Starting to layout scaffolding for UI based on RAD Debugger/Ryan's UI Series

code/ui.odin

@@ -0,0 +1,212 @@
+package sectr
+
+// Based off Ryan Fleury's UI Series & Epic's RAD Debugger which directly implements a version of it.
+// You will see Note(rjf) these are comments directly from the RAD Debugger codebase by Fleury.
+// TODO(Ed) If I can, I would like this to be its own package, but the nature of packages in odin may make this difficult.
+
+// TODO(Ed) : This is in Raddbg base_types.h, consider moving outside of UI.
+Axis2 :: enum {
+	Invalid =  -1,
+	X,
+	Y,
+	Count,
+}
+
+UI_SizeKind :: enum u32 {
+	Null,
+	Pixels,
+	Points,
+	TextContent,
+	PercentOfParent,
+	ChildrenSum,
+}
+
+UI_Size :: struct {
+	kind       : UI_SizeKind,
+	value      : f32,
+	strictness : f32,
+}
+
+UI_Size2 : struct {
+	kind       : [Axis2.Count]UI_SizeKind,
+	value      : Vec2,
+	strictness : Vec2,
+}
+
+UI_Layout :: struct {
+	placeholder : int
+}
+
+UI_Key :: struct {
+	opaque : [1]u64,
+}
+
+UI_BoxFlag :: enum u64 {
+	// Note(rjf) : Interaction
+	Mouse_Clickable,
+	Keyboard_Clickable,
+	Click_To_Focus,
+	Scroll,
+	View_Scroll_X,
+	View_Scroll_Y,
+	View_Clamp_X,
+	View_Clamp_Y,
+	Focus_Active,
+	Focus_Active_Disabled,
+	Focus_Hot,
+	Focus_Hot_Disabled,
+	Default_Focus_Nav_X,
+	Default_Focus_Nav_Y,
+	Default_Focus_Edit,
+	Focus_Nav_Skip,
+	Disabled,
+
+	// Note(rjf) : Layout
+	Floating_X,
+	Floating_Y,
+	Fixed_Width,
+	Fixed_Height,
+	Allow_Overflow_X,
+	Allow_Overflow_Y,
+	Skip_View_Off_X,
+	Skip_View_Off_Y,
+
+	// Note(rjf) : Appearance / Animation
+	Draw_Drop_Shadow,
+	Draw_Background_Blur,
+	Draw_Background,
+	Draw_Border,
+	Draw_Side_Top,
+	Draw_Side_Bottom,
+	Draw_Side_Left,
+	Draw_Side_Right,
+	Draw_Text,
+	Draw_Text_Fastpath_Codepoint,
+	Draw_Hot_Effects,
+	Draw_Overlay,
+	Draw_Bucket,
+	Clip,
+	Animate_Pos_X,
+	Animate_Pos_Y,
+	Disable_Text_Trunc,
+	Disable_ID_String,
+	Disable_Focus_Viz,
+	Require_Focus_Background,
+	Has_Display_String,
+	Has_Fuzzy_Match_Ranges,
+	Round_Children_By_Parent,
+}
+UI_BoxFlags :: bit_set[UI_BoxFlag; u64]
+
+UI_BoxFlags_Null      :: UI_BoxFlags {}
+UI_BoxFlags_Clickable :: UI_BoxFlags { .Mouse_Clickable, .Keyboard_Clickable }
+
+UI_NullLabel :: ""
+
+// Note(Ed) : This is called UI_Widget in the substack series, its called box in raddbg
+// This eventually gets renamed by part 4 of the series to UI_Box.
+// However, its essentially a UI_Node or UI_BaselineEntity, etc.
+// Think of godot's Control nodes I guess.
+UI_Box :: struct {
+	// Note(rjf) : persistent links
+	hash : struct {
+		next, prev : ^ UI_Box,
+	},
+
+	// Note(rjf) : Per-build links & data
+	first, last, prev, next : ^ UI_Box,
+	num_children : i32,
+
+	// Note(rjf) : Key + generation info
+	key                      : UI_Key,
+	last_frame_touched_index : u64,
+
+	// Note(rjf) : Per-frame info provided by builders
+	flags : UI_BoxFlags,
+	semantic_size    : [Axis2.Count]UI_Size,
+
+	// Note(rjf) : Computed every frame
+	computed_rel_pos : Vec2,
+	computed_size    : Vec2,
+	//rect : Rng2F32
+
+	// Note(rjf) : Persistent data
+	hot    : f32,
+	active : f32,
+
+	// bg_color  : Color,
+	// txt_color : Color,
+}
+
+UI_Signal :: struct {
+	box : UI_Box,
+	cursor_pos : Vec2,
+	drag_delta : Vec2,
+	scroll     : Vec2,
+	left_clicked     : b8,
+	right_clicked    : b8,
+	double_clicked   : b8,
+	keyboard_clicked : b8,
+	pressed    : b8,
+	released   : b8,
+	dragging   : b8,
+	hovering   : b8,
+	mouse_over : b8,
+	commit     : b8,
+}
+
+ui_key_null :: proc() -> UI_Key {
+	return {}
+}
+
+ui_key_from_string :: proc( value : string ) -> UI_Key {
+	 return {}
+}
+
+ui_key_match :: proc( a, b : UI_Key ) -> b32 {
+	 return false
+}
+
+ui_box_make :: proc( flags : UI_BoxFlags, label : string ) -> (^ UI_Box) {
+	return nil
+}
+
+ui_box_equip_display_string :: proc( box : ^ UI_Box, display_string : string ) {
+
+}
+
+ui_box_equip_child_layout_axis :: proc( box : ^ UI_Box, axis : Axis2 ) {
+
+}
+
+ui_push_parent :: proc( box : ^ UI_Box ) -> (^ UI_Box) {
+	return nil
+}
+
+ui_pop_parent :: proc() -> (^ UI_Box) {
+	return nil
+}
+
+ui_signal_from_box :: proc( box : ^ UI_Box ) -> UI_Signal {
+	return {}
+}
+
+ui_button :: proc( label : string ) -> UI_Signal {
+	button_flags : UI_BoxFlags =
+		UI_BoxFlags_Clickable & {
+			.Draw_Border,
+			.Draw_Text,
+			.Draw_Background,
+			.Focus_Hot,
+			.Focus_Active,
+		}
+	box    := ui_box_make( button_flags, label )
+	signal := ui_signal_from_box( box )
+	return signal
+}
+
+ui_spacer :: proc ( label : string = UI_NullLabel ) -> UI_Signal {
+	box    := ui_box_make( UI_BoxFlags_Null, label )
+	signal := ui_signal_from_box( box )
+	return signal
+}