add basic heat transfer #4

This commit is contained in:
Cat Flynn 2022-12-07 00:08:03 +00:00
parent c013ab0057
commit 26d3ce9a0e
4 changed files with 66 additions and 14 deletions

View File

@ -5,6 +5,6 @@
[resource]
resource_local_to_scene = true
shader = ExtResource( 1 )
shader_param/lowColor = Color( 0.0313726, 0, 1, 1 )
shader_param/highColor = Color( 1, 0, 0, 1 )
shader_param/lowColor = Color( 0, 0, 0, 1 )
shader_param/highColor = Color( 1, 0.560784, 0, 1 )
shader_param/t = null

View File

@ -16,4 +16,5 @@ Grid = NodePath("../Grid")
[node name="Clock" parent="." instance=ExtResource( 4 )]
[connection signal="OnTick" from="Clock" to="Grid" method="_on_Clock_OnTick"]
[connection signal="OnTick" from="Clock" to="Debug UI" method="_on_Clock_OnTick"]

View File

@ -15,11 +15,11 @@ public class GridCursor : Sprite
_grid = GetNode<WorldGrid>(Grid);
_material = (ShaderMaterial)Material;
}
public override void _Input(InputEvent @event)
{
base._Input(@event);
if (@event is InputEventMouseMotion mouseMoveEvent)
{
var pos = mouseMoveEvent.Position;
@ -37,7 +37,7 @@ public class GridCursor : Sprite
{
var pos = mouseButtonEvent.Position;
_grid.GetGridPos(pos, out var x, out var y);
_grid.ToggleTileHighlight(x, y);
_grid.SetTileValue(x, y, 1.0f);
_material.SetShaderParam(T, 1f);
}
else

View File

@ -8,11 +8,15 @@ public class WorldGrid : Node2D
[Export]
public int Size { get; set; }
[Export]
public int CellSize { get; set; }
[Export]
public float DiffusionCoefficient { get; set; } = 0.01f;
private Tile[,] _tiles;
private float[,] _nextValues = null;
// Called when the node enters the scene tree for the first time.
public override void _Ready()
@ -23,18 +27,18 @@ public class WorldGrid : Node2D
public override void _Process(float delta)
{
base._Process(delta);
for (int x = 0; x < Size; x++)
{
for (int y = 0; y < Size; y++)
{
var tile = _tiles[x, y];
var material = tile.material;
material.SetShaderParam("t", tile.isHighlighted ? 1f : 0f);
material.SetShaderParam("t", tile.value);
}
}
}
public bool IsInBounds(int x, int y)
{
return x >= 0 && x < Size && y >= 0 && y < Size;
@ -47,7 +51,7 @@ public class WorldGrid : Node2D
_tiles[x, y].isHighlighted ^= true;
}
public void SetTileValue(int x, int y, float value)
{
_tiles[x, y].value = value;
@ -75,8 +79,9 @@ public class WorldGrid : Node2D
private void GenerateGrid(int size)
{
this.Clear();
_tiles = new Tile[size, size];
_nextValues = new float[size, size];
for (int x = 0; x < size; x++)
{
@ -85,7 +90,7 @@ public class WorldGrid : Node2D
var tile = new Tile();
tile.isHighlighted = false;
tile.value = 0.0f;
var node = TileScene.Instance<Node2D>();
this.AddChild(node);
var position = new Vector2
@ -96,9 +101,55 @@ public class WorldGrid : Node2D
node.Position = position;
var canvasItem = (CanvasItem)node;
tile.material = (ShaderMaterial)canvasItem.Material;
_tiles[x, y] = tile;
}
}
}
public void _on_Clock_OnTick(int ticks)
{
Diffuse();
}
private float TransferHeat(float t0, float alpha, float nx, float ny, float px, float py)
{
float d2tdx2 = nx - 2 * t0 + px;
float d2tdy2 = ny - 2 * t0 + py;
return t0 + alpha * (d2tdx2 + d2tdy2);
}
private void GetNeighbourTemperatures(int x, int y, out float nx, out float ny, out float px, out float py)
{
// default value
var t = _tiles[x, y].value;
nx = x > 0 ? _tiles[x - 1, y].value : t;
px = x < Size - 1 ? _tiles[x + 1, y].value : t;
ny = y > 0 ? _tiles[x, y - 1].value : t;
py = y < Size - 1 ? _tiles[x, y + 1].value : t;
}
private void Diffuse()
{
for (int x = 0; x < Size; x++)
{
for (int y = 0; y < Size; y++)
{
float t = _tiles[x, y].value;
var D = DiffusionCoefficient;
GetNeighbourTemperatures(
x, y,
out var nx,
out var ny,
out var px,
out var py);
// current value
_nextValues[x, y] = TransferHeat(t, D, nx, ny, px, py);
}
}
}
}