local data = {
    -- these are declared as uniform on all shaders
    shared = {
        uniform = {
            time = 0,
        },
    },

    vertex = {
        uniform = {
            camera_matrix = "mat4",
            model_matrix = "mat4",
        },
        attributes = {
            position = "vec2",
        },
        vertex_attributes = {
            {pos = "vec2"},
            {uv = "vec2"},
            {color = "vec4"},
        },
        -- if main is not defined it will wrap void main() { *line here* } around the line
        source = "gl_Position = camera_matrix * model_matrix * vec4(position, 0.0, 1.0);"
    },

    fragment = {
        uniform = {
            add_color = 0, -- guess the type and use passed var as default if not passed
            global_color = Color(1,1,1,1),
            texture = Texture(16,16):Fill(function()
                return 255, 255, 255, 255
            end),
        },
        -- when attributes is used outside of vertex they are simply sent from vertex shader
        -- as "__out_foo" and then grabbed from the other shader with a macro to turn its name
        -- back to "foo" with #define
        attributes = {
            uv = "vec2",
            color = "vec4",
        },
        source = [[
            out vec4 frag_color;

            vec4 texel = texture2D(texture, uv);

            void main()
            {
                if (add_color > 0.5)
                {
                    frag_color = texel * color;
                    frag_color.xyz = frag_color.xyz + global_color.xyz;
                    frag_color.w = frag_color.w * global_color.w;
                }
                else
                {
                    frag_color = texel * color * global_color;
                }
            }
        ]]
    }
}

local mat = Material("2d_rect", data)

-- this creates buffer from the vertex_attributes field in our material
local buffer = mat:CreateVertexBuffer({
    {pos = {0, 0}, uv = {0, 1}, color = {1,1,1,1}},
    {pos = {0, 1}, uv = {0, 0}, color = {1,1,1,1}},
    {pos = {1, 1}, uv = {1, 0}, color = {1,1,1,1}},

    {pos = {1, 1}, uv = {1, 0}, color = {1,1,1,1}},
    {pos = {1, 0}, uv = {1, 1}, color = {1,1,1,1}},
    {pos = {0, 0}, uv = {0, 1}, color = {1,1,1,1}},
})

event.AddListener("OnDraw2D", "hm", function()

    -- use the built in matrices cause we dont have our own (yet!)
    gl.Translatef(50, 50, 0)
    gl.Scalef(100, 100, 0)

    gl.GetFloatv(e.GL_MODELVIEW_MATRIX, render.model_matrix)
    gl.GetFloatv(e.GL_PROJECTION_MATRIX, render.camera_matrix)

    --set the uniform fields
    mat.model_matrix = render.model_matrix
    mat.camera_matrix = render.camera_matrix
    mat.global_color = HSVToColor(glfw.GetTime())

    buffer:Draw(mat)
end)