From 87e6c1118b4c047a0e55fb6aaea60337bae571bb Mon Sep 17 00:00:00 2001
From: omigamedev <omarator@gmail.com>
Date: Sat, 13 Jun 2026 22:59:24 +0200
Subject: [PATCH] Extract stroke draw main pass texture dispatch

---
 docs/modernization/debt.md                |  4 ++
 docs/modernization/tasks.md               |  8 ++-
 tests/paint_renderer/compositor_tests.cpp | 71 +++++++++++++++++++++++
 3 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/docs/modernization/debt.md b/docs/modernization/debt.md
index 25a8299..a387978 100644
--- a/docs/modernization/debt.md
+++ b/docs/modernization/debt.md
@@ -529,6 +529,10 @@ agent or engineer to remove them without reconstructing context from chat.
   has regression coverage for retained mixer-state callback ordering through
   `execute_legacy_canvas_stroke_mix_pass(...)`; the live path still owns the
   concrete mixer framebuffer setup and GL capability toggles.
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::stroke_draw()` main-pass
+  texture dispatch now has regression coverage through
+  `make_legacy_canvas_stroke_main_pass_texture_dispatch(...)`; the live path
+  still owns the concrete texture objects and sampler state.
 - 2026-06-13: DEBT-0036 was narrowed again. `Canvas::draw_merge` checkerboard
   background shader setup and final merged-texture redraw setup now route
   through `legacy_canvas_draw_merge_services.h`. The retained Canvas path still
diff --git a/docs/modernization/tasks.md b/docs/modernization/tasks.md
index 9f4d868..996916f 100644
--- a/docs/modernization/tasks.md
+++ b/docs/modernization/tasks.md
@@ -575,7 +575,7 @@ Done Checks:
 
 ### STR-020 - Extract Stroke Draw Main Pass Texture Dispatch
 
-Status: Ready
+Status: Done
 Score: +1 renderer boundary and OpenGL parity
 Debt: `DEBT-0036`
 Scope: `src/canvas.cpp`, `src/legacy_canvas_stroke_execution_services.h`, `tests/paint_renderer/compositor_tests.cpp`
@@ -601,6 +601,12 @@ Validation:
 ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_compositor|pp_paint_renderer_stroke_execution" --output-on-failure
 ```
 
+### Completed Task Log
+
+| Date | Task | Score | Validation | Commit |
+| --- | --- | --- | --- | --- |
+| 2026-06-13 | STR-020 | +1 renderer boundary and OpenGL parity | `ctest --preset desktop-fast --build-config Debug -R "pp_paint_renderer_compositor|pp_paint_renderer_stroke_execution" --output-on-failure` | `pending` |
+
 Progress Notes:
 
 - 2026-06-13: `NodeStrokePreview::draw_stroke_immediate()` now routes final
diff --git a/tests/paint_renderer/compositor_tests.cpp b/tests/paint_renderer/compositor_tests.cpp
index 5698b7d..3c59eb4 100644
--- a/tests/paint_renderer/compositor_tests.cpp
+++ b/tests/paint_renderer/compositor_tests.cpp
@@ -1729,6 +1729,74 @@ void plans_canvas_stroke_dual_material_intent(pp::tests::Harness& h)
     PP_EXPECT(h, has_texture_binding(dual_composite_pattern, CanvasStrokeTextureRole::pattern, 2));
 }
 
+void legacy_canvas_stroke_main_pass_texture_dispatch_preserves_order(pp::tests::Harness& h)
+{
+    std::vector<std::string> steps;
+    const auto dispatch = pp::panopainter::make_legacy_canvas_stroke_main_pass_texture_dispatch(
+        [&](int slot) {
+            steps.emplace_back("activate:" + std::to_string(slot));
+        },
+        [&] {
+            steps.emplace_back("bind-tip");
+        },
+        [&] {
+            steps.emplace_back("unbind-tip");
+        },
+        [&] {
+            steps.emplace_back("bind-pattern");
+        },
+        [&] {
+            steps.emplace_back("bind-mixer");
+        },
+        [&] {
+            steps.emplace_back("unbind-mixer");
+        });
+
+    pp::panopainter::bind_legacy_canvas_stroke_texture_inputs(
+        std::array {
+            pp::panopainter::LegacyCanvasStrokeTextureBinding {
+                .input = pp::panopainter::LegacyCanvasStrokeTextureInput::brush_tip,
+                .slot = 0,
+            },
+            pp::panopainter::LegacyCanvasStrokeTextureBinding {
+                .input = pp::panopainter::LegacyCanvasStrokeTextureInput::pattern,
+                .slot = 2,
+            },
+            pp::panopainter::LegacyCanvasStrokeTextureBinding {
+                .input = pp::panopainter::LegacyCanvasStrokeTextureInput::mixer,
+                .slot = 3,
+            },
+        },
+        dispatch);
+
+    pp::panopainter::unbind_legacy_canvas_stroke_texture_inputs(
+        std::array {
+            pp::panopainter::LegacyCanvasStrokeTextureBinding {
+                .input = pp::panopainter::LegacyCanvasStrokeTextureInput::mixer,
+                .slot = 3,
+            },
+            pp::panopainter::LegacyCanvasStrokeTextureBinding {
+                .input = pp::panopainter::LegacyCanvasStrokeTextureInput::brush_tip,
+                .slot = 0,
+            },
+        },
+        dispatch);
+
+    const std::vector<std::string> expected {
+        "activate:0",
+        "bind-tip",
+        "activate:2",
+        "bind-pattern",
+        "activate:3",
+        "bind-mixer",
+        "activate:3",
+        "unbind-mixer",
+        "activate:0",
+        "unbind-tip",
+    };
+    PP_EXPECT(h, steps == expected);
+}
+
 void plans_canvas_stroke_commit_erase_sequence(pp::tests::Harness& h)
 {
     const auto plan = plan_canvas_stroke_commit_sequence(
@@ -3598,6 +3666,9 @@ int main()
     harness.run("rejects_bad_stroke_composite_plans", rejects_bad_stroke_composite_plans);
     harness.run("plans_canvas_stroke_material_passes", plans_canvas_stroke_material_passes);
     harness.run("plans_canvas_stroke_dual_material_intent", plans_canvas_stroke_dual_material_intent);
+    harness.run(
+        "legacy_canvas_stroke_main_pass_texture_dispatch_preserves_order",
+        legacy_canvas_stroke_main_pass_texture_dispatch_preserves_order);
     harness.run("plans_canvas_stroke_commit_erase_sequence", plans_canvas_stroke_commit_erase_sequence);
     harness.run("plans_canvas_stroke_commit_composite_sequence", plans_canvas_stroke_commit_composite_sequence);
     harness.run(