void clearLightAndCollectSources(VoxelManipulator &v, VoxelArea a,
enum LightBank bank, INodeDefManager *ndef,
std::set<v3s16> & light_sources,
std::map<v3s16, u8> & unlight_from)
{
// The full area we shall touch
VoxelArea required_a = a;
required_a.pad(v3s16(0,0,0));
// Make sure we have access to it
v.emerge(a);
for(s32 x=a.MinEdge.X; x<=a.MaxEdge.X; x++)
for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
{
v3s16 p(x,y,z);
MapNode &n = v.getNodeRefUnsafe(p);
u8 oldlight = n.getLight(bank, ndef);
n.setLight(bank, 0, ndef);
// If node sources light, add to list
u8 source = ndef->get(n).light_source;
if(source != 0)
light_sources.insert(p);
// Collect borders for unlighting
if((x==a.MinEdge.X || x == a.MaxEdge.X
|| y==a.MinEdge.Y || y == a.MaxEdge.Y
|| z==a.MinEdge.Z || z == a.MaxEdge.Z)
&& oldlight != 0)
{
unlight_from[p] = oldlight;
}
}
}
SunlightPropagateResult propagateSunlight(VoxelManipulator &v, VoxelArea a,
bool inexistent_top_provides_sunlight,
std::set<v3s16> & light_sources,
INodeDefManager *ndef)
{
// Return values
bool bottom_sunlight_valid = true;
// The full area we shall touch extends one extra at top and bottom
VoxelArea required_a = a;
required_a.pad(v3s16(0,1,0));
// Make sure we have access to it
v.emerge(a);
s16 max_y = a.MaxEdge.Y;
s16 min_y = a.MinEdge.Y;
for(s32 x=a.MinEdge.X; x<=a.MaxEdge.X; x++)
for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
{
v3s16 p_overtop(x, max_y+1, z);
bool overtop_has_sunlight = false;
// If overtop node does not exist, trust heuristics
if(!v.exists(p_overtop))
overtop_has_sunlight = inexistent_top_provides_sunlight;
else if(v.getNodeRefUnsafe(p_overtop).getContent() == CONTENT_IGNORE)
overtop_has_sunlight = inexistent_top_provides_sunlight;
// Otherwise refer to it's light value
else
overtop_has_sunlight = (v.getNodeRefUnsafe(p_overtop).getLight(
LIGHTBANK_DAY, ndef) == LIGHT_SUN);
// Copy overtop's sunlight all over the place
u8 incoming_light = overtop_has_sunlight ? LIGHT_SUN : 0;
for(s32 y=max_y; y>=min_y; y--)
{
v3s16 p(x,y,z);
MapNode &n = v.getNodeRefUnsafe(p);
if(incoming_light == 0) {
// Do nothing
} else if(incoming_light == LIGHT_SUN &&
ndef->get(n).sunlight_propagates) {
// Do nothing
} else if(ndef->get(n).sunlight_propagates == false) {
incoming_light = 0;
} else {
incoming_light = diminish_light(incoming_light);
}
u8 old_light = n.getLight(LIGHTBANK_DAY, ndef);
if(incoming_light > old_light)
n.setLight(LIGHTBANK_DAY, incoming_light, ndef);
if(diminish_light(incoming_light) != 0)
light_sources.insert(p);
}
// Check validity of sunlight at top of block below if it
// hasn't already been proven invalid
if(bottom_sunlight_valid)
{
bool sunlight_should_continue_down = (incoming_light == LIGHT_SUN);
v3s16 p_overbottom(x, min_y-1, z);
if(!v.exists(p_overbottom) ||
v.getNodeRefUnsafe(p_overbottom
).getContent() == CONTENT_IGNORE) {
// Is not known, cannot compare
} else {
bool overbottom_has_sunlight = (v.getNodeRefUnsafe(p_overbottom
).getLight(LIGHTBANK_DAY, ndef) == LIGHT_SUN);
if(sunlight_should_continue_down != overbottom_has_sunlight) {
bottom_sunlight_valid = false;
}
}
}
}
return SunlightPropagateResult(bottom_sunlight_valid);
}
