public void Execute(Entity _, int index, [ReadOnly] ref LocalToWorld localToWorld, ref TankFireCountdown countdown,
ref Rotation rotation)
{
// launching cannonball
countdown.SecondsUntilFire -= DeltaTime;
if (countdown.SecondsUntilFire <= 0)
{
countdown.SecondsUntilFire = math.fmod(countdown.SecondsUntilFire, FirePeriod) + FirePeriod;
// start and end positions
int2 playerBoxCoords = TerrainSystem.PositionToBlockCoords(PlayerPosition.x, PlayerPosition.z, TerrainSize);
int playerBoxIndex = TerrainSystem.BlockCoordsToIndex(playerBoxCoords, TerrainSize);
float playerBoxHeight = BlockHeights[playerBoxIndex];
float3 startPos = math.mul(localToWorld.Value, new float4(0, 0, 0, 1)).xyz;
float3 endPos = TerrainSystem.BlockCoordsToPosition(playerBoxCoords, playerBoxHeight, TerrainSize);
endPos.y += CANNONBALL_RADIUS + 0.01f; // extra 0.01 to avoid false positive collisions at endPos
float distance = math.distance(endPos.xz, startPos.xz);
float duration = distance / CANNONBALL_SPEED;
if (duration < 0.0001f)
{
duration = 1.0f;
}
// binary searching to determine height of cannonball arc
float low = math.max(startPos.y, endPos.y);
float high = low * 2;
float paraA, paraB, paraC;
// look for height of arc that won't hit boxes
while (true)
{
Parabola.Create(startPos.y, high, endPos.y, out paraA, out paraB, out paraC);
if (!PathHitsTerrain(BlockBoundingBoxes, TerrainSize, startPos, endPos, paraA, paraB, paraC))
{
// high enough
break;
}
// not high enough. Double value
low = high;
high *= 2;
// failsafe
if (high > 9999)
{
return; // skip launch
}
}
// do binary searches to narrow down
while (high - low > CANNONBALL_PARABOLA_PRECISION)
{
float mid = (low + high) / 2;
Parabola.Create(startPos.y, mid, endPos.y, out paraA, out paraB, out paraC);
if (PathHitsTerrain(BlockBoundingBoxes, TerrainSize, startPos, endPos, paraA, paraB, paraC))
{
// not high enough
low = mid;
}
else
{
// too high
high = mid;
}
}
// launch with calculated height
float height = (low + high) / 2;
Parabola.Create(startPos.y, height, endPos.y, out paraA, out paraB, out paraC);
Entity ballEntity = CommandBuffer.Instantiate(index, CannonballPrefab);
CommandBuffer.SetComponent(index, ballEntity, new Translation {
Value = startPos
});
CommandBuffer.SetComponent(index, ballEntity, new ArcState
{
Parabola = new float3(paraA, paraB, paraC),
StartTime = ElapsedTime,
Duration = duration,
StartPos = startPos,
EndPos = endPos,
});
// set cannon rotation
{
const float t = 0.01f;
float altitudeAngle = -math.atan2(
Parabola.Solve(paraA, paraB, paraC, t) - Parabola.Solve(paraA, paraB, paraC, 0.0f),
t * distance);
rotation.Value = quaternion.Euler(altitudeAngle, 0, 0);
}
}
}
public void Execute(ref Translation position, ref ArcState arc)
{
float t = ElapsedTime - arc.StartTime;
if (t > arc.Duration)
{
// Compute the next arc info
int2 playerCoords = TerrainSystem.PositionToBlockCoords(position.Value.x, position.Value.z, TerrainSize);
int2 dir = math.clamp(MouseBoxCoords - playerCoords,
new int2(-1, -1), new int2(1, 1));
int2 destCoords = playerCoords + dir;
// If destination is outside the terrain bounds, don't move.
if (destCoords.x < 0 || destCoords.x >= TerrainSize.x ||
destCoords.y < 0 || destCoords.y >= TerrainSize.y)
{
destCoords = playerCoords;
}
int playerBlockIndex = TerrainSystem.BlockCoordsToIndex(playerCoords, TerrainSize);
int destBlockIndex = TerrainSystem.BlockCoordsToIndex(destCoords, TerrainSize);
// If destination is occupied, don't move.
if (IsBlockOccupied[destBlockIndex] != 0)
{
destCoords = playerCoords;
destBlockIndex = playerBlockIndex;
}
float playerBlockHeight = BlockHeights[playerBlockIndex];
float destBlockHeight = BlockHeights[destBlockIndex];
float parabolaHeight = math.max(playerBlockHeight, destBlockHeight);
if (dir.x != 0 && dir.y != 0)
{
// If jumping diagonally, the parabola height must take into account the directly
// adjacent blocks as well.
int2 adjacentCoordsX = playerCoords + new int2(dir.x, 0);
if (adjacentCoordsX.x >= 0 && adjacentCoordsX.x < TerrainSize.x)
{
int adjacentIndexX = TerrainSystem.BlockCoordsToIndex(adjacentCoordsX, TerrainSize);
float adjacentHeightX = BlockHeights[adjacentIndexX];
parabolaHeight = math.max(parabolaHeight, adjacentHeightX);
}
int2 adjacentCoordsZ = playerCoords + new int2(0, dir.y);
if (adjacentCoordsZ.y >= 0 && adjacentCoordsZ.y < TerrainSize.y)
{
int adjacentIndexZ = TerrainSystem.BlockCoordsToIndex(adjacentCoordsZ, TerrainSize);
float adjacentHeightZ = BlockHeights[adjacentIndexZ];
parabolaHeight = math.max(parabolaHeight, adjacentHeightZ);
}
}
parabolaHeight += BOUNCE_HEIGHT;
Parabola.Create(playerBlockHeight, parabolaHeight, destBlockHeight,
out arc.Parabola.x, out arc.Parabola.y, out arc.Parabola.z);
arc.StartPos =
TerrainSystem.BlockCoordsToPosition(playerCoords, playerBlockHeight, TerrainSize);
arc.EndPos =
TerrainSystem.BlockCoordsToPosition(destCoords, destBlockHeight, TerrainSize);
arc.StartTime = ElapsedTime;
float distance = math.distance(playerCoords, destCoords);
arc.Duration = math.max(1, distance) * BOUNCE_BASE_DURATION;
}
else
{
// Get the current height along the parabola
float s = t / arc.Duration;
position.Value = new float3(
math.lerp(arc.StartPos.x, arc.EndPos.x, s),
Parabola.Solve(arc.Parabola.x, arc.Parabola.y, arc.Parabola.z, s),
math.lerp(arc.StartPos.z, arc.EndPos.z, s)
);
}
}
