local shader;
local program = [[
extern Texture img;
extern number dt;
Color effect(Color col, Texture tex, vec2 uv, vec2 screen)
{
	return Texel(img, uv);
	//return vec4(1, 0, 1, 1);
    //return sin(dt)*Texel(tex, uv) * Texel(img, uv);
}
]]
local img
local img2
function jin.core.onLoad()
    shader = jin.graphics.newShader(program)
    img = jin.graphics.newTexture("img.png")
    img2 = jin.graphics.newTexture("img2.bmp")
end

function jin.core.onEvent(e)
    if e.type == "quit" then 
        jin.core.stop()
    end
end

local dt = 0
function jin.core.onDraw()
    dt = dt + 0.1
	jin.graphics.useShader(shader)
    shader:sendTexture("img", img2)
	shader:sendNumber("dt", dt)
    jin.graphics.draw(img, 0, 0)
    jin.graphics.unuseShader()
end