108 lines
3.2 KiB
Lua
108 lines
3.2 KiB
Lua
|
--[[
|
||
|
|
The MIT License (MIT)
|
||
|
|
|
||
|
|
Original code: Copyright (c) 2015 Josef Patoprsty
|
||
|
|
Port to moonshine: Copyright (c) 2017 Matthias Richter <vrld@vrld.org>
|
||
|
|
|
||
|
|
Based on work by: ioxu
|
||
|
|
|
||
|
|
https://www.love2d.org/forums/viewtopic.php?f=4&t=3733&start=120#p71099
|
||
|
|
|
||
|
|
Based on work by: Fabien Sanglard
|
||
|
|
|
||
|
|
http://fabiensanglard.net/lightScattering/index.php
|
||
|
|
|
||
|
|
Based on work from:
|
||
|
|
|
||
|
|
[Mitchell]: Kenny Mitchell "Volumetric Light Scattering as a Post-Process" GPU Gems 3 (2005).
|
||
|
|
[Mitchell2]: Jason Mitchell "Light Shaft Rendering" ShadersX3 (2004).
|
||
|
|
|
||
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||
|
|
of this software and associated documentation files (the "Software"), to deal
|
||
|
|
in the Software without restriction, including without limitation the rights
|
||
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||
|
|
copies of the Software, and to permit persons to whom the Software is
|
||
|
|
furnished to do so, subject to the following conditions:
|
||
|
|
|
||
|
|
The above copyright notice and this permission notice shall be included in all
|
||
|
|
copies or substantial portions of the Software.
|
||
|
|
|
||
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||
|
|
SOFTWARE.
|
||
|
|
]]--
|
||
|
|
|
||
|
|
return function(moonshine)
|
||
|
|
local shader = love.graphics.newShader[[
|
||
|
|
extern number exposure;
|
||
|
|
extern number decay;
|
||
|
|
extern number density;
|
||
|
|
extern number weight;
|
||
|
|
extern vec2 light_position;
|
||
|
|
extern number samples;
|
||
|
|
|
||
|
|
vec4 effect(vec4 color, Image tex, vec2 uv, vec2 px) {
|
||
|
|
color = Texel(tex, uv);
|
||
|
|
|
||
|
|
vec2 offset = (uv - light_position) * density / samples;
|
||
|
|
number illumination = decay;
|
||
|
|
vec4 c = vec4(.0, .0, .0, 1.0);
|
||
|
|
|
||
|
|
for (int i = 0; i < int(samples); ++i) {
|
||
|
|
uv -= offset;
|
||
|
|
c += Texel(tex, uv) * illumination * weight;
|
||
|
|
illumination *= decay;
|
||
|
|
}
|
||
|
|
|
||
|
|
return vec4(c.rgb * exposure + color.rgb, color.a);
|
||
|
|
}]]
|
||
|
|
|
||
|
|
|
||
|
|
local setters, light_position = {}
|
||
|
|
|
||
|
|
for _,k in ipairs{"exposure", "decay", "density", "weight"} do
|
||
|
|
setters[k] = function(v)
|
||
|
|
shader:send(k, math.min(1, math.max(0, tonumber(v) or 0)))
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
setters.light_position = function(v)
|
||
|
|
light_position = {unpack(v)}
|
||
|
|
shader:send("light_position", v)
|
||
|
|
end
|
||
|
|
|
||
|
|
setters.light_x = function(v)
|
||
|
|
assert(type(v) == "number", "Invalid value for `light_x'")
|
||
|
|
setters.light_position{v, light_position[2]}
|
||
|
|
end
|
||
|
|
|
||
|
|
setters.light_y = function(v)
|
||
|
|
assert(type(v) == "number", "Invalid value for `light_y'")
|
||
|
|
setters.light_position{light_position[1], v}
|
||
|
|
end
|
||
|
|
|
||
|
|
setters.samples = function(v)
|
||
|
|
shader:send("samples", math.max(1,tonumber(v) or 1))
|
||
|
|
end
|
||
|
|
|
||
|
|
local defaults = {
|
||
|
|
exposure = 0.25,
|
||
|
|
decay = 0.95,
|
||
|
|
density = 0.15,
|
||
|
|
weight = 0.5,
|
||
|
|
light_position = {0.5,0.5},
|
||
|
|
samples = 70
|
||
|
|
}
|
||
|
|
|
||
|
|
return moonshine.Effect{
|
||
|
|
name = "godsray",
|
||
|
|
shader = shader,
|
||
|
|
setters = setters,
|
||
|
|
defaults = defaults
|
||
|
|
}
|
||
|
|
end
|