commit a7dbf255883d6a217f9735c55f3dbbe915a0fb9e
author Piotr Dobrowolski <informatic@hackerspace.pl> Fri Jul 08 00:21:37 2022 +0200
committer informatic <informatic@hackerspace.pl> Mon Jul 11 08:35:12 2022 +0000
tree 1c7bb8b2ec3a82b6f63feaaa5ca3ffe1d7694b73
parent 8f986c181b13198cc263d0d2f2c4a080db9959ca

hswaw/signage: reuse compiled shader, better error handling

Shader will now only be recompiled whenever its code changes. This helps
with hangs on node transitions on underpowered devices.

If shader reload failed an error message will now be rendered over an
existing shader.

File load errors are properly handled.

Change-Id: I97a75b85620614252040b76e4f3aaa0ea1f0a7e3
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1337
Reviewed-by: q3k <q3k@hackerspace.pl>

hswaw/signage/nodes/shadertoy.lua

diff --git a/hswaw/signage/nodes/shadertoy.lua b/hswaw/signage/nodes/shadertoy.lua
index 871ef12..52c8f31 100644
--- a/hswaw/signage/nodes/shadertoy.lua
+++ b/hswaw/signage/nodes/shadertoy.lua
@@ -5,6 +5,7 @@
 function node:init(config)
   node.super.init(self, config)
 
+  self.prevShaderData = nil
   self.path = self.path or "test.glsl"
   self.resolution = self.resolution or {1280, 720}
 
@@ -13,6 +14,10 @@
 
 function node:beforeEnter()
   self:loadShader()
+  if self.iSystem and self.iSystem.iGlobalTime then
+    print("Resetting time")
+    self.iSystem.iGlobalTime = 0
+  end
 end
 
 function node:loadShader()
@@ -26,8 +31,20 @@
     }
     ]]
     local file = io.open(self.path, "r")
+
+    if file == nil then
+        self.shaderLoadError = self.path .. " does not exist"
+        return
+    end
+
     local shaderData = file:read("*all")
 
+    if self.prevShaderData == shaderData then
+      print("Shader didn't change, not reloading")
+      return
+    end
+
+    self.prevShaderData = shaderData
     shaderData = string.gsub(shaderData,"texture2D","Texel")
     shaderData = string.gsub(shaderData,"iTime","iGlobalTime")
     shaderData = string.gsub(shaderData,"precision highp float;","")
@@ -62,16 +79,16 @@
       shaderData = shaderData.."\n"..ender
     end
 
-    print('Shader loaded')
+    print("Shader loaded, compiling...")
 
     self.shaderLoadError = nil
-    shaderLoaded, self.shader = pcall(love.graphics.newShader, shaderData)
+    shaderLoaded, shader = pcall(love.graphics.newShader, shaderData)
     if not shaderLoaded then
-      print('Shader load failed:', self.shader)
-      self.shaderLoadError = self.shader
-      self.shader = nil
+      print("Shader compile failed:", shader)
+      self.shaderLoadError = shader
     else
-      print(shaderLoaded, self.shader)
+      self.shader = shader
+
       if iSystem.iResolution then
         self.shader:send("iResolution",iSystem.iResolution)
       end
@@ -95,12 +112,7 @@
   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
+  if self.shader ~= nil then
     oldCanvas = love.graphics.getCanvas( )
     love.graphics.setColor( 1.0, 1.0, 1.0 )
     self.canvas:renderTo(function ()
@@ -112,6 +124,12 @@
 
     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
+
+  if self.shaderLoadError ~= nil then
+    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');
+  end
 end
 
 return node