From 8f75d451e4634b790da251db16d21e0c4d12cc76 Mon Sep 17 00:00:00 2001
From: Aleksander <aleksander@oo8.dev>
Date: Wed, 24 Sep 2025 21:53:43 +0200
Subject: [PATCH] working scissor proof of concept

---
 uidev/assets/gui/various_widgets.xml       |  6 +-
 wgui/src/drawing.rs                        | 36 +++++----
 wgui/src/gfx/pass.rs                       | 16 ++--
 wgui/src/gfx/pipeline.rs                   | 16 ++--
 wgui/src/renderer_vk/context.rs            | 93 ++++++++++++++--------
 wgui/src/renderer_vk/rect.rs               |  4 +-
 wgui/src/renderer_vk/text/text_renderer.rs | 33 +++-----
 wgui/src/widget/label.rs                   | 16 ++--
 wgui/src/widget/mod.rs                     | 50 ++++++------
 wgui/src/widget/rectangle.rs               | 18 +++--
 wgui/src/widget/sprite.rs                  | 33 ++++----
 11 files changed, 175 insertions(+), 146 deletions(-)

diff --git a/uidev/assets/gui/various_widgets.xml b/uidev/assets/gui/various_widgets.xml
index 3485880..b8ba9b8 100644
--- a/uidev/assets/gui/various_widgets.xml
+++ b/uidev/assets/gui/various_widgets.xml
@@ -11,9 +11,9 @@
       <div margin_left="16" gap="8" flex_direction="column">
         <label id="label_current_option" text="Click any of these buttons" size="20" weight="bold" />
         <div gap="4">
-          <Button id="button_red" text="Red button" width="220" height="32" color="#FF0000" />
-          <Button id="button_aqua" text="Aqua button" width="220" height="32" color="#00FFFF" />
-          <Button id="button_yellow" text="Yellow button" width="220" height="32" color="#FFFF00" />
+          <Button id="button_red" text="Red button" width="150" height="32" color="#FF0000" />
+          <Button id="button_aqua" text="Aqua button" width="150" height="32" color="#00FFFF" />
+          <Button id="button_yellow" text="Yellow button" width="150" height="32" color="#FFFF00" />
         </div>
         <Button id="button_click_me" text="Click me" width="128" height="24" color="#FFFFFF" />
 
diff --git a/wgui/src/drawing.rs b/wgui/src/drawing.rs
index e1603b8..926d7d5 100644
--- a/wgui/src/drawing.rs
+++ b/wgui/src/drawing.rs
@@ -5,6 +5,7 @@ use glam::{Mat4, Vec2};
 use taffy::TraversePartialTree;
 
 use crate::{
+	drawing,
 	layout::Widget,
 	renderer_vk::text::custom_glyph::CustomGlyph,
 	transform_stack::{self, TransformStack},
@@ -111,26 +112,18 @@ pub struct Rectangle {
 	pub round_units: u8,
 }
 
-#[derive(Clone, Copy)]
-pub struct Scissor {
-	pub x: u32,
-	pub y: u32,
-	pub w: u32,
-	pub h: u32,
-}
-
-pub struct RenderPrimitive {
+pub struct PrimitiveExtent {
 	pub(super) boundary: Boundary,
 	pub(super) transform: Mat4,
-	pub(super) depth: f32,
-	pub(super) payload: PrimitivePayload,
+	pub(super) depth: f32, // FIXME: remove this
 }
 
-pub enum PrimitivePayload {
-	Rectangle(Rectangle),
-	Text(Rc<RefCell<Buffer>>),
-	Sprite(Option<CustomGlyph>), //option because we want as_slice
-	Scissor(Scissor),
+pub enum RenderPrimitive {
+	Rectangle(PrimitiveExtent, Rectangle),
+	Text(PrimitiveExtent, Rc<RefCell<Buffer>>),
+	Sprite(PrimitiveExtent, Option<CustomGlyph>), //option because we want as_slice
+	ScissorEnable(Boundary),
+	ScissorDisable,
 }
 
 fn draw_widget(
@@ -161,6 +154,13 @@ fn draw_widget(
 		dim: Vec2::new(l.size.width, l.size.height),
 	});
 
+	// FIXME: this is temporary
+	// FIXME: implement scissor stack (do not allow growing!)
+	if info.is_some() {
+		let boundary = drawing::Boundary::construct(state.transform_stack);
+		state.primitives.push(drawing::RenderPrimitive::ScissorEnable(boundary));
+	}
+
 	let draw_params = widget::DrawParams {
 		node_id,
 		taffy_layout: l,
@@ -171,6 +171,10 @@ fn draw_widget(
 
 	draw_children(layout, state, node_id, &transform);
 
+	if info.is_some() {
+		state.primitives.push(drawing::RenderPrimitive::ScissorDisable);
+	}
+
 	state.transform_stack.pop();
 
 	if let Some(info) = &info {
diff --git a/wgui/src/gfx/pass.rs b/wgui/src/gfx/pass.rs
index 8318286..2dc3c0c 100644
--- a/wgui/src/gfx/pass.rs
+++ b/wgui/src/gfx/pass.rs
@@ -14,7 +14,7 @@ use vulkano::{
 	},
 	pipeline::{
 		Pipeline, PipelineBindPoint,
-		graphics::{vertex_input::Vertex, viewport::Viewport},
+		graphics::{self, vertex_input::Vertex, viewport::Viewport},
 	},
 };
 
@@ -38,6 +38,7 @@ where
 		vertices: Range<u32>,
 		instances: Range<u32>,
 		descriptor_sets: Vec<Arc<DescriptorSet>>,
+		vk_scissor: &graphics::viewport::Scissor,
 	) -> anyhow::Result<Self> {
 		let viewport = Viewport {
 			offset: [0.0, 0.0],
@@ -64,6 +65,7 @@ where
 		unsafe {
 			command_buffer
 				.set_viewport(0, smallvec![viewport])?
+				.set_scissor(0, smallvec![*vk_scissor])?
 				.bind_pipeline_graphics(pipeline_inner)?
 				.bind_descriptor_sets(
 					PipelineBindPoint::Graphics,
@@ -88,12 +90,7 @@ where
 		})
 	}
 
-	pub fn update_sampler(
-		&self,
-		set: usize,
-		texture: Arc<ImageView>,
-		filter: Filter,
-	) -> anyhow::Result<()> {
+	pub fn update_sampler(&self, set: usize, texture: Arc<ImageView>, filter: Filter) -> anyhow::Result<()> {
 		let sampler = Sampler::new(
 			self.graphics.device.clone(),
 			SamplerCreateInfo {
@@ -105,10 +102,7 @@ where
 		)?;
 
 		unsafe {
-			self.descriptor_sets[set].update_by_ref(
-				[WriteDescriptorSet::image_view_sampler(0, texture, sampler)],
-				[],
-			)?;
+			self.descriptor_sets[set].update_by_ref([WriteDescriptorSet::image_view_sampler(0, texture, sampler)], [])?;
 		}
 
 		Ok(())
diff --git a/wgui/src/gfx/pipeline.rs b/wgui/src/gfx/pipeline.rs
index 6813b26..1b0afd3 100644
--- a/wgui/src/gfx/pipeline.rs
+++ b/wgui/src/gfx/pipeline.rs
@@ -16,7 +16,7 @@ use vulkano::{
 	pipeline::{
 		DynamicState, GraphicsPipeline, Pipeline, PipelineLayout,
 		graphics::{
-			GraphicsPipelineCreateInfo,
+			self, GraphicsPipelineCreateInfo,
 			color_blend::{AttachmentBlend, ColorBlendAttachmentState, ColorBlendState},
 			input_assembly::{InputAssemblyState, PrimitiveTopology},
 			multisample::MultisampleState,
@@ -91,7 +91,7 @@ where
 					}],
 					..Default::default()
 				}),
-				dynamic_state: std::iter::once(DynamicState::Viewport).collect(),
+				dynamic_state: [DynamicState::Viewport, DynamicState::Scissor].into_iter().collect(),
 				subpass: Some(subpass.into()),
 				..GraphicsPipelineCreateInfo::layout(layout)
 			},
@@ -105,7 +105,6 @@ where
 		})
 	}
 
-	
 	pub fn inner(&self) -> Arc<GraphicsPipeline> {
 		self.pipeline.clone()
 	}
@@ -151,11 +150,7 @@ where
 	}
 
 	#[allow(clippy::needless_pass_by_value)]
-	pub fn uniform_buffer_upload<T>(
-		&self,
-		set: usize,
-		data: Vec<T>,
-	) -> anyhow::Result<Arc<DescriptorSet>>
+	pub fn uniform_buffer_upload<T>(&self, set: usize, data: Vec<T>) -> anyhow::Result<Arc<DescriptorSet>>
 	where
 		T: BufferContents + Copy,
 	{
@@ -163,8 +158,7 @@ where
 			self.graphics.memory_allocator.clone(),
 			SubbufferAllocatorCreateInfo {
 				buffer_usage: BufferUsage::UNIFORM_BUFFER,
-				memory_type_filter: MemoryTypeFilter::PREFER_DEVICE
-					| MemoryTypeFilter::HOST_SEQUENTIAL_WRITE,
+				memory_type_filter: MemoryTypeFilter::PREFER_DEVICE | MemoryTypeFilter::HOST_SEQUENTIAL_WRITE,
 				..Default::default()
 			},
 		);
@@ -219,6 +213,7 @@ where
 		vertices: Range<u32>,
 		instances: Range<u32>,
 		descriptor_sets: Vec<Arc<DescriptorSet>>,
+		vk_scissor: &graphics::viewport::Scissor,
 	) -> anyhow::Result<WGfxPass<V>> {
 		WGfxPass::new(
 			&self.clone(),
@@ -227,6 +222,7 @@ where
 			vertices,
 			instances,
 			descriptor_sets,
+			vk_scissor,
 		)
 	}
 }
diff --git a/wgui/src/renderer_vk/context.rs b/wgui/src/renderer_vk/context.rs
index 3fb43f5..16e2dd0 100644
--- a/wgui/src/renderer_vk/context.rs
+++ b/wgui/src/renderer_vk/context.rs
@@ -3,10 +3,10 @@ use std::{cell::RefCell, rc::Rc, sync::Arc};
 use cosmic_text::Buffer;
 use glam::{Mat4, Vec2, Vec3};
 use slotmap::{SlotMap, new_key_type};
-use vulkano::{buffer::view, pipeline::graphics::viewport};
+use vulkano::pipeline::graphics::viewport;
 
 use crate::{
-	drawing::{self, Scissor},
+	drawing::{self},
 	gfx::{WGfx, cmd::GfxCommandBuffer},
 };
 
@@ -25,11 +25,17 @@ struct RendererPass<'a> {
 	text_areas: Vec<TextArea<'a>>,
 	text_renderer: TextRenderer,
 	rect_renderer: RectRenderer,
-	scissor: Option<Scissor>,
+	scissor: Option<drawing::Boundary>,
+	pixel_scale: f32,
 }
 
 impl RendererPass<'_> {
-	fn new(text_atlas: &mut TextAtlas, rect_pipeline: RectPipeline, scissor: Option<Scissor>) -> anyhow::Result<Self> {
+	fn new(
+		text_atlas: &mut TextAtlas,
+		rect_pipeline: RectPipeline,
+		scissor: Option<drawing::Boundary>,
+		pixel_scale: f32,
+	) -> anyhow::Result<Self> {
 		let text_renderer = TextRenderer::new(text_atlas)?;
 		let rect_renderer = RectRenderer::new(rect_pipeline)?;
 
@@ -39,6 +45,7 @@ impl RendererPass<'_> {
 			rect_renderer,
 			text_areas: Vec::new(),
 			scissor,
+			pixel_scale,
 		})
 	}
 
@@ -53,20 +60,34 @@ impl RendererPass<'_> {
 			return Ok(());
 		}
 
-		let vk_scissor = if let Some(scissor) = self.scissor {
-			viewport::Scissor {
-				offset: [scissor.x, scissor.y],
-				extent: [scissor.w, scissor.h],
+		let vk_scissor = match self.scissor {
+			Some(scissor) => {
+				let mut x = scissor.pos.x;
+				let mut y = scissor.pos.y;
+				let mut w = scissor.size.x;
+				let mut h = scissor.size.y;
+
+				// handle out-of-bounds scissors (x/y < 0)
+				if x < 0.0 {
+					w += x;
+					x = 0.0;
+				}
+
+				if y < 0.0 {
+					h += y;
+					y = 0.0;
+				}
+
+				viewport::Scissor {
+					offset: [(x * self.pixel_scale) as u32, (y * self.pixel_scale) as u32],
+					extent: [(w * self.pixel_scale) as u32, (h * self.pixel_scale) as u32],
+				}
 			}
-		} else {
-			viewport::Scissor::default()
+			None => viewport::Scissor::default(),
 		};
 
-		// TODO?
-		// cmd_buf.command_buffer.set_scissor(0, smallvec::smallvec![vk_scissor])?;
-
 		self.submitted = true;
-		self.rect_renderer.render(gfx, viewport, cmd_buf)?;
+		self.rect_renderer.render(gfx, viewport, &vk_scissor, cmd_buf)?;
 
 		{
 			let mut font_system = FONT_SYSTEM.lock();
@@ -81,7 +102,7 @@ impl RendererPass<'_> {
 			)?;
 		}
 
-		self.text_renderer.render(text_atlas, viewport, cmd_buf)?;
+		self.text_renderer.render(text_atlas, viewport, &vk_scissor, cmd_buf)?;
 
 		Ok(())
 	}
@@ -202,7 +223,7 @@ impl Context {
 
 		let mut passes = Vec::<RendererPass>::new();
 		let mut needs_new_pass = true;
-		let mut next_scissor: Option<Scissor> = None;
+		let mut next_scissor: Option<drawing::Boundary> = None;
 
 		for primitive in primitives {
 			if needs_new_pass {
@@ -210,54 +231,60 @@ impl Context {
 					&mut atlas.text_atlas,
 					shared.rect_pipeline.clone(),
 					next_scissor,
+					self.pixel_scale,
 				)?);
-				next_scissor = None;
 				needs_new_pass = false;
 			}
 
 			let pass = passes.last_mut().unwrap(); // always safe
 
-			match &primitive.payload {
-				drawing::PrimitivePayload::Rectangle(rectangle) => {
+			match &primitive {
+				drawing::RenderPrimitive::Rectangle(extent, rectangle) => {
 					pass
 						.rect_renderer
-						.add_rect(primitive.boundary, *rectangle, &primitive.transform, primitive.depth);
+						.add_rect(extent.boundary, *rectangle, &extent.transform, extent.depth);
 				}
-				drawing::PrimitivePayload::Text(text) => {
+				drawing::RenderPrimitive::Text(extent, text) => {
 					pass.text_areas.push(TextArea {
 						buffer: text.clone(),
-						left: primitive.boundary.pos.x * self.pixel_scale,
-						top: primitive.boundary.pos.y * self.pixel_scale,
+						left: extent.boundary.pos.x * self.pixel_scale,
+						top: extent.boundary.pos.y * self.pixel_scale,
 						bounds: TextBounds::default(), //FIXME: just using boundary coords here doesn't work
 						scale: self.pixel_scale,
 						default_color: cosmic_text::Color::rgb(0, 0, 0),
 						custom_glyphs: &[],
-						depth: primitive.depth,
-						transform: primitive.transform,
+						depth: extent.depth,
+						transform: extent.transform,
 					});
 				}
-				drawing::PrimitivePayload::Sprite(sprites) => {
+				drawing::RenderPrimitive::Sprite(extent, sprites) => {
 					pass.text_areas.push(TextArea {
 						buffer: self.empty_text.clone(),
-						left: primitive.boundary.pos.x * self.pixel_scale,
-						top: primitive.boundary.pos.y * self.pixel_scale,
+						left: extent.boundary.pos.x * self.pixel_scale,
+						top: extent.boundary.pos.y * self.pixel_scale,
 						bounds: TextBounds::default(),
 						scale: self.pixel_scale,
 						custom_glyphs: sprites.as_slice(),
 						default_color: cosmic_text::Color::rgb(255, 0, 255),
-						depth: primitive.depth,
-						transform: primitive.transform,
+						depth: extent.depth,
+						transform: extent.transform,
 					});
 				}
-				drawing::PrimitivePayload::Scissor(scissor) => {
-					next_scissor = Some(*scissor);
+				drawing::RenderPrimitive::ScissorEnable(boundary) => {
+					next_scissor = Some(*boundary);
+					needs_new_pass = true;
+				}
+				drawing::RenderPrimitive::ScissorDisable => {
+					next_scissor = None;
 					needs_new_pass = true;
 				}
 			}
 		}
 
+		log::info!("count {}", passes.len());
+
 		for mut pass in passes {
-			pass.submit(&shared.gfx, &mut self.viewport, cmd_buf, &mut atlas.text_atlas)?
+			pass.submit(&shared.gfx, &mut self.viewport, cmd_buf, &mut atlas.text_atlas)?;
 		}
 
 		Ok(())
diff --git a/wgui/src/renderer_vk/rect.rs b/wgui/src/renderer_vk/rect.rs
index 2461e6d..1f2f7d4 100644
--- a/wgui/src/renderer_vk/rect.rs
+++ b/wgui/src/renderer_vk/rect.rs
@@ -4,7 +4,7 @@ use glam::Mat4;
 use vulkano::{
 	buffer::{BufferContents, BufferUsage, Subbuffer},
 	format::Format,
-	pipeline::graphics::{input_assembly::PrimitiveTopology, vertex_input::Vertex},
+	pipeline::graphics::{self, input_assembly::PrimitiveTopology, vertex_input::Vertex},
 };
 
 use crate::{
@@ -136,6 +136,7 @@ impl RectRenderer {
 		&mut self,
 		gfx: &Arc<WGfx>,
 		viewport: &mut Viewport,
+		vk_scissor: &graphics::viewport::Scissor,
 		cmd_buf: &mut GfxCommandBuffer,
 	) -> anyhow::Result<()> {
 		let res = viewport.resolution();
@@ -154,6 +155,7 @@ impl RectRenderer {
 					0..4,
 					0..self.rect_vertices.len() as _,
 					vec![set0, set1],
+					vk_scissor,
 				)?;
 				CachedPass { pass, res }
 			}
diff --git a/wgui/src/renderer_vk/text/text_renderer.rs b/wgui/src/renderer_vk/text/text_renderer.rs
index cb9dd0e..1f489fe 100644
--- a/wgui/src/renderer_vk/text/text_renderer.rs
+++ b/wgui/src/renderer_vk/text/text_renderer.rs
@@ -13,6 +13,7 @@ use glam::{Mat4, Vec2, Vec3};
 use vulkano::{
 	buffer::{BufferUsage, Subbuffer},
 	command_buffer::CommandBufferUsage,
+	pipeline::graphics,
 };
 
 struct CachedPass {
@@ -78,12 +79,7 @@ impl TextRenderer {
 				let height = (glyph.height * text_area.scale).round() as u16;
 
 				let (x, y, x_bin, y_bin) = if glyph.snap_to_physical_pixel {
-					(
-						x.round() as i32,
-						y.round() as i32,
-						SubpixelBin::Zero,
-						SubpixelBin::Zero,
-					)
+					(x.round() as i32, y.round() as i32, SubpixelBin::Zero, SubpixelBin::Zero)
 				} else {
 					let (x, x_bin) = SubpixelBin::new(x);
 					let (y, y_bin) = SubpixelBin::new(y);
@@ -252,6 +248,7 @@ impl TextRenderer {
 		&mut self,
 		atlas: &TextAtlas,
 		viewport: &mut Viewport,
+		vk_scissor: &graphics::viewport::Scissor,
 		cmd_buf: &mut GfxCommandBuffer,
 	) -> anyhow::Result<()> {
 		if self.glyph_vertices.is_empty() {
@@ -277,6 +274,7 @@ impl TextRenderer {
 					0..4,
 					0..self.glyph_vertices.len() as u32,
 					descriptor_sets,
+					vk_scissor,
 				)?;
 				CachedPass { pass, res }
 			}
@@ -351,10 +349,7 @@ fn prepare_glyph(
 				if let Some(a) = inner.try_allocate(image.width as usize, image.height as usize) {
 					break a;
 				}
-				if !par
-					.atlas
-					.grow(par.font_system, par.cache, image.content_type)?
-				{
+				if !par.atlas.grow(par.font_system, par.cache, image.content_type)? {
 					anyhow::bail!(
 						"Atlas full. atlas: {:?} cache_key: {:?}",
 						image.content_type,
@@ -393,16 +388,14 @@ fn prepare_glyph(
 
 		inner.glyphs_in_use.insert(par.cache_key);
 		// Insert the glyph into the cache and return the details reference
-		inner
-			.glyph_cache
-			.get_or_insert(par.cache_key, || GlyphDetails {
-				width: image.width,
-				height: image.height,
-				gpu_cache,
-				atlas_id,
-				top: image.top,
-				left: image.left,
-			})
+		inner.glyph_cache.get_or_insert(par.cache_key, || GlyphDetails {
+			width: image.width,
+			height: image.height,
+			gpu_cache,
+			atlas_id,
+			top: image.top,
+			left: image.left,
+		})
 	};
 
 	let mut x = par.x + i32::from(details.left);
diff --git a/wgui/src/widget/label.rs b/wgui/src/widget/label.rs
index c18092f..be80922 100644
--- a/wgui/src/widget/label.rs
+++ b/wgui/src/widget/label.rs
@@ -5,7 +5,7 @@ use slotmap::Key;
 use taffy::AvailableSpace;
 
 use crate::{
-	drawing::{self, Boundary},
+	drawing::{self, Boundary, PrimitiveExtent},
 	event::CallbackDataCommon,
 	globals::Globals,
 	i18n::{I18n, Translation},
@@ -118,12 +118,14 @@ impl WidgetObj for WidgetLabel {
 			buffer.set_size(&mut font_system, Some(boundary.size.x), Some(boundary.size.y));
 		}
 
-		state.primitives.push(drawing::RenderPrimitive {
-			boundary,
-			depth: state.depth,
-			payload: drawing::PrimitivePayload::Text(self.buffer.clone()),
-			transform: state.transform_stack.get().transform,
-		});
+		state.primitives.push(drawing::RenderPrimitive::Text(
+			PrimitiveExtent {
+				boundary,
+				depth: state.depth,
+				transform: state.transform_stack.get().transform,
+			},
+			self.buffer.clone(),
+		));
 	}
 
 	fn measure(
diff --git a/wgui/src/widget/mod.rs b/wgui/src/widget/mod.rs
index 5ebaf8e..1f680ea 100644
--- a/wgui/src/widget/mod.rs
+++ b/wgui/src/widget/mod.rs
@@ -4,7 +4,7 @@ use super::drawing::RenderPrimitive;
 
 use crate::{
 	any::AnyTrait,
-	drawing,
+	drawing::{self, PrimitiveExtent},
 	event::{
 		self, CallbackData, CallbackDataCommon, CallbackMetadata, Event, EventAlterables, EventListenerKind,
 		EventListenerVec, MouseWheelEvent,
@@ -244,34 +244,38 @@ impl WidgetState {
 
 		// Horizontal handle
 		if enabled_horiz && info.handle_size.x < 1.0 {
-			state.primitives.push(drawing::RenderPrimitive {
-				boundary: drawing::Boundary::from_pos_size(
-					Vec2::new(
-						transform.pos.x + transform.dim.x * (1.0 - info.handle_size.x) * self.data.scrolling.x,
-						transform.pos.y + transform.dim.y - thickness - margin,
+			state.primitives.push(drawing::RenderPrimitive::Rectangle(
+				PrimitiveExtent {
+					boundary: drawing::Boundary::from_pos_size(
+						Vec2::new(
+							transform.pos.x + transform.dim.x * (1.0 - info.handle_size.x) * self.data.scrolling.x,
+							transform.pos.y + transform.dim.y - thickness - margin,
+						),
+						Vec2::new(transform.dim.x * info.handle_size.x, thickness),
 					),
-					Vec2::new(transform.dim.x * info.handle_size.x, thickness),
-				),
-				depth: state.depth,
-				transform: transform.transform,
-				payload: drawing::PrimitivePayload::Rectangle(rect_params),
-			});
+					depth: state.depth,
+					transform: transform.transform,
+				},
+				rect_params,
+			));
 		}
 
 		// Vertical handle
 		if enabled_vert && info.handle_size.y < 1.0 {
-			state.primitives.push(drawing::RenderPrimitive {
-				boundary: drawing::Boundary::from_pos_size(
-					Vec2::new(
-						transform.pos.x + transform.dim.x - thickness - margin,
-						transform.pos.y + transform.dim.y * (1.0 - info.handle_size.y) * self.data.scrolling.y,
+			state.primitives.push(drawing::RenderPrimitive::Rectangle(
+				PrimitiveExtent {
+					boundary: drawing::Boundary::from_pos_size(
+						Vec2::new(
+							transform.pos.x + transform.dim.x - thickness - margin,
+							transform.pos.y + transform.dim.y * (1.0 - info.handle_size.y) * self.data.scrolling.y,
+						),
+						Vec2::new(thickness, transform.dim.y * info.handle_size.y),
 					),
-					Vec2::new(thickness, transform.dim.y * info.handle_size.y),
-				),
-				depth: state.depth,
-				transform: transform.transform,
-				payload: drawing::PrimitivePayload::Rectangle(rect_params),
-			});
+					depth: state.depth,
+					transform: transform.transform,
+				},
+				rect_params,
+			));
 		}
 	}
 
diff --git a/wgui/src/widget/rectangle.rs b/wgui/src/widget/rectangle.rs
index e5a258d..a1f8eeb 100644
--- a/wgui/src/widget/rectangle.rs
+++ b/wgui/src/widget/rectangle.rs
@@ -1,7 +1,7 @@
 use slotmap::Key;
 
 use crate::{
-	drawing::{self, GradientMode},
+	drawing::{self, GradientMode, PrimitiveExtent},
 	layout::WidgetID,
 	widget::util::WLength,
 };
@@ -43,19 +43,21 @@ impl WidgetObj for WidgetRectangle {
 			WLength::Percent(percent) => (f32::min(boundary.size.x, boundary.size.y) * percent / 2.0) as u8,
 		};
 
-		state.primitives.push(drawing::RenderPrimitive {
-			boundary,
-			depth: state.depth,
-			transform: state.transform_stack.get().transform,
-			payload: drawing::PrimitivePayload::Rectangle(drawing::Rectangle {
+		state.primitives.push(drawing::RenderPrimitive::Rectangle(
+			PrimitiveExtent {
+				boundary,
+				depth: state.depth,
+				transform: state.transform_stack.get().transform,
+			},
+			drawing::Rectangle {
 				color: self.params.color,
 				color2: self.params.color2,
 				gradient: self.params.gradient,
 				border: self.params.border,
 				border_color: self.params.border_color,
 				round_units,
-			}),
-		});
+			},
+		));
 	}
 
 	fn get_id(&self) -> WidgetID {
diff --git a/wgui/src/widget/sprite.rs b/wgui/src/widget/sprite.rs
index a30dea7..3e5dd3a 100644
--- a/wgui/src/widget/sprite.rs
+++ b/wgui/src/widget/sprite.rs
@@ -4,7 +4,7 @@ use cosmic_text::{Attrs, Buffer, Color, Shaping, Weight};
 use slotmap::Key;
 
 use crate::{
-	drawing::{self},
+	drawing::{self, PrimitiveExtent},
 	layout::WidgetID,
 	renderer_vk::text::{
 		DEFAULT_METRICS, FONT_SYSTEM,
@@ -55,12 +55,14 @@ impl WidgetObj for WidgetSprite {
 				snap_to_physical_pixel: true,
 			};
 
-			state.primitives.push(drawing::RenderPrimitive {
-				boundary,
-				depth: state.depth,
-				payload: drawing::PrimitivePayload::Sprite(Some(glyph)),
-				transform: state.transform_stack.get().transform,
-			});
+			state.primitives.push(drawing::RenderPrimitive::Sprite(
+				PrimitiveExtent {
+					boundary,
+					depth: state.depth,
+					transform: state.transform_stack.get().transform,
+				},
+				Some(glyph),
+			));
 		} else {
 			// Source not set or not available, display error text
 			let mut buffer = Buffer::new_empty(DEFAULT_METRICS);
@@ -73,13 +75,16 @@ impl WidgetObj for WidgetSprite {
 				// set text last in order to avoid expensive re-shaping
 				buffer.set_text("Error", &attrs, Shaping::Basic);
 			}
-			state.primitives.push(drawing::RenderPrimitive {
-				boundary,
-				depth: state.depth,
-				payload: drawing::PrimitivePayload::Text(Rc::new(RefCell::new(buffer))),
-				transform: state.transform_stack.get().transform,
-			});
-		}
+
+			state.primitives.push(drawing::RenderPrimitive::Text(
+				PrimitiveExtent {
+					boundary,
+					depth: state.depth,
+					transform: state.transform_stack.get().transform,
+				},
+				Rc::new(RefCell::new(buffer)),
+			))
+		};
 	}
 
 	fn measure(