vn[0];
            shi->orn[1]= -shi->vn[1];
            shi->orn[2]= -shi->vn[2];
        }
        
        if(texco & TEXCO_STRESS) {
            float *s1, *s2, *s3;
            
            s1= RE_vertren_get_stress(obr, v1, 0);
            s2= RE_vertren_get_stress(obr, v2, 0);
            s3= RE_vertren_get_stress(obr, v3, 0);
            if(s1 && s2 && s3) {
                shi->stress= l*s3[0] - u*s1[0] - v*s2[0];
                if(shi->stress<1.0f) shi->stress-= 1.0f;
                else shi->stress= (shi->stress-1.0f)/shi->stress;
            }
            else shi->stress= 0.0f;
        }
        
        if(texco & TEXCO_TANGENT) {
            if((mode & MA_TANGENT_V)==0) {
                /* just prevent surprises */
                shi->tang[0]= shi->tang[1]= shi->tang[2]= 0.0f;
                shi->nmaptang[0]= shi->nmaptang[1]= shi->nmaptang[2]= 0.0f;
            }
        }
    }
    
    /* this only avalailable for scanline renders */
    if(shi->depth==0) {
        float x= shi->xs;
        float y= shi->ys;
        
        if(texco & TEXCO_WINDOW) {
            shi->winco[0]= -1.0f + 2.0f*x/(float)R.winx;
            shi->winco[1]= -1.0f + 2.0f*y/(float)R.winy;
            shi->winco[2]= 0.0f;
            if(shi->osatex) {
                shi->dxwin[0]= 2.0f/(float)R.winx;
                shi->dywin[1]= 2.0f/(float)R.winy;
                shi->dxwin[1]= shi->dxwin[2]= 0.0f;
                shi->dywin[0]= shi->dywin[2]= 0.0f;
            }
        }

        if(texco & TEXCO_STICKY) {
            float *s1, *s2, *s3;
            
            s1= RE_vertren_get_sticky(obr, v1, 0);
            s2= RE_vertren_get_sticky(obr, v2, 0);
            s3= RE_vertren_get_sticky(obr, v3, 0);
            
            if(s1 && s2 && s3) {
                float obwinmat[4][4], winmat[4][4], ho1[4], ho2[4], ho3[4];
                float Zmulx, Zmuly;
                float hox, hoy, l, dl, u, v;
                float s00, s01, s10, s11, detsh;
                
                /* old globals, localized now */
                Zmulx=  ((float)R.winx)/2.0f; Zmuly=  ((float)R.winy)/2.0f;

                zbuf_make_winmat(&R, winmat);
                if(shi->obi->flag & R_TRANSFORMED)
                    mult_m4_m4m4(obwinmat, winmat, obi->mat);
                else
                    copy_m4_m4(obwinmat, winmat);

                zbuf_render_project(obwinmat, v1->co, ho1);
                zbuf_render_project(obwinmat, v2->co, ho2);
                zbuf_render_project(obwinmat, v3->co, ho3);
                
                s00= ho3[0]/ho3[3] - ho1[0]/ho1[3];
                s01= ho3[1]/ho3[3] - ho1[1]/ho1[3];
                s10= ho3[0]/ho3[3] - ho2[0]/ho2[3];
                s11= ho3[1]/ho3[3] - ho2[1]/ho2[3];
                
                detsh= s00*s11-s10*s01;
                detsh= (detsh != 0.0f)? 1.0f/detsh: 0.0f;
                s00*= detsh; s01*=detsh; 
                s10*=detsh; s11*=detsh;
                
                /* recalc u and v again */
                hox= x/Zmulx -1.0f;
                hoy= y/Zmuly -1.0f;
                u= (hox - ho3[0]/ho3[3])*s11 - (hoy - ho3[1]/ho3[3])*s10;
                v= (hoy - ho3[1]/ho3[3])*s00 - (hox - ho3[0]/ho3[3])*s01;
                l= 1.0f+u+v;
                
                shi->sticky[0]= l*s3[0]-u*s1[0]-v*s2[0];
                shi->sticky[1]= l*s3[1]-u*s1[1]-v*s2[1];
                shi->sticky[2]= 0.0f;
                
                if(shi->osatex) {
                    float dxuv[2], dyuv[2];
                    dxuv[0]=  s11/Zmulx;
                    dxuv[1]=  - s01/Zmulx;
                    dyuv[0]=  - s10/Zmuly;
                    dyuv[1]=  s00/Zmuly;
                    
                    dl= dxuv[0] + dxuv[1];
                    shi->dxsticky[0]= dl*s3[0] - dxuv[0]*s1[0] - dxuv[1]*s2[0];
                    shi->dxsticky[1]= dl*s3[1] - dxuv[0]*s1[1] - dxuv[1]*s2[1];
                    dl= dyuv[0] + dyuv[1];
                    shi->dysticky[0]= dl*s3[0] - dyuv[0]*s1[0] - dyuv[1]*s2[0];
                    shi->dysticky[1]= dl*s3[1] - dyuv[0]*s1[1] - dyuv[1]*s2[1];
                }
            }
        }
    } /* else {
     Note! For raytracing winco is not set, important because thus means all shader input's need to have their variables set to zero else in-initialized values are used
    */
    if (shi->do_manage) {
        if(mode & (MA_VERTEXCOL|MA_VERTEXCOLP|MA_FACETEXTURE)) {
            srgb_to_linearrgb_v3_v3(shi->vcol, shi->vcol);
        }
    }
    
}

/* ****************** ShadeSample ************************************** */

/* initialize per part, not per pixel! */
void shade_input_initialize(ShadeInput *shi, RenderPart *pa, RenderLayer *rl, int sample)
{
    
    memset(shi, 0, sizeof(ShadeInput));
    
    shi->sample= sample;
    shi->thread= pa->thread;
    shi->do_preview= (R.r.scemode & R_MATNODE_PREVIEW) != 0;
    shi->do_manage= (R.r.color_mgt_flag & R_COLOR_MANAGEMENT);
    shi->lay= rl->lay;
    shi->layflag= rl->layflag;
    shi->passflag= rl->passflag;
    shi->combinedflag= ~rl->pass_xor;
    shi->mat_override= rl->mat_override;
    shi->light_override= rl->light_override;
//  shi->rl= rl;
    /* note shi.depth==0  means first hit, not raytracing */
    
}

/* initialize per part, not per pixel! */
void shade_sample_initialize(ShadeSample *ssamp, RenderPart *pa, RenderLayer *rl)
{
    int a, tot;
    
    tot= R.osa==0?1:R.osa;
    
    for(a=0; a<tot; a++) {
        shade_input_initialize(&ssamp->shi[a], pa, rl, a);
        memset(&ssamp->shr[a], 0, sizeof(ShadeResult));
    }
    
    get_sample_layers(pa, rl, ssamp->rlpp);
}

/* Do AO or (future) GI */
void shade_samples_do_AO(ShadeSample *ssamp)
{
    if(!(R.r.mode & R_SHADOW))
        return;
    if(!(R.r.mode & R_RAYTRACE) && !(R.wrld.ao_gather_method == WO_AOGATHER_APPROX))
        return;
    
    if(R.wrld.mode & (WO_AMB_OCC|WO_ENV_LIGHT|WO_INDIRECT_LIGHT)) {
        ShadeInput *shi= &ssamp->shi[0];
        int sample;

        if(((shi->passflag & SCE_PASS_COMBINED) && (shi->combinedflag & (SCE_PASS_AO|SCE_PASS_ENVIRONMENT|SCE_PASS_INDIRECT)))
            || (shi->passflag & (SCE_PASS_AO|SCE_PASS_ENVIRONMENT|SCE_PASS_INDIRECT)))
            for(sample=0; sample<ssamp->tot; shi++, sample++)
                if(!(shi->mode & MA_SHLESS))
                    ambient_occlusion(shi);     /* stores in shi->ao[] */
    }
}


void shade_samples_fill_with_ps(ShadeSample *ssamp, PixStr *ps, int x, int y)
{
    ShadeInput *shi;
    float xs, ys;
    
    ssamp->tot= 0;
    
    for(shi= ssamp->shi; ps; ps= ps->next) {
        shade_input_set_triangle(shi, ps->obi, ps->facenr, 1);
        
        if(shi->vlr) {  /* NULL happens for env material or for 'all z' */
            unsigned short curmask= ps->mask;
            
            /* full osa is only set for OSA renders */
            if(shi->vlr->flag & R_FULL_OSA) {
                short shi_cp= 0, samp;
                
                for(samp=0; samp<R.osa; samp++) {
                    if(curmask & (1<<samp)) {
                        /* zbuffer has this inverse corrected, ensures xs,ys are inside pixel */
                        xs= (float)x + R.jit[samp][0] + 0.5f;
                        ys= (float)y + R.jit[samp][1] + 0.5f;
                        
                        if(shi_cp)
                            shade_input_copy_triangle(shi, shi-1);
                        
                        shi->mask= (1<<samp);
//                      shi->rl= ssamp->rlpp[samp];
                        shi->samplenr= R.shadowsamplenr[shi->thread]++; /* this counter is not being reset per pixel */
                        shade_input_set_viewco(shi, x, y, xs, ys, (float)ps->z);
                        shade_input_set_uv(shi);
                        if(shi_cp==0)
                            shade_input_set_normals(shi);
                        else  /* XXX shi->flippednor messes up otherwise */
                            shade_input_set_vertex_normals(shi);
                        
                        shi_cp= 1;
                        shi++;
                    }
                }
            }
            else {
                if(R.osa) {
                    short b= R.samples->centmask[curmask];
                    xs= (float)x + R.samples->centLut[b & 15] + 0.5f;
                    ys= (float)y + R.samples->centLut[b>>4] + 0.5f;
                }
                else {
                    xs= (float)x + 0.5f;
                    ys= (float)y + 0.5f;
                }

                shi->mask= curmask;
                shi->samplenr= R.shadowsamplenr[shi->thread]++;
                shade_input_set_viewco(shi, x, y, xs, ys, (float)ps->z);
                shade_input_set_uv(shi);
                shade_input_set_normals(shi);
                shi++;
            }
            
            /* total sample amount, shi->sample is static set in initialize */
            if(shi!=ssamp->shi)
                ssamp->tot= (shi-1)->sample + 1;
        }
    }
}

/* shades samples, returns true if anything happened */
int shade_samples(ShadeSample *ssamp, PixStr *ps, int x, int y)
{
    shade_samples_fill_with_ps(ssamp, ps, x, y);
    
    if(ssamp->tot) {
        ShadeInput *shi= ssamp->shi;
        ShadeResult *shr= ssamp->shr;
        int samp;
        
        /* if shadow or AO? */
        shade_samples_do_AO(ssamp);
        
        /* if shade (all shadepinputs have same passflag) */
        if(ssamp->shi[0].passflag & ~(SCE_PASS_Z|SCE_PASS_INDEXOB|SCE_PASS_INDEXMA)) {

            for(samp=0; samp<ssamp->tot; samp++, shi++, shr++) {
                shade_input_set_shade_texco(shi);
                shade_input_do_shade(shi, shr);
            }
        }
        else if(shi->passflag & SCE_PASS_Z) {
            for(samp=0; samp<ssamp->tot; samp++, shi++, shr++)
                shr->z= -shi->co[2];
        }
        
        return 1;
    }
    return 0;
}