CODEWITHSUNDEEP
java
Mike Fitz
Mike Fitz

Reputation: 101

2D Tile based smooth lighting

I already have a lightmap and lighting algorithm that is functional: tiles w/ lightmap

I am not using OpenGl, I do not need raycasted shadows, I just want the lightmap to blend in a gradient between the vertices of the lightmap so it is smooth instead of blocky. One way I saw this done was as follows: draw an image one pixel for each tile that contains the lightmap data, then scale it up using the size of the tiles and interpolation. However I don't understand how to do this and using this lightmapimage.getScaledInstance(w,h,Image.SCALE_SMOOTH) simply produces the same effect as in the image above only incredibly slower. How do I go about smoothing the lighting in a resource-efficient way?

Upvotes: 1

Views: 275

Answers (1)

Mike Fitz
Mike Fitz

Reputation: 101

I figured it out. For anyone interested in 2D tile-based smooth lighting, here is my solution: after drawing the lightmap to a small scale image where each pixel represents one tile, use an AffineTransformOp of type bilinear.(the tile size is 10x10)

BufferedImage after = new BufferedImage(lightmap.getWidth()*10, lightmap.getHeight()*10, BufferedImage.TYPE_INT_ARGB);
AffineTransform at = new AffineTransform();
at.scale(10, 10);
AffineTransformOp scaleOp = new AffineTransformOp(at, AffineTransformOp.TYPE_BILINEAR);
after = scaleOp.filter(lightmap, after);
g.drawImage(after,0,0,null);

Upvotes: 1

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