local gl = honey.gl

local module = {}
setmetatable(module, {__index=_G})
setfenv(1, module)


local cache = {}

-- load an image into a gl texture
local function loadImage(filename)
	local data, width, height = honey.image.load(filename, 4)
	local texture = gl.GenTextures()
	gl.BindTexture(gl.TEXTURE_2D, texture)
	gl.TexImage2D(
		gl.TEXTURE_2D, 0,
		gl.RGBA, width, height,
		gl.RGBA, gl.UNSIGNED_BYTE, data
	)
	gl.GenerateMipmap(gl.TEXTURE_2D)
	honey.image.destroy(data)
	return texture
end

-- cached get a texture
get = function(filename)
	if not cache[filename] then
		cache[filename] = loadImage(filename)
	end
	return cache[filename]
end

-- remove a texture from the cache
forget = function(filename)
	local texture = cache[filename]
	if texture then
		gl.DeleteTextures(texture)
	end
	cache[filename] = nil
end

-- remove all textures from the cache
clearCache = function(filename)
	for key in pairs(cache) do
		forget(key)
	end
end

return module