kinda got text rendering working as well as multi draw call

kubi-ui-examples/examples/text.rs

@@ -0,0 +1,70 @@
+use std::time::Instant;
+use glam::{UVec2, vec4};
+use glium::{backend::glutin::SimpleWindowBuilder, Surface};
+use winit::{
+  event::{Event, WindowEvent},
+  event_loop::{EventLoopBuilder, ControlFlow}
+};
+use kubi_ui::{
+  KubiUi,
+  element::{
+    UiElement,
+    progress_bar::ProgressBar,
+    container::{Container, Sides, Alignment},
+    rect::Rect, text::Text
+  },
+  interaction::IntoInteractable,
+  UiSize,
+  UiDirection, IfModified,
+};
+use kubi_ui_glium::GliumUiRenderer;
+
+fn main() {
+  kubi_logging::init();
+
+  let event_loop = EventLoopBuilder::new().build().unwrap();
+  let (window, display) = SimpleWindowBuilder::new().build(&event_loop);
+
+  let mut kui = KubiUi::new();
+  let mut backend = GliumUiRenderer::new(&display);
+
+  let instant = Instant::now();
+  event_loop.run(|event, window_target| {
+    window_target.set_control_flow(ControlFlow::Poll);
+    match event {
+      Event::WindowEvent { event: WindowEvent::CloseRequested, .. } => {
+        window_target.exit();
+      },
+      Event::AboutToWait => {
+        let mut frame = display.draw();
+        frame.clear_color_srgb(0.5, 0.5, 0.5, 0.);
+
+        let resolution = UVec2::from(display.get_framebuffer_dimensions()).as_vec2();
+
+        kui.begin();
+
+        kui.add(Container {
+          gap: 5.,
+          padding: Sides::all(5.),
+          align: (Alignment::Begin, Alignment::Begin),
+          size: (UiSize::Percentage(1.), UiSize::Percentage(1.)),
+          elements: vec![
+            Box::new(Text {
+              text: "Heloworld!Loremipsumsimdoloramet".into(),
+              ..Default::default()
+            }),
+          ],
+          ..Default::default()
+        }, resolution);
+
+        kui.end();
+
+        backend.update(&kui);
+        backend.draw(&mut frame, resolution);
+
+        frame.finish().unwrap();
+      }
+      _ => (),
+    }
+  }).unwrap();
+}

kubi-ui-glium/shaders/fragment.frag

@@ -1,11 +1,21 @@
 #version 300 es
 
 precision highp float;
+precision highp sampler2D;
 
 out vec4 out_color;
 in vec4 vtx_color;
+in vec2 vtx_uv;
+uniform bool use_tex;
+uniform sampler2D tex;
 
 void main() {
-  if (vtx_color.w <= 0.) discard;
-  out_color = vtx_color;
+  //if (vtx_color.w <= 0.) discard;
+  vec4 tex_color;
+  if (use_tex) {
+    tex_color = texture(tex, vtx_uv);
+  } else {
+    tex_color = vec4(1.);
+  }
+  out_color = tex_color * vtx_color;
 }

kubi-ui-glium/shaders/vertex.vert

@@ -3,12 +3,15 @@
 precision highp float;
 
 uniform vec2 resolution;
+in vec2 uv;
 in vec4 color;
 in vec2 position;
 out vec4 vtx_color;
+out vec2 vtx_uv;
 
 void main() {
   vtx_color = color;
+  vtx_uv = uv;
   vec2 pos2d = (vec2(2., -2.) * (position / resolution)) + vec2(-1, 1);
   gl_Position = vec4(pos2d, 0., 1.);
 }

kubi-ui-glium/src/lib.rs

@@ -1,14 +1,17 @@
+use std::rc::Rc;
 use glam::Vec2;
 use glium::{
   Surface, DrawParameters, Blend,
   Program, VertexBuffer, IndexBuffer,
-  backend::Facade,
+  backend::{Facade, Context},
+  texture::{SrgbTexture2d, RawImage2d},
   index::PrimitiveType,
-  implement_vertex, uniform, texture::{SrgbTexture2d, RawImage2d},
+  implement_vertex,
+  uniform, uniforms::DynamicUniforms,
 };
 use kubi_ui::{
   KubiUi,
-  draw::{UiDrawPlan, UiVertex},
+  draw::{UiDrawPlan, UiVertex, BindTexture},
   text::FontTextureInfo, IfModified,
 };
 
@@ -36,10 +39,10 @@ impl From<UiVertex> for Vertex {
 implement_vertex!(Vertex, position, color, uv);
 
 struct BufferPair {
-  vertex_buffer: glium::VertexBuffer<Vertex>,
-  index_buffer: glium::IndexBuffer<u32>,
-  vertex_count: usize,
-  index_count: usize,
+  pub vertex_buffer: glium::VertexBuffer<Vertex>,
+  pub index_buffer: glium::IndexBuffer<u32>,
+  pub vertex_count: usize,
+  pub index_count: usize,
 }
 
 impl BufferPair {
@@ -102,65 +105,121 @@ impl BufferPair {
   }
 }
 
-pub struct GliumUiRenderer {
-  program: glium::Program,
+struct GlDrawCall {
+  active: bool,
   buffer: BufferPair,
+  bind_texture: Option<Rc<SrgbTexture2d>>,
+}
+
+pub struct GliumUiRenderer {
+  context: Rc<Context>,
+  program: glium::Program,
+  font_texture: Option<Rc<SrgbTexture2d>>,
+  plan: Vec<GlDrawCall>,
 }
 
 impl GliumUiRenderer {
   pub fn new<F: Facade>(facade: &F) -> Self {
-    log::info!("init glium backend for ui");
-    log::debug!("init program");
-    let program = Program::from_source(facade, VERTEX_SHADER, FRAGMENT_SHADER, None).unwrap();
+    log::info!("init glium backend for kui");
     Self {
-      program,
-      buffer: BufferPair::new(facade)
+      program: Program::from_source(facade, VERTEX_SHADER, FRAGMENT_SHADER, None).unwrap(),
+      context: Rc::clone(facade.get_context()),
+      font_texture: None,
+      plan: vec![]
     }
   }
 
   pub fn update_draw_plan(&mut self, plan: &UiDrawPlan) {
-    assert!(plan.calls.len() == 1, "multiple draw calls not supported yet");
-    let data_vtx = &plan.calls[0].vertices.iter().copied().map(Vertex::from).collect::<Vec<_>>();
-    let data_idx = &plan.calls[0].indices;
-    self.buffer.write_data(data_vtx, data_idx);
+    if plan.calls.len() > self.plan.len() {
+      self.plan.resize_with(plan.calls.len(), || {
+        GlDrawCall {
+          buffer: BufferPair::new(&self.context),
+          bind_texture: None,
+          active: false,
+        }
+      });
+    } else {
+      for step in &mut self.plan[plan.calls.len()..] {
+        step.active = false;
+      }
+    }
+    for (idx, call) in plan.calls.iter().enumerate() {
+      let data_vtx = &call.vertices.iter().copied().map(Vertex::from).collect::<Vec<_>>()[..];
+      let data_idx = &call.indices[..];
+      self.plan[idx].active = true;
+      self.plan[idx].buffer.write_data(data_vtx, data_idx);
+      self.plan[idx].bind_texture = match call.bind_texture {
+        Some(BindTexture::FontTexture) => {
+          const NO_FNT_TEX: &str = "Font texture exists in draw plan but not yet inited. Make sure to call update_font_texture() *before* update_draw_plan()";
+          Some(Rc::clone(self.font_texture.as_ref().expect(NO_FNT_TEX)))
+        },
+        None => None,
+      }
+    }
   }
 
   pub fn update_font_texture(&mut self, font_texture: &FontTextureInfo) {
-    //HACK: get context from buffer
-    let ctx = self.buffer.index_buffer.get_context();
-    SrgbTexture2d::new(ctx, RawImage2d::from_raw_rgb(
-      font_texture.data.to_owned(),
-      (font_texture.size.x, font_texture.size.y)
-    )).unwrap();
+    log::debug!("updating font texture");
+    self.font_texture = Some(Rc::new(SrgbTexture2d::new(
+      &self.context,
+      RawImage2d::from_raw_rgba(
+        font_texture.data.to_owned(),
+        (font_texture.size.x, font_texture.size.y)
+      )
+    ).unwrap()));
   }
 
   pub fn update(&mut self, kui: &KubiUi) {
-    if let Some(plan) = kui.draw_plan().if_modified() {
-      self.update_draw_plan(plan);
-    }
     if let Some(texture) = kui.font_texture().if_modified() {
       self.update_font_texture(texture);
     }
+    if let Some(plan) = kui.draw_plan().if_modified() {
+      self.update_draw_plan(plan);
+    }
   }
 
   pub fn draw(&self, frame: &mut glium::Frame, resolution: Vec2) {
-    if self.buffer.is_empty() {
-      return
-    }
-
     let params = DrawParameters {
       blend: Blend::alpha_blending(),
       ..Default::default()
     };
 
-    frame.draw(
-      self.buffer.vertex_buffer.slice(0..self.buffer.vertex_count).unwrap(),
-      self.buffer.index_buffer.slice(0..self.buffer.index_count).unwrap(),
-      &self.program,
-      &uniform! {
-        resolution: resolution.to_array(),
-      },
-      &params,
-    ).unwrap();
+    for step in &self.plan {
+      if !step.active {
+        continue
+      }
+
+      if step.buffer.is_empty() {
+        continue
+      }
+
+      let vtx_buffer = step.buffer.vertex_buffer.slice(0..step.buffer.vertex_count).unwrap();
+      let idx_buffer = step.buffer.index_buffer.slice(0..step.buffer.index_count).unwrap();
+
+      if let Some(bind_texture) = step.bind_texture.as_ref() {
+        frame.draw(
+          vtx_buffer,
+          idx_buffer,
+          &self.program,
+          &uniform! {
+            resolution: resolution.to_array(),
+            tex: bind_texture.as_ref(),
+            use_tex: true,
+          },
+          &params,
+        ).unwrap();
+      } else {
+        frame.draw(
+          vtx_buffer,
+          idx_buffer,
+          &self.program,
+          &uniform! {
+            resolution: resolution.to_array(),
+            use_tex: false,
+          },
+          &params,
+        ).unwrap();
+      }
+    }
   }
 }

kubi-ui/src/draw.rs

@@ -1,4 +1,4 @@
-use crate::{IfModified, text::TextRenderer};
+use crate::{IfModified, text::{TextRenderer, FontHandle}};
 
 use std::borrow::Cow;
 use glam::{Vec2, Vec4, vec2};
@@ -63,22 +63,75 @@ pub struct UiDrawPlan {
   pub calls: Vec<UiDrawCall>
 }
 
+struct CallSwapper {
+  calls: Vec<UiDrawCall>,
+  call: UiDrawCall,
+}
+
+impl CallSwapper {
+  pub fn new() -> Self {
+    Self {
+      calls: vec![],
+      call: UiDrawCall::default(),
+    }
+  }
+
+  pub fn current(&self) -> &UiDrawCall {
+    &self.call
+  }
+
+  pub fn current_mut(&mut self) -> &mut UiDrawCall {
+    &mut self.call
+  }
+
+  pub fn swap(&mut self) {
+    self.calls.push(std::mem::replace(&mut self.call, UiDrawCall::default()));
+  }
+
+  pub fn finish(mut self) -> Vec<UiDrawCall> {
+    self.calls.push(self.call);
+    self.calls
+  }
+}
+
 impl UiDrawPlan {
-  pub fn build(calls: &UiDrawCommands, tr: &mut TextRenderer) -> Self {
-    let mut call = UiDrawCall::default();
-    for command in &calls.commands {
+  pub fn build(draw_commands: &UiDrawCommands, tr: &mut TextRenderer) -> Self {
+    let mut swapper = CallSwapper::new();
+    let mut prev_command = None;
+    for command in &draw_commands.commands {
+
+      let do_swap = if let Some(prev_command) = prev_command {
+        std::mem::discriminant(prev_command) != std::mem::discriminant(command)
+      } else {
+        false
+      };
+
+      if do_swap {
+        swapper.swap();
+      }
+
+      if do_swap || prev_command.is_none() {
+        match command {
+          UiDrawCommand::Rectangle { .. } => (),
+          UiDrawCommand::Text { .. } => {
+            swapper.current_mut().bind_texture = Some(BindTexture::FontTexture);
+          }
+        }
+      }
+
+      let vidx = swapper.current().vertices.len() as u32;
+
       match command {
         UiDrawCommand::Rectangle { position, size, color } => {
-          let idx = call.vertices.len() as u32;
-          call.indices.extend([idx, idx + 1, idx + 2, idx, idx + 2, idx + 3]);
-          call.vertices.extend([
+          swapper.current_mut().indices.extend([vidx, vidx + 1, vidx + 2, vidx, vidx + 2, vidx + 3]);
+          swapper.current_mut().vertices.extend([
             UiVertex {
               position: *position,
               color: *color,
               uv: vec2(0.0, 0.0),
             },
             UiVertex {
-              position: *position + Vec2::new(size.x, 0.0),
+              position: *position + vec2(size.x, 0.0),
               color: *color,
               uv: vec2(1.0, 0.0),
             },
@@ -88,19 +141,45 @@ impl UiDrawPlan {
               uv: vec2(1.0, 1.0),
             },
             UiVertex {
-              position: *position + Vec2::new(0.0, size.y),
+              position: *position + vec2(0.0, size.y),
               color: *color,
               uv: vec2(0.0, 1.0),
             },
           ]);
         },
         UiDrawCommand::Text { position, size, color, text } => {
-          todo!()
+          for char in text.chars() {
+            tr.glyph(FontHandle(0), char, *size);
+          }
+          swapper.current_mut().indices.extend([vidx, vidx + 1, vidx + 2, vidx, vidx + 2, vidx + 3]);
+          swapper.current_mut().vertices.extend([
+            UiVertex {
+              position: *position,
+              color: *color,
+              uv: vec2(0.0, 0.0),
+            },
+            UiVertex {
+              position: *position + vec2(32., 0.0),
+              color: *color,
+              uv: vec2(1.0, 0.0),
+            },
+            UiVertex {
+              position: *position + vec2(32., 32.),
+              color: *color,
+              uv: vec2(1.0, 1.0),
+            },
+            UiVertex {
+              position: *position + vec2(0.0, 32.),
+              color: *color,
+              uv: vec2(0.0, 1.0),
+            },
+          ]);
         }
       }
+      prev_command = Some(command);
     }
     Self {
-      calls: vec![call]
+      calls: swapper.finish()
     }
   }
 }

kubi-ui/src/element.rs

@@ -12,6 +12,7 @@ mod builtin {
   pub mod container;
   pub mod spacer;
   pub mod progress_bar;
+  pub mod text;
 }
 
 #[cfg(feature = "builtin_elements")]

kubi-ui/src/element/builtin/text.rs

@@ -0,0 +1,56 @@
+use std::borrow::Cow;
+use glam::{vec2, Vec4};
+use crate::{
+  LayoutInfo,
+  UiSize,
+  element::UiElement,
+  state::StateRepo,
+  measure::Response,
+  draw::UiDrawCommand
+};
+
+pub struct Text {
+  pub text: Cow<'static, str>,
+  pub size: (UiSize, UiSize),
+  pub color: Vec4,
+}
+
+impl Default for Text {
+  fn default() -> Self {
+    Self {
+      text: "".into(),
+      size: (UiSize::Percentage(1.), UiSize::Pixels(32.)),
+      color: Vec4::new(1., 1., 1., 1.),
+    }
+  }
+}
+
+impl UiElement for Text {
+  fn measure(&self, _state: &StateRepo, layout: &LayoutInfo) -> Response {
+    Response {
+      size: vec2(
+        match self.size.0 {
+          UiSize::Auto => layout.max_size.x,
+          UiSize::Percentage(percentage) => layout.max_size.x * percentage,
+          UiSize::Pixels(pixels) => pixels,
+        },
+        match self.size.1 {
+          UiSize::Auto => layout.max_size.y,
+          UiSize::Percentage(percentage) => layout.max_size.y * percentage,
+          UiSize::Pixels(pixels) => pixels,
+        },
+      ),
+      hints: Default::default(),
+      user_data: None
+    }
+  }
+
+  fn process(&self, _measure: &Response, _state: &mut StateRepo, layout: &LayoutInfo, draw: &mut Vec<UiDrawCommand>) {
+    draw.push(UiDrawCommand::Text {
+      text: self.text.clone(),
+      position: layout.position,
+      size: 32,
+      color: self.color,
+    });
+  }
+}

kubi-ui/src/text/texman.rs

@@ -60,7 +60,7 @@ impl FontTextureManager {
     FontTextureManager {
       glyph_cache: HashMap::new(),
       packer: DensePacker::new(size.x as i32, size.y as i32),
-      font_texture: vec![0; (size.x * size.y) as usize],
+      font_texture: vec![0; (size.x * size.y * 4) as usize],
       font_texture_size: size,
       modified: false,
     }
@@ -79,17 +79,18 @@ impl FontTextureManager {
   }
 
   /// Either looks up the glyph in the cache or renders it and adds it to the cache.
-  fn glyph_allocate(&mut self, font_manager: &FontManager, font_handle: FontHandle, character: char, size: u8) -> (bool, Arc<GlyphCacheEntry>) {
+  pub fn glyph(&mut self, font_manager: &FontManager, font_handle: FontHandle, character: char, size: u8) -> Arc<GlyphCacheEntry> {
     let key = GlyphCacheKey {
       font_index: font_handle.0,
       character,
       size,
     };
     if let Some(entry) = self.glyph_cache.get(&key) {
-      return (false, Arc::clone(entry));
+      return Arc::clone(entry);
     }
     let font = font_manager.get(font_handle).unwrap();
     let (metrics, bitmap) = font.rasterize(character, size as f32);
+    log::debug!("rasterized glyph: {:?}, {:?}", metrics, bitmap);
     let texture_position = self.packer.pack(metrics.width as i32, metrics.height as i32, false).unwrap();
     let texture_size = uvec2(metrics.width as u32, metrics.height as u32);
     let entry = Arc::new(GlyphCacheEntry {
@@ -99,30 +100,37 @@ impl FontTextureManager {
       size: texture_size,
     });
     self.glyph_cache.insert_unique_unchecked(key, Arc::clone(&entry));
-    (true, entry)
+    self.glyph_place(&entry);
+    self.modified = true;
+    entry
   }
 
   /// Place glyph onto the font texture.
   fn glyph_place(&mut self, entry: &GlyphCacheEntry) {
     let tex_size = self.font_texture_size;
-    let GlyphCacheEntry { size, position, .. } = entry;
+    let GlyphCacheEntry { size, position, data, .. } = entry;
+    //println!("{size:?} {position:?}");
     for y in 0..size.y {
       for x in 0..size.x {
         let src = (size.x * y + x) as usize;
-        let dst = (tex_size.x * (y + position.y as u32) + (x + position.x as u32)) as usize;
-        self.font_texture[dst] = entry.data[src];
+        let dst = (tex_size.x * (y + position.y as u32) + (x + position.x as u32)) as usize * 4;
+        self.font_texture[dst..=(dst + 3)].copy_from_slice(&[255, 0, 0, data[src]]);
+        self.font_texture[dst] = data[src];
+        //print!("{} ", if data[src] > 0 {'#'} else {'.'});
+        //print!("{src} {dst} / ");
       }
+      //println!();
     }
   }
 
-  pub fn glyph(&mut self, font_manager: &FontManager, font_handle: FontHandle, character: char, size: u8) -> Arc<GlyphCacheEntry> {
-    let (is_new, glyph) = self.glyph_allocate(font_manager, font_handle, character, size);
-    if is_new {
-      self.glyph_place(&glyph);
-      self.modified = true;
-    }
-    glyph
-  }
+  // pub fn glyph(&mut self, font_manager: &FontManager, font_handle: FontHandle, character: char, size: u8) -> Arc<GlyphCacheEntry> {
+  //   let (is_new, glyph) = self.glyph_allocate(font_manager, font_handle, character, size);
+  //   if is_new {
+  //     self.glyph_place(&glyph);
+  //     self.modified = true;
+  //   }
+  //   glyph
+  // }
 }
 
 impl Default for FontTextureManager {