Just Game Maker. When I say blending operations I'm talking about GM7 Pro's draw_set_blend_mode_ext(source, destination) function. So when you draw the filter over the tiles, it creates an effect.
Pseudo Code:
Create the tile coordinates. Either by script or reading them in from an external source.
Copy parts of the tile set image as tiles and draw them to a new surface.
After drawing the tiles, draw the filter tiled over the entire surface. Using blending operations.
The blending operation I used: draw_set_blend_mode_ext(bm_dest_color,
bm_inv_dest_alpha);
Do this for as many layers as you need. I recommend only using 2 layers. A lower and upper.
Draw a part (Use view coordinates) of each layer to the screen using an object, at the desired depth.
Mind you, I am still testing the performance of this concept. So far so good. I should warn you, not every video card supports surfaces.
