no_overflow & SMODS.UIScrollBox: Cutting-edge technology

lovely/ui_overflow.toml

@@ -0,0 +1,87 @@
+[manifest]
+version = "1.0.0"
+dump_lua = true
+priority = -10
+
+# Allow use stencil in global canvas
+# Game:draw()
+[[patches]]
+[patches.pattern]
+target = "game.lua"
+pattern = '''love.graphics.setCanvas{self.CANVAS}'''
+position = "at"
+payload = '''
+love.graphics.setCanvas{self.CANVAS, stencil = true}
+'''
+match_indent = true
+
+# Limit overflow container size
+# UIBox:calculate_xywh()
+[[patches]]
+[patches.pattern]
+target = "engine/ui.lua"
+pattern = '''_nt.h = math.max(_ct.h + padding, _nt.h)-- '''
+position = "after"
+payload = '''
+if node.config and node.config.no_overflow then
+    if node.config.w then
+        _nt.w = node.config.w
+    elseif node.config.maxw then
+        _nt.w = math.min(_nt.w, node.config.maxw)
+    end
+    if node.config.h then
+        _nt.h = node.config.h
+    elseif node.config.maxh then
+        _nt.h = math.min(_nt.h, node.config.maxh)
+    end
+end
+'''
+match_indent = true
+
+# Prevent text be rescaled by overflow container
+# UIBox:calculate_xywh()
+[[patches]]
+[patches.pattern]
+target = "engine/ui.lua"
+pattern = '''fac = fac*restriction/(node.config.maxw and _ct.w or _ct.h)'''
+position = "after"
+payload = '''
+if node.config.no_overflow then fac = _scale or 1 end
+'''
+match_indent = true
+
+# Limit overflow container size during filling
+# UIElement:set_wh()
+[[patches]]
+[patches.pattern]
+target = "engine/ui.lua"
+pattern = '''if w.UIT == G.UIT.C then w.T.h = _max_h end'''
+position = "after"
+payload = '''
+if w.config and w.config.no_overflow then
+    if w.config.w then
+        w.T.w = w.config.w
+    elseif w.config.maxw then
+        w.T.w = math.min(w.T.w, w.config.maxw)
+    end
+    if w.config.h then
+        w.T.h = w.config.h
+    elseif w.config.maxh then
+        w.T.h = math.min(w.T.h, w.config.maxh)
+    end
+end
+'''
+match_indent = true
+
+# Exclude overflowed elements from colliding
+# Controller:get_cursor_collision()
+[[patches]]
+[patches.pattern]
+target = "engine/controller.lua"
+pattern = '''if v:collides_with_point(cursor_trans) and not v.REMOVED then'''
+position = "at"
+payload = '''
+if v:collides_with_point(cursor_trans) and not v.REMOVED and v:inside_overflow_boundaries(cursor_trans) then
+'''
+match_indent = true
+overwrite = false

lsp_def/ui.lua

@@ -3,6 +3,9 @@
 SMODS.GUI = {}
 SMODS.GUI.DynamicUIManager = {}
 
+--- @type table<function>
+SMODS.stencil_stack = {}
+
 ---@type string|"achievements"|"config"|"credits"|"mod_desc"|"additions"
 SMODS.LAST_SELECTED_MOD_TAB = ""
 
@@ -53,14 +56,76 @@ G.UIT = {
 ---@field vert? boolean Sets if the text is drawn vertically.
 ---@field object? Node Object to render.
 ---@field role? "Major"|"Minor"|"Glued" Sets object's role type.
+---@field no_overflow? boolean Renders node as overflow container: constrain it's size, truncate drawing and prevent colliding child nodes which go outside of parent's boundaries
 
 --- Internal class for annotating UIBox/UIElement tables before being turned into objects.
 ---@class UINode: table
 ---@field n G.UIT Type of UIBox/UIElement
 ---@field config UINode.config Config of the UINode.
 ---@field nodes? UINode[] Child UINodes
 
+--
+
+---@class SMODS.UIScrollBox.input
+---@field content Moveable | { definition: UINode, config: table, T?: table } Moveable or UIBox definition to render inside scrollable content (passed to G.UIT.O).
+---@field container? { node_config?: UINode.config, config?: table, T?: table } UIBox args for scroll container which will be moved to create scroll effect.
+---@field overflow? { node_config?: UINode.config, config?: table, T?: table } UIBox args for main element.
+---@field progress? { x?: number, y?: number } Value of scroll content relative offset in directions (0-1). Keeps reference for original table.
+---@field offset? { x?: number, y?: number } Value of scroll content absolute offset in directions (in game units). Keeps reference for original table.
+---@field sync_mode? "offset" | "progress" | "none" Sync mode. `offset` sync progress to match offset, `progress` sync offset to match progress, `none` disables syncing. Default is `progress`.
+---@field scroll_move? fun(self: SMODS.UIScrollBox, dt: number) Function which called every frame before scroll syncing and can be used to perform automatic scrolling.
+
+--- Element for displaying scrollable content
+---@class SMODS.UIScrollBox: UIBox
+---@field content Moveable Displayed content.
+---@field content_container UIBox Container which positions `content` according to scroll offset.
+---@field scroll_args SMODS.UIScrollBox.input Input args
+---@field scroll_progress { x: number, y: number } Relative offset of scroll content in directions (0-1). Keeps reference for original table.
+---@field scroll_offset { x: number, y: number } Absolute offset of scroll content in directions (in game units). Keeps reference for original table.
+---@field scroll_sync_mode "offset" | "progress" | "none" Sync mode. `offset` sync progress to match offset, `progress` sync offset to match progress, `none` disables syncing. Default is `progress`.
+---@overload fun(args: SMODS.UIScrollBox.input): SMODS.UIScrollBox
+SMODS.UIScrollBox = {}
+SMODS.UIScrollBox.__index = SMODS.UIScrollBox
+SMODS.UIScrollBox.super = UIBox
+
+---@return number, number
+--- Distance of content overflow in both directions
+function SMODS.UIScrollBox:get_scroll_distance() end
+
+--- Update offset to match progress. Called every frame if `scroll_sync_mode = "progress"`
+function SMODS.UIScrollBox:sync_scroll_offset() end
+
+--- Update progress to match offset. Called every frame if `scroll_sync_mode = "offset"`
+function SMODS.UIScrollBox:sync_scroll_progress() end
+
+---@param t? { x?: number, y?: number }
+--- Set new table for offset (keeps reference), and sync progress to match new offset
+function SMODS.UIScrollBox:set_scroll_offset(t) end
+
+---@param t? { x?: number, y?: number }
+--- Set new table for progress (keeps reference), and sync offset to match new progress
+function SMODS.UIScrollBox:set_scroll_progress(t) end
+
+---@param dt number
+---@param init? boolean Is sync called during initialization
+--- Perform syncing according to `scroll_sync_mode`, and position elements to match result offset
+function SMODS.UIScrollBox:sync_scroll(dt, init) end
+
 -- UI Functions
+
+---@param stencil_fn fun(exit?: boolean)
+--- Add new stencil to stencil stack; result stencil is sum of all stencils in stack
+function SMODS.push_to_stencil_stack(stencil_fn) end
+
+--- Discard last applied stencil in stack
+function SMODS.pop_from_stencil_stack() end
+
+--- Cleanup stencil stack
+function SMODS.reset_stencil_stack() end
+
+--- Reload stencil stack by cleaning up current stencil and redrawing all stencils from stack
+function SMODS.reload_stencil_stack() end
+
 ---@param str string
 ---@return any
 --- Unpacks provided string. 

src/ui.lua

@@ -1,6 +1,201 @@
 SMODS.GUI = {}
 SMODS.GUI.DynamicUIManager = {}
 
+-- used to properly truncate overflow content inside another overflow content
+SMODS.stencil_stack = {}
+
+function SMODS.push_to_stencil_stack(stencil_fn)
+    assert(type(stencil_fn) == "function", "No stencil function passed to SMODS.push_to_stencil_stack")
+    local old_level = #SMODS.stencil_stack
+	local new_level = old_level + 1
+
+    love.graphics.setStencilTest("equal", old_level)
+	love.graphics.stencil(function()
+		stencil_fn(false)
+	end, "increment", 1, true)
+	love.graphics.setStencilTest("equal", new_level)
+
+	SMODS.stencil_stack[new_level] = stencil_fn
+end
+function SMODS.pop_from_stencil_stack()
+    local old_level = #SMODS.stencil_stack
+	local new_level = old_level - 1
+
+    local stencil_fn = SMODS.stencil_stack[old_level]
+	if not stencil_fn then
+		return
+	end
+
+    love.graphics.setStencilTest("equal", old_level)
+	love.graphics.stencil(function()
+		stencil_fn(true)
+	end, "decrement", 1, true)
+	love.graphics.setStencilTest("equal", new_level)
+
+	SMODS.stencil_stack[old_level] = nil
+end
+function SMODS.reset_stencil_stack()
+    EMPTY(SMODS.stencil_stack)
+    love.graphics.setStencilTest()
+    love.graphics.stencil(function() end)
+end
+function SMODS.reload_stencil_stack()
+    local stack_snapshot = SMODS.shallow_copy(SMODS.stencil_stack)
+    SMODS.reset_stencil_stack()
+    for _, stencil_fn in ipairs(stack_snapshot) do
+        SMODS.push_to_stencil_stack(stencil_fn)
+    end
+end
+
+local gameDrawRef = Game.draw
+function Game:draw(...)
+    SMODS.reset_stencil_stack()
+    gameDrawRef(self, ...)
+end
+
+--
+
+local uieDrawChildrenRef = UIElement.draw_children
+function UIElement:draw_children(...)
+	local stenciled = false
+	if self.states.visible and self.config and self.config.no_overflow then
+        -- draw stencil for overflow container
+		stenciled = true
+		SMODS.push_to_stencil_stack(function(exit)
+			prep_draw(self, 1)
+			love.graphics.scale(1 / G.TILESIZE)
+			love.graphics.setColor(0, 0, 0, 1)
+
+			if self.config.r and self.VT.w > 0.01 then
+				self:draw_pixellated_rect("fill", 0)
+			else
+				love.graphics.rectangle("fill", 0, 0, self.VT.w * G.TILESIZE, self.VT.h * G.TILESIZE)
+			end
+
+			love.graphics.pop()
+		end)
+	end
+	uieDrawChildrenRef(self, ...)
+    -- cancel stencil for overflow container
+	if stenciled then SMODS.pop_from_stencil_stack() end
+end
+
+
+-- collision check
+function Node:inside_overflow_boundaries(point)
+    -- Use cached value if present for current point
+	if self.overflow_check_timer == G.TIMERS.REAL and self.overflow_check_point == point then
+		return self.overflow_check_result or false
+	end
+	self.overflow_check_timer = G.TIMERS.REAL
+    self.overflow_check_point = point
+    local r = true
+
+    -- No parent = no overflow can be done so collide as usual
+    if not self.parent then r = true
+    -- If parent has overflow then we should check do we collide with it and if not, all children in it cannot be collided too
+    elseif self.parent.config and self.parent.config.no_overflow and not Node.collides_with_point(self.parent, point) then r = false
+    -- Otherwise process all parents looking for first non-collideable overflow
+    else r = Node.inside_overflow_boundaries(self.parent, point) end
+
+    self.overflow_check_result = r
+    return r
+end
+
+--
+
+SMODS.UIScrollBox = UIBox:extend()
+function SMODS.UIScrollBox:init(args)
+    args = SMODS.merge_defaults(args, { content = {}, container = {}, overflow = {}, sync_mode = "progress" })
+    args.progress = SMODS.merge_defaults(args.progress, { x = 0, y = 0 })
+    args.offset = SMODS.merge_defaults(args.offset, { x = 0, y = 0 })
+
+	self.scroll_args = args
+	self.scroll_progress = args.progress
+	self.scroll_offset = args.offset
+	self.scroll_sync_mode = args.sync_mode
+
+	if args.content and args.content.is and args.content:is(Object) then
+		self.content = args.content
+	else
+		self.content = UIBox(args.content)
+	end
+
+    args.container.config = SMODS.merge_defaults(args.container.config, { align = "cm", offset = { x = 0, y = 0 } })
+    args.container.node_config = SMODS.merge_defaults(args.container.node_config, { colour = G.C.CLEAR })
+	args.container.definition = {
+		n = G.UIT.ROOT,
+		config = args.container.node_config,
+		nodes = {
+			{
+				n = G.UIT.O,
+				config = {
+					object = self.content,
+				},
+			},
+		},
+	}
+	self.content_container = UIBox(args.container)
+
+    args.overflow.config = SMODS.merge_defaults(args.overflow.config, {})
+    args.overflow.node_config = SMODS.merge_defaults(args.overflow.node_config, { colour = G.C.CLEAR, no_overflow = true })
+	args.overflow.definition = {
+		n = G.UIT.ROOT,
+		config = args.overflow.node_config,
+		nodes = {
+			{
+				n = G.UIT.O,
+				config = {
+					object = self.content_container,
+				},
+			},
+		},
+	}
+
+	UIBox.init(self, args.overflow)
+
+	self:sync_scroll(0, true)
+end
+function SMODS.UIScrollBox:get_scroll_distance()
+	return math.max(0, self.content_container.T.w - self.T.w), math.max(0, self.content_container.T.h - self.T.h)
+end
+function SMODS.UIScrollBox:sync_scroll_offset()
+	local dx, dy = self:get_scroll_distance()
+	self.scroll_offset.x = dx * (self.scroll_progress.x or 0)
+	self.scroll_offset.y = dy * (self.scroll_progress.y or 0)
+end
+function SMODS.UIScrollBox:sync_scroll_progress()
+	local dx, dy = self:get_scroll_distance()
+	self.scroll_progress.x = (dx == 0 and 0) or ((self.offset.x or 0) / dx)
+	self.scroll_progress.y = (dy == 0 and 0) or ((self.offset.y or 0) / dy)
+end
+function SMODS.UIScrollBox:set_scroll_offset(t)
+	self.scroll_offset = SMODS.merge_defaults(t, { x = 0, y = 0 })
+	self:sync_scroll_progress()
+end
+function SMODS.UIScrollBox:set_scroll_progress(t)
+	self.scroll_progress = SMODS.merge_defaults(t, { x = 0, y = 0 })
+	self:sync_scroll_offset()
+end
+function SMODS.UIScrollBox:sync_scroll(dt, init)
+	if self.scroll_sync_mode == "progress" then
+        self:sync_scroll_offset()
+	elseif self.scroll_sync_mode == "offset" then
+		self:sync_scroll_progress()
+	end
+	self.content_container.config.offset.x = -(self.scroll_offset.x or 0)
+	self.content_container.config.offset.y = -(self.scroll_offset.y or 0)
+end
+function SMODS.UIScrollBox:update(dt)
+	if self.scroll_args.scroll_move then
+		self.scroll_args.scroll_move(self, dt)
+	end
+	self:sync_scroll(dt)
+	UIBox.update(self, dt)
+end
+
+--
+
 function STR_UNPACK(str)
     local chunk, err = loadstring(str)
     if chunk then