UpdateTiles

The UpdateTiles() API allows you to update the color offset and flag values of multiple tiles at once. Simply supply an array of tile IDs and the new tile’s color offset and a flag value. This helper method uses the Tile() API under the hood to update each tile, so any changes to a tile’s color offset will automatically force it to be redrawn to the tilemap cache layer. Use this when you don’t need to make changes to each tile’s sprite ID and don’t want to manually iterate over large collections of tiles manually.

Usage

UpdateTiles ( ids, column, row, width, colorOffset, flag )

Arguments

Name

Value

Description

ids

int[]

An array of sprite IDs to use for each tile being updated.

column

int

Start column of the first tile to update. The 0 column is on the far left of the tilemap.

row

int

Start row of the first tile to update. The 0 row is on the top of the tilemap.

colorOffset

int

An optional color offset int value to be applied to each updated tile.

flag

int

An optional flag int value to be applied to each updated tile.

Example

In this example, we are going to read all of the tiles and see which ones have sprites assigned to them. We’ll be using the following Tilemap:

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Next, we’ll set up 4 palettes to apply to each of these tiles:

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Finally, we’ll change each tile’s colorOffset value over several frames to give the impression that the background is fading up and down:

Lua
C#
Lua
-- Set up a time and delay
local time = 0
local delay = 800
-- This will be the direction value for the transition
local dir = 1
-- Total number of palettes for transition
local max = 3
-- Current palette ID
local paletteID = 0
-- Loop through all of the tiles and find the ones that have sprites
local mapSize = TilemapSize()
local totalTiles = mapSize.x * mapSize.y
-- Store all of the tiles that should be updated
local tileIDs = {}
function Init()
-- Loop through all of the tiles in the tilemap
for i = 1, totalTiles do
-- The index is offset by 1 since the first tile starts at 0
local index = (i - 1)
-- Convert the loop index to a column,row position
local pos = CalculatePosition(index, mapSize.x)
-- Check to see if the tile has a sprite
if(Tile(pos.x, pos.y).spriteID > - 1) then
-- Save the tile index value
table.insert(tileIDs, index)
end
end
end
function Update(timeDelta)
-- Increase the time on each frame and test if it is greater than the delay
time = time + timeDelta
if(time > delay) then
-- Update the palette ID based on the direction
paletteID = paletteID + dir
-- Test if the palette ID is too small or too large and reverse the direction
if(paletteID >= max) then
dir = -1
elseif(paletteID <= 0) then
dir = 1
end
-- Reset the time value
time = 0
-- Update each tile's color offset
UpdateTiles(tileIDs, PaletteOffset(paletteID))
end
end
function Draw()
-- Redraw the display
RedrawDisplay()
-- Draw the text for the palette and color ID
DrawText("Palette " .. paletteID, 32, 16, DrawMode.Sprite, "large", 15)
end
C#
class UpdateTilesExample : GameChip
{
// Set up a time and delay
private int time;
private int delay = 800;
// This will be the direction value for the transition
private int dir = 1;
// Total number of palettes for transition
private int max = 3;
// Current palette ID
private int paletteID;
// Store the tilemap dimensions
private Point mapSize;
private int totalTiles;
// Store all of the tiles that should be updated
int[] tileIDs;
public override void Init()
{
// Set the tilemap dimensions
mapSize = TilemapSize();
totalTiles = mapSize.X * mapSize.Y;
// We'll use a list to store tile IDs
var tileList = new List<int>();
// Loop through all of the tiles in the tilemap
for (int i = 0; i < totalTiles; i++)
{
// Convert the loop index to a column,row position
var pos = CalculatePosition(i, mapSize.X);
// Check to see if the tile has a sprite
if (Tile(pos.X, pos.Y).spriteID > -1)
{
tileList.Add(i);
}
}
// Convert the tileList into an array
tileIDs = tileList.ToArray();
}
public override void Update(int timeDelta)
{
// Increase the time on each frame and test if it is greater than the delay
time = time + timeDelta;
if (time > delay)
{
// Update the palette ID based on the direction
paletteID += dir;
// Test if the palette ID is too small or too large and reverse the direction
if (paletteID >= max)
{
dir = -1;
}
else if (paletteID <= 0)
{
dir = 1;
}
// Reset the time value
time = 0;
// Update each tile's color offset
UpdateTiles(tileIDs, PaletteOffset(paletteID));
}
}
public override void Draw()
{
// Redraw the display
RedrawDisplay();
// Draw the text for the palette and color ID
DrawText("Palette " + paletteID, 32, 16, DrawMode.Sprite, "large", 15);
}
}

One thing to note is that while this demo shows how to modify individual tiles at run-time, it’s important to point out that this approach may have bad performance impacts. If you need to modify large groups of tiles, try indexing them in the tilemap during startup and only iterate over tiles you know you need to update.

Running this code will output the following:

image alt text