1 files changed, 64 insertions, 0 deletions
diff --git a/libs/moonshine/sketch.lua b/libs/moonshine/sketch.lua
new file mode 100644
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+++ b/libs/moonshine/sketch.lua
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+--[[
+The MIT License (MIT)
+
+Copyright (c) 2015 Martin Felis
+Copyright (c) 2017 Matthias Richter
+
+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 noisetex = love.image.newImageData(256,256)
+  noisetex:mapPixel(function()
+    return love.math.random(),love.math.random(), 0, 0
+  end)
+  noisetex = love.graphics.newImage(noisetex)
+  noisetex:setWrap ("repeat", "repeat")
+  noisetex:setFilter("nearest", "nearest")
+
+  local shader = love.graphics.newShader[[
+    extern Image noisetex;
+    extern number amp;
+    extern vec2 center;
+
+    vec4 effect(vec4 color, Image texture, vec2 tc, vec2 _) {
+      vec2 displacement = Texel(noisetex, tc + center).rg;
+      tc += normalize(displacement * 2.0 - vec2(1.0)) * amp;
+
+      return Texel(texture, tc);
+    }]]
+
+  shader:send("noisetex", noisetex)
+
+  local setters = {}
+  setters.amp = function(v)
+    shader:send("amp", math.max(0, tonumber(v) or 0))
+  end
+  setters.center = function(v)
+    assert(type(v) == "table" and #v == 2, "Invalid value for `center'")
+    shader:send("center", v)
+  end
+
+  return moonshine.Effect{
+    name = "sketch",
+    shader = shader,
+    setters = setters,
+    defaults = {amp = .0007, center = {0,0}}
+  }
+end