nodes/shadertoy: WIP simple shader rendering node

nodes/shadertoy.lua

@@ -0,0 +1,118 @@
+local node = Node:extend('nodes.shadertoy', {})
+
+local smallFont = love.graphics.newFont('fonts/Lato-Light.ttf', 20)
+
+function node:init(config)
+  node.super.init(self, config)
+
+  self.path = self.path or "test.glsl"
+  self.resolution = self.resolution or {1280, 720}
+
+  self:loadShader()
+end
+
+function node:beforeEnter()
+  self:loadShader()
+end
+
+function node:loadShader()
+    local iSystem = {}
+    local header = ""
+    local ender=[[
+    vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
+      vec2 fragCoord = texture_coords * iResolution.xy;
+      mainImage( color, fragCoord );
+      return color;
+    }
+    ]]
+    local file = love.filesystem.newFile(self.path)
+    file:open("r")
+    local shaderData = file:read()
+
+    shaderData = string.gsub(shaderData,"texture2D","Texel")
+    shaderData = string.gsub(shaderData,"iTime","iGlobalTime")
+    shaderData = string.gsub(shaderData,"precision highp float;","")
+
+    if string.find(shaderData,"iGlobalTime") then
+      iSystem.iGlobalTime=0
+      if not string.find(shaderData,"number iGlobalTime") then
+        header="extern number iGlobalTime;\n"..header
+      end
+    end
+
+    -- TODO
+    -- if string.find(shaderData,"iChannel") then
+    --   iSystem.iChannel={}
+    --   for k,v in pairs(shaderChannel) do
+    --     header="extern Image iChannel"..k..";\n"..header
+    --   end
+    -- end
+
+    if string.find(shaderData,"iMouse") then
+      iSystem.iMouse = {0, 0, -1, -1}
+      header = "extern vec4 iMouse;\n"..header
+    end
+
+    if string.find(shaderData,"iResolution") then
+      iSystem.iResolution = {self.resolution[1], self.resolution[2],1}
+      header = "extern vec3 iResolution;\n"..header
+    end
+
+    shaderData = header..shaderData
+    if not string.find(shaderData,"vec4 effect") then
+      shaderData = shaderData.."\n"..ender
+    end
+
+    print('Shader loaded')
+
+    self.shaderLoadError = nil
+    shaderLoaded, self.shader = pcall(love.graphics.newShader, shaderData)
+    if not shaderLoaded then
+      print('Shader load failed:', self.shader)
+      self.shaderLoadError = self.shader
+      self.shader = nil
+    else
+      print(shaderLoaded, self.shader)
+      if iSystem.iResolution then
+        self.shader:send("iResolution",iSystem.iResolution)
+      end
+
+      self.iSystem = iSystem
+      self.canvas = love.graphics.newCanvas(self.resolution[1], self.resolution[2])
+      self.renderCanvas = love.graphics.newCanvas(self.resolution[1], self.resolution[2])
+    end
+end
+
+function node:update(dt)
+  if self.shader ~= nil then
+    if self.iSystem.iGlobalTime then
+      self.iSystem.iGlobalTime=self.iSystem.iGlobalTime+dt
+      self.shader:send("iGlobalTime", self.iSystem.iGlobalTime)
+    end
+  end
+end
+
+function node:render()
+  love.graphics.setColor( 0, 0, 0 )
+  love.graphics.rectangle("fill", 0, 0, love.graphics.getWidth(), love.graphics.getHeight())
+
+  if self.shaderLoadError ~= nil then
+    print('render!')
+    love.graphics.setColor(1.0, 0.0, 0.0, 1.0)
+    love.graphics.setFont(smallFont)
+    love.graphics.printf(self.shaderLoadError, 0, 0.1*love.graphics.getHeight(), love.graphics.getWidth(), 'left');
+  elseif self.shader ~= nil then
+    oldCanvas = love.graphics.getCanvas( )
+    love.graphics.setColor( 1.0, 1.0, 1.0 )
+    self.canvas:renderTo(function ()
+      love.graphics.setShader(self.shader)
+      love.graphics.draw(self.renderCanvas)
+      love.graphics.setShader()
+    end)
+    love.graphics.setCanvas(oldCanvas)
+
+    love.graphics.draw(self.canvas,0,0,math.pi,love.graphics.getWidth() / self.resolution[1], love.graphics.getHeight() / self.resolution[2], self.resolution[1], self.resolution[2])
+  end
+end
+
+return node