CMP_displace.c

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/*
 * $Id: CMP_displace.c 36202 2011-04-17 22:47:23Z broken $
 *
 * ***** 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 "../CMP_util.h"


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

static bNodeSocketType cmp_node_displace_in[]= {
        {       SOCK_RGBA, 1, "Image",                  0.8f, 0.8f, 0.8f, 1.0f, 0.0f, 1.0f},
        {       SOCK_VECTOR, 1, "Vector",                       1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f},
        {       SOCK_VALUE, 1, "X Scale",                               0.0f, 0.0f, 0.0f, 0.0f, -1000.0f, 1000.0f},
        {       SOCK_VALUE, 1, "Y Scale",                               0.0f, 0.0f, 0.0f, 0.0f, -1000.0f, 1000.0f},
        {       -1, 0, ""       }
};
static bNodeSocketType cmp_node_displace_out[]= {
        {       SOCK_RGBA, 0, "Image",                  0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f},
        {       -1, 0, ""       }
};

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

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(ListBase *lb)
{
        static bNodeType ntype;

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

        nodeRegisterType(lb, &ntype);
}