node_composite_tonemap.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.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Alfredo de Greef  (eeshlo)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "node_composite_util.h"

static bNodeSocketTemplate cmp_node_tonemap_in[]= {
    {   SOCK_RGBA, 1, "Image",          1.0f, 1.0f, 1.0f, 1.0f},
    {   -1, 0, ""   }
};
static bNodeSocketTemplate cmp_node_tonemap_out[]= {
    {   SOCK_RGBA, 0, "Image"},
    {   -1, 0, ""   }
};


static float avgLogLum(CompBuf *src, float* auto_key, float* Lav, float* Cav)
{
    float lsum = 0;
    int p = src->x*src->y;
    fRGB* bc = (fRGB*)src->rect;
    float avl, maxl = -1e10f, minl = 1e10f;
    const float sc = 1.f/(src->x*src->y);
    *Lav = 0.f;
    while (p--) {
        float L = 0.212671f*bc[0][0] + 0.71516f*bc[0][1] + 0.072169f*bc[0][2];
        *Lav += L;
        fRGB_add(Cav, bc[0]);
        lsum += (float)log((double)MAX2(L, 0.0) + 1e-5);
        maxl = (L > maxl) ? L : maxl;
        minl = (L < minl) ? L : minl;
        bc++;
    }
    *Lav *= sc;
    fRGB_mult(Cav, sc);
    maxl = log((double)maxl + 1e-5); minl = log((double)minl + 1e-5f); avl = lsum*sc;
    *auto_key = (maxl > minl) ? ((maxl - avl) / (maxl - minl)) : 1.f;
    return exp((double)avl);
}


static void tonemap(NodeTonemap* ntm, CompBuf* dst, CompBuf* src)
{
    int x, y;
    float dr, dg, db, al, igm = (ntm->gamma==0.f) ? 1 : (1.f / ntm->gamma);
    float auto_key, Lav, Cav[3] = {0, 0, 0};

    al = avgLogLum(src, &auto_key, &Lav, Cav);
    al = (al == 0.f) ? 0.f : (ntm->key / al);

    if (ntm->type == 1) {
        // Reinhard/Devlin photoreceptor
        const float f = exp((double)-ntm->f);
        const float m = (ntm->m > 0.f) ? ntm->m : (0.3f + 0.7f*pow((double)auto_key, 1.4));
        const float ic = 1.f - ntm->c, ia = 1.f - ntm->a;
        if (ntm->m == 0.f) printf("tonemap node, M: %g\n", m); 
        for (y=0; y<src->y; ++y) {
            fRGB* sp = (fRGB*)&src->rect[y*src->x*src->type];
            fRGB* dp = (fRGB*)&dst->rect[y*src->x*src->type];
            for (x=0; x<src->x; ++x) {
                const float L = 0.212671f*sp[x][0] + 0.71516f*sp[x][1] + 0.072169f*sp[x][2];
                float I_l = sp[x][0] + ic*(L - sp[x][0]);
                float I_g = Cav[0] + ic*(Lav - Cav[0]);
                float I_a = I_l + ia*(I_g - I_l);
                dp[x][0] /= (dp[x][0] + pow((double)f*I_a, (double)m));
                I_l = sp[x][1] + ic*(L - sp[x][1]);
                I_g = Cav[1] + ic*(Lav - Cav[1]);
                I_a = I_l + ia*(I_g - I_l);
                dp[x][1] /= (dp[x][1] + pow((double)f*I_a,(double)m));
                I_l = sp[x][2] + ic*(L - sp[x][2]);
                I_g = Cav[2] + ic*(Lav - Cav[2]);
                I_a = I_l + ia*(I_g - I_l);
                dp[x][2] /= (dp[x][2] + pow((double)f*I_a, (double)m));
            }
        }
        return;
    }

    // Reinhard simple photographic tm (simplest, not using whitepoint var)
    for (y=0; y<src->y; y++) {
        fRGB* sp = (fRGB*)&src->rect[y*src->x*src->type];
        fRGB* dp = (fRGB*)&dst->rect[y*src->x*src->type];
        for (x=0; x<src->x; x++) {
            fRGB_copy(dp[x], sp[x]);
            fRGB_mult(dp[x], al);
            dr = dp[x][0] + ntm->offset;
            dg = dp[x][1] + ntm->offset;
            db = dp[x][2] + ntm->offset;
            dp[x][0] /= ((dr == 0.f) ? 1.f : dr);
            dp[x][1] /= ((dg == 0.f) ? 1.f : dg);
            dp[x][2] /= ((db == 0.f) ? 1.f : db);
            if (igm != 0.f) {
                dp[x][0] = pow((double)MAX2(dp[x][0], 0.), igm);
                dp[x][1] = pow((double)MAX2(dp[x][1], 0.), igm);
                dp[x][2] = pow((double)MAX2(dp[x][2], 0.), igm);
            }
        }
    }
}


static void node_composit_exec_tonemap(void *UNUSED(data), bNode *node, bNodeStack **in, bNodeStack **out)
{
    CompBuf *new, *img = in[0]->data;

    if ((img==NULL) || (out[0]->hasoutput==0)) return;

    if (img->type != CB_RGBA)
        img = typecheck_compbuf(img, CB_RGBA);
    
    new = dupalloc_compbuf(img);

    tonemap(node->storage, new, img);

    out[0]->data = new;
    
    if(img!=in[0]->data)
        free_compbuf(img);
}

static void node_composit_init_tonemap(bNodeTree *UNUSED(ntree), bNode* node, bNodeTemplate *UNUSED(ntemp))
{
    NodeTonemap *ntm = MEM_callocN(sizeof(NodeTonemap), "node tonemap data");
    ntm->type = 1;
    ntm->key = 0.18;
    ntm->offset = 1;
    ntm->gamma = 1;
    ntm->f = 0;
    ntm->m = 0; // actual value is set according to input
    // default a of 1 works well with natural HDR images, but not always so for cgi.
    // Maybe should use 0 or at least lower initial value instead
    ntm->a = 1;
    ntm->c = 0;
    node->storage = ntm;
}

void register_node_type_cmp_tonemap(bNodeTreeType *ttype)
{
    static bNodeType ntype;

    node_type_base(ttype, &ntype, CMP_NODE_TONEMAP, "Tonemap", NODE_CLASS_OP_COLOR, NODE_OPTIONS);
    node_type_socket_templates(&ntype, cmp_node_tonemap_in, cmp_node_tonemap_out);
    node_type_size(&ntype, 150, 120, 200);
    node_type_init(&ntype, node_composit_init_tonemap);
    node_type_storage(&ntype, "NodeTonemap", node_free_standard_storage, node_copy_standard_storage);
    node_type_exec(&ntype, node_composit_exec_tonemap);

    nodeRegisterType(ttype, &ntype);
}