From 7dcf76c3aa299a51d1dcac3a2bb3691217a5992c Mon Sep 17 00:00:00 2001
From: omigamedev <omarator@gmail.com>
Date: Wed, 3 Jun 2026 05:59:36 +0200
Subject: [PATCH] Route VR UI viewport scissor through renderer GL

---
 docs/modernization/build-inventory.md |  6 ++--
 docs/modernization/roadmap.md         |  3 ++
 src/app_vr.cpp                        | 47 +++++++++++++++++++++++++--
 3 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/docs/modernization/build-inventory.md b/docs/modernization/build-inventory.md
index 16087f4..1b73482 100644
--- a/docs/modernization/build-inventory.md
+++ b/docs/modernization/build-inventory.md
@@ -463,9 +463,9 @@ Known local toolchain state:
   policy and dispatch application consumed by `App::init`, tested runtime
   version/vendor/renderer/GLSL string query dispatch, tested default clear
   color/buffer dispatch consumed by `App::clear`, tested app UI
-  viewport/scissor dispatch consumed by `App::draw`, plus renderer API to
-  OpenGL token mapping and command-planning contracts used by the OpenGL parity
-  work.
+  viewport/scissor dispatch consumed by `App::draw` and `App::vr_draw_ui`,
+  plus renderer API to OpenGL token mapping and command-planning contracts used
+  by the OpenGL parity work.
 - `pano_cli plan-cloud-upload` exposes `pp_app_core` cloud upload availability,
   new-document warning, publish prompt, and save-before-upload planning as JSON;
   the live cloud upload command consumes the same start contract before
diff --git a/docs/modernization/roadmap.md b/docs/modernization/roadmap.md
index 5286f36..e5b8b8d 100644
--- a/docs/modernization/roadmap.md
+++ b/docs/modernization/roadmap.md
@@ -528,6 +528,9 @@ Main app UI viewport and scissor execution now dispatch through tested
 `pp_renderer_gl` viewport/scissor contracts, leaving `App::draw` and UI node
 clipping to provide rectangles while the backend owns scissor-state tokens and
 the live OpenGL call sequence.
+VR UI framebuffer viewport and scissor-test setup now also consumes those
+`pp_renderer_gl` contracts, keeping desktop and VR UI rendering aligned while
+the retained OpenVR app path is split incrementally.
 Windows RenderDoc frame capture hooks now also dispatch through
 `PlatformServices`, keeping capture integration in the platform service while
 leaving non-Windows adapters as no-ops.
diff --git a/src/app_vr.cpp b/src/app_vr.cpp
index 4b22ba7..c966c32 100644
--- a/src/app_vr.cpp
+++ b/src/app_vr.cpp
@@ -24,6 +24,44 @@ void unbind_texture_2d()
     glBindTexture(pp::renderer::gl::texture_2d_target(), 0);
 }
 
+void enable_opengl_state(std::uint32_t state) noexcept
+{
+    glEnable(static_cast<GLenum>(state));
+}
+
+void disable_opengl_state(std::uint32_t state) noexcept
+{
+    glDisable(static_cast<GLenum>(state));
+}
+
+void set_opengl_viewport(std::int32_t x, std::int32_t y, std::int32_t width, std::int32_t height) noexcept
+{
+    glViewport(static_cast<GLint>(x), static_cast<GLint>(y), static_cast<GLsizei>(width), static_cast<GLsizei>(height));
+}
+
+void apply_vr_ui_viewport(pp::renderer::gl::OpenGlViewportRect viewport)
+{
+    const auto status = pp::renderer::gl::apply_opengl_viewport(
+        viewport,
+        pp::renderer::gl::OpenGlViewportDispatch {
+            .viewport = set_opengl_viewport,
+        });
+    if (!status.ok())
+        LOG("OpenGL VR UI viewport failed: %s", status.message);
+}
+
+void apply_vr_ui_scissor_test(bool enabled)
+{
+    const auto status = pp::renderer::gl::apply_opengl_scissor_test(
+        enabled,
+        pp::renderer::gl::OpenGlScissorTestDispatch {
+            .enable = enable_opengl_state,
+            .disable = disable_opengl_state,
+        });
+    if (!status.ok())
+        LOG("OpenGL VR UI scissor test failed: %s", status.message);
+}
+
 }
 
 bool trigger_down = false;
@@ -55,13 +93,16 @@ void App::vr_draw_ui()
 {
     uirtt.bindFramebuffer();
     uirtt.clear();
-    glViewport(0, 0, uirtt.getWidth(), uirtt.getHeight());
-    glEnable(pp::renderer::gl::scissor_test_state());
+    apply_vr_ui_viewport(pp::renderer::gl::OpenGlViewportRect {
+        .width = static_cast<std::int32_t>(uirtt.getWidth()),
+        .height = static_cast<std::int32_t>(uirtt.getHeight()),
+    });
+    apply_vr_ui_scissor_test(true);
     auto observer = std::bind(&App::update_ui_observer, this, std::placeholders::_1);
     for (int i = 1; i < layout[main_id]->m_children.size(); i++)
         layout[main_id]->m_children[i]->watch(observer);
     //msgbox->watch(observer);
-    glDisable(pp::renderer::gl::scissor_test_state());
+    apply_vr_ui_scissor_test(false);
     uirtt.unbindFramebuffer();
 }