From 0500646f082260a0438b0175e79c98073aac6384 Mon Sep 17 00:00:00 2001
From: Erik <erik.nihlen@gmail.com>
Date: Sun, 14 Jun 2026 18:49:52 +0200
Subject: [PATCH] fix(D.2b): draw UI chrome behind content (TextRenderer Flush
 layer order)
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TextRenderer.Flush batched by primitive type and flushed rects -> text ->
sprites LAST, so the 8-piece chrome (incl. the center fill) painted OVER the
vital bars + numbers ("the window is drawn in front of the bars"). Reorder to
sprites -> rects -> text so chrome composites behind widget fills + text.

Correct while bars are solid rects; when bars become gradient SPRITES this must
move to true submission/painter order (sprite-on-sprite z) — noted inline as the
D.2b follow-up.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/AcDream.App/Rendering/TextRenderer.cs | 46 +++++++++++++----------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/src/AcDream.App/Rendering/TextRenderer.cs b/src/AcDream.App/Rendering/TextRenderer.cs
index b07a9d40..a0252518 100644
--- a/src/AcDream.App/Rendering/TextRenderer.cs
+++ b/src/AcDream.App/Rendering/TextRenderer.cs
@@ -197,26 +197,15 @@ public sealed unsafe class TextRenderer : IDisposable
         _gl.Enable(EnableCap.Blend);
         _gl.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha);
 
-        // Untextured rects first — they form panel backgrounds.
-        if (_rectVerts > 0)
-        {
-            _shader.SetInt("uUseTexture", 0);
-            UploadBuffer(_rectBuf);
-            _gl.DrawArrays(PrimitiveType.Triangles, 0, (uint)_rectVerts);
-        }
+        // LAYERED compositing for the UI (background → fill → text):
+        //   1. RGBA dat sprites  — window chrome / panel backgrounds (behind)
+        //   2. Untextured rects  — widget fills (e.g. vital bars) on the chrome
+        //   3. Text glyphs       — on top
+        // NOTE: this type-bucketed order is correct while bars are solid rects.
+        // When bars become gradient SPRITES, this must move to true submission
+        // (painter) order so sprite-on-sprite z is preserved (D.2b follow-up).
 
-        // Textured text glyphs.
-        if (_textVerts > 0 && font is not null)
-        {
-            _shader.SetInt("uUseTexture", 1);
-            _gl.ActiveTexture(TextureUnit.Texture0);
-            _gl.BindTexture(TextureTarget.Texture2D, font.TextureId);
-            _shader.SetInt("uTex", 0);
-            UploadBuffer(_textBuf);
-            _gl.DrawArrays(PrimitiveType.Triangles, 0, (uint)_textVerts);
-        }
-
-        // RGBA dat sprites — one draw call per distinct GL texture.
+        // 1. RGBA dat sprites first — one draw call per distinct GL texture.
         if (hasSprites)
         {
             _shader.SetInt("uUseTexture", 2);
@@ -231,6 +220,25 @@ public sealed unsafe class TextRenderer : IDisposable
             }
         }
 
+        // 2. Untextured rects — widget fills on top of the chrome.
+        if (_rectVerts > 0)
+        {
+            _shader.SetInt("uUseTexture", 0);
+            UploadBuffer(_rectBuf);
+            _gl.DrawArrays(PrimitiveType.Triangles, 0, (uint)_rectVerts);
+        }
+
+        // 3. Textured text glyphs on top.
+        if (_textVerts > 0 && font is not null)
+        {
+            _shader.SetInt("uUseTexture", 1);
+            _gl.ActiveTexture(TextureUnit.Texture0);
+            _gl.BindTexture(TextureTarget.Texture2D, font.TextureId);
+            _shader.SetInt("uTex", 0);
+            UploadBuffer(_textBuf);
+            _gl.DrawArrays(PrimitiveType.Triangles, 0, (uint)_textVerts);
+        }
+
         // Restore GL state.
         _gl.DepthMask(true);
         if (!wasBlend) _gl.Disable(EnableCap.Blend);