From 6dcb9aea907314ace3b160940c9d7204ab02db2f Mon Sep 17 00:00:00 2001 From: Rudolf Polzer Date: Thu, 26 Aug 2010 06:05:04 +0200 Subject: [PATCH] make the algorithm a bit more customizable --- misc/tools/fft-normalmap-to-heightmap.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/misc/tools/fft-normalmap-to-heightmap.c b/misc/tools/fft-normalmap-to-heightmap.c index a31b022f..909f591f 100644 --- a/misc/tools/fft-normalmap-to-heightmap.c +++ b/misc/tools/fft-normalmap-to-heightmap.c @@ -38,6 +38,8 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, double scale, double offset) { int x, y; + int fx, fy; + int ffx, ffy; double nx, ny, nz; double v, vmin, vmax; #ifndef C99 @@ -86,23 +88,26 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, for(y = 0; y < h; ++y) for(x = 0; x < w; ++x) { - int fx = x; - int fy = y; + fx = x; + fy = y; if(fx > w/2) fx -= w; if(fy > h/2) fy -= h; + /* these must have the same sign as fx and fy (so ffx*fx + ffy*fy is nonzero), otherwise do not matter */ + ffx = fx; + ffy = fy; #ifdef C99 if(fx||fy) - freqspace1[(w*y+x)] = _Complex_I * (fx * freqspace1[(w*y+x)] + fy * freqspace2[(w*y+x)]) / (fx*fx + fy*fy) / TWO_PI; + freqspace1[(w*y+x)] = _Complex_I * (ffx * freqspace1[(w*y+x)] + ffy * freqspace2[(w*y+x)]) / (ffx*fx + ffy*fy) / TWO_PI; else freqspace1[(w*y+x)] = 0; #else if(fx||fy) { save = freqspace1[(w*y+x)][0]; - freqspace1[(w*y+x)][0] = -(fx * freqspace1[(w*y+x)][1] + fy * freqspace2[(w*y+x)][1]) / (fx*fx + fy*fy) / TWO_PI; - freqspace1[(w*y+x)][1] = (fx * save + fy * freqspace2[(w*y+x)][0]) / (fx*fx + fy*fy) / TWO_PI; + freqspace1[(w*y+x)][0] = -(ffx * freqspace1[(w*y+x)][1] + ffy * freqspace2[(w*y+x)][1]) / (ffx*fx + ffy*fy) / TWO_PI; + freqspace1[(w*y+x)][1] = (ffx * save + ffy * freqspace2[(w*y+x)][0]) / (ffx*fx + ffy*fy) / TWO_PI; } else { -- 2.30.2