new workspace

wgui/src/drawing.rs

@@ -0,0 +1,200 @@
+use std::{cell::RefCell, rc::Rc};
+
+use cosmic_text::Buffer;
+use glam::{Mat4, Vec2};
+use taffy::TraversePartialTree;
+
+use crate::{
+	layout::BoxWidget,
+	renderer_vk::text::custom_glyph::CustomGlyph,
+	transform_stack::{self, TransformStack},
+	widget::{self},
+};
+
+use super::{layout::Layout, widget::DrawState};
+
+pub struct ImageHandle {
+	// to be implemented, will contain pixel data (RGB or RGBA) loaded via "ImageBank" or something by the gui
+}
+
+#[derive(Debug, Default, Clone, Copy, PartialEq)]
+pub struct Boundary {
+	pub pos: Vec2,
+	pub size: Vec2,
+}
+
+impl Boundary {
+	pub fn from_pos_size(pos: Vec2, size: Vec2) -> Self {
+		Self { pos, size }
+	}
+
+	pub fn construct(transform_stack: &TransformStack) -> Self {
+		let transform = transform_stack.get();
+
+		Self {
+			pos: Vec2::new(transform.pos.x, transform.pos.y),
+			size: Vec2::new(transform.dim.x, transform.dim.y),
+		}
+	}
+}
+
+#[derive(Copy, Clone)]
+pub struct Color {
+	pub r: f32,
+	pub g: f32,
+	pub b: f32,
+	pub a: f32,
+}
+
+impl Color {
+	pub fn new(r: f32, g: f32, b: f32, a: f32) -> Self {
+		Self { r, g, b, a }
+	}
+}
+
+impl Default for Color {
+	fn default() -> Self {
+		// opaque black
+		Self::new(0.0, 0.0, 0.0, 1.0)
+	}
+}
+
+#[repr(u8)]
+#[derive(Default, Clone, Copy)]
+pub enum GradientMode {
+	#[default]
+	None,
+	Horizontal,
+	Vertical,
+	Radial,
+}
+
+#[derive(Default, Clone, Copy)]
+pub struct Rectangle {
+	pub color: Color,
+	pub color2: Color,
+	pub gradient: GradientMode,
+
+	pub border: f32, // width in pixels
+	pub border_color: Color,
+
+	pub round_units: u8,
+}
+
+pub struct RenderPrimitive {
+	pub(super) boundary: Boundary,
+	pub(super) transform: Mat4,
+	pub(super) depth: f32,
+	pub(super) payload: PrimitivePayload,
+}
+
+pub enum PrimitivePayload {
+	Rectangle(Rectangle),
+	Text(Rc<RefCell<Buffer>>),
+	Sprite(Option<CustomGlyph>), //option because we want as_slice
+}
+
+fn draw_widget(
+	layout: &Layout,
+	state: &mut DrawState,
+	node_id: taffy::NodeId,
+	style: &taffy::Style,
+	widget: &BoxWidget,
+	parent_transform: &glam::Mat4,
+) {
+	let Ok(l) = layout.tree.layout(node_id) else {
+		debug_assert!(false);
+		return;
+	};
+
+	let mut widget_state = widget.lock().unwrap();
+
+	let transform = widget_state.data.transform * *parent_transform;
+
+	let (shift, info) = match widget::get_scrollbar_info(l) {
+		Some(info) => (widget_state.get_scroll_shift(&info, l), Some(info)),
+		None => (Vec2::default(), None),
+	};
+
+	state.transform_stack.push(transform_stack::Transform {
+		pos: Vec2::new(l.location.x, l.location.y) - shift,
+		transform,
+		dim: Vec2::new(l.size.width, l.size.height),
+	});
+
+	let draw_params = widget::DrawParams {
+		node_id,
+		taffy_layout: l,
+		style,
+	};
+
+	widget_state.draw_all(state, &draw_params);
+
+	draw_children(layout, state, node_id, &transform);
+
+	state.transform_stack.pop();
+
+	if let Some(info) = &info {
+		widget_state.draw_scrollbars(state, &draw_params, info);
+	}
+}
+
+fn draw_children(
+	layout: &Layout,
+	state: &mut DrawState,
+	parent_node_id: taffy::NodeId,
+	model: &glam::Mat4,
+) {
+	for node_id in layout.tree.child_ids(parent_node_id) {
+		let Some(widget_id) = layout.tree.get_node_context(node_id).cloned() else {
+			debug_assert!(false);
+			continue;
+		};
+
+		let Ok(style) = layout.tree.style(node_id) else {
+			debug_assert!(false);
+			continue;
+		};
+
+		let Some(widget) = layout.widget_states.get(widget_id) else {
+			debug_assert!(false);
+			continue;
+		};
+
+		state.depth += 0.01;
+		draw_widget(layout, state, node_id, style, widget, model);
+		state.depth -= 0.01;
+	}
+}
+
+pub fn draw(layout: &Layout) -> anyhow::Result<Vec<RenderPrimitive>> {
+	let mut primitives = Vec::<RenderPrimitive>::new();
+	let mut transform_stack = TransformStack::new();
+	let model = glam::Mat4::IDENTITY;
+
+	let Some(root_widget) = layout.widget_states.get(layout.root_widget) else {
+		panic!();
+	};
+
+	let Ok(style) = layout.tree.style(layout.root_node) else {
+		panic!();
+	};
+
+	let mut params = DrawState {
+		primitives: &mut primitives,
+		transform_stack: &mut transform_stack,
+		layout,
+		depth: 0.0,
+	};
+
+	draw_widget(
+		layout,
+		&mut params,
+		layout.root_node,
+		style,
+		root_widget,
+		&model,
+	);
+
+	Ok(primitives)
+}