void TerrainFunction::AddFunction(TerrainPatch& patch) const {
// Read all frequently used data from pGrid.
const vec2& world_south_west(patch.GetSouthWest());
const vec2& world_north_east(patch.GetNorthEast());
const int vertex_count_x = patch.GetVertexRes();
const int vertex_count_y = patch.GetVertexRes();
const float grid_width = patch.GetPatchSize();
const float grid_height = patch.GetPatchSize();
float a;
// Calculate start X vertex index.
int vertex_minimum_x;
a = position_.x-outer_radius_;
if (a <= world_south_west.x) {
vertex_minimum_x = 0;
} else {
vertex_minimum_x = (int)::floor((a-world_south_west.x) * vertex_count_x / grid_width);
}
// Calculate end X vertex index.
int vertex_maximum_x;
a = position_.x+outer_radius_;
if (a >= world_north_east.x) {
vertex_maximum_x = vertex_count_x;
} else {
vertex_maximum_x = (int)::ceil((a-world_south_west.x) * vertex_count_x / grid_width);
}
// Calculate start Y vertex index.
int vertex_minimum_y;
a = position_.y-outer_radius_;
if (a <= world_south_west.y) {
vertex_minimum_y = 0;
} else {
vertex_minimum_y = (int)::floor((a-world_south_west.y) * vertex_count_y / grid_height);
}
// Calculate end Y vertex index.
int vertex_maximum_y;
a = position_.y+outer_radius_;
if (a >= world_north_east.y) {
vertex_maximum_y = vertex_count_y;
} else {
vertex_maximum_y = (int)::ceil((a-world_south_west.y) * vertex_count_y / grid_height);
}
patch.IterateOverPatch(*this, vertex_minimum_x, vertex_maximum_x, vertex_minimum_y, vertex_maximum_y);
}
void TerrainFunctionGroup::AddFunctions(TerrainPatch& patch) const {
// No optimizations like the ones in TerrainFunction are possible.
patch.IterateOverPatch(*this, 0, patch.GetVertexRes(), 0, patch.GetVertexRes());
}