snths_ui/ui.odin

147 lines
3.7 KiB
Odin

package synthas_ui
v2 :: [2]f32
rect2 :: struct {x, y, width, height: f32}
@private rect_get_tl :: #force_inline proc(rect: rect2) -> v2 {return {rect.x, rect.y}}
@private rect_get_tr :: #force_inline proc(rect: rect2) -> v2 {return {rect.x + rect.width, rect.y}}
@private rect_get_br :: #force_inline proc(rect: rect2) -> v2 {return {rect.x + rect.width, rect.y + rect.height}}
@private rect_get_bl :: #force_inline proc(rect: rect2) -> v2 {return {rect.x, rect.y + rect.height}}
@private rect_grow :: proc(rect: rect2, amount: v2) -> rect2 {
return {rect.x - amount.x / 2.0, rect.y - amount.y / 2.0, rect.width + amount.x, rect.height + amount.y}
}
@private ctx: ^Context
Context :: struct {
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,
using config: ElementConfiguration,
type: ElementType,
}
ElementConfiguration :: struct {
label: cstring,
color: [4]u8,
margin, padding: v2,
}
ElementType :: enum {
Container,
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.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
}
element_get_outer_area :: proc(element: Element) -> rect2 {
return rect_grow(element.area, element.margin * 2.0)
}
element_get_inner_area :: proc(element: Element) -> rect2 {
return rect_grow(element.area, -element.padding * 2.0)
}
container_begin :: proc(dimensions: Dimensions, config: ElementConfiguration) {
ctx.element_position += config.margin
size := _resolve_dimensions(dimensions) - config.margin * 2.0
area := rect2{**ctx.element_position, **size}
ctx.element_position += config.padding
element := Element{area = area, config = config, type = .Container}
append(&ctx.elements, element)
container := _element_last()
append(&ctx.container_stack, container)
}
container_end :: proc() {
container := pop(&ctx.container_stack)
// TODO: Set flex
outer := element_get_outer_area(container^)
ctx.element_position = rect_get_bl(outer)
}
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 {
inner := element_get_inner_area(container^)
container_size := inner.width if axis == .X else inner.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]
}