From 79a2d66880bea156e4d81c5bde2d2b4d6b11f368 Mon Sep 17 00:00:00 2001
From: Alessandro Mauri <alemauri001@gmail.com>
Date: Mon, 5 May 2025 16:23:26 +0200
Subject: [PATCH] update project to c3 0.7.1

---
 TODO                          | 34 ++++++++++++++--
 lib/schrift.c3l/libschrift.c3 |  6 +--
 src/cache.c3                  | 31 ++++++++-------
 src/fifo.c3                   | 17 ++++----
 src/main.c3                   | 74 ++++++++++++++++++-----------------
 src/ugui_atlas.c3             | 43 ++++++++++++++++----
 src/ugui_button.c3            | 65 ++++++++++++++++++++++++------
 src/ugui_cmd.c3               | 12 +++---
 src/ugui_core.c3              | 37 ++++++++----------
 src/ugui_div.c3               | 12 +++---
 src/ugui_font.c3              | 43 ++++++++++----------
 src/ugui_input.c3             |  8 ++--
 src/ugui_layout.c3            | 32 +++++++--------
 src/ugui_shapes.c3            | 34 ++++++++--------
 src/ugui_slider.c3            |  8 ++--
 src/ugui_sprite.c3            | 40 ++++++++++---------
 src/ugui_text.c3              |  2 +-
 src/vtree.c3                  | 64 ++++++++++++++----------------
 18 files changed, 324 insertions(+), 238 deletions(-)

diff --git a/TODO b/TODO
index 9b412a2..1817dd9 100644
--- a/TODO
+++ b/TODO
@@ -13,6 +13,8 @@ to maintain focus until mouse release (fix scroll bars)
 [x] Clip element bounds to parent div, specifically text
 [ ] Resizeable divs
 [ ] Implement a z index and sort command buffer based on that
+    [ ] Ctx.set_z_index()
+    [ ] Sort command buffer on insertion
 [ ] Standardize element handling, for example all buttons do almost the same thing, so write a lot of boiler plate and reuse it
 [x] The id combination in gen_id() uses an intger division, which is costly, use another combination function that is non-linear and doesn't use division
 [ ] Animations, somehow
@@ -33,12 +35,19 @@ to maintain focus until mouse release (fix scroll bars)
 [ ] Subdivide modules into ugui::ug for exported functions and ugui::core for
     internal use functions (used to create widgets)
 [ ] The render loop RAPES the gpu, valve pls fix
+[ ] The way the element structures are implemented wastes a lot of memory since
+    each struct Elem, struct Cmd, etc. is as big as the largest element. It would
+    be better to use a different allcation strategy.
+[ ] Add a way to handle time events like double clicks
 
 ## Layout
 
 [ ] Text reflow
 [x] Flexbox
 [ ] Center elements to the row/column
+[ ] Text wrapping
+[ ] Consider a multi-pass recursive approach to layout (like https://github.com/nicbarker/clay)
+    instead of the curren multi-frame approach.
 
 ## Input
 
@@ -51,15 +60,16 @@ to maintain focus until mouse release (fix scroll bars)
 ## Commands
 
 [x] rect commads should have:
-_ border width
-_ border radius
+	- border width
+	- border radius
 [x] add a command to update an atlas
 [ ] New window command, useful for popups
 
-## Atlases
+## Atlas
 
 [ ] Add an interface to create, destroy, update and get atlases based on their ids
 [ ] Implement multiple font atlases
+[ ] Pixel format conversion
 
 ## Fonts
 
@@ -79,3 +89,21 @@ _ border radius
 [ ] Icon Buttons
 [x] Switch
 [x] Checkbox
+[ ] Selectable text box
+
+## Main / exaple
+
+[ ] Create maps from ids to textures and images instead of hardcoding them
+
+
+## API
+
+[ ] Introduce a Layout structure that specifies the positioning of elements inside
+    a Div element. This would allow specifying alignment, maximum and minimum sizing
+    margins between children, etc.
+    This is different from style which is applied per-element.
+[ ] Remove Ids for element that don't need them. Such elements are button, toggles,
+    and all elements which do not have internal data that has to be cached and/or
+    queried by the user for later use. This allows for smaller caches and in general
+    reduces some load, since most of the stuff is recomputed for every frame.
+
diff --git a/lib/schrift.c3l/libschrift.c3 b/lib/schrift.c3l/libschrift.c3
index dde82a5..699d296 100644
--- a/lib/schrift.c3l/libschrift.c3
+++ b/lib/schrift.c3l/libschrift.c3
@@ -1,8 +1,8 @@
 module schrift;
 
-def SftFont = void*;
-def SftUChar = uint;
-def SftGlyph = uint;
+alias SftFont  = void*;
+alias SftUChar = uint;
+alias SftGlyph = uint;
 
 const int SFT_DOWNWARD_Y = 0x01;
 
diff --git a/src/cache.c3 b/src/cache.c3
index fac5cf2..130ffd1 100644
--- a/src/cache.c3
+++ b/src/cache.c3
@@ -1,4 +1,4 @@
-module cache(<Key, Value, SIZE>);
+module cache{Key, Value, SIZE};
 
 /* LRU Cache
  * The cache uses a pool (array) to store all the elements, each element has
@@ -14,12 +14,13 @@ module cache(<Key, Value, SIZE>);
 //        happens at the same time
 
 import std::core::mem;
+import std::core::mem::allocator;
 import std::collections::bitset;
 import std::collections::map;
 
-def BitArr = bitset::BitSet(<SIZE>) @private;
-def IdTable = map::HashMap(<Key, usz>) @private;
-def IdTableEntry = map::Entry(<Key, usz>) @private;
+alias BitArr = bitset::BitSet{SIZE};
+alias IdTable = map::HashMap{Key, usz};
+alias IdTableEntry = map::Entry{Key, usz};
 
 const usz CACHE_NCYCLES = (usz)(SIZE * 2.0/3.0);
 
@@ -42,9 +43,9 @@ macro Cache.cycle(&cache) @private {
 	}
 }
 
-fn void! Cache.init(&cache)
+fn void? Cache.init(&cache)
 {
-	cache.table.new_init(capacity: SIZE);
+	cache.table.init(allocator::heap(), capacity: SIZE);
 	// FIXME: this shit is SLOW
 	foreach (idx, bit : cache.used) { cache.used[idx] = false; }
 	foreach (idx, bit : cache.present) { cache.present[idx] = false; }
@@ -57,7 +58,7 @@ fn void Cache.free(&cache)
 	(void)mem::free(cache.pool);
 }
 
-fn Value*! Cache.search(&cache, Key id)
+fn Value*? Cache.search(&cache, Key id)
 {
 	// get_entry() faults on miss
 	IdTableEntry* entry = cache.table.get_entry(id)!;
@@ -65,14 +66,14 @@ fn Value*! Cache.search(&cache, Key id)
 	/* MISS, wrong key */
 	if (entry.key != id) {
 		cache.table.remove(id)!;
-		return SearchResult.MISSING?;
+		return NOT_FOUND?;
 	}
 
 	/* MISS, the data is not valid (not present) */
 	if (!cache.present[entry.value]) {
 		// if the data is not present but it is still in the table, remove it
 		cache.table.remove(id)!;
-		return SearchResult.MISSING?;
+		return NOT_FOUND?;
 	}
 
 	/* HIT, set as recently used */
@@ -82,7 +83,7 @@ fn Value*! Cache.search(&cache, Key id)
 
 fn void Cache.remove(&cache, Key id)
 {
-	IdTableEntry*! entry = cache.table.get_entry(id);
+	IdTableEntry*? entry = cache.table.get_entry(id);
 	if (catch entry) {
 		return;
 	}
@@ -105,7 +106,7 @@ fn usz Cache.get_free_spot(&cache) @private
 	return 0;
 }
 
-fn Value*! Cache.insert_at(&cache, Value *g, Key id, usz index) @private
+fn Value*? Cache.insert_at(&cache, Value *g, Key id, usz index) @private
 {
 	// TODO: verify index, g and id
 	Value* spot;
@@ -122,17 +123,17 @@ fn Value*! Cache.insert_at(&cache, Value *g, Key id, usz index) @private
 }
 
 // Insert an element in the cache, returns the index
-fn Value*! Cache.insert_new(&cache, Value* g, Key id)
+fn Value*? Cache.insert_new(&cache, Value* g, Key id)
 {
 	usz index = cache.get_free_spot();
 	return cache.insert_at(g, id, index);
 }
 
-fn Value*! Cache.get_or_insert(&cache, Value* g, Key id, bool *is_new = null)
+fn Value*? Cache.get_or_insert(&cache, Value* g, Key id, bool *is_new = null)
 {
-	Value*! c = cache.search(id);
+	Value*? c = cache.search(id);
 	if (catch e = c) {
-		if (e != SearchResult.MISSING) {
+		if (e != NOT_FOUND) {
 			return e?;
 		} else {
 			// if the element is new (inserted) set the is_new flag
diff --git a/src/fifo.c3 b/src/fifo.c3
index dbc50f0..b4c49d4 100644
--- a/src/fifo.c3
+++ b/src/fifo.c3
@@ -1,11 +1,8 @@
-module fifo(<Type>);
+module fifo{Type};
 
 import std::core::mem;
 
-fault FifoErr {
-	FULL,
-	EMPTY,
-}
+faultdef FULL, EMPTY;
 
 // TODO: specify the allocator
 
@@ -15,7 +12,7 @@ struct Fifo {
 	usz count;
 }
 
-fn void! Fifo.init(&fifo, usz size)
+fn void? Fifo.init(&fifo, usz size)
 {
 	fifo.arr = mem::new_array(Type, size);
 	fifo.out = 0;
@@ -27,20 +24,20 @@ fn void Fifo.free(&fifo)
 	(void)mem::free(fifo.arr);
 }
 
-fn void! Fifo.enqueue(&fifo, Type *elem)
+fn void? Fifo.enqueue(&fifo, Type *elem)
 {
 	if (fifo.count >= fifo.arr.len) {
-		return FifoErr.FULL?;
+		return FULL?;
 	}
 	usz in = (fifo.out + fifo.count) % fifo.arr.len;
 	fifo.arr[in] = *elem;
 	fifo.count++;
 }
 
-fn Type*! Fifo.dequeue(&fifo)
+fn Type*? Fifo.dequeue(&fifo)
 {
 	if (fifo.count == 0) {
-		return FifoErr.EMPTY?;
+		return EMPTY?;
 	}
 	Type *ret = &fifo.arr[fifo.out];
 	fifo.count--;
diff --git a/src/main.c3 b/src/main.c3
index 7b710fd..e0c1737 100644
--- a/src/main.c3
+++ b/src/main.c3
@@ -7,7 +7,7 @@ import std::time;
 import std::collections::ringbuffer;
 import std::core::string;
 
-def Times = ringbuffer::RingBuffer(<time::NanoDuration, 128>);
+alias Times = ringbuffer::RingBuffer{time::NanoDuration[128]};
 
 fn void Times.print_stats(&times)
 {
@@ -40,7 +40,7 @@ fn TimeStats Times.get_stats(&times)
 	}
 	avg = (NanoDuration)((ulong)avg/128.0);
 
-	return TimeStats{.min = min, .max = max, .avg = avg};
+	return {.min = min, .max = max, .avg = avg};
 }
 
 
@@ -115,12 +115,12 @@ void main()
 
 macro rl::Color ugui::Color.conv(color)
 {
-	return rl::Color{.r = color.r, .g = color.g, .b = color.b, .a = color.a};
+	return {.r = color.r, .g = color.g, .b = color.b, .a = color.a};
 }
 
 macro rl::Rectangle Rect.conv(rect)
 {
-	return rl::Rectangle{.x = rect.x, .y = rect.y, .width = rect.w, .height = rect.h};
+	return {.x = rect.x, .y = rect.y, .width = rect.w, .height = rect.h};
 }
 
 fn int main(String[] args)
@@ -169,11 +169,13 @@ fn int main(String[] args)
 		mod.lctrl = rl::isKeyDown(rl::KEY_LEFT_CONTROL);
 		ui.input_mod_keys(mod);
 
+		/*
 		for (rl::KeyboardKey key; (key = (KeyboardKey)rl::getKeyPressed()) != 0;) {
 			ZString kname = rl::getKeyName(key);
 			if (kname == null) continue;
 			ui.input_text_unicode(kname.str_view());
 		}
+		*/
 
 
 		/* Start Input Handling */
@@ -203,29 +205,29 @@ fn int main(String[] args)
 
 		if (ui.check_key_combo(ugui::KMOD_CTRL, "q")) break;
 
-		ui.div_begin("main", Rect{.w=-100})!!;
-		{|
+		ui.div_begin("main", {.w=-100})!!;
+		{
 			ui.layout_set_column()!!;
-			if (ui.button("button0", Rect{0,0,30,30}, toggle)!!.mouse_press) {
+			if (ui.button("button0", {0,0,30,30}, toggle)!!.mouse_press) {
 				io::printn("press button0");
 				toggle = !toggle;
 			}
 			//ui.layout_next_column()!!;
-			if (ui.button("button1", Rect{0,0,30,30})!!.mouse_press) {
+			if (ui.button("button1", {0,0,30,30})!!.mouse_press) {
 				io::printn("press button1");
 			}
 			//ui.layout_next_column()!!;
-			if (ui.button("button2", Rect{0,0,30,30})!!.mouse_release) {
+			if (ui.button("button2", {0,0,30,30})!!.mouse_release) {
 				io::printn("release button2");
 			}
 
 			ui.layout_set_row()!!;
 			ui.layout_next_row()!!;
 			static float rf, gf, bf, af;
-			ui.slider_ver("slider_r", Rect{0,0,30,100}, &rf)!!;
-			ui.slider_ver("slider_g", Rect{0,0,30,100}, &gf)!!;
-			ui.slider_ver("slider_b", Rect{0,0,30,100}, &bf)!!;
-			ui.slider_ver("slider_a", Rect{0,0,30,100}, &af)!!;
+			ui.slider_ver("slider_r", {0,0,30,100}, &rf)!!;
+			ui.slider_ver("slider_g", {0,0,30,100}, &gf)!!;
+			ui.slider_ver("slider_b", {0,0,30,100}, &bf)!!;
+			ui.slider_ver("slider_a", {0,0,30,100}, &af)!!;
 
 			ui.layout_next_column()!!;
 			ui.text_unbounded("text1", "Ciao Mamma\nAbilità ⚡\n'\udb80\udd2c'")!!;
@@ -235,8 +237,8 @@ fn int main(String[] args)
 
 			ui.layout_next_row()!!;
 			static bool check;
-			ui.checkbox("check1", "", Point{}, &check, "tick")!!;
-			ui.toggle("toggle1", "", Point{}, &toggle)!!;
+			ui.checkbox("check1", "", {}, &check, "tick")!!;
+			ui.toggle("toggle1", "", {}, &toggle)!!;
 
 /*
 			ui.layout_set_column()!!;
@@ -248,33 +250,33 @@ fn int main(String[] args)
 			ui.layout_next_row()!!;
 			ui.button_label(" E ")!!;
 */
-		|};
+		};
 		ui.draw_sprite("sprite1", "tux")!!;
 		ui.div_end()!!;
 
 		ui.div_begin("second", ugui::DIV_FILL, scroll_x: true, scroll_y: true)!!;
-		{|
+		{
 			ui.layout_set_column()!!;
 			static float slider2 = 0.5;
-			if (ui.slider_ver("slider", Rect{0,0,30,100}, &slider2)!!.update) {
+			if (ui.slider_ver("slider", {0,0,30,100}, &slider2)!!.update) {
 				io::printfn("other slider: %f", slider2);
 			}
-			ui.button("button0", Rect{0,0,50,50})!!;
-			ui.button("button1", Rect{0,0,50,50})!!;
-			ui.button("button2", Rect{0,0,50,50})!!;
-			ui.button("button3", Rect{0,0,50,50})!!;
+			ui.button("button0", {0,0,50,50})!!;
+			ui.button("button1", {0,0,50,50})!!;
+			ui.button("button2", {0,0,50,50})!!;
+			ui.button("button3", {0,0,50,50})!!;
 			if (toggle) {
-				ui.button("button4", Rect{0,0,50,50})!!;
-				ui.button("button5", Rect{0,0,50,50})!!;
-				ui.button("button6", Rect{0,0,50,50})!!;
-				ui.button("button7", Rect{0,0,50,50})!!;
+				ui.button("button4", {0,0,50,50})!!;
+				ui.button("button5", {0,0,50,50})!!;
+				ui.button("button6", {0,0,50,50})!!;
+				ui.button("button7", {0,0,50,50})!!;
 			}
 			ui.layout_next_column()!!;
 			ui.layout_set_row()!!;
 			static float f1, f2;
-			ui.slider_hor("hs1", Rect{0,0,100,30}, &f1)!!;
-			ui.slider_hor("hs2", Rect{0,0,100,30}, &f2)!!;
-		|};
+			ui.slider_hor("hs1", {0,0,100,30}, &f1)!!;
+			ui.slider_hor("hs2", {0,0,100,30}, &f2)!!;
+		};
 		ui.div_end()!!;
 
 		// Timings counter
@@ -282,12 +284,12 @@ fn int main(String[] args)
 		TimeStats uts = ui_times.get_stats();
 
 		ui.layout_set_floating()!!;
-		ui.div_begin("fps", Rect{0, ui.height-100, -300, 100})!!;
-		{|
+		ui.div_begin("fps", {0, ui.height-100, -300, 100})!!;
+		{
 			ui.layout_set_column()!!;
 			ui.text_unbounded("draw times", string::tformat("ui avg: %s\ndraw avg: %s\nTOT: %s", uts.avg, dts.avg, uts.avg+dts.avg))!!;
 			ui.text_unbounded("ui text input", (String)ui.input.keyboard.text[..])!!;
-		|};
+		};
 		ui.div_end()!!;
 
 		ui.frame_end()!!;
@@ -341,15 +343,15 @@ fn int main(String[] args)
 					rl::endShaderMode();
 				} else if (cmd.sprite.texture_id == sprite_id) {
 					// FIXME: THIS CODE IS SHIT, REAL DOO DOO
-					{|
+					{
 					if (cmd.sprite.type == SpriteType.SPRITE_MSDF) {
 						rl::beginShaderMode(msdf_shader);
 						defer rl::endShaderMode();
-						rl::drawTexturePro(sprite_texture, cmd.sprite.texture_rect.conv(), cmd.sprite.rect.conv(), rl::Vector2{0.0f, 0.0f}, 0.0f, cmd.sprite.hue.conv());
+						rl::drawTexturePro(sprite_texture, cmd.sprite.texture_rect.conv(), cmd.sprite.rect.conv(), {0.0f, 0.0f}, 0.0f, cmd.sprite.hue.conv());
 					} else {
-						rl::drawTexturePro(sprite_texture, cmd.sprite.texture_rect.conv(), cmd.sprite.rect.conv(), rl::Vector2{0.0f, 0.0f}, 0.0f, cmd.sprite.hue.conv());
+						rl::drawTexturePro(sprite_texture, cmd.sprite.texture_rect.conv(), cmd.sprite.rect.conv(), {0.0f, 0.0f}, 0.0f, cmd.sprite.hue.conv());
 					}
-					|};
+					};
 				} else {
 					io::printfn("unknown texture id: %d", cmd.sprite.texture_id);
 				}
diff --git a/src/ugui_atlas.c3 b/src/ugui_atlas.c3
index 8745fd7..7f3a40b 100644
--- a/src/ugui_atlas.c3
+++ b/src/ugui_atlas.c3
@@ -2,10 +2,7 @@ module ugui;
 
 import std::io;
 
-fault UgAtlasError {
-	CANNOT_PLACE,
-	INVALID_TYPE,
-}
+faultdef CANNOT_PLACE, INVALID_TYPE;
 
 enum AtlasType {
 	ATLAS_GRAYSCALE,
@@ -33,7 +30,39 @@ macro usz AtlasType.bpp(type)
 	}
 }
 
-fn void! Atlas.new(&atlas, Id id, AtlasType type, ushort width, ushort height)
+macro typeid AtlasType.underlying(type)
+{
+	switch (type) {
+	case ATLAS_GRAYSCALE: return char;
+	case ATLAS_R8G8B8A8: return uint;
+	}
+}
+
+/*
+// FIXME: in and out types are not always known at compile time
+macro @pixel_convert(p, AtlasType $in, AtlasType $out)
+{
+	$if $in == $out:
+		return p;
+	$else
+		$switch
+		$case $in == ATLAS_R8G8B8A8 && $out == ATLAS_GRAYSCALE:
+			var r = ((p >> 0)  & 0xff);
+			var g = ((p >> 8)  & 0xff);
+			var b = ((p >> 16) & 0xff);
+			var a = ((p >> 24) & 0xff);
+			if (a == 0)	return (char)0;
+			return (ATLAS_GRAYSCALE.underlying())(((float)r+g+b) / 3.0f);
+		$case $in == ATLAS_GRAYSCALE && $out == ATLAS_R8G8B8A8:
+			var x = (char)(p/3.0);
+			return (ATLAS_R8G8B8A8.underlying())(x|(x<<8)|(x<<16)|(255<<24));
+		$default: $error "Unimplemented pixel format conversion";
+		$endswitch
+	$endif
+}
+*/
+
+fn void? Atlas.new(&atlas, Id id, AtlasType type, ushort width, ushort height)
 {
 	atlas.id = id;
 	atlas.type = type;
@@ -66,7 +95,7 @@ fn void Atlas.free(&atlas)
 // place a rect inside the atlas
 // uses a row first algorithm
 // TODO: use a skyline algorithm https://jvernay.fr/en/blog/skyline-2d-packer/implementation/
-fn Point! Atlas.place(&atlas, char[] pixels, ushort w, ushort h, ushort stride)
+fn Point? Atlas.place(&atlas, char[] pixels, ushort w, ushort h, ushort stride)
 {
 	Point p;
 
@@ -79,7 +108,7 @@ fn Point! Atlas.place(&atlas, char[] pixels, ushort w, ushort h, ushort stride)
 		if (atlas.row.x + w <= atlas.width && atlas.row.y + h <= atlas.height) {
 			p = atlas.row;
 		} else {
-			return UgAtlasError.CANNOT_PLACE?;
+			return CANNOT_PLACE?;
 		}
 	}
 
diff --git a/src/ugui_button.c3 b/src/ugui_button.c3
index cd76206..f9582bc 100644
--- a/src/ugui_button.c3
+++ b/src/ugui_button.c3
@@ -10,7 +10,7 @@ struct ElemButton {
 // draw a button, return the events on that button
 // FIXME: "state" should be renamed "active" to toggle between an usable button and
 //        an inactive (greyed-out) button
-fn ElemEvents! Ctx.button(&ctx, String label, Rect size, bool state = false)
+fn ElemEvents? Ctx.button(&ctx, String label, Rect size, bool state = false)
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -22,14 +22,14 @@ fn ElemEvents! Ctx.button(&ctx, String label, Rect size, bool state = false)
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_BUTTON;
 	} else if (elem.type != ETYPE_BUTTON) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	elem.bounds = ctx.position_element(parent, size, true);
 
 	// if the bounds are null the element is outside the div view,
 	//  no interaction should occur so just return
-	if (elem.bounds.is_null()) { return ElemEvents{}; }
+	if (elem.bounds.is_null()) { return {}; }
 
 	Color col = 0x0000ffffu.to_rgba();
 	elem.events = ctx.get_elem_events(elem);
@@ -45,7 +45,7 @@ fn ElemEvents! Ctx.button(&ctx, String label, Rect size, bool state = false)
 	return elem.events;
 }
 
-fn ElemEvents! Ctx.button_label(&ctx, String label, Rect size = Rect{0,0,short.max,short.max}, bool state = false)
+fn ElemEvents? Ctx.button_label(&ctx, String label, Rect size = {0,0,short.max,short.max}, bool state = false)
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -60,11 +60,11 @@ fn ElemEvents! Ctx.button_label(&ctx, String label, Rect size = Rect{0,0,short.m
 
 	short line_height = (short)ctx.font.ascender - (short)ctx.font.descender;
 	Rect text_size = ctx.get_text_bounds(label)!;
-	Rect btn_size = text_size.add(Rect{0,0,10,10});
+	Rect btn_size = text_size.add({0,0,10,10});
 
 	// 2. Layout
 	elem.bounds = ctx.position_element(parent, btn_size, true);
-	if (elem.bounds.is_null()) { return ElemEvents{}; }
+	if (elem.bounds.is_null()) { return {}; }
 
 	Color col = 0x0000ffffu.to_rgba();
 	elem.events = ctx.get_elem_events(elem);
@@ -86,9 +86,50 @@ fn ElemEvents! Ctx.button_label(&ctx, String label, Rect size = Rect{0,0,short.m
 	return elem.events;
 }
 
+fn ElemEvents? Ctx.button_icon(&ctx, String label, String icon, String on_icon = "", bool state = false)
+{
+	Id id = ctx.gen_id(label)!;
+
+	Elem *parent = ctx.get_parent()!;
+	Elem *elem = ctx.get_elem(id)!;
+	// add it to the tree
+	ctx.tree.add(id, ctx.active_div)!;
+
+	if (elem.flags.is_new) {
+		elem.type = ETYPE_BUTTON;
+	} else if (elem.type != ETYPE_BUTTON) {
+		return WRONG_ELEMENT_TYPE?;
+	}
+
+	Sprite* def_sprite = ctx.sprite_atlas.get(icon)!;
+	Sprite* on_sprite = ctx.sprite_atlas.get(on_icon) ?? &&(Sprite){};
+	Rect max_size = def_sprite.rect().max(on_sprite.rect());
+
+	elem.bounds = ctx.position_element(parent, max_size, true);
+
+	// if the bounds are null the element is outside the div view,
+	//  no interaction should occur so just return
+	if (elem.bounds.is_null()) { return {}; }
+
+	Color col = 0x0000ffffu.to_rgba();
+	elem.events = ctx.get_elem_events(elem);
+
+	Id tex_id = ctx.sprite_atlas.id;
+	if (state && on_icon != "") {
+		ctx.push_sprite(elem.bounds, on_sprite.uv(), tex_id, type: on_sprite.type)!;
+	} else {
+		ctx.push_sprite(elem.bounds, def_sprite.uv(), tex_id, type: def_sprite.type)!;
+	}
+
+	// Draw the button
+	ctx.push_rect(elem.bounds, col, do_border: true, do_radius: true)!;
+
+	return elem.events;
+}
+
 // FIXME: this should be inside the style
 const ushort DEFAULT_CHECKBOX_SIZE = 16;
-fn void! Ctx.checkbox(&ctx, String label, String description, Point off, bool* state, String tick_sprite = {})
+fn void? Ctx.checkbox(&ctx, String label, String description, Point off, bool* state, String tick_sprite = {})
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -102,7 +143,7 @@ fn void! Ctx.checkbox(&ctx, String label, String description, Point off, bool* s
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_BUTTON;
 	} else if (elem.type != ETYPE_BUTTON) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	Rect size = {off.x, off.y, DEFAULT_CHECKBOX_SIZE, DEFAULT_CHECKBOX_SIZE};
@@ -116,7 +157,7 @@ fn void! Ctx.checkbox(&ctx, String label, String description, Point off, bool* s
 	if (elem.events.mouse_hover && elem.events.mouse_release) *state = !(*state);
 
 	Color col;
-	if (tick_sprite != String{}) {
+	if (tick_sprite != {}) {
 		col = ctx.style.bgcolor;
 		ctx.push_rect(elem.bounds, col, do_border: true, do_radius: true)!;
 		if (*state) {
@@ -135,7 +176,7 @@ fn void! Ctx.checkbox(&ctx, String label, String description, Point off, bool* s
 
 // FIXME: this should be inside the style
 const short DEFAULT_SWITCH_SIZE = 16;
-fn void! Ctx.toggle(&ctx, String label, String description, Point off, bool* state)
+fn void? Ctx.toggle(&ctx, String label, String description, Point off, bool* state)
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -149,7 +190,7 @@ fn void! Ctx.toggle(&ctx, String label, String description, Point off, bool* sta
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_BUTTON;
 	} else if (elem.type != ETYPE_BUTTON) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	Rect size = {off.x, off.y, DEFAULT_SWITCH_SIZE*2, DEFAULT_SWITCH_SIZE};
@@ -171,6 +212,6 @@ fn void! Ctx.toggle(&ctx, String label, String description, Point off, bool* sta
 	// Draw the button
 	// FIXME: THIS IS SHIT
 	ctx.push_rect(elem.bounds, ctx.style.bgcolor, do_border: true, do_radius: true)!;
-	Rect t = elem.bounds.add(Rect{*state ? (DEFAULT_SWITCH_SIZE+3) : +3, +3, -DEFAULT_SWITCH_SIZE-6, -6});
+	Rect t = elem.bounds.add({*state ? (DEFAULT_SWITCH_SIZE+3) : +3, +3, -DEFAULT_SWITCH_SIZE-6, -6});
 	ctx.push_rect(t, col, do_border: false, do_radius: true)!;
 }
diff --git a/src/ugui_cmd.c3 b/src/ugui_cmd.c3
index 9524dc3..eee78d4 100644
--- a/src/ugui_cmd.c3
+++ b/src/ugui_cmd.c3
@@ -68,7 +68,7 @@ macro Ctx.push_cmd(&ctx, Cmd *cmd)
 
 // FIXME: is this really the best solution?
 // "rect" is the bounding box of the element, which includes the border and the padding (so not just the content)
-fn void! Ctx.push_rect(&ctx, Rect rect, Color color, bool do_border = false, bool do_padding = false, bool do_radius = false)
+fn void? Ctx.push_rect(&ctx, Rect rect, Color color, bool do_border = false, bool do_padding = false, bool do_radius = false)
 {
 	Rect border = ctx.style.border;
 	Rect padding = ctx.style.padding;
@@ -101,7 +101,7 @@ fn void! Ctx.push_rect(&ctx, Rect rect, Color color, bool do_border = false, boo
 }
 
 // TODO: add texture id
-fn void! Ctx.push_sprite(&ctx, Rect bounds, Rect texture, Id texture_id, Color hue = 0xffffffffu.to_rgba(), SpriteType type = SPRITE_NORMAL)
+fn void? Ctx.push_sprite(&ctx, Rect bounds, Rect texture, Id texture_id, Color hue = 0xffffffffu.to_rgba(), SpriteType type = SPRITE_NORMAL)
 {
 	Cmd cmd = {
 		.type = CMD_SPRITE,
@@ -114,7 +114,7 @@ fn void! Ctx.push_sprite(&ctx, Rect bounds, Rect texture, Id texture_id, Color h
 	ctx.push_cmd(&cmd)!;
 }
 
-fn void! Ctx.push_string(&ctx, Rect bounds, String text, Color hue = 0xffffffffu.to_rgba())
+fn void? Ctx.push_string(&ctx, Rect bounds, String text, Color hue = 0xffffffffu.to_rgba())
 {
 	if (text.len == 0) {
 		return;
@@ -163,10 +163,10 @@ fn void! Ctx.push_string(&ctx, Rect bounds, String text, Color hue = 0xffffffffu
 	}
 
 	// FIXME: we never get here if an error was thrown before
-	ctx.push_scissor(Rect{})!;
+	ctx.push_scissor({})!;
 }
 
-fn void! Ctx.push_update_atlas(&ctx, Atlas* atlas)
+fn void? Ctx.push_update_atlas(&ctx, Atlas* atlas)
 {
 	Cmd up = {
 		.type = CMD_UPDATE_ATLAS,
@@ -181,7 +181,7 @@ fn void! Ctx.push_update_atlas(&ctx, Atlas* atlas)
 	ctx.push_cmd(&up)!;
 }
 
-fn void! Ctx.push_scissor(&ctx, Rect rect)
+fn void? Ctx.push_scissor(&ctx, Rect rect)
 {
 	Cmd sc = {
 		.type = CMD_SCISSOR,
diff --git a/src/ugui_core.c3 b/src/ugui_core.c3
index c330efe..8c4cf75 100644
--- a/src/ugui_core.c3
+++ b/src/ugui_core.c3
@@ -9,7 +9,7 @@ import std::core::string;
 
 
 // element ids are just long ints
-def Id = usz;
+alias Id = usz;
 
 enum ElemType {
 	ETYPE_NONE,
@@ -54,20 +54,15 @@ struct Elem {
 
 
 // relationships between elements are stored in a tree, it stores just the ids
-def IdTree = vtree::VTree(<Id>) @private;
+alias IdTree = vtree::VTree{Id};
 
 // elements themselves are kept in a cache
 const uint MAX_ELEMENTS = 256;
-def ElemCache = cache::Cache(<Id, Elem, MAX_ELEMENTS>) @private;
+alias ElemCache = cache::Cache{Id, Elem, MAX_ELEMENTS};
 
-def CmdQueue = fifo::Fifo(<Cmd>);
+alias CmdQueue = fifo::Fifo{Cmd};
 
-fault UgError {
-	INVALID_SIZE,
-	EVENT_UNSUPPORTED,
-	UNEXPECTED_ELEMENT,
-	WRONG_ELEMENT_TYPE,
-}
+faultdef INVALID_SIZE, EVENT_UNSUPPORTED, UNEXPECTED_ELEMENT, WRONG_ELEMENT_TYPE;
 
 const Rect DIV_FILL = { .x = 0, .y = 0, .w = 0, .h = 0 };
 
@@ -128,7 +123,7 @@ struct Ctx {
 }
 
 // return a pointer to the parent of the current active div
-fn Elem*! Ctx.get_parent(&ctx)
+fn Elem*? Ctx.get_parent(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	return ctx.cache.search(parent_id);
@@ -140,7 +135,7 @@ const uint GOLDEN_RATIO = 0x9E3779B9;
 
 // generate an id combining the hashes of the parent id and the label
 // with the Cantor pairing function
-macro Id! Ctx.gen_id(&ctx, String label)
+macro Id? Ctx.gen_id(&ctx, String label)
 {
 	Id id1 = ctx.tree.get(ctx.active_div)!;
 	Id id2 = label.hash();
@@ -153,7 +148,7 @@ macro Id! Ctx.gen_id(&ctx, String label)
 
 // get or push an element from the cache, return a pointer to it
 // resets all flags except is_new which is set accordingly
-fn Elem*! Ctx.get_elem(&ctx, Id id)
+fn Elem*? Ctx.get_elem(&ctx, Id id)
 {
 	Elem empty_elem;
 	bool is_new;
@@ -170,10 +165,10 @@ fn Elem*! Ctx.get_elem(&ctx, Id id)
 // THIS HAS TO BE A MACRO SINCE IT RETURNS A POINTER TO A TEMPORARY VALUE
 macro Elem* Ctx.find_elem(&ctx, Id id)
 {
-	Elem*! elem;
+	Elem*? elem;
 	elem = ctx.cache.search(id);
 	if (catch elem) {
-		return &&Elem{};
+		return &&(Elem){};
 	}
 	return elem;
 }
@@ -194,7 +189,7 @@ macro Ctx.get_elem_by_tree_idx(&ctx, isz idx) @private
 	return ctx.cache.search(id);
 }
 
-fn void! Ctx.init(&ctx)
+fn void? Ctx.init(&ctx)
 {
 	ctx.tree.init(MAX_ELEMENTS)!;
 	defer catch { (void)ctx.tree.free(); }
@@ -208,9 +203,9 @@ fn void! Ctx.init(&ctx)
 	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.margin  = {2, 2, 2, 2};
+	ctx.style.border  = {2, 2, 2, 2};
+	ctx.style.padding = {1, 1, 1, 1};
 	ctx.style.radius  = 5;
 	ctx.style.bgcolor = 0x282828ffu.to_rgba();
 	ctx.style.fgcolor = 0xfbf1c7ffu.to_rgba();
@@ -226,7 +221,7 @@ fn void Ctx.free(&ctx)
 	(void)ctx.sprite_atlas.free();
 }
 
-fn void! Ctx.frame_begin(&ctx)
+fn void? Ctx.frame_begin(&ctx)
 {
 
 	// 2. Get the root element from the cache and update it
@@ -268,7 +263,7 @@ fn void! Ctx.frame_begin(&ctx)
 	// TODO: add a background color taken from a theme or config
 }
 
-fn void! Ctx.frame_end(&ctx)
+fn void? Ctx.frame_end(&ctx)
 {
 	Elem* root = ctx.get_elem_by_tree_idx(0)!;
 	root.div.layout = LAYOUT_ROW;
diff --git a/src/ugui_div.c3 b/src/ugui_div.c3
index da175cf..bff69a3 100644
--- a/src/ugui_div.c3
+++ b/src/ugui_div.c3
@@ -28,7 +28,7 @@ struct ElemDiv {
 // if the width or height are negative the width or height will be calculated based on the children size
 // sort similar to a flexbox, and the minimum size is set by the negative of the width or height
 // FIXME: there is a bug if the size.w or size.h == -0
-fn void! Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, bool scroll_y = false)
+fn void? Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, bool scroll_y = false)
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -42,7 +42,7 @@ fn void! Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, boo
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_DIV;
 	} else if (elem.type != ETYPE_DIV) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 	elem.div.scroll_x.enabled = scroll_x;
 	elem.div.scroll_y.enabled = scroll_y;
@@ -55,16 +55,16 @@ fn void! Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, boo
 		.h = size.h < 0 ? max(elem.div.pcb.h, (short)-size.h) : size.h,
 	};
 	elem.bounds = ctx.position_element(parent, wanted_size);
-	elem.div.children_bounds = Rect{};
+	elem.div.children_bounds = {};
 
 	// update the ctx scissor
 	ctx.div_scissor = elem.bounds;
 	ctx.push_scissor(elem.bounds)!;
 
 	// 4. Fill the div fields
-	elem.div.origin_c = Point{
+	elem.div.origin_c = {
 		.x = elem.bounds.x,
-		.y = elem.bounds.y,
+		.y = elem.bounds.y
 	};
 	elem.div.origin_r = elem.div.origin_c;
 	elem.div.layout   = parent.div.layout;
@@ -79,7 +79,7 @@ fn void! Ctx.div_begin(&ctx, String label, Rect size, bool scroll_x = false, boo
 	// TODO: check resizeable
 }
 
-fn void! Ctx.div_end(&ctx)
+fn void? Ctx.div_end(&ctx)
 {
 	// swap the children bounds
 	Elem* parent = ctx.get_parent()!;
diff --git a/src/ugui_font.c3 b/src/ugui_font.c3
index 535432d..5afe033 100644
--- a/src/ugui_font.c3
+++ b/src/ugui_font.c3
@@ -4,13 +4,15 @@ import schrift;
 import grapheme;
 import std::collections::map;
 import std::core::mem;
+import std::core::mem::allocator;
 import std::io;
 import std::ascii;
 
 
 // unicode code point, different type for a different hash
-def Codepoint = uint;
+alias Codepoint = uint;
 
+//macro uint Codepoint.hash(self) => ((uint)self).hash();
 
 /* width and height of a glyph contain the kering advance
  * (u,v)
@@ -40,14 +42,9 @@ struct Glyph {
 }
 
 const uint FONT_CACHED = 255;
-def GlyphTable = map::HashMap(<Codepoint, Glyph>) @private;
+alias GlyphTable = map::HashMap{Codepoint, Glyph};
 
-fault UgFontError {
-	TTF_LOAD_FAILED,
-	MISSING_GLYPH,
-	BAD_GLYPH_METRICS,
-	RENDER_ERROR,
-}
+faultdef TTF_LOAD_FAILED, MISSING_GLYPH, BAD_GLYPH_METRICS, RENDER_ERROR;
 
 struct Font {
 	schrift::Sft sft;
@@ -61,14 +58,14 @@ struct Font {
 	bool should_update; // should send update_atlas command, resets at frame_end()
 }
 
-fn void! Font.load(&font, String name, ZString path, uint height, float scale)
+fn void? Font.load(&font, String name, ZString path, uint height, float scale)
 {
-	font.table.new_init(capacity: FONT_CACHED);
+	font.table.init(allocator::heap(), capacity: FONT_CACHED);
 	font.id = name.hash();
 
 	font.size = height*scale;
 
-	font.sft = schrift::Sft{
+	font.sft = {
 		.xScale = (double)font.size,
 		.yScale = (double)font.size,
 		.flags = schrift::SFT_DOWNWARD_Y,
@@ -77,7 +74,7 @@ fn void! Font.load(&font, String name, ZString path, uint height, float scale)
 	font.sft.font = schrift::loadfile(path);
 	if (font.sft.font == null) {
 		font.table.free();
-		return UgFontError.TTF_LOAD_FAILED?;
+		return TTF_LOAD_FAILED?;
 	}
 
 	schrift::SftLMetrics lmetrics;
@@ -98,13 +95,13 @@ fn void! Font.load(&font, String name, ZString path, uint height, float scale)
 	}
 }
 
-fn Glyph*! Font.get_glyph(&font, Codepoint code)
+fn Glyph*? Font.get_glyph(&font, Codepoint code)
 {
-	Glyph*! gp;
+	Glyph*? gp;
 	gp = font.table.get_ref(code);
 
 	if (catch excuse = gp) {
-		if (excuse != SearchResult.MISSING) {
+		if (excuse != NOT_FOUND) {
 			return excuse?;
 		}
 	} else {
@@ -117,12 +114,12 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code)
 	schrift::SftGlyph gid;
 	schrift::SftGMetrics gmtx;
 
-	if (schrift::lookup(&font.sft, code, &gid) < 0) {
-		return UgFontError.MISSING_GLYPH?;
+	if (schrift::lookup(&font.sft, (SftUChar)code, &gid) < 0) {
+		return MISSING_GLYPH?;
 	}
 
 	if (schrift::gmetrics(&font.sft, gid, &gmtx) < 0) {
-		return UgFontError.BAD_GLYPH_METRICS?;
+		return BAD_GLYPH_METRICS?;
 	}
 
 	schrift::SftImage img = {
@@ -132,7 +129,7 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code)
 	char[] pixels = mem::new_array(char, (usz)img.width * img.height);
 	img.pixels = pixels;
 	if (schrift::render(&font.sft, gid, img) < 0) {
-		return UgFontError.RENDER_ERROR?;
+		return RENDER_ERROR?;
 	}
 
 	glyph.code = code;
@@ -163,7 +160,7 @@ fn void Font.free(&font)
 	schrift::freefont(font.sft.font);
 }
 
-fn void! Ctx.load_font(&ctx, String name, ZString path, uint height, float scale = 1.0)
+fn void? Ctx.load_font(&ctx, String name, ZString path, uint height, float scale = 1.0)
 {
 	return ctx.font.load(name, path, height, scale);
 }
@@ -174,7 +171,7 @@ fn void! Ctx.load_font(&ctx, String name, ZString path, uint height, float scale
 fn Codepoint str_to_codepoint(char[] str, usz* off)
 {
 	Codepoint cp;
-	isz b = grapheme::decode_utf8(str, str.len, &cp);
+	isz b = grapheme::decode_utf8(str, str.len, (uint*)&cp);
 	if (b == 0 || b > str.len) {
 		return 0;
 	}
@@ -182,7 +179,7 @@ fn Codepoint str_to_codepoint(char[] str, usz* off)
 	return cp;
 }
 
-fn Rect! Ctx.get_text_bounds(&ctx, String text)
+fn Rect? Ctx.get_text_bounds(&ctx, String text)
 {
 	Rect text_bounds;
 	short line_height = (short)ctx.font.ascender - (short)ctx.font.descender;
@@ -219,7 +216,7 @@ fn Point Ctx.center_text(&ctx, Rect text_bounds, Rect bounds)
 	short dw = bounds.w - text_bounds.w;
 	short dh = bounds.h - text_bounds.h;
 
-	return Point{.x = dw/2, .y = dh/2};
+	return {.x = dw/2, .y = dh/2};
 }
 
 // TODO: check if the font is present in the context
diff --git a/src/ugui_input.c3 b/src/ugui_input.c3
index 1911d9f..abad51c 100644
--- a/src/ugui_input.c3
+++ b/src/ugui_input.c3
@@ -45,10 +45,10 @@ const ModKeys KMOD_CTRL  = {.lctrl  = true, .rctrl  = true};
 const ModKeys KMOD_SHIFT = {.lshift = true, .rshift = true};
 const ModKeys KMOD_ALT   = {.lalt   = true, .ralt   = true};
 const ModKeys KMOD_GUI   = {.lgui   = true, .rgui   = true};
-const ModKeys KMOD_NONE  = ModKeys{};
+const ModKeys KMOD_NONE  = {};
 const ModKeys KMOD_ANY   = (ModKeys)(ModKeys.inner.max);
 
-const MouseButtons BTN_NONE   = MouseButtons{};
+const MouseButtons BTN_NONE   = {};
 const MouseButtons BTN_ANY    = (MouseButtons)(MouseButtons.inner.max);
 const MouseButtons BTN_LEFT   = {.btn_left   = true};
 const MouseButtons BTN_MIDDLE = {.btn_middle = true};
@@ -72,10 +72,10 @@ fn bool Ctx.check_key_combo(&ctx, ModKeys mod, String keys)
 }
 
 // Window size was changed
-fn void! Ctx.input_window_size(&ctx, short width, short height)
+fn void? Ctx.input_window_size(&ctx, short width, short height)
 {
 	if (width <= 0 || height <= 0) {
-		return UgError.INVALID_SIZE?;
+		return INVALID_SIZE?;
 	}
 	ctx.input.events.resize = ctx.width != width || ctx.height != height;
 	ctx.width = width;
diff --git a/src/ugui_layout.c3 b/src/ugui_layout.c3
index 3a2ac9a..feba610 100644
--- a/src/ugui_layout.c3
+++ b/src/ugui_layout.c3
@@ -7,71 +7,71 @@ enum Layout {
 	LAYOUT_ABSOLUTE,
 }
 
-fn void! Ctx.layout_set_row(&ctx)
+fn void? Ctx.layout_set_row(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	Elem *parent = ctx.cache.search(parent_id)!;
 
 	if (parent.type != ETYPE_DIV) {
 		// what?
-		return UgError.UNEXPECTED_ELEMENT?;
+		return UNEXPECTED_ELEMENT?;
 	}
 
 	parent.div.layout = LAYOUT_ROW;
 }
 
-fn void! Ctx.layout_set_column(&ctx)
+fn void? Ctx.layout_set_column(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	Elem *parent = ctx.cache.search(parent_id)!;
 
 	if (parent.type != ETYPE_DIV) {
 		// what?
-		return UgError.UNEXPECTED_ELEMENT?;
+		return UNEXPECTED_ELEMENT?;
 	}
 
 	parent.div.layout = LAYOUT_COLUMN;
 }
 
-fn void! Ctx.layout_set_floating(&ctx)
+fn void? Ctx.layout_set_floating(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	Elem *parent = ctx.cache.search(parent_id)!;
 
 	if (parent.type != ETYPE_DIV) {
 		// what?
-		return UgError.UNEXPECTED_ELEMENT?;
+		return UNEXPECTED_ELEMENT?;
 	}
 
 	parent.div.layout = LAYOUT_FLOATING;
 }
 
-fn void! Ctx.layout_next_row(&ctx)
+fn void? Ctx.layout_next_row(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	Elem *parent = ctx.cache.search(parent_id)!;
 
 	if (parent.type != ETYPE_DIV) {
-		return UgError.UNEXPECTED_ELEMENT?;
+		return UNEXPECTED_ELEMENT?;
 	}
 
-	parent.div.origin_r = Point{
+	parent.div.origin_r = {
 		.x = parent.bounds.x,
 		.y = parent.div.children_bounds.bottom_right().y,
 	};
 	parent.div.origin_c = parent.div.origin_r;
 }
 
-fn void! Ctx.layout_next_column(&ctx)
+fn void? Ctx.layout_next_column(&ctx)
 {
 	Id parent_id = ctx.tree.get(ctx.active_div)!;
 	Elem *parent = ctx.cache.search(parent_id)!;
 
 	if (parent.type != ETYPE_DIV) {
-		return UgError.UNEXPECTED_ELEMENT?;
+		return UNEXPECTED_ELEMENT?;
 	}
 
-	parent.div.origin_c = Point{
+	parent.div.origin_c = {
 		.x = parent.div.children_bounds.bottom_right().x,
 		.y = parent.bounds.y,
 	};
@@ -124,7 +124,7 @@ fn Rect Ctx.position_element(&ctx, Elem *parent, Rect rect, bool style = false)
 	case LAYOUT_ABSOLUTE: // absolute position, this is a no-op, return the rect
 		return rect;
 	default: // error
-		return Rect{};
+		return {};
 	}
 
 	// 2. Compute the parent's view
@@ -166,11 +166,11 @@ fn Rect Ctx.position_element(&ctx, Elem *parent, Rect rect, bool style = false)
 	child_occupied  = child_occupied.grow(rect.size());
 
 	// 4. Update the parent's origin
-	div.origin_r = Point{
+	div.origin_r = {
 		.x = child_occupied.bottom_right().x,
 		.y = origin.y,
 	};
-	div.origin_c = Point{
+	div.origin_c = {
 		.x = origin.x,
 		.y = child_occupied.bottom_right().y,
 	};
@@ -191,6 +191,6 @@ fn Rect Ctx.position_element(&ctx, Elem *parent, Rect rect, bool style = false)
 	if (child_placement.collides(parent_view)) {
 		return child_placement.off(parent.get_view_off().neg());
 	} else {
-		return Rect{};
+		return {};
 	}
 }
diff --git a/src/ugui_shapes.c3 b/src/ugui_shapes.c3
index 39a782c..ebef525 100644
--- a/src/ugui_shapes.c3
+++ b/src/ugui_shapes.c3
@@ -19,7 +19,7 @@ macro bool Rect.contains(Rect a, Rect b)
 // returns the intersection of a and b
 macro Rect Rect.intersection(Rect a, Rect b)
 {
-	return Rect{
+	return {
 		.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),
@@ -39,7 +39,7 @@ macro bool Rect.is_null(Rect r) => r.x == 0 && r.y == 0 && r.x == 0 && r.w == 0;
 // returns the element-wise addition of r1 and r2
 macro Rect Rect.add(Rect r1, Rect r2)
 {
-	return Rect{
+	return {
 		.x = r1.x + r2.x,
 		.y = r1.y + r2.y,
 		.w = r1.w + r2.w,
@@ -50,7 +50,7 @@ macro Rect Rect.add(Rect r1, Rect r2)
 // returns the element-wise subtraction of r1 and r2
 macro Rect Rect.sub(Rect r1, Rect r2)
 {
-	return Rect{
+	return {
 		.x = r1.x - r2.x,
 		.y = r1.y - r2.y,
 		.w = r1.w - r2.w,
@@ -61,7 +61,7 @@ macro Rect Rect.sub(Rect r1, Rect r2)
 // returns the element-wise multiplication of r1 and r2
 macro Rect Rect.mul(Rect r1, Rect r2)
 {
-	return Rect{
+	return {
 		.x = r1.x * r2.x,
 		.y = r1.y * r2.y,
 		.w = r1.w * r2.w,
@@ -71,7 +71,7 @@ macro Rect Rect.mul(Rect r1, Rect r2)
 
 macro Point Rect.position(Rect r)
 {
-	return Point{
+	return {
 		.x = r.x,
 		.y = r.y,
 	};
@@ -79,7 +79,7 @@ macro Point Rect.position(Rect r)
 
 macro Point Rect.size(Rect r)
 {
-	return Point{
+	return {
 		.x = r.w,
 		.y = r.h,
 	};
@@ -87,7 +87,7 @@ macro Point Rect.size(Rect r)
 
 macro Rect Rect.max(Rect a, Rect b)
 {
-	return Rect{
+	return {
 		.x = max(a.x, b.x),
 		.y = max(a.y, b.y),
 		.w = max(a.w, b.w),
@@ -97,7 +97,7 @@ macro Rect Rect.max(Rect a, Rect b)
 
 macro Rect Rect.min(Rect a, Rect b)
 {
-	return Rect{
+	return {
 		.x = min(a.x, b.x),
 		.y = min(a.y, b.y),
 		.w = min(a.w, b.w),
@@ -108,7 +108,7 @@ macro Rect Rect.min(Rect a, Rect b)
 // Offset a rect by a point
 macro Rect Rect.off(Rect r, Point p)
 {
-	return Rect{
+	return {
 		.x = r.x + p.x,
 		.y = r.y + p.y,
 		.w = r.w,
@@ -119,7 +119,7 @@ macro Rect Rect.off(Rect r, Point p)
 // Resize a rect width and height
 macro Rect Rect.grow(Rect r, Point p)
 {
-	return Rect{
+	return {
 		.x = r.x,
 		.y = r.y,
 		.w = r.w + p.x,
@@ -130,7 +130,7 @@ macro Rect Rect.grow(Rect r, Point p)
 // Return the bottom-right corner of a rectangle
 macro Point Rect.bottom_right(Rect r)
 {
-	return Point{
+	return {
 		.x = r.x + r.w,
 		.y = r.y + r.h,
 	};
@@ -153,7 +153,7 @@ macro bool Point.in_rect(Point p, Rect r)
 
 macro Point Point.add(Point a, Point b)
 {
-	return Point{
+	return {
 		.x = a.x + b.x,
 		.y = a.y + b.y,
 	};
@@ -161,17 +161,17 @@ macro Point Point.add(Point a, Point b)
 
 macro Point Point.sub(Point a, Point b)
 {
-	return Point{
+	return {
 		.x = a.x - b.x,
 		.y = a.y - b.y,
 	};
 }
 
-macro Point Point.neg(Point p) => Point{-p.x, -p.y};
+macro Point Point.neg(Point p) => {-p.x, -p.y};
 
 macro Point Point.max(Point a, Point b)
 {
-	return Point{
+	return {
 		.x = max(a.x, b.x),
 		.y = max(a.y, b.y),
 	};
@@ -179,7 +179,7 @@ macro Point Point.max(Point a, Point b)
 
 macro Point Point.min(Point a, Point b)
 {
-	return Point{
+	return {
 		.x = min(a.x, b.x),
 		.y = min(a.y, b.y),
 	};
@@ -195,7 +195,7 @@ struct Color{
 
 macro Color uint.to_rgba(uint u)
 {
-	return Color{
+	return {
 		.r = (char)((u >> 24) & 0xff),
 		.g = (char)((u >> 16) & 0xff),
 		.b = (char)((u >> 8) & 0xff),
diff --git a/src/ugui_slider.c3 b/src/ugui_slider.c3
index 1d76376..cdcccf8 100644
--- a/src/ugui_slider.c3
+++ b/src/ugui_slider.c3
@@ -16,7 +16,7 @@ struct ElemSlider {
 <*
 @require value != null
 *>
-fn ElemEvents! Ctx.slider_hor(&ctx,
+fn ElemEvents? Ctx.slider_hor(&ctx,
     String label,
     Rect size,
     float* value,
@@ -35,7 +35,7 @@ fn ElemEvents! Ctx.slider_hor(&ctx,
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_SLIDER;
 	} else if (elem.type != ETYPE_SLIDER) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	// 2. Layout
@@ -79,7 +79,7 @@ fn ElemEvents! Ctx.slider_hor(&ctx,
  * | |
  * +-+
  */
-fn ElemEvents! Ctx.slider_ver(&ctx,
+fn ElemEvents? Ctx.slider_ver(&ctx,
     String label,
     Rect size,
     float* value,
@@ -98,7 +98,7 @@ fn ElemEvents! Ctx.slider_ver(&ctx,
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_SLIDER;
 	} else if (elem.type != ETYPE_SLIDER) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	// 2. Layout
diff --git a/src/ugui_sprite.c3 b/src/ugui_sprite.c3
index b4a83f2..1f94b27 100644
--- a/src/ugui_sprite.c3
+++ b/src/ugui_sprite.c3
@@ -1,5 +1,6 @@
 module ugui;
 
+import std::core::mem::allocator;
 import std::collections::map;
 import std::io;
 import mqoi;
@@ -20,7 +21,7 @@ struct Sprite {
 	ushort w, h;
 }
 
-def SpriteMap = map::HashMap(<Id, Sprite>);
+alias SpriteMap = map::HashMap{Id, Sprite};
 
 struct SpriteAtlas {
 	Id id;
@@ -34,20 +35,20 @@ struct ElemSprite {
 }
 
 // name: some examples are "icons" or "images"
-fn void! SpriteAtlas.init(&this, String name, AtlasType type, ushort width, ushort height)
+fn void? SpriteAtlas.init(&this, String name, AtlasType type, ushort width, ushort height)
 {
 	// FIXME: for now only R8G8B8A8 format is supported
 	if (type != ATLAS_R8G8B8A8) {
-		return UgAtlasError.INVALID_TYPE?;
+		return INVALID_TYPE?;
 	}
 
 	this.id = name.hash();
 	this.atlas.new(this.id, AtlasType.ATLAS_R8G8B8A8, width, height)!;
-	this.sprites.new_init(capacity: SRITES_PER_ATLAS);
+	this.sprites.init(allocator::heap(), capacity: SRITES_PER_ATLAS);
 	this.should_update = false;
 }
 
-fn void! SpriteAtlas.free(&this)
+fn void? SpriteAtlas.free(&this)
 {
 	this.atlas.free();
 	this.sprites.free();
@@ -55,7 +56,7 @@ fn void! SpriteAtlas.free(&this)
 
 // FIXME: this should throw an error when a different pixel format than the atlas' is used
 //        or convert from the source's pixel format to the atlas'
-fn Sprite*! SpriteAtlas.insert(&this, String name, SpriteType type, char[] pixels, ushort w, ushort h, ushort stride)
+fn Sprite*? SpriteAtlas.insert(&this, String name, SpriteType type, char[] pixels, ushort w, ushort h, ushort stride)
 {
 	Sprite s;
 	s.id = name.hash();
@@ -70,18 +71,21 @@ fn Sprite*! SpriteAtlas.insert(&this, String name, SpriteType type, char[] pixel
 	return this.sprites.get_ref(s.id);
 }
 
-fn Sprite*! SpriteAtlas.get(&this, String name)
+fn Sprite*? SpriteAtlas.get(&this, String name)
 {
 	Id id = name.hash();
 	return this.sprites.get_ref(id);
 }
 
-fn Sprite*! SpriteAtlas.get_by_id(&this, Id id)
+fn Sprite*? SpriteAtlas.get_by_id(&this, Id id)
 {
 	return this.sprites.get_ref(id);
 }
 
-fn void! Ctx.sprite_atlas_create(&ctx, String name, AtlasType type, ushort w, ushort h)
+macro Rect Sprite.rect(s) => {0,0,s.w,s.h};
+macro Rect Sprite.uv(s) => {s.u,s.v,s.w,s.h};
+
+fn void? Ctx.sprite_atlas_create(&ctx, String name, AtlasType type, ushort w, ushort h)
 {
 	ctx.sprite_atlas.init(name, type, w, h)!;
 }
@@ -91,12 +95,12 @@ fn Id Ctx.get_sprite_atlas_id(&ctx, String name)
 	return name.hash();
 }
 
-fn void! Ctx.import_sprite_memory(&ctx, String name, char[] pixels, ushort w, ushort h, ushort stride, SpriteType type = SPRITE_NORMAL)
+fn void? Ctx.import_sprite_memory(&ctx, String name, char[] pixels, ushort w, ushort h, ushort stride, SpriteType type = SPRITE_NORMAL)
 {
 	ctx.sprite_atlas.insert(name, type, pixels, w, h, stride)!;
 }
 
-fn void! Ctx.import_sprite_file_qoi(&ctx, String name, String path, SpriteType type = SPRITE_NORMAL)
+fn void? Ctx.import_sprite_file_qoi(&ctx, String name, String path, SpriteType type = SPRITE_NORMAL)
 {
 	mqoi::Desc image_desc;
 	uint w, h;
@@ -108,7 +112,7 @@ fn void! Ctx.import_sprite_file_qoi(&ctx, String name, String path, SpriteType t
 		mqoi::desc_push(&image_desc, file.read_byte()!);
 	}
 	if (mqoi::desc_verify(&image_desc, &w, &h) != 0) {
-		return IoError.FILE_NOT_VALID?;
+		return io::FILE_NOT_VALID?;
 	}
 
 	mqoi::Dec dec;
@@ -123,7 +127,7 @@ fn void! Ctx.import_sprite_file_qoi(&ctx, String name, String path, SpriteType t
 		mqoi::dec_push(&dec, file.read_byte()!);
 
 		while ((px = mqoi::dec_pop(&dec)) != null) {
-			pixels[idx..idx+3] = px.value;
+			pixels[idx..idx+3] = px.value[..];
 			idx += 4;
 		}
 	}
@@ -131,7 +135,7 @@ fn void! Ctx.import_sprite_file_qoi(&ctx, String name, String path, SpriteType t
 	ctx.sprite_atlas.insert(name, type, pixels, (ushort)w, (ushort)h, (ushort)w)!;
 }
 
-fn void! Ctx.draw_sprite(&ctx, String label, String name, Point off = {0,0})
+fn void? Ctx.draw_sprite(&ctx, String label, String name, Point off = {0,0})
 {
 	Id id = ctx.gen_id(label)!;
 
@@ -143,7 +147,7 @@ fn void! Ctx.draw_sprite(&ctx, String label, String name, Point off = {0,0})
 	if (elem.flags.is_new) {
 		elem.type = ETYPE_SPRITE;
 	} else if (elem.type != ETYPE_SPRITE) {
-		return UgError.WRONG_ELEMENT_TYPE?;
+		return WRONG_ELEMENT_TYPE?;
 	}
 
 	Sprite* sprite = ctx.sprite_atlas.get(name)!;
@@ -163,11 +167,9 @@ fn void! Ctx.draw_sprite(&ctx, String label, String name, Point off = {0,0})
 	return ctx.push_sprite(elem.bounds, uv, tex_id)!;
 }
 
-fn void! Ctx.draw_sprite_raw(&ctx, String name, Rect bounds)
+fn void? Ctx.draw_sprite_raw(&ctx, String name, Rect bounds)
 {
 	Sprite* sprite = ctx.sprite_atlas.get(name)!;
-	Rect uv = { sprite.u, sprite.v, sprite.w, sprite.h };
-	//Rect bounds = Rect{ 0, 0, sprite.w, sprite.h }.off(off);
 	Id tex_id = ctx.sprite_atlas.id;
-	return ctx.push_sprite(bounds, uv, tex_id, type: sprite.type)!;
+	return ctx.push_sprite(bounds, sprite.uv(), tex_id, type: sprite.type)!;
 }
diff --git a/src/ugui_text.c3 b/src/ugui_text.c3
index 18628e0..dea4562 100644
--- a/src/ugui_text.c3
+++ b/src/ugui_text.c3
@@ -6,7 +6,7 @@ struct ElemText {
 	char* str;
 }
 
-fn void! Ctx.text_unbounded(&ctx, String label, String text)
+fn void? Ctx.text_unbounded(&ctx, String label, String text)
 {
 	Id id = ctx.gen_id(label)!;
 
diff --git a/src/vtree.c3 b/src/vtree.c3
index 8cdcff7..0a1e851 100644
--- a/src/vtree.c3
+++ b/src/vtree.c3
@@ -1,4 +1,4 @@
-module vtree(<ElemType>);
+module vtree{ElemType};
 
 import std::core::mem;
 import std::io;
@@ -9,13 +9,7 @@ struct VTree {
 	isz[] refs, ordered_refs;
 }
 
-fault VTreeError {
-	CANNOT_SHRINK,
-	INVALID_REFERENCE,
-	TREE_FULL,
-	REFERENCE_NOT_PRESENT,
-	INVALID_ARGUMENT,
-}
+faultdef CANNOT_SHRINK, INVALID_REFERENCE, TREE_FULL, REFERENCE_NOT_PRESENT, INVALID_ARGUMENT;
 
 macro VTree.ref_is_valid(&tree, isz ref) { return (ref >= 0 && ref < tree.refs.len); }
 macro VTree.ref_is_present(&tree, isz ref) { return tree.refs[ref] >= 0; }
@@ -27,11 +21,11 @@ macro @zero()
 	$if $assignable(0, ElemType):
 		return 0;
 	$else
-		return ElemType{};
+		return {};
 	$endif
 }
 
-fn void! VTree.init(&tree, usz size)
+fn void? VTree.init(&tree, usz size)
 {
 	tree.vector = mem::new_array(ElemType, size);
 	defer catch { (void)mem::free(tree.vector); }
@@ -74,7 +68,7 @@ fn void VTree.pack(&tree)
 			tree.vector[free_spot] = tree.vector[i];
 			tree.refs[free_spot]   = tree.refs[i];
 
-			tree.vector[i] = @zero();
+			tree.vector[i] = {};
 			tree.refs[i]   = -1;
 
 			// and move all references
@@ -90,18 +84,18 @@ fn void VTree.pack(&tree)
 	}
 }
 
-fn void! VTree.resize(&tree, usz newsize)
+fn void? VTree.resize(&tree, usz newsize)
 {
 	// return error when shrinking with too many elements
 	if (newsize < tree.elements) {
-		return VTreeError.CANNOT_SHRINK?;
+		return CANNOT_SHRINK?;
 	}
 
 	// pack the vector when shrinking to avoid data loss
 	if ((int)newsize < tree.size()) {
 		// FIXME: packing destroys all references to elements of vec
 		//        so shrinking may cause dangling pointers
-		return VTreeError.CANNOT_SHRINK?;
+		return CANNOT_SHRINK?;
 	}
 
 	usz old_size = tree.size();
@@ -122,22 +116,22 @@ fn void! VTree.resize(&tree, usz newsize)
 }
 
 // add an element to the tree, return it's ref
-fn isz! VTree.add(&tree, ElemType elem, isz parent)
+fn isz? VTree.add(&tree, ElemType elem, isz parent)
 {
 	// invalid parent
 	if (!tree.ref_is_valid(parent)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	// no space left
 	if (tree.elements >= tree.size()) {
-		return VTreeError.TREE_FULL?;
+		return TREE_FULL?;
 	}
 
 	// check if the parent exists
 	// if there are no elements in the tree the first add will set the root
 	if (!tree.ref_is_present(parent) && tree.elements != 0) {
-		return VTreeError.REFERENCE_NOT_PRESENT?;
+		return REFERENCE_NOT_PRESENT?;
 	}
 
 	// get the first free spot
@@ -149,7 +143,7 @@ fn isz! VTree.add(&tree, ElemType elem, isz parent)
 		}
 	}
 	if (free_spot < 0) {
-		return VTreeError.TREE_FULL?;
+		return TREE_FULL?;
 	}
 
 	// finally add the element
@@ -162,10 +156,10 @@ fn isz! VTree.add(&tree, ElemType elem, isz parent)
 
 // prune the tree starting from the ref
 // returns the number of pruned elements
-fn usz! VTree.prune(&tree, isz ref)
+fn usz? VTree.prune(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
@@ -196,10 +190,10 @@ fn usz VTree.nuke(&tree)
 }
 
 // find the size of the subtree starting from ref
-fn usz! VTree.subtree_size(&tree, isz ref)
+fn usz? VTree.subtree_size(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
@@ -218,20 +212,20 @@ fn usz! VTree.subtree_size(&tree, isz ref)
 }
 
 // iterate through the first level children, use a cursor like strtok_r
-fn isz! VTree.children_it(&tree, isz parent, isz *cursor)
+fn isz? VTree.children_it(&tree, isz parent, isz *cursor)
 {
 	if (cursor == null) {
-		return VTreeError.INVALID_ARGUMENT?;
+		return INVALID_ARGUMENT?;
 	}
 
 	// if the cursor is out of bounds then we are done for sure
 	if (!tree.ref_is_valid(*cursor)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	// same for the parent, if it's invalid it can't have children
 	if (!tree.ref_is_valid(parent) || !tree.ref_is_present(parent)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	// find the first child, update the cursor and return the ref
@@ -256,10 +250,10 @@ fn isz! VTree.children_it(&tree, isz parent, isz *cursor)
  *         /   \    [6]
  *       [4]   [5]
  */
-fn isz! VTree.level_order_it(&tree, isz ref, isz *cursor)
+fn isz? VTree.level_order_it(&tree, isz ref, isz *cursor)
 {
 	if (cursor == null) {
-		return VTreeError.INVALID_ARGUMENT?;
+		return INVALID_ARGUMENT?;
 	}
 
 	isz[] queue = tree.ordered_refs;
@@ -303,27 +297,27 @@ fn isz! VTree.level_order_it(&tree, isz ref, isz *cursor)
 	return -1;
 }
 
-fn isz! VTree.parentof(&tree, isz ref)
+fn isz? VTree.parentof(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
-		return VTreeError.REFERENCE_NOT_PRESENT?;
+		return REFERENCE_NOT_PRESENT?;
 	}
 
 	return tree.refs[ref];
 }
 
-fn ElemType! VTree.get(&tree, isz ref)
+fn ElemType? VTree.get(&tree, isz ref)
 {
 	if (!tree.ref_is_valid(ref)) {
-		return VTreeError.INVALID_REFERENCE?;
+		return INVALID_REFERENCE?;
 	}
 
 	if (!tree.ref_is_present(ref)) {
-		return VTreeError.REFERENCE_NOT_PRESENT?;
+		return REFERENCE_NOT_PRESENT?;
 	}
 
 	return tree.vector[ref];