public static void ComputeRecursiveShadowcasting(VisionMap vision, AbstractLevel level, int playerX, int playerY, int maxRadius, bool lightWalls)
{
Contract.Requires <ArgumentNullException>(level != null, "level");
Contract.Requires <ArgumentNullException>(vision != null, "vision");
// map.ClearVisibility();
vision.ClearVisibility();
if (maxRadius == 0)
{
int max_radius_x = level.Width - playerX;
int max_radius_y = level.Height - playerY;
max_radius_x = Math.Max(max_radius_x, playerX);
max_radius_y = Math.Max(max_radius_y, playerY);
maxRadius = (int)(Math.Sqrt(max_radius_x * max_radius_x + max_radius_y * max_radius_y)) + 1;
}
int r2 = maxRadius * maxRadius;
/* recursive shadow casting */
for (int oct = 0; oct < 8; oct++)
{
CastLight(vision, level, playerX, playerY, 1, 1.0f, 0.0f, maxRadius, r2, mult[0, oct], mult[1, oct], mult[2, oct], mult[3, oct], 0, lightWalls);
}
// map.Cells[playerX, playerY].Visible = true;
vision.SetVisibility(playerX, playerY, true);
}
private static void CastLight(VisionMap vision, AbstractLevel level, int cx, int cy, int row, float start, float end, int radius, int r2, int xx, int xy, int yx, int yy, int id, bool light_walls)
{
Contract.Requires <ArgumentNullException>(vision != null, "vision");
Contract.Requires <ArgumentNullException>(level != null, "level");
float new_start = 0.0f;
if (start < end)
{
return;
}
for (int j = row; j < radius + 1; j++)
{
int dx = -j - 1;
int dy = -j;
bool blocked = false;
while (dx <= 0)
{
dx++;
int X = cx + dx * xx + dy * xy;
int Y = cy + dx * yx + dy * yy;
if ((uint)X < (uint)level.Width && (uint)Y < (uint)level.Height)
{
// int offset = X + Y * level.Width;
float l_slope = (dx - 0.5f) / (dy + 0.5f);
float r_slope = (dx + 0.5f) / (dy - 0.5f);
if (start < r_slope)
{
continue;
}
else if (end > l_slope)
{
break;
}
// if (dx * dx + dy * dy <= r2 && (light_walls || level.Cells[X, Y].Transparent))
if (dx * dx + dy * dy <= r2 && (light_walls || level.IsTransparent(X, Y)))
{
// map.Cells[X, Y].Visible = true;
vision.SetVisibility(X, Y, true);
}
if (blocked)
{
// if (!level.Cells[X, Y].Transparent)
if (!level.IsTransparent(X, Y))
{
new_start = r_slope;
continue;
}
else
{
blocked = false;
start = new_start;
}
}
else
{
// if (!level.Cells[X, Y].Transparent && j < radius)
if (!level.IsTransparent(X, Y) && j < radius)
{
blocked = true;
CastLight(vision, level, cx, cy, j + 1, start, l_slope, radius, r2, xx, xy, yx, yy, id + 1, light_walls);
new_start = r_slope;
}
}
}
}
if (blocked)
{
break;
}
}
}
