do not write zero alpha values

[xonotic/xonotic.git] / misc / tools / fft-normalmap-to-heightmap.c

diff --git a/misc/tools/fft-normalmap-to-heightmap.c b/misc/tools/fft-normalmap-to-heightmap.c
index 1db9eba757026ab5a113ea28e6079f1f253a06b2..8d95d5c6f5f4325d13e8746c0a1cadc61c3318d0 100644 (file)
--- 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;
+       double ffx, ffy;
        double nx, ny, nz;
        double v, vmin, vmax;
 #ifndef C99
@@ -48,9 +50,9 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h,
        fftw_complex *imgspace2 = fftw_malloc(w*h * sizeof(fftw_complex));
        fftw_complex *freqspace1 = fftw_malloc(w*h * sizeof(fftw_complex));
        fftw_complex *freqspace2 = fftw_malloc(w*h * sizeof(fftw_complex));
-       fftw_plan i12f1 = fftw_plan_dft_2d(w, h, imgspace1, freqspace1, FFTW_FORWARD, FFTW_ESTIMATE);
-       fftw_plan i22f2 = fftw_plan_dft_2d(w, h, imgspace2, freqspace2, FFTW_FORWARD, FFTW_ESTIMATE);
-       fftw_plan f12i1 = fftw_plan_dft_2d(w, h, freqspace1, imgspace1, FFTW_BACKWARD, FFTW_ESTIMATE);
+       fftw_plan i12f1 = fftw_plan_dft_2d(h, w, imgspace1, freqspace1, FFTW_FORWARD, FFTW_ESTIMATE);
+       fftw_plan i22f2 = fftw_plan_dft_2d(h, w, imgspace2, freqspace2, FFTW_FORWARD, FFTW_ESTIMATE);
+       fftw_plan f12i1 = fftw_plan_dft_2d(h, w, freqspace1, imgspace1, FFTW_BACKWARD, FFTW_ESTIMATE);
 
        for(y = 0; y < h; ++y)
        for(x = 0; x < w; ++x)
@@ -86,23 +88,27 @@ 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 */
+               /* it basically decides how artifacts are distributed */
+               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
                {
@@ -235,9 +241,9 @@ void hmap_to_nmap(unsigned char *map, int w, int h, int src_chan, double scale)
        fftw_complex *imgspace2 = fftw_malloc(w*h * sizeof(fftw_complex));
        fftw_complex *freqspace1 = fftw_malloc(w*h * sizeof(fftw_complex));
        fftw_complex *freqspace2 = fftw_malloc(w*h * sizeof(fftw_complex));
-       fftw_plan i12f1 = fftw_plan_dft_2d(w, h, imgspace1, freqspace1, FFTW_FORWARD, FFTW_ESTIMATE);
-       fftw_plan f12i1 = fftw_plan_dft_2d(w, h, freqspace1, imgspace1, FFTW_BACKWARD, FFTW_ESTIMATE);
-       fftw_plan f22i2 = fftw_plan_dft_2d(w, h, freqspace2, imgspace2, FFTW_BACKWARD, FFTW_ESTIMATE);
+       fftw_plan i12f1 = fftw_plan_dft_2d(h, w, imgspace1, freqspace1, FFTW_FORWARD, FFTW_ESTIMATE);
+       fftw_plan f12i1 = fftw_plan_dft_2d(h, w, freqspace1, imgspace1, FFTW_BACKWARD, FFTW_ESTIMATE);
+       fftw_plan f22i2 = fftw_plan_dft_2d(h, w, freqspace2, imgspace2, FFTW_BACKWARD, FFTW_ESTIMATE);
 
        for(y = 0; y < h; ++y)
        for(x = 0; x < w; ++x)
@@ -264,6 +270,8 @@ void hmap_to_nmap(unsigned char *map, int w, int h, int src_chan, double scale)
                imgspace1[(w*y+x)][0] = (v - 128.0) / 127.0;
                imgspace1[(w*y+x)][1] = 0;
 #endif
+               if(v < 1)
+                       v = 1; /* do not write alpha zero */
                map[(w*y+x)*4+3] = floor(v + 0.5);
        }
 
@@ -348,11 +356,11 @@ void hmap_to_nmap_local(unsigned char *map, int w, int h, int src_chan, double s
        int i, j;
        double *img_reduced = malloc(w*h * sizeof(double));
        static const double filter[3][3] = { /* filter to derive one component */
-               { -1, 0, 1 },
-               { -2, 0, 2 },
-               { -1, 0, 1 }
+               {  -3, 0,  3 },
+               { -10, 0, 10 },
+               {  -3, 0,  3 }
        };
-       static const double filter_mult = 0.125;
+       static const double filter_mult = 0.03125;
 
        for(y = 0; y < h; ++y)
        for(x = 0; x < w; ++x)
@@ -374,6 +382,8 @@ void hmap_to_nmap_local(unsigned char *map, int w, int h, int src_chan, double s
                                break;
                }
                img_reduced[(w*y+x)] = (v - 128.0) / 127.0;
+               if(v < 1)
+                       v = 1; /* do not write alpha zero */
                map[(w*y+x)*4+3] = floor(v + 0.5);
        }