Tweaks to TextureAtlasBuilder.finish() (#887)

Tweaks to TextureAtlasBuilder.finish()

crates/bevy_sprite/src/texture_atlas_builder.rs

@@ -86,28 +86,37 @@ impl TextureAtlasBuilder {
 
         while rect_placements.is_none() {
             if current_width > max_width || current_height > max_height {
-                rect_placements = None;
                 break;
             }
+
+            let last_attempt = current_height == max_height && current_width == max_width;
+
             let mut target_bins = std::collections::BTreeMap::new();
             target_bins.insert(0, TargetBin::new(current_width, current_height, 1));
-            atlas_texture = Texture::new_fill(
-                Vec2::new(current_width as f32, current_height as f32),
-                &[0, 0, 0, 0],
-                TextureFormat::Rgba8UnormSrgb,
-            );
+
             rect_placements = match pack_rects(
                 &self.rects_to_place,
                 target_bins,
                 &volume_heuristic,
                 &contains_smallest_box,
             ) {
-                Ok(rect_placements) => Some(rect_placements),
+                Ok(rect_placements) => {
+                    atlas_texture = Texture::new_fill(
+                        Vec2::new(current_width as f32, current_height as f32),
+                        &[0, 0, 0, 0],
+                        TextureFormat::Rgba8UnormSrgb,
+                    );
+                    Some(rect_placements)
+                }
                 Err(rectangle_pack::RectanglePackError::NotEnoughBinSpace) => {
-                    current_width *= 2;
-                    current_height *= 2;
+                    current_height = bevy_math::clamp(current_height * 2, 0, max_height);
+                    current_width = bevy_math::clamp(current_width * 2, 0, max_width);
                     None
                 }
+            };
+
+            if last_attempt {
+                break;
             }
         }