public void UpdateLight()
{
RenderTexture filterMap = entity.world.lightSystem.filterFrame;
RenderTexture lightAtlas = entity.world.lightSystem.lightAtlas;
// Render filtermap under the light
_view.Center = worldPosition;
_view.Size = new Vector2f(2f * _radius, 2f * _radius);
_view.Viewport = new FloatRect(0, 0, 1, 1);
filterMap.SetView(_view);
filterMap.Clear(Color.White);
entity.world.graphics.Render(filterMap, RenderMode.LIGHT_FILTER, layerMask);
filterMap.Display();
// Calculate light atlas viewport
int framesX = LightSystem.ATLAS_SIZE / LightSystem.ATLAS_FRAME_SIZE;
int framesY = LightSystem.ATLAS_SIZE / LightSystem.ATLAS_FRAME_SIZE;
int frameX = atlasIndex % framesX;
int frameY = atlasIndex / framesX;
FloatRect viewport = new FloatRect(
(float)frameX / (float)framesX,
(float)frameY / (float)framesY,
1f / (float)framesX,
1f / (float)framesY
);
_view.Reset(new FloatRect(
0, 0, LightSystem.ATLAS_FRAME_SIZE, LightSystem.ATLAS_FRAME_SIZE
));
_view.Viewport = viewport;
// Configure light shader
Shader shader = entity.world.lightSystem.lightShader;
shader.SetParameter("lightPos", new Vector2f(filterMap.Size.X / 2, filterMap.Size.Y / 2));
shader.SetParameter("filterMap", filterMap.Texture);
shader.SetParameter("lightColor", color);
shader.SetParameter("fragOffset", new Vector2f(
frameX * LightSystem.ATLAS_FRAME_SIZE,
LightSystem.ATLAS_SIZE - LightSystem.ATLAS_FRAME_SIZE - frameY * LightSystem.ATLAS_FRAME_SIZE
));
// Render the light in a sub-rectangle of the lightAtlas
RenderStates lightRenderStates = new RenderStates(shader);
lightRenderStates.BlendMode = BlendMode.None;
_fillRect.Size = _view.Size;
_fillRect.FillColor = new Color(255, 255, 255, 255);
lightAtlas.SetView(_view);
lightAtlas.Draw(_fillRect, lightRenderStates);
// Draw cookie
if (_cookieSprite != null)
{
_cookieSprite.Position = _view.Size / 2;
lightAtlas.Draw(_cookieSprite, new RenderStates(BlendMode.Multiply));
}
needUpdate = false;
}