static bool AIHasClearLine(
Vec2i from, Vec2i to, IsBlockedFunc isBlockedFunc)
{
// Find all tiles that overlap with the line (from, to)
// Uses Bresenham that crosses interiors of tiles
HasClearLineData data;
data.IsBlocked = isBlockedFunc;
data.data = &gMap;
return HasClearLineXiaolinWu(from, to, &data);
}
void SoundPlayAtPlusDistance(
SoundDevice *device, Mix_Chunk *data,
const Vec2i pos, const int plusDistance)
{
int distance, bearing;
Vec2i closestLeftEar, closestRightEar;
Vec2i origin;
// Find closest set of ears to the sound
if (CHEBYSHEV_DISTANCE(
pos.x, pos.y, device->earLeft1.x, device->earLeft1.y) <
CHEBYSHEV_DISTANCE(
pos.x, pos.y, device->earLeft2.x, device->earLeft2.y))
{
closestLeftEar = device->earLeft1;
}
else
{
closestLeftEar = device->earLeft2;
}
if (CHEBYSHEV_DISTANCE(
pos.x, pos.y, device->earRight1.x, device->earRight1.y) <
CHEBYSHEV_DISTANCE(
pos.x, pos.y, device->earRight2.x, device->earRight2.y))
{
closestRightEar = device->earRight1;
}
else
{
closestRightEar = device->earRight2;
}
origin = CalcClosestPointOnLineSegmentToPoint(
closestLeftEar, closestRightEar, pos);
CalcChebyshevDistanceAndBearing(origin, pos, &distance, &bearing);
HasClearLineData lineData;
lineData.IsBlocked = IsPosNoSee;
lineData.data = &gMap;
bool isMuffled = false;
if (!HasClearLineXiaolinWu(pos, origin, &lineData))
{
isMuffled = true;
}
SoundPlayAtPosition(
&gSoundDevice, data, distance + plusDistance, bearing, isMuffled);
}
// Perform LOS by casting rays from the centre to the edges, terminating
// whenever an obstruction or out-of-range is reached.
void DrawBufferLOS(DrawBuffer *buffer, Vec2i center)
{
int sightRange = gConfig.Game.SightRange; // Note: can be zero
LOSData data;
data.b = buffer;
data.center.x = center.x / TILE_WIDTH - buffer->xStart;
data.center.y = center.y / TILE_HEIGHT - buffer->yStart;
data.sightRange2 = sightRange * sightRange;
// First mark center tile and all adjacent tiles as visible
// +-+-+-+
// |V|V|V|
// +-+-+-+
// |V|C|V|
// +-+-+-+
// |V|V|V| (C=center, V=visible)
// +-+-+-+
Vec2i end;
for (end.x = data.center.x - 1; end.x < data.center.x + 2; end.x++)
{
for (end.y = data.center.y - 1; end.y < data.center.y + 2; end.y++)
{
Tile *tile = GetTile(buffer, end);
if (tile)
{
tile->flags |= MAPTILE_IS_VISIBLE;
}
}
}
// Work out the perimeter of the LOS casts
Vec2i origin = Vec2iZero();
if (sightRange > 0)
{
// Limit the perimeter to the sight range
origin.x = MAX(origin.x, data.center.x - sightRange);
origin.y = MAX(origin.y, data.center.y - sightRange);
}
Vec2i perimSize = Vec2iScale(Vec2iMinus(data.center, origin), 2);
// Start from the top-left cell, and proceed clockwise around
end = origin;
HasClearLineData lineData;
lineData.IsBlocked = IsNextTileBlockedAndSetVisibility;
lineData.data = &data;
// Top edge
for (; end.x < origin.x + perimSize.x; end.x++)
{
HasClearLineXiaolinWu(data.center, end, &lineData);
}
// right edge
for (; end.y < origin.y + perimSize.y; end.y++)
{
HasClearLineXiaolinWu(data.center, end, &lineData);
}
// bottom edge
for (; end.x > origin.x; end.x--)
{
HasClearLineXiaolinWu(data.center, end, &lineData);
}
// left edge
for (; end.y > origin.y; end.y--)
{
HasClearLineXiaolinWu(data.center, end, &lineData);
}
// Second pass: make any non-visible obstructions that are adjacent to
// visible non-obstructions visible too
// This is to ensure runs of walls stay visible
for (end.y = origin.y; end.y < origin.y + perimSize.y; end.y++)
{
for (end.x = origin.x; end.x < origin.x + perimSize.x; end.x++)
{
Tile *tile = GetTile(buffer, end);
if (!tile || !(tile->flags & MAPTILE_NO_SEE))
{
continue;
}
// Check sight range
if (data.sightRange2 > 0 &&
DistanceSquared(data.center, end) >= data.sightRange2)
{
continue;
}
SetObstructionVisible(buffer, end, tile);
}
}
}
