io.stdout:setvbuf("no")
local shader
local img
local img2
function jin.core.onLoad()
    local str = jin.filesystem.read("metaball.shader")
    shader = jin.graphics.newShader(str)
    local bitmap = jin.graphics.newBitmap("img.png")
    -- local bitmap2 = jin.graphics.newBitmap("img2.bmp")
    img = jin.graphics.newTexture(bitmap)
    -- img2 = jin.graphics.newTexture(bitmap2)
end

local mx, my = 0, 0
local sw, sh = jin.graphics.getSize()
function jin.core.onEvent(e)
    if e.type == "Quit" then 
        jin.core.stop()
    end
    if e.type == "KeyDown" then 
        if e.key == "Escape" then 
            jin.core.stop()
        end
    end
    if e.type == "MouseMotion" then 
        -- if e.button == "left" then 
            mx = e.x 
            my = e.y
        -- end
    end
end

local dt = 0
function jin.core.onDraw()
    -- dt = dt + 0.1
    jin.graphics.useShader(shader)
    shader:sendNumber("feather", 1 )
    shader:sendVec2("scaleFactor", 1, 1)
    shader:sendVec2("distortionFactor", 1, 1)
    jin.graphics.draw(img, mx, my, 1, 1)
    jin.graphics.unuseShader()
end