Cannot use stencils while effect is active.

[RuairiD]

The following code crashes:

local moonshine = require('moonshine')
local effect = moonshine(moonshine.effects.crt)
local stencilFunction = (function ()
    love.graphics.rectangle('fill', 100, 100, 100, 100)
end)

function love.draw()
    effect(function ()
        love.graphics.setColor(1, 1, 1, 1)
        love.graphics.stencil(stencilFunction, "replace", 1)
        love.graphics.setStencilTest("greater", 0)
        love.graphics.rectangle('fill', 0, 0, 300, 300)
        love.graphics.setStencilTest()
    end)
end

...with the following error:

Error: main.lua:11: Drawing to the stencil buffer with a Canvas active requires either stencil=true or a custom stencil-type Canvas to be used, in setCanvas.
stack traceback:
    [string "boot.lua"]:637: in function <[string "boot.lua"]:633>
    [C]: in function 'stencil'
    main.lua:11: in function 'func'
    moonshine/init.lua:68: in function 'effect'
    main.lua:9: in function 'draw'
    [string "boot.lua"]:513: in function <[string "boot.lua"]:493>
    [C]: in function 'xpcall'

I was able to fix this by adding 'stencil=true' when calling love.graphics.setCanvas within chain.draw i.e.

diff --git a/init.lua b/init.lua
index 431c6c0..cb58a12 100644
--- a/init.lua
+++ b/init.lua
@@ -63,7 +63,7 @@ moonshine.chain = function(w,h,effect)
     local fg_r, fg_g, fg_b, fg_a = love.graphics.getColor()

     -- draw scene to front buffer
-    love.graphics.setCanvas((buffer())) -- parens are needed: take only front buffer
+    love.graphics.setCanvas{(buffer()), stencil=true} -- parens are needed: take only front buffer
     love.graphics.clear(love.graphics.getBackgroundColor())
     func(...)

Shall I make a PR for this?

[Xella37]

I think this is fixed. I'm able to use stencils within the shader without using "stencil=true".