/**
* Convert given data into normal map
* To get height of current pixel the grey scale value will be computed
**/
shared_array<byte> nrCTextureLoader::heightmap_to_normalmap (shared_array<byte>& data, int width, int height){
// define putput
shared_array<byte> dst (new byte[width*height*4]);
shared_array<byte> src = rgba2luminance(data,width,height);
// go through all pixels
for (int x=1; x < width-1; x++){
for (int y=1; y < height-1; y++){
// wir lesen zunaechst uns interessierte werte aus
byte g1 = src[y*width + x+1];
byte g2 = src[y*width + x-1];
vec3 dfdx(2.0f, 0.0f, 4.0*float(g1-g2)/255.0f);
// und jetzt das andere
g1 = src[(y+1)*width + x];
g2 = src[(y-1)*width + x];
vec3 dfdy(0.f, 2.0f, 4.0*float(g1 - g2)/255.0f);
// verrechnen und speichern
vec3 n = cross(dfdx, dfdy);
n.normalize();
// Ergebnis speichern
dst[y*4*width + x*4 + 0] = range_compress(n[0]);
dst[y*4*width + x*4 + 1] = range_compress(n[1]);
dst[y*4*width + x*4 + 2] = range_compress(n[2]);
dst[y*4*width + x*4 + 3] = 255;
}
}
// kopiere den Inhalt von den Rändern zu den letzten Pixeln
for(int i = 0; i < width; i++)
{
dst[0*4*width + i*4 + 0] = dst[1*4*width + i*4 + 0];
dst[0*4*width + i*4 + 1] = dst[1*4*width + i*4 + 1];
dst[0*4*width + i*4 + 2] = dst[1*4*width + i*4 + 2];
dst[0*4*width + i*4 + 3] = dst[1*4*width + i*4 + 3];
dst[(height-1)*4*width + i*4 + 0] = dst[(height-2)*4*width + i*4 + 0];
dst[(height-1)*4*width + i*4 + 1] = dst[(height-2)*4*width + i*4 + 1];
dst[(height-1)*4*width + i*4 + 2] = dst[(height-2)*4*width + i*4 + 2];
dst[(height-1)*4*width + i*4 + 3] = dst[(height-2)*4*width + i*4 + 3];
}
for(int j = 0; j < height; j++)
{
dst[j*4*width + 0*4 + 0] = dst[j*4*width + 1*4 + 0];
dst[j*4*width + 0*4 + 1] = dst[j*4*width + 1*4 + 1];
dst[j*4*width + 0*4 + 2] = dst[j*4*width + 1*4 + 2];
dst[j*4*width + 0*4 + 3] = dst[j*4*width + 1*4 + 3];
dst[j*4*width + (width-1)*4 + 0] = dst[j*4*width + (width-2)*4 + 0];
dst[j*4*width + (width-1)*4 + 1] = dst[j*4*width + (width-2)*4 + 1];
dst[j*4*width + (width-1)*4 + 2] = dst[j*4*width + (width-2)*4 + 2];
dst[j*4*width + (width-1)*4 + 3] = dst[j*4*width + (width-2)*4 + 3];
}
return dst;
}
char * range_easy_compress(easy_lr* elr, const char ** c_nodes) {
apr_pool_clear(elr->querypool);
char * retval;
// FIXME copy/reference bits from real lr into easy_lr to expose warnings/errors
retval = strdup(range_compress(elr->lr, elr->querypool, c_nodes));
apr_pool_clear(elr->querypool);
return retval;
}
