normals.cpp

void FWstorage::mesh::calcNormals()
{
    if (normList.size == 0 && normList.data == NULL){
        if ((vertList.size == 0) || (meshList.size == 0)) { throw(FW_ERROR_UNKNOWN); return; }

        // 1.
        array_t<vec3float> perMeshNormals;
        array_t<vec3float> normVectors;

        _MEMORY_SET_ROW_ perMeshNormals.insert(meshList.size);
        _MEMORY_SET_ROW_ normVectors.insert(meshList.size);

        _MEMORY_SET_ROW_ normList.insert(vertList.size);
        vec3float a, b, c, v1, v2, tmpv;
        for (unsigned int i=0; i<meshList.size; i++){
            a = vertList[meshList[i].x];
            b = vertList[meshList[i].y];
            c = vertList[meshList[i].z];

            v1 = a-b;  //AB
            v2 = a-c;  //AC

            tmpv = v1.crossProduct(v2);

            perMeshNormals[i] = tmpv;
        }

        // 2.
        int norm_index = 0;
        for(register unsigned int i=0; i<vertList.size; i++) {  // and again ...
            for (register unsigned int l=0; l<meshList.size; l++){
                if  ((meshList[l].x == i) || (meshList[l].y == i) || (meshList[l].z == i)){
                    normVectors[norm_index] = perMeshNormals[l];
                    norm_index++;
                }
            }

            while (norm_index > 1){
                norm_index = ceil((float)norm_index/2.0);
                for (register int j=0, k=0 ; k<norm_index; (j+=2, k++)){    // i>>j !{
                    if (j+1 > norm_index){
                        normVectors[k] = normVectors[j];    // leave as it was before
                    } else {
                        v1 = normVectors[j];
                        v2 = normVectors[j+1];
                        tmpv = v1+v2;           // sum only only, normalization later.
                        normVectors[k] = tmpv;
                    }
                }
            }
            normVectors[0] /= normVectors[0].vlen();
            normList[i] = normVectors[0];
            norm_index = 0;
        }
        _MEMORY_SET_ROW_ perMeshNormals.clear();
        _MEMORY_SET_ROW_ normVectors.clear();
    }
}