ugui/src/ugui_core.c3

331 lines
6.9 KiB

module ugui;
import vtree;
import cache;
import fifo;
import std::io;
import std::core::string;
struct Rect {
short x, y, w, h;
}
struct Point {
short x, y;
}
struct Color{
char r, g, b, a;
}
// element ids are just long ints
def Id = usz;
enum ElemType {
ETYPE_NONE,
ETYPE_DIV,
ETYPE_BUTTON,
ETYPE_SLIDER,
ETYPE_TEXT,
}
bitstruct ElemFlags : uint {
bool updated : 0;
bool has_focus : 1;
bool is_new : 2;
}
bitstruct ElemEvents : uint {
bool key_press : 0;
bool key_release : 1;
bool key_hold : 2;
bool mouse_hover : 3;
bool mouse_press : 4;
bool mouse_release : 5;
bool mouse_hold : 6;
bool update : 7;
}
struct ElemText {
char* str;
}
// element structure
struct Elem {
Id id;
ElemFlags flags;
ElemEvents events;
Rect bounds;
ElemType type;
union {
ElemDiv div;
ElemButton button;
ElemSlider slider;
ElemText text;
}
}
// relationships between elements are stored in a tree, it stores just the ids
def IdTree = vtree::VTree(<Id>) @private;
// elements themselves are kept in a cache
const uint MAX_ELEMENTS = 1024;
def ElemCache = cache::Cache(<Id, Elem, MAX_ELEMENTS>) @private;
def CmdQueue = fifo::Fifo(<Cmd>);
fault UgError {
INVALID_SIZE,
EVENT_UNSUPPORTED,
UNEXPECTED_ELEMENT,
WRONG_ELEMENT_TYPE,
}
macro Color uint_to_rgba(uint $u) {
return Color{
.r = (char)(($u >> 24) & 0xff),
.g = (char)(($u >> 16) & 0xff),
.b = (char)(($u >> 8) & 0xff),
.a = (char)(($u >> 0) & 0xff)
};
}
const Rect DIV_FILL = { .x = 0, .y = 0, .w = 0, .h = 0 };
const uint STACK_STEP = 10;
const uint MAX_ELEMS = 128;
const uint MAX_CMDS = 256;
const uint ROOT_ID = 1;
enum Layout {
ROW,
COLUMN,
FLOATING
}
// global style, similar to the css box model
struct Style { // css box model
Rect padding;
Rect border;
Rect margin;
Color bgcolor; // background color
Color fgcolor; // foreground color
Color brcolor; // border color
ushort radius;
}
struct Ctx {
Layout layout;
IdTree tree;
ElemCache cache;
CmdQueue cmd_queue;
// total size in pixels of the context
ushort width, height;
Style style;
Font font;
bool has_focus;
struct input {
InputEvents events;
struct mouse {
Point pos, delta;
// mouse_down: bitmap of mouse buttons that are held
// mouse_updated: bitmap of mouse buttons that have been updated
// mouse_released = mouse_updated & ~mouse_down
// mouse_pressed = mouse_updated & mouse_down
MouseButtons down;
MouseButtons updated;
}
}
isz active_div; // tree node indicating the current active div
}
macro point_in_rect(Point p, Rect r)
{
return (p.x >= r.x && p.x <= r.x + r.w) && (p.y >= r.y && p.y <= r.y + r.h);
}
// return true if rect a contains b
macro bool Rect.contains(Rect a, Rect b)
{
return (a.x <= b.x && a.y <= b.y && a.x+a.w >= b.x+b.w && a.y+a.h >= b.y+b.h);
}
macro Rect Rect.intersection(Rect a, Rect b)
{
return Rect{
.x = (short)max(a.x, b.x),
.y = (short)max(a.y, b.y),
.w = (short)min(a.x+a.w, b.x+b.w) - (short)max(a.x, b.x),
.h = (short)min(a.y+a.h, b.y+b.h) - (short)max(a.y, b.y),
};
}
// rect intersection not null
macro bool Rect.collides(Rect a, Rect b)
{
return !(a.x > b.x+b.w || a.x+a.w < b.x || a.y > b.y+b.h || a.y+a.h < b.y);
}
macro bool Rect.is_null(r) => r.x == 0 && r.y == 0 && r.x == 0 && r.w == 0;
// return a pointer to the parent of the current active div
fn Elem*! Ctx.get_parent(&ctx)
{
// FIXME: if the tree held pointers to the elements then no more
// redundant cache search
Id parent_id = ctx.tree.get(ctx.active_div)!;
return ctx.cache.search(parent_id);
}
// get or push an element from the cache, return a pointer to it
// resets all flags except is_new which is set accordingly
macro Ctx.get_elem(&ctx, Id id)
{
Elem empty_elem;
bool is_new;
Elem* c_elem;
c_elem = ctx.cache.get_or_insert(&empty_elem, id, &is_new)!;
c_elem.flags = (ElemFlags)0;
c_elem.flags.is_new = is_new;
return c_elem;
}
// this searches an element in the cache by label, it does not create a new element
// if it does't find one
macro Ctx.get_elem_by_label(&ctx, String label)
{
Id id = label.hash();
return ctx.cache.search(id);
}
macro Ctx.get_elem_by_tree_idx(&ctx, isz idx) @private
{
Id id = ctx.tree.get(ctx.active_div)!;
return ctx.cache.search(id);
}
fn void! Ctx.init(&ctx)
{
ctx.tree.init(MAX_ELEMENTS)!;
defer catch { (void)ctx.tree.free(); }
ctx.cache.init()!;
defer catch { (void)ctx.cache.free(); }
ctx.cmd_queue.init(MAX_ELEMENTS)!;
defer catch { (void)ctx.cmd_queue.free(); }
ctx.layout = Layout.ROW;
ctx.active_div = 0;
// TODO: add style config
ctx.style.margin = Rect{2, 2, 2, 2};
ctx.style.border = Rect{2, 2, 2, 2};
ctx.style.padding = Rect{1, 1, 1, 1};
ctx.style.radius = 5;
ctx.style.bgcolor = uint_to_rgba(0x282828ff);
ctx.style.fgcolor = uint_to_rgba(0xfbf1c7ff);
ctx.style.brcolor = uint_to_rgba(0xd79921ff);
}
fn void Ctx.free(&ctx)
{
(void)ctx.tree.free();
(void)ctx.cache.free();
(void)ctx.cmd_queue.free();
(void)ctx.font.free();
}
fn void! Ctx.frame_begin(&ctx)
{
// 2. Get the root element from the cache and update it
Elem* c_elem = ctx.get_elem(ROOT_ID)!;
// The root should have the updated flag only if the size of the window
// was changed between frames, this propagates an element size recalculation
// down the element tree
c_elem.flags.updated = ctx.input.events.resize | ctx.input.events.force_update;
ctx.input.events.force_update = false;
// if the window has focus then the root element also has focus, no other
// computation needed, child elements need to check the mouse positon and
// other stuff
c_elem.flags.has_focus = ctx.has_focus;
Elem def_root = {
.id = ROOT_ID,
.type = ETYPE_DIV,
.bounds = {
.w = ctx.width,
.h = ctx.height,
},
.div = {
.layout = LAYOUT_ROW,
.children_bounds = {
.w = ctx.width,
.h = ctx.height,
}
},
.flags = c_elem.flags,
};
*c_elem = def_root;
// 3. Push the root element into the element tree
ctx.active_div = ctx.tree.add(ROOT_ID, 0)!;
// The root element does not push anything to the stack
// TODO: add a background color taken from a theme or config
}
fn void! Ctx.force_update(&ctx)
{
ctx.input.events.force_update = true;
}
fn void! Ctx.frame_end(&ctx)
{
Elem* root = ctx.get_elem_by_tree_idx(0)!;
root.div.layout = LAYOUT_ROW;
// 1. clear the tree
ctx.tree.nuke();
// 2. clear input fields
bool f = ctx.input.events.force_update;
ctx.input.events = (InputEvents)0;
ctx.input.events.force_update = f;
// send atlas updates
if (ctx.font.should_update) {
ctx.push_update_atlas(&ctx.font.atlas)!;
ctx.font.should_update = false;
}
$if 1:
// draw mouse position
Cmd cmd = {
.type = CMD_RECT,
.rect.rect = {
.x = ctx.input.mouse.pos.x - 2,
.y = ctx.input.mouse.pos.y - 2,
.w = 4,
.h = 4,
},
.rect.color = uint_to_rgba(0xff00ffff)
};
ctx.cmd_queue.enqueue(&cmd)!;
$endif
}
<*
* @ensure elem != null
*>
fn bool Ctx.is_hovered(&ctx, Elem *elem)
{
return point_in_rect(ctx.input.mouse.pos, elem.bounds);
}