Way I have thought of and attempted:
Having prerendered light so i only calculate it every 2 frames instead of 1
I have thought about using a shader to do all of the calculation but not sure how to
Here is my code
try {
if (ENABLED) {
// This calculation works out where to render the tiles by culling all of the others
int camX = (int) (camera.position.x + (MasterTile.TILE_WIDTH / 2) - camera.viewportWidth / 2) / MasterTile.TILE_WIDTH;
int camY = (int) (camera.position.y + (MasterTile.TILE_HEIGHT / 2) - camera.viewportHeight / 2) / MasterTile.TILE_HEIGHT;
int camZoomFixX = (int) (((camera.zoom - 1) * 100) / (MasterTile.TILE_WIDTH / 10));
int camZoomFixY = (int) (((camera.zoom - 1) * 100) / (MasterTile.TILE_WIDTH / 10));
int offset = 1;
if (camZoomFixX < 0)
camZoomFixX = 0;
if (camZoomFixY < 0)
camZoomFixY = 0;
int startX = camX - (camZoomFixX + offset);
int toX = (camX + TileRenderer.AMOUNT_WIDTH) + (camZoomFixX + offset);
int startY = camY - (camZoomFixY + offset);
int toY = (camY + TileRenderer.AMOUNT_HEIGHT) + (camZoomFixY + offset);
// This is the beginning of the light calculation
// It works by going through each tile and each tile will loop over every light and
// use an equation which will add to the tile brightness and will work out the final result
{
for (int x = startX; x < toX; x++) {
for (int y = startY; y < toY; y++) {
if (x < 0 || x > TileRenderer.map.getWidth() - 1 || y < 0 || y > TileRenderer.map.getHeight() - 1)
continue;
float tileBrightness = 0;
for (int i = 0; i < lights.size; i++) {
MasterTile tile = lights.get(i);
if (tile == null)
continue;
float distance = Vector2.dst(tile.getX() / MasterTile.TILE_WIDTH, tile.getY() / MasterTile.TILE_HEIGHT, x, y);
tileBrightness += Math.max(0, 1 - distance / MAX_DISTANCE); // Linear equation
}
float defaultAlpha = ambientColour.a;
tempColor.set(0, 0, 0, ambient);
tempColor.lerp(ambientColour, tileBrightness);
ambientColour.a = 1.0f - tileBrightness;
spriteBatch.setColor(tempColor);
spriteBatch.draw(pixelTexture, x * MasterTile.TILE_WIDTH, y * MasterTile.TILE_HEIGHT, MasterTile.TILE_WIDTH, MasterTile.TILE_HEIGHT);
ambientColour.a = defaultAlpha;
}
}
}
}
} catch (NullPointerException e) {
System.err.println("Light was not loaded!");
System.err.println(e.getMessage());
}
// Resets colour to white
spriteBatch.setColor(Color.WHITE);
