static float3 GetSimulatedPosition(float3 start, float3 end, float paraA, float paraB, float paraC, float t)
{
return(new Vector3(
math.lerp(start.x, end.x, t),
Parabola.Solve(paraA, paraB, paraC, t),
math.lerp(start.z, end.z, t)
));
}
public static Vector3 GetSimulatedPosition(Vector3 start, Vector3 end, float paraA, float paraB, float paraC, float t)
{
return(new Vector3(
Mathf.LerpUnclamped(start.x, end.x, t),
Parabola.Solve(paraA, paraB, paraC, t),
Mathf.LerpUnclamped(start.z, end.z, t)
));
}
public unsafe void Execute(Entity entity, int entityIndex, ref Translation cannonballPos, ref ArcState arc)
{
float t = ElapsedTime - arc.StartTime;
if (t >= 0 && t < arc.Duration)
{
// Test for collisions with the player
const float COLLISION_DISTANCE_SQ =
(PLAYER_RADIUS + TankFireSystem.CANNONBALL_RADIUS) *
(PLAYER_RADIUS + TankFireSystem.CANNONBALL_RADIUS);
if (math.lengthsq(cannonballPos.Value - PlayerCenterPosition) < COLLISION_DISTANCE_SQ)
{
if (!EnableInvincibility)
{
// game over! add a NewGame entity to trigger the NewGameSystem to restart.
Entity gameOverEntity = CommandBuffer.CreateEntity(entityIndex);
CommandBuffer.AddComponent(entityIndex, gameOverEntity, new NewGameTag());
}
}
// Get the current height along the parabola & update cannonball pos
float s = t / arc.Duration;
cannonballPos.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)
);
}
else if (t >= arc.Duration)
{
// Cannonball has reached the end of its path; damage the block it hit
// TODO(@cort): If the destination block has been damaged/lowered since the shot was fired, the shot will "land" in the air above the block. Original game does this too.
int2 boxCoords = TerrainSystem.PositionToBlockCoords(cannonballPos.Value.x, cannonballPos.Value.z, TerrainSize);
int boxIndex = TerrainSystem.BlockCoordsToIndex(boxCoords, TerrainSize);
Entity boxEntity = BlockEntities[boxIndex];
int * blockHitsPtr = (int *)BlockHitCounts.GetUnsafePtr() + boxIndex;
int newCount = Interlocked.Increment(ref *blockHitsPtr);
if (newCount == 1)
{
CommandBuffer.AddComponent(entityIndex, boxEntity, new UpdateBlockTransformTag());
}
// TODO(@cort): There is a (relatively benign) race condition here. There's no guarantee that the last job
// to update the hit counts array will also write the last command that updates the BlockHeight component.
// This means that if >1 cannonball hits a block in a single frame, some of the hits may not damage the block.
// One solution would be commands that allow mutating component values rather than setting them to a value
// known at record time. https://github.com/Unity-Technologies/dots/issues/632
float currentBoxHeight = BlockHeights[boxIndex];
CommandBuffer.SetComponent(entityIndex, boxEntity,
new BlockHeight
{
Value = math.max(BLOCK_HEIGHT_MIN, currentBoxHeight - newCount * BoxHeightDamage)
});
// destroy the cannonball
CommandBuffer.DestroyEntity(entityIndex, entity);
}
}
/// <summary>
/// Uses parabola to determine bounce position at time t.
/// </summary>
/// <param name="t">t in [0, 1].</param>
private Vector3 bouncePosition(float t)
{
float y = Parabola.Solve(paraA, paraB, paraC, t);
Vector3 startPos = TerrainArea.instance.LocalPositionFromBox(startBox.col, startBox.row);
Vector3 endPos = TerrainArea.instance.LocalPositionFromBox(endBox.col, endBox.row);
float x = Mathf.Lerp(startPos.x, endPos.x, t);
float z = Mathf.Lerp(startPos.z, endPos.z, t);
return(new Vector3(x, y, z));
}
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);
}
}
}
// Update is called once per frame
void Update()
{
UpdateTranslation();
RotateTowardsPlayer();
time += Time.deltaTime;
if (time >= Game.instance.tankLaunchPeriod)
{
// launching cannonball
time -= Game.instance.tankLaunchPeriod;
// start and end positions
Vector3 start = transform.localPosition;
Vector2Int playerBox = TerrainArea.instance.BoxFromLocalPosition(Player.instance.transform.localPosition);
Vector3 end = TerrainArea.instance.LocalPositionFromBox(playerBox.x, playerBox.y, TerrainArea.instance.GetBox(playerBox.x, playerBox.y).top + Cannonball.RADIUS);
float distance = (new Vector2(end.z - start.z, end.x - start.x)).magnitude;
float duration = distance / Cannonball.SPEED;
if (duration < .0001f)
{
duration = 1;
}
// binary searching to determine height of cannonball arc
float low = Mathf.Max(start.y, end.y);
float high = low * 2;
float paraA, paraB, paraC;
// look for height of arc that won't hit boxes
while (true)
{
Parabola.Create(start.y, high, end.y, out paraA, out paraB, out paraC);
if (!Cannonball.CheckBoxCollision(start, end, 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 > Game.instance.playerParabolaPrecision)
{
float mid = (low + high) / 2;
Parabola.Create(start.y, mid, end.y, out paraA, out paraB, out paraC);
if (Cannonball.CheckBoxCollision(start, end, paraA, paraB, paraC))
{
// not high enough
low = mid;
}
else
{
// too high
high = mid;
}
}
// launch with calculated height
float height = (low + high) / 2;
Cannonball cannonball = Cannonball.Create(transform.parent, start);
cannonball.Launch(end, height, duration);
// set cannon rotation
SetCannonRotation(Mathf.Atan2(Parabola.Solve(paraA, paraB, paraC, .1f) - Parabola.Solve(paraA, paraB, paraC, 0), .1f) * Mathf.Rad2Deg);
}
}
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)
);
}
}