node_composite_displace.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): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "node_composite_util.h"


/* **************** Displace  ******************** */

static bNodeSocketTemplate cmp_node_displace_in[]= {
    {   SOCK_RGBA, 1, "Image",          1.0f, 1.0f, 1.0f, 1.0f},
    {   SOCK_VECTOR, 1, "Vector",           1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, PROP_TRANSLATION},
    {   SOCK_FLOAT, 1, "X Scale",               0.0f, 0.0f, 0.0f, 0.0f, -1000.0f, 1000.0f, PROP_FACTOR},
    {   SOCK_FLOAT, 1, "Y Scale",               0.0f, 0.0f, 0.0f, 0.0f, -1000.0f, 1000.0f, PROP_FACTOR},
    {   -1, 0, ""   }
};
static bNodeSocketTemplate cmp_node_displace_out[]= {
    {   SOCK_RGBA, 0, "Image"},
    {   -1, 0, ""   }
};

/* minimum distance (in pixels) a pixel has to be displaced
 * in order to take effect */
#define DISPLACE_EPSILON    0.01f

static void do_displace(bNode *node, CompBuf *stackbuf, CompBuf *cbuf, CompBuf *vecbuf, float *UNUSED(veccol), CompBuf *xbuf,  CompBuf *ybuf, float *xscale, float *yscale)
{
    ImBuf *ibuf;
    int x, y;
    float p_dx, p_dy;   /* main displacement in pixel space */
    float d_dx, d_dy;
    float dxt, dyt;
    float u, v;
    float xs, ys;
    float vec[3], vecdx[3], vecdy[3];
    float col[3];
    
    ibuf= IMB_allocImBuf(cbuf->x, cbuf->y, 32, 0);
    ibuf->rect_float= cbuf->rect;
    
    for(y=0; y < stackbuf->y; y++) {
        for(x=0; x < stackbuf->x; x++) {
            /* calc pixel coordinates */
            qd_getPixel(vecbuf, x-vecbuf->xof, y-vecbuf->yof, vec);
            
            if (xbuf)
                qd_getPixel(xbuf, x-xbuf->xof, y-xbuf->yof, &xs);
            else
                xs = xscale[0];
            
            if (ybuf)
                qd_getPixel(ybuf, x-ybuf->xof, y-ybuf->yof, &ys);
            else
                ys = yscale[0];

            /* clamp x and y displacement to triple image resolution - 
             * to prevent hangs from huge values mistakenly plugged in eg. z buffers */
            CLAMP(xs, -stackbuf->x*4, stackbuf->x*4);
            CLAMP(ys, -stackbuf->y*4, stackbuf->y*4);
            
            p_dx = vec[0] * xs;
            p_dy = vec[1] * ys;
            
            /* if no displacement, then just copy this pixel */
            if (fabsf(p_dx) < DISPLACE_EPSILON && fabsf(p_dy) < DISPLACE_EPSILON) {
                qd_getPixel(cbuf, x-cbuf->xof, y-cbuf->yof, col);
                qd_setPixel(stackbuf, x, y, col);
                continue;
            }
            
            /* displaced pixel in uv coords, for image sampling */
            u = (x - cbuf->xof - p_dx + 0.5f) / (float)stackbuf->x;
            v = (y - cbuf->yof - p_dy + 0.5f) / (float)stackbuf->y;
            
            
            /* calc derivatives */
            qd_getPixel(vecbuf, x-vecbuf->xof+1, y-vecbuf->yof, vecdx);
            qd_getPixel(vecbuf, x-vecbuf->xof, y-vecbuf->yof+1, vecdy);
            d_dx = vecdx[0] * xs;
            d_dy = vecdy[0] * ys;

            /* clamp derivatives to minimum displacement distance in UV space */
            dxt = p_dx - d_dx;
            dyt = p_dy - d_dy;

            dxt = signf(dxt)*maxf(fabsf(dxt), DISPLACE_EPSILON)/(float)stackbuf->x;
            dyt = signf(dyt)*maxf(fabsf(dyt), DISPLACE_EPSILON)/(float)stackbuf->y;
            
            ibuf_sample(ibuf, u, v, dxt, dyt, col);
            qd_setPixel(stackbuf, x, y, col);
            
            if(node->exec & NODE_BREAK) break;
        }
        
        if(node->exec & NODE_BREAK) break;
    }
    IMB_freeImBuf(ibuf);
    
    
/* simple method for reference, linear interpolation */
/*  
    int x, y;
    float dx, dy;
    float u, v;
    float vec[3];
    float col[3];
    
    for(y=0; y < stackbuf->y; y++) {
        for(x=0; x < stackbuf->x; x++) {
            qd_getPixel(vecbuf, x, y, vec);
            
            dx = vec[0] * (xscale[0]);
            dy = vec[1] * (yscale[0]);
            
            u = (x - dx + 0.5f) / (float)stackbuf->x;
            v = (y - dy + 0.5f) / (float)stackbuf->y;
            
            qd_getPixelLerp(cbuf, u*cbuf->x - 0.5f, v*cbuf->y - 0.5f, col);
            qd_setPixel(stackbuf, x, y, col);
        }
    }
*/
}


static void node_composit_exec_displace(void *UNUSED(data), bNode *node, bNodeStack **in, bNodeStack **out)
{
    if(out[0]->hasoutput==0)
        return;
    
    if(in[0]->data && in[1]->data) {
        CompBuf *cbuf= in[0]->data;
        CompBuf *vecbuf= in[1]->data;
        CompBuf *xbuf= in[2]->data;
        CompBuf *ybuf= in[3]->data;
        CompBuf *stackbuf;
        
        cbuf= typecheck_compbuf(cbuf, CB_RGBA);
        vecbuf= typecheck_compbuf(vecbuf, CB_VEC3);
        xbuf= typecheck_compbuf(xbuf, CB_VAL);
        ybuf= typecheck_compbuf(ybuf, CB_VAL);
        
        stackbuf= alloc_compbuf(cbuf->x, cbuf->y, CB_RGBA, 1); /* allocs */

        do_displace(node, stackbuf, cbuf, vecbuf, in[1]->vec, xbuf, ybuf, in[2]->vec, in[3]->vec);
        
        out[0]->data= stackbuf;
        
        
        if(cbuf!=in[0]->data)
            free_compbuf(cbuf);
        if(vecbuf!=in[1]->data)
            free_compbuf(vecbuf);
    }
}

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

    node_type_base(ttype, &ntype, CMP_NODE_DISPLACE, "Displace", NODE_CLASS_DISTORT, NODE_OPTIONS);
    node_type_socket_templates(&ntype, cmp_node_displace_in, cmp_node_displace_out);
    node_type_size(&ntype, 140, 100, 320);
    node_type_exec(&ntype, node_composit_exec_displace);

    nodeRegisterType(ttype, &ntype);
}