WIP: Persistent order support for rooted boxes (top-most boxes)

I wasn't expecting it to be this to bad to support it...

Also:
* I renamed some of the files to group better with the virtual codebase view

code/ui_layout.odin

@@ -143,5 +143,143 @@ ui_set_layout :: #force_inline proc( layout : UI_Layout, preset : UI_StylePreset
 Widget Layout Ops
 */
 
-ui_layout_children_horizontally :: proc( container : ^UI_Box, direction : UI_LayoutDirectionX, width_ref : ^f32 ) {
+ui_layout_children_horizontally :: proc( container : ^UI_Box, direction : UI_LayoutDirectionX, width_ref : ^f32 )
+{
+	container_width : f32
+	if width_ref != nil {
+		container_width = width_ref ^
+	}
+	else {
+		container_width = container.computed.content.max.x - container.computed.content.min.x
+	}
+
+	// do layout calculations for the children
+	total_stretch_ratio : f32 = 0.0
+	size_req_children   : f32 = 0
+	for child := container.first; child != nil; child = child.next
+	{
+		using child.layout
+		scaled_width_by_height : b32 = b32(.Scale_Width_By_Height_Ratio in flags)
+		if .Fixed_Width in flags
+		{
+			if scaled_width_by_height {
+				height := size.max.y != 0 ? size.max.y : container_width
+				width  := height * size.min.x
+
+				size_req_children += width
+				continue
+			}
+
+			size_req_children += size.min.x
+			continue
+		}
+
+		total_stretch_ratio += anchor.ratio.x
+	}
+
+	avail_flex_space := container_width - size_req_children
+
+	allocate_space :: proc( child : ^UI_Box, total_stretch_ratio, avail_flex_space : f32 )
+	{
+		using child.layout
+		if ! (.Fixed_Width in flags) {
+			size.min.x = anchor.ratio.x * (1 / total_stretch_ratio) * avail_flex_space
+		}
+		flags    |= {.Fixed_Width}
+	}
+
+	space_used : f32 = 0.0
+	switch direction{
+		case .Right_To_Left:
+			for child := container.last; child != nil; child = child.prev {
+				allocate_space(child, total_stretch_ratio, avail_flex_space)
+				using child.layout
+				anchor      = range2({0, 0}, {0, 0})
+				alignment   = { 0, 1 }// - hbox.layout.alignment
+				pos.x       = space_used
+				space_used += size.min.x
+				size.min.y  = container.computed.content.max.y - container.computed.content.min.y
+			}
+		case .Left_To_Right:
+			for child := container.first; child != nil; child = child.next {
+				allocate_space(child, total_stretch_ratio, avail_flex_space)
+				using child.layout
+				anchor      = range2({0, 0}, {0, 0})
+				alignment   = { 0, 1 }
+				pos.x       = space_used
+				space_used += size.min.x
+				size.min.y  = container.computed.content.max.y - container.computed.content.min.y
+			}
+	}
+}
+
+ui_layout_children_vertically :: proc( container : ^UI_Box, direction : UI_LayoutDirectionY, height_ref : ^f32 )
+{
+	container_height : f32
+	if height_ref != nil {
+		container_height = height_ref ^
+	}
+	else {
+		container_height = container.computed.content.max.y - container.computed.content.min.y
+	}
+
+	// do layout calculations for the children
+	total_stretch_ratio : f32 = 0.0
+	size_req_children   : f32 = 0
+	for child := container.first; child != nil; child = child.next
+	{
+		using child.layout
+		scaled_width_by_height : b32 = b32(.Scale_Width_By_Height_Ratio in flags)
+		if .Fixed_Height in flags
+		{
+			if scaled_width_by_height {
+				width  := size.max.x != 0 ? size.max.x : container_height
+				height := width * size.min.y
+
+				size_req_children += height
+				continue
+			}
+
+			size_req_children += size.min.y
+			continue
+		}
+
+		total_stretch_ratio += anchor.ratio.y
+	}
+
+	avail_flex_space := container_height - size_req_children
+
+	allocate_space :: proc( child : ^UI_Box, total_stretch_ratio, avail_flex_space : f32 )
+	{
+		using child.layout
+		if ! (.Fixed_Height in flags) {
+			size.min.y = anchor.ratio.y * (1 / total_stretch_ratio) * avail_flex_space
+		}
+		flags    |= {.Fixed_Height}
+		alignment = {0, 0}
+	}
+
+	space_used : f32 = 0.0
+	switch direction {
+		case .Top_To_Bottom:
+			for child := container.last; child != nil; child = child.prev {
+				allocate_space(child, total_stretch_ratio, avail_flex_space)
+				using child.layout
+				anchor      = range2({0, 0}, {0, 1})
+				// alignment   = {0, 1}
+				pos.y       = space_used
+				space_used += size.min.y
+				size.min.x  = container.computed.content.max.x - container.computed.content.min.x
+			}
+		case .Bottom_To_Top:
+			for child := container.first; child != nil; child = child.next {
+				allocate_space(child, total_stretch_ratio, avail_flex_space)
+				using child.layout
+				anchor      = range2({0, 0}, {0, 1})
+				// alignment   = {0, 1}
+				pos.y       = space_used
+				space_used += size.min.y
+				size.min.x  = container.computed.content.max.x - container.computed.content.min.x
+			}
+	}
 }