frontend-tools: Add a lua script that draws an analog clock

Closes jp9000/obs-studio#1159

UI/frontend-plugins/frontend-tools/data/scripts/clock-source.lua

+obs = obslua
+bit = require("bit")
+
+source_def = {}
+source_def.id = "lua_clock_source"
+source_def.output_flags = bit.bor(obs.OBS_SOURCE_VIDEO, obs.OBS_SOURCE_CUSTOM_DRAW)
+
+source_def.get_name = function()
+	return "Lua Clock"
+end
+
+source_def.create = function(source, settings)
+	local data = {}
+	data.image = obs.gs_image_file()
+	data.hour_image = obs.gs_image_file()
+	data.minute_image = obs.gs_image_file()
+	data.second_image = obs.gs_image_file()
+
+	image_source_load(data.image, script_path() .. "clock-source/dial.png")
+	image_source_load(data.hour_image, script_path() .. "clock-source/hour.png")
+	image_source_load(data.minute_image, script_path() .. "clock-source/minute.png")
+	image_source_load(data.second_image, script_path() .. "clock-source/second.png")
+
+	return data
+end
+
+function image_source_load(image, file)
+	obs.obs_enter_graphics();
+	obs.gs_image_file_free(image);
+	obs.obs_leave_graphics();
+
+	obs.gs_image_file_init(image, file);
+
+	obs.obs_enter_graphics();
+	obs.gs_image_file_init_texture(image);
+	obs.obs_leave_graphics();
+
+	if not image.loaded then
+		print("failed to load texture " .. file);
+	end
+end
+
+source_def.update = function(data, settings)
+	image_source_load(data)
+end
+
+source_def.video_render = function(data, effect)
+	if not data.image.texture then
+		return;
+	end
+
+	local time = os.date("*t")
+	local seconds = time.sec
+	local mins = time.min + seconds / 60.0;
+	local hours = time.hour + (mins * 60.0) / 3600.0;
+
+	effect = obs.obs_get_base_effect(obs.OBS_EFFECT_DEFAULT)
+
+	obs.gs_blend_state_push()
+	obs.gs_reset_blend_state()
+
+	while obs.gs_effect_loop(effect, "Draw") do
+		obs.obs_source_draw(data.image.texture, 0, 0, data.image.cx, data.image.cy, false);
+	end
+
+	obs.gs_matrix_push()
+	obs.gs_matrix_translate3f(250, 250, 0)
+	obs.gs_matrix_rotaa4f(0.0, 0.0, 1.0, 2 * math.pi / 60 * mins);
+	obs.gs_matrix_translate3f(-250, -250, 0)
+
+	while obs.gs_effect_loop(effect, "Draw") do
+		obs.obs_source_draw(data.minute_image.texture, 0, 0, data.image.cx, data.image.cy, false);
+	end
+
+	obs.gs_matrix_pop()
+
+	obs.gs_matrix_push()
+	obs.gs_matrix_translate3f(250, 250, 0)
+	obs.gs_matrix_rotaa4f(0.0, 0.0, 1.0, 2.0 * math.pi / 12 * hours);
+	obs.gs_matrix_translate3f(-250, -250, 0)
+
+	while obs.gs_effect_loop(effect, "Draw") do
+		obs.obs_source_draw(data.hour_image.texture, 0, 0, data.image.cx, data.image.cy, false);
+	end
+
+	obs.gs_matrix_pop()
+
+	obs.gs_matrix_push()
+	obs.gs_matrix_translate3f(250, 250, 0)
+	obs.gs_matrix_rotaa4f(0.0, 0.0, 1.0, 2 * math.pi / 60 * seconds);
+	obs.gs_matrix_translate3f(-250, -250, 0)
+
+	while obs.gs_effect_loop(effect, "Draw") do
+		obs.obs_source_draw(data.second_image.texture, 0, 0, data.image.cx, data.image.cy, false);
+	end
+
+	obs.gs_matrix_pop()
+
+	obs.gs_blend_state_pop()
+end
+
+source_def.get_width = function(data)
+	return 500
+end
+
+source_def.get_height = function(data)
+	return 500
+end
+
+function script_description()
+	return "Adds a \"Lua Clock\" source which draws an animated analog clock."
+end
+
+obs.obs_register_source(source_def)