/// <summary>
/// The fastest form of visibility updates -- radius-based, no line of sights checks.
/// 最快的可见性更新形-基于半径，不进行视线检查。
/// 向buffer1的r填充可见性
/// </summary>
void RevealUsingRadius(IFOWRevealer r, float worldToTex)
{
// Position relative to the fog of war
//相对于战争迷雾的位置
Vector3 pos = (r.GetPosition() - mOrigin) * worldToTex; //纹理上的坐标
float radius = r.GetRadius() * worldToTex - radiusOffset; //纹理上的半径
// Coordinates we'll be dealing with
//我们将要处理的坐标
//RoundToInt返回四舍五入到最接近的整数的f
int xmin = Mathf.RoundToInt(pos.x - radius);
int ymin = Mathf.RoundToInt(pos.z - radius);
int xmax = Mathf.RoundToInt(pos.x + radius);
int ymax = Mathf.RoundToInt(pos.z + radius);
int cx = Mathf.RoundToInt(pos.x);
int cy = Mathf.RoundToInt(pos.z);
cx = Mathf.Clamp(cx, 0, textureSize - 1);
cy = Mathf.Clamp(cy, 0, textureSize - 1);
int radiusSqr = Mathf.RoundToInt(radius * radius);
for (int y = ymin; y < ymax; ++y)
{
if (y > -1 && y < textureSize)
{
int yw = y * textureSize;
for (int x = xmin; x < xmax; ++x)
{
if (x > -1 && x < textureSize)
{
int xd = x - cx;
int yd = y - cy;
int dist = xd * xd + yd * yd;
// Reveal this pixel
if (dist < radiusSqr)
{
mBuffer1[x + yw].r = 255;
}
}
}
}
}
}
