/**
* @brief update then given LightShadow (create it if the given on is null)
* according to the given Light, ShadingBody and Edge
*/
static public LightShadow UpdateShadow(
LightShadow _toBeUpdate, Light _light,
ShadingBody _body, int _edgeIndex)
{
if (_edgeIndex > _body.GetVerticesNumber())
{
return(null);
}
Vector2 startPoint = _body.GetVertexInWorld(_edgeIndex);
Vector2 endPoint = _body.GetVertexInWorld((_edgeIndex + 1) % _body.GetVerticesNumber());
Vector2 startTill = startPoint +
_light.GetLightDirection(startPoint) * ShadowDistance;
Vector2 endTill = endPoint +
_light.GetLightDirection(endPoint) * ShadowDistance;
// update _toBeUpdate
LightShadow shadow = _toBeUpdate;
if (shadow == null)
{
shadow = new LightShadow();
}
shadow.m_vertexList[0] = startPoint;
shadow.m_vertexList[1] = startTill;
shadow.m_vertexList[2] = endTill;
shadow.m_vertexList[3] = endPoint;
// TODO: not here
shadow.UpdateDrawVertex();
return(shadow);
}
public void RemoveShadingBody(ShadingBody _shadingBody)
{
int shadingBoydID = _shadingBody.ID;
if (m_shadingBodyDict.ContainsKey(shadingBoydID))
{
m_shadingBodyDict.Remove(shadingBoydID);
}
if (m_shadingBody2LightDict.ContainsKey(shadingBoydID))
{
HashSet <int> lights = m_shadingBody2LightDict[shadingBoydID];
foreach (int lightID in lights)
{
// remove from light2ShadingBody
// TODO: compromise
if (m_light2ShadingBodyDict.ContainsKey(lightID))
{
m_light2ShadingBodyDict[lightID].Remove(shadingBoydID);
}
// remove lightShadow
int lightShadingBodyEdgeID = GetLightShadowBodyEdgeID(lightID, shadingBoydID, _shadingBody.GetVerticesNumber());
if (m_lightShadowEdgeDict.ContainsKey(lightShadingBodyEdgeID))
{
m_lightShadowEdgeDict.Remove(lightShadingBodyEdgeID);
}
}
m_shadingBody2LightDict.Remove(shadingBoydID);
}
ReturnID(shadingBoydID, m_freeShadowBodyIDList);
return;
}
public void AddShadowBody(ShadingBody _shadowBody)
{
// assign an id
_shadowBody.ID = FetchNewID(m_freeShadowBodyIDList);
m_shadingBodyDict.Add(_shadowBody.ID, _shadowBody);
// TODO: considering
}
public void RemoveLight(Light _light)
{
int lightID = _light.ID;
if (m_lightDict.ContainsKey(lightID))
{
m_lightDict.Remove(lightID);
}
if (m_light2ShadingBodyDict.ContainsKey(lightID))
{
HashSet <int> shadingBodies = m_light2ShadingBodyDict[lightID];
foreach (int shadingBodyID in shadingBodies)
{
// remove from shadingBody2Light
m_shadingBody2LightDict[shadingBodyID].Remove(lightID);
// remove lightShadow
ShadingBody shadingBody = m_shadingBodyDict[shadingBodyID];
int lightShadingBodyEdgeID = GetLightShadowBodyEdgeID(lightID, shadingBodyID, shadingBody.GetVerticesNumber());
if (m_lightShadowEdgeDict.ContainsKey(lightShadingBodyEdgeID))
{
m_lightShadowEdgeDict.Remove(lightShadingBodyEdgeID);
}
}
m_light2ShadingBodyDict.Remove(lightID);
}
ReturnID(lightID, m_freeLightIDList);
return;
}
/**
* @brief if the edge should cast shadow
*/
virtual public bool ShouldEdgeHasShadow(ShadingBody _shadingBody, int _edge)
{
Vector2 startPoint = _shadingBody.GetVertexInWorld(_edge);
Vector2 edgeVector2 = _shadingBody.GetVertexInWorld((_edge + 1) % _shadingBody.GetVerticesNumber())
- startPoint;
Vector3 edgeVector3 = new Vector3(edgeVector2.X, edgeVector2.Y, 0.0f);
Vector3 normal = Vector3.Cross(edgeVector3, -Vector3.UnitZ);
Vector2 lightDirection = GetLightDirection(startPoint);
Vector2 normal2D = new Vector2(normal.X, normal.Y);
return(Vector2.Dot(normal2D, lightDirection) < 0.0f);
}
/**
* @brief render lightmap into m_accumulateLight
*/
public override void DoRender(int _timeLastFrame)
{
// Prepare accumulate
GraphicsDevice graphicsDevice = Mgr <GraphicsDevice> .Singleton;
Renderer.SetColorTarget(m_accumulateLight);
RenderAmbientColor(graphicsDevice);
Renderer.CancelColorTarget();
// for each light
foreach (KeyValuePair <int, Light> keyValue in m_lightDict)
{
// TODO: test if the light affects current scene
// init light map
Renderer.SetColorTarget(m_lightMap);
graphicsDevice.Clear(Color.Black);
// draw light
// TODO: draw light
keyValue.Value.Draw(_timeLastFrame);
// substract shadow
if (m_light2ShadingBodyDict.ContainsKey(keyValue.Key))
{
foreach (int shadingBodyID in m_light2ShadingBodyDict[keyValue.Key])
{
ShadingBody shadingBody = m_shadingBodyDict[shadingBodyID];
for (int i = 0; i < shadingBody.GetVerticesNumber(); ++i)
{
int lightShadingBodyEdgeID = GetLightShadowBodyEdgeID(keyValue.Key, shadingBodyID, i);
if (m_lightShadowEdgeDict.ContainsKey(lightShadingBodyEdgeID))
{
m_lightShadowEdgeDict[lightShadingBodyEdgeID].Draw(_timeLastFrame);
}
}
}
}
Renderer.CancelColorTarget();
// add to accumulate
Renderer.SetColorTarget(m_preAccumulateLight);
m_accumulateEffect.CurrentTechnique = m_accumulateEffect.Techniques["Main"];
m_accumulateEffect.Parameters["PreColor"].SetValue((Texture2D)m_accumulateLight);
m_accumulateEffect.Parameters["LightMap"].SetValue((Texture2D)m_lightMap);
m_accumulateEffect.CurrentTechnique.Passes["P0"].Apply();
RenderQuad();
Renderer.CancelColorTarget();
RenderTarget2D temp = m_preAccumulateLight;
m_preAccumulateLight = m_accumulateLight;
m_accumulateLight = temp;
}
}
/**
* @brief update lightShadow because the given shadingbody has moved
* the algorithm check all the lights then update:
* 1. m_shadingBody2LightDict
* 2. m_light2ShadingBodyDict
* 3. m_lightShadwEdgeDict
* and it also create and remove LightShadow
*/
public void UpdateShadowBody(ShadingBody _shadowBody)
{
HashSet <int> oldLight;
if (m_shadingBody2LightDict.ContainsKey(_shadowBody.ID))
{
oldLight = m_shadingBody2LightDict[_shadowBody.ID];
}
else
{
oldLight = new HashSet <int>();
}
foreach (KeyValuePair <int, Light> keyValue in m_lightDict)
{
// if body in light
if (keyValue.Value.IsBodyInLightRange(_shadowBody.GetVertices(), _shadowBody.GetTransform2World()))
{
// update shadow
int edgeNumber = _shadowBody.GetVerticesNumber();
for (int e = 0; e < edgeNumber; ++e)
{
int lightShadowBodyEdgeID = GetLightShadowBodyEdgeID(keyValue.Key, _shadowBody.ID, e);
// if edge under light
if (keyValue.Value.ShouldEdgeHasShadow(_shadowBody, e))
{
m_lightShadowEdgeDict[lightShadowBodyEdgeID] =
LightShadow.UpdateShadow(m_lightShadowEdgeDict[lightShadowBodyEdgeID],
keyValue.Value, _shadowBody, e);
m_lightShadowEdgeDict[lightShadowBodyEdgeID].Enable = true;
}
// else
else
{
// TODO: not only disable, but also remove it
m_lightShadowEdgeDict[lightShadowBodyEdgeID].Enable = false;
}
}
// update light 2 shadow and shadow 2 light
if (!m_light2ShadingBodyDict.ContainsKey(keyValue.Key))
{
m_light2ShadingBodyDict[keyValue.Key] = new HashSet <int>();
}
m_light2ShadingBodyDict[keyValue.Key].Add(_shadowBody.ID);
if (!m_shadingBody2LightDict.ContainsKey(_shadowBody.ID))
{
m_shadingBody2LightDict[_shadowBody.ID] = new HashSet <int>();
}
m_shadingBody2LightDict[_shadowBody.ID].Add(keyValue.Key);
}
// else
else
{
// if light in old-light
if (oldLight.Contains(keyValue.Key))
{
// remove shadow
int edgeNumber = _shadowBody.GetVerticesNumber();
for (int e = 0; e < edgeNumber; ++e)
{
int lightShadowBodyEdgeID = GetLightShadowBodyEdgeID(keyValue.Key, _shadowBody.ID, e);
if (m_lightShadowEdgeDict.ContainsKey(lightShadowBodyEdgeID))
{
// TODO: not only disable
m_lightShadowEdgeDict[lightShadowBodyEdgeID].Enable = false;
}
}
// update light2 2 shadow and shadow 2 light
oldLight.Remove(keyValue.Key);
if (m_light2ShadingBodyDict.ContainsKey(keyValue.Key))
{
m_light2ShadingBodyDict[keyValue.Key].Remove(_shadowBody.ID);
}
}
}
}
}