Initial commit

ui.odin

@@ -0,0 +1,137 @@
+package synthas_ui
+
+v2 :: [2]f32
+rect2 :: struct {x, y, width, height: f32}
+
+@private rect_get_bl :: proc(rect: rect2) -> v2 {
+	return {rect.x, rect.y + rect.height}
+}
+
+@private ctx: ^Context
+
+Context :: struct {
+	container_position, element_position: v2,
+	container_stack: [dynamic]^Element,
+	elements: [dynamic]Element,
+	same_line: bool,
+}
+
+init :: proc(state: ^Context, element_capacity: int, allocator := context.allocator) {
+	state.container_stack = make(type_of(state.container_stack), 0, 8, allocator)
+	state.elements = make(type_of(state.elements), 0, element_capacity, allocator)
+}
+
+Element :: struct {
+	area: rect2,
+	label: cstring,
+	color: [4]u8,
+	data: ElementData,
+}
+
+ElementData :: union {
+	ElementData_Container,
+	ElementData_Button,
+}
+
+Size_Pixels :: distinct f32
+Size_Percentage :: distinct f32
+Size_Flex :: distinct bool
+
+Size :: union {
+	Size_Pixels,
+	Size_Percentage,
+	Size_Flex,
+}
+
+Dimensions :: struct {
+	width, height: Size,
+}
+
+Axis :: enum {X, Y}
+
+start :: proc(ui_context: ^Context, position: v2) {
+	ctx = ui_context
+	ctx.container_position = position
+	ctx.element_position = position
+	clear(&ctx.container_stack)
+	clear(&ctx.elements)
+}
+
+end :: proc() -> []Element {
+	elements := ctx.elements[:]
+	ctx = nil
+	return elements
+}
+
+same_line :: proc() {
+	ctx.same_line = true
+}
+
+ElementData_Container :: struct {
+	margin, padding: v2,
+}
+
+container_begin :: proc(dimensions: Dimensions, margin: v2, padding: v2, label: cstring, color: [4]u8) {
+	ctx.container_position += margin
+	area := rect2{**ctx.container_position, **_resolve_dimensions(dimensions)}
+	ctx.element_position = ctx.container_position + padding
+	data := ElementData_Container {margin = margin, padding = padding}
+	element := Element{area = area, color = color, label = label, data = data}
+	append(&ctx.elements, element)
+	container := _element_last()
+	append(&ctx.container_stack, container)
+}
+
+container_end :: proc() {
+	container := pop(&ctx.container_stack)
+	// TODO: Set flex
+	data := container.data.(ElementData_Container)
+	ctx.container_position = rect_get_bl(container.area) + data.margin.y
+	ctx.element_position = ctx.container_position
+}
+
+ElementData_Button :: struct {
+}
+
+button :: proc(dimensions: Dimensions) {
+	area := _context_advance_area(dimensions)
+}
+
+_context_advance_area :: proc(dimensions: Dimensions) -> rect2 {
+	return {}
+}
+
+_resolve_dimensions :: proc(dimensions: Dimensions) -> v2 {
+	return {_resolve_size(dimensions.width, .X), _resolve_size(dimensions.height, .Y)}
+}
+
+_resolve_size :: proc(size: Size, axis: Axis) -> f32 {
+	switch value in size {
+	case Size_Pixels:
+		return cast(f32)value
+	case Size_Percentage:
+		if container := _container_last(); container != nil {
+			container_size := container.area.width if axis == .X else container.area.height
+			return container_size * cast(f32)value
+		} else {
+			panic("Cannot use dimension Size_Percentage without an outer container")
+		}
+	case Size_Flex:
+		return 0.0
+	}
+	unreachable()
+}
+
+_container_last :: proc() -> ^Element {
+	if len(ctx.container_stack) == 0 {
+		return nil
+	}
+	return ctx.container_stack[len(ctx.container_stack) - 1]
+}
+
+_element_last :: proc() -> ^Element {
+	if len(ctx.elements) == 0 {
+		return nil
+	}
+	return &ctx.elements[len(ctx.elements) - 1]
+}