From f61aa6734f7185feac769fb3a128abca4e3890d2 Mon Sep 17 00:00:00 2001
From: griffi-gh <prasol258@gmail.com>
Date: Wed, 21 Feb 2024 23:56:55 +0100
Subject: [PATCH] x

---
 hui/src/draw/atlas.rs | 51 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 42 insertions(+), 9 deletions(-)

diff --git a/hui/src/draw/atlas.rs b/hui/src/draw/atlas.rs
index ca08402..c630cac 100644
--- a/hui/src/draw/atlas.rs
+++ b/hui/src/draw/atlas.rs
@@ -1,4 +1,4 @@
-use glam::UVec2;
+use glam::{uvec2, UVec2};
 use hashbrown::HashMap;
 use nohash_hasher::BuildNoHashHasher;
 use rect_packer::DensePacker;
@@ -41,7 +41,7 @@ impl TextureAtlasManager {
       packer: DensePacker::new(size.x as i32, size.y as i32),
       count: 0,
       size: UVec2::new(0, 0),
-      data: Vec::new(),
+      data: vec![0; (size.x * size.y * CHANNEL_COUNT) as usize],
       allocations: HashMap::default(),
     }
   }
@@ -53,9 +53,11 @@ impl TextureAtlasManager {
       self.data.resize((new_size.x * new_size.y * CHANNEL_COUNT) as usize, 0);
       for y in (1..self.size.y).rev() {
         for x in (0..self.size.x).rev() {
-          let idx = (y * self.size.x + x) as usize;
-          let new_idx = (y * new_size.x + x) as usize;
-          self.data[new_idx] = self.data[idx];
+          let idx = ((y * self.size.x + x) * CHANNEL_COUNT) as usize;
+          let new_idx = ((y * new_size.x + x) * CHANNEL_COUNT) as usize;
+          for c in 0..(CHANNEL_COUNT as usize) {
+            self.data[new_idx + c] = self.data[idx + c];
+          }
         }
       }
     } else {
@@ -65,8 +67,10 @@ impl TextureAtlasManager {
     self.size = new_size;
   }
 
-  /// Allocate a new texture region in the atlas
-  pub fn allocate(&mut self, size: UVec2) -> Option<TextureHandle> {
+  /// Allocate a new texture region in the atlas and return a handle to it\
+  /// Returns None if the texture could not be allocated due to lack of space\
+  /// Use `allocate_resize` to allocate a texture and resize the atlas if necessary
+  fn allocate(&mut self, size: UVec2) -> Option<TextureHandle> {
     let result = self.packer.pack(size.x as i32, size.y as i32, true)?;
     let index = self.count;
     self.count += 1;
@@ -81,9 +85,34 @@ impl TextureAtlasManager {
     Some(TextureHandle { index })
   }
 
+  /// Allocate a new texture region in the atlas and resize the atlas if necessary\
+  /// This function should never fail under normal circumstances.
+  fn allocate_resize(&mut self, size: UVec2) -> TextureHandle {
+    let mut new_size = self.size;
+    while !self.packer.can_pack(size.x as i32, size.y as i32, true) {
+      new_size *= 2;
+      self.packer.resize(new_size.x as i32, new_size.y as i32);
+    }
+    self.resize(new_size);
+    self.allocate(size).unwrap()
+  }
+
   /// Allocate a new texture region in the atlas and copy the data into it
-  pub fn add(&mut self, width: u32, data: &[u8]) {
-    todo!()
+  pub fn add(&mut self, width: usize, data: &[u8]) -> TextureHandle {
+    let size = uvec2(width as u32, (data.len() / (width * CHANNEL_COUNT as usize)) as u32);
+    let handle = self.allocate_resize(size);
+    let allocation = self.allocations.get_mut(&handle.index).unwrap();
+    assert!(!allocation.rotated, "Rotated textures are not implemented yet");
+    for y in 0..size.y {
+      for x in 0..size.x {
+        let src_idx = (y * size.x + x) * CHANNEL_COUNT;
+        let dst_idx = ((allocation.position.y + y) * self.size.x + allocation.position.x + x) * CHANNEL_COUNT;
+        for c in 0..CHANNEL_COUNT as usize {
+          self.data[dst_idx as usize + c] = data[src_idx as usize + c];
+        }
+      }
+    }
+    handle
   }
 
   pub fn modify(&mut self, handle: TextureHandle) {
@@ -94,6 +123,10 @@ impl TextureAtlasManager {
     todo!()
   }
 
+  pub fn atlas_size(&self) -> UVec2 {
+    self.size
+  }
+
   pub fn get(&self, handle: TextureHandle) -> Option<&TextureAllocation> {
     self.allocations.get(&handle.index)
   }