1 files changed, 60 insertions, 0 deletions
diff --git a/libs/moonshine/vignette.lua b/libs/moonshine/vignette.lua
new file mode 100644
index 0000000..f13fb8b
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+++ b/libs/moonshine/vignette.lua
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+--[[
+Public domain:
+
+Copyright (C) 2017 by Matthias Richter <vrld@vrld.org>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+]]--
+
+return function(moonshine)
+  local shader = love.graphics.newShader[[
+    extern number radius;
+    extern number softness;
+    extern number opacity;
+    extern vec4 color;
+
+    vec4 effect(vec4 c, Image tex, vec2 tc, vec2 _)
+    {
+      number aspect = love_ScreenSize.x / love_ScreenSize.y;
+      aspect = max(aspect, 1.0 / aspect); // use different aspect when in portrait mode
+      number v = 1.0 - smoothstep(radius, radius-softness,
+                                  length((tc - vec2(0.5)) * aspect));
+      return mix(Texel(tex, tc), color, v*opacity);
+    }]]
+
+  local setters = {}
+  for _,k in ipairs{"radius", "softness", "opacity"} do
+    setters[k] = function(v) shader:send(k, math.max(0, tonumber(v) or 0)) end
+  end
+  setters.color = function(c)
+    assert(type(c) == "table" and #c == 3, "Invalid value for `color'")
+    assert(c[1] <= 1, "Colors should be normalized in [0,1]")
+    shader:send("color", {
+      (tonumber(c[1]) or 0),
+      (tonumber(c[2]) or 0),
+      (tonumber(c[3]) or 0),
+      1
+    })
+  end
+
+  return moonshine.Effect{
+    name = "vignette",
+    shader = shader,
+    setters = setters,
+    defaults = {
+      radius = .8,
+      softness = .5,
+      opacity = .5,
+      color = {0,0,0}
+    }
+  }
+end