1 files changed, 62 insertions, 0 deletions
diff --git a/libs/moonshine/boxblur.lua b/libs/moonshine/boxblur.lua
new file mode 100644
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+++ b/libs/moonshine/boxblur.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 radius_x, radius_y = 3, 3
+  local shader = love.graphics.newShader[[
+    extern vec2 direction;
+    extern number radius;
+    vec4 effect(vec4 color, Image texture, vec2 tc, vec2 _) {
+      vec4 c = vec4(0.0);
+
+      for (float i = -radius; i <= radius; i += 1.0)
+      {
+        c += Texel(texture, tc + i * direction);
+      }
+      return c / (2.0 * radius + 1.0) * color;
+    }]]
+
+  local setters = {}
+  setters.radius = function(v)
+    if type(v) == "number" then
+      radius_x, radius_y = v, v
+    elseif type(v) == "table" and #v >= 2 then
+      radius_x, radius_y = tonumber(v[1] or v.h or v.x), tonumber(v[2] or v.v or v.y)
+    else
+      error("Invalid argument `radius'")
+    end
+  end
+  setters.radius_x = function(v) radius_x = tonumber(v) end
+  setters.radius_y = function(v) radius_y = tonumber(v) end
+
+  local draw = function(buffer)
+    shader:send('direction', {1 / love.graphics.getWidth(), 0})
+    shader:send('radius', math.floor(radius_x + .5))
+    moonshine.draw_shader(buffer, shader)
+
+    shader:send('direction', {0, 1 / love.graphics.getHeight()})
+    shader:send('radius', math.floor(radius_y + .5))
+    moonshine.draw_shader(buffer, shader)
+  end
+
+  return moonshine.Effect{
+    name = "boxblur",
+    draw = draw,
+    setters = setters,
+    defaults = {radius = 3}
+  }
+end