void ComputeAndMergeStartLine(Octant octant, ShadowLine shadowLine)
{
int mainStep = 0;
Vector2 currentPosition;
for (int sideStep = 1; sideStep <= LINE_PATCH && _visibleMap.Contains(currentPosition = octant.GetPosition(mainStep, sideStep)); sideStep++) // 边缘方向从1开始，跳过观察者所在的位置
{
Shadow projection = ShadowLine.GetQuadProjection(mainStep, sideStep);
DrawShadow(shadowLine, currentPosition, projection);
UpdateShadowLine(currentPosition, shadowLine, projection);
}
}
bool ComputeAndMergeALineAndGetIsFullShadow(Octant octant, int mainStep, ShadowLine shadowLine)
{
/*
* 循环到一行结束或地图边界
* {
* 获取投影
* 通过投影判断可见度并存入视野
* 通过投影判断是否遮挡视线并存入阴影线
* }
* 返回阴影是否覆盖了整个八分角
*/
Vector2 currentPosition;
for (int sideStep = 0; sideStep <= mainStep + LINE_PATCH && _visibleMap.Contains(currentPosition = octant.GetPosition(mainStep, sideStep)); sideStep++)
{
Shadow projection = ShadowLine.GetQuadProjection(mainStep, sideStep);
DrawShadow(shadowLine, currentPosition, projection);
UpdateShadowLine(currentPosition, shadowLine, projection);
}
return(shadowLine.IsFullShadow());
}