Thank you very much!
FlySoft

Awesome sample and thanks for sharing. I’m going to take a look at it and try to incorperate it into one of my mini 2d projects.

-John

What I want to do is only draw the cached “cutted” static lights (by cutted, I mean, the light source and removing the parts that are shadowed), as the shadows are already in the dynamic shadows’ RenderTarget2D.

But now I’m trying to add some static shadows to my game, and for that I’m trying to calculate all the static shadows during the level loading period, and then just draw a texture with the static lights and shadows. The problem is that I’m not very good at graphics programming, and although I’m storing all the precalculated shadows in a big texture (with RenderTarget2D.GetTexture()) my problem is when my camera scrolls. RenderTarget2D gives me a texture with the viewport’s size, so when I move around and the camera moves, the rectangle containing the shadows stays in place :S What I need (I guess) is a bigger RenderTarget2D, with the size of the whole level, but I don’t know how to do this (gives me error when I try this. Any ideas?

With dynamic shadows I have no problem, as it calculates on each frame the lights and shadows position related to the camera position.

Thanks, sorry for the huge question.

within the DrawLightmap method

I moved the

foreach (ConvexHull hull in World1.Worldobjects)
{
hull.Draw(gT, World1.cam.get_transformation(GraphicsDevice));
}

right after the

foreach (ConvexHull ch in World1.Worldobjects)
{
//draw shadow
if (ch != null)
{

ch.DrawShadows(light, World1.cam.get_transformation(GraphicsDevice));

}
}

so to recap in DrawLightmap method it should look like the following:

foreach (LightSource light in lights)
{
//clear alpha to 1
ClearAlphaToOne();

//draw all shadows
//write only to the alpha channel, which sets alpha to 0
GraphicsDevice.RenderState.ColorWriteChannels = ColorWriteChannels.Alpha;
GraphicsDevice.RenderState.CullMode = CullMode.None;
GraphicsDevice.RenderState.AlphaBlendEnable = true;
GraphicsDevice.RenderState.DestinationBlend = Blend.Zero;
GraphicsDevice.RenderState.SourceBlend = Blend.One;

foreach (ConvexHull ch in World1.Worldobjects)
{
//draw shadow
if (ch != null)
{

ch.DrawShadows(light, World1.cam.get_transformation(GraphicsDevice));

}
}
foreach (ConvexHull hull in World1.Worldobjects)
{
hull.Draw(gT, World1.cam.get_transformation(GraphicsDevice));
}

GraphicsDevice.RenderState.ColorWriteChannels = ColorWriteChannels.All;

//draw the light shape
//where Alpha is 0, nothing will be written
//This is the light
spriteBatch.Begin(SpriteBlendMode.AlphaBlend, SpriteSortMode.Immediate, SaveStateMode.SaveState, World1.cam.get_transformation(GraphicsDevice));
GraphicsDevice.RenderState.DestinationBlend = Blend.One;
GraphicsDevice.RenderState.SourceBlend = Blend.DestinationAlpha;
GraphicsDevice.RenderState.BlendFunction = BlendFunction.Add;
GraphicsDevice.RenderState.SeparateAlphaBlendEnabled = true;
light.Draw(spriteBatch);
spriteBatch.End();

}

Now this will have the hulls lit up (fully) when light touches it

If you would prefer them without light then make sure your color value is passed with an alpha of 0.

this is my line to create the object (hull)

objects = new ConvexHull(game2, Points, new Color(0,0,0,0), new Vector2(X, Y));

Well this seems to have worked for me anyway.