Route import and node texture setup through helpers

docs/modernization/debt.md

@@ -18,6 +18,14 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Recent Reductions
 
+- 2026-06-13: DEBT-0036 was narrowed again. `NodeViewport` retained preview
+  draw and `NodePanelGrid` sun-overlay `Texture` shader setup now route
+  through `legacy_canvas_draw_merge_services.h`; the node paths still own
+  texture/sampler binding, viewport/state setup, and draw execution.
+- 2026-06-13: DEBT-0036 was narrowed again. `Canvas::import_layer` retained
+  object-draw `Texture` shader setup now routes through
+  `legacy_canvas_draw_merge_services.h`; import_layer still owns texture upload,
+  sampler/texture binding, draw callbacks, and object geometry.
 - 2026-06-13: DEBT-0036 was narrowed again. `NodeImage` and
   `NodeImageTexture` retained plain image `Texture` shader setup now routes
   through `legacy_canvas_draw_merge_services.h`; the nodes still own

docs/modernization/roadmap.md

@@ -3021,6 +3021,10 @@ Results:
   stroke composite shader setup helper, while render-task ordering, framebuffer
   copy bounds, sampler/texture binding, and draw execution remain in retained
   canvas-mode code.
+- `Canvas::import_layer` retained object drawing now shares the draw-merge
+  texture shader setup helper for flat and spherical imports, while texture
+  upload, sampler/texture binding, draw callbacks, and object geometry remain in
+  retained Canvas code.
 - `Canvas::thumbnail_generate` checkerboard redraw and final texture blending
   now share the retained draw-merge shader setup helpers, while destination
   copies, sampler/texture binding, readback, and draw execution remain in
@@ -3040,6 +3044,10 @@ Results:
   retained draw-merge texture shader setup helper for `Texture`, `Tex`, and
   `MVP` setup. Texture/sampler binding, atlas setup, blend state, and draw
   execution remain in the node paths.
+- `NodeViewport` preview drawing and `NodePanelGrid` sun-overlay drawing now
+  share the retained draw-merge texture shader setup helper for `Texture`,
+  `Tex`, and `MVP` setup. Texture/sampler binding, viewport/state setup, and
+  draw execution remain in the node paths.
 - `Canvas::stroke_draw_mix` now shares the retained stroke composite shader
   helper for mixer-pass `CompDraw` setup, while preserving its caller-specific
   texture slot uniforms. Mixer framebuffer/scissor state, sampler and texture

src/canvas.cpp

@@ -2049,9 +2049,11 @@ void Canvas::import_equirectangular_thread(std::string file_path, std::shared_pt
             m_sampler.bind(0);
             set_active_texture_unit(0);
             tex.bind();
-            ShaderManager::use(kShader::Texture);
+            pp::panopainter::setup_legacy_canvas_draw_merge_texture_shader(
-            ShaderManager::u_int(kShaderUniform::Tex, 0);
+                pp::panopainter::LegacyCanvasDrawMergeTextureUniforms {
-            ShaderManager::u_mat4(kShaderUniform::MVP, glm::scale(glm::vec3(-1, -1, 1)));
+                    .mvp = glm::scale(glm::vec3(-1, -1, 1)),
+                    .texture_slot = 0,
+                });
             plane.draw_fill();
             tex.unbind();
             m_sampler.unbind();
@@ -2069,10 +2071,12 @@ void Canvas::import_equirectangular_thread(std::string file_path, std::shared_pt
             m_sampler.bind(0);
             set_active_texture_unit(0);
             tex.bind();
-            ShaderManager::use(kShader::Texture);
+            pp::panopainter::setup_legacy_canvas_draw_merge_texture_shader(
-            ShaderManager::u_int(kShaderUniform::Tex, 0);
+                pp::panopainter::LegacyCanvasDrawMergeTextureUniforms {
-            ShaderManager::u_mat4(kShaderUniform::MVP, proj * camera *
+                    .mvp = proj * camera *
-                glm::eulerAngleY(glm::radians(180.f)) * glm::scale(glm::vec3(1, -1, 1)));
+                        glm::eulerAngleY(glm::radians(180.f)) * glm::scale(glm::vec3(1, -1, 1)),
+                    .texture_slot = 0,
+                });
             sphere.draw_fill();
             tex.unbind();
             m_sampler.unbind();

src/node_panel_grid.cpp

@@ -1,5 +1,6 @@
 #include "pch.h"
 #include "app_core/grid_ui.h"
+#include "legacy_canvas_draw_merge_services.h"
 #include "legacy_grid_ui_services.h"
 #include "legacy_ui_overlay_services.h"
 #include "log.h"
@@ -343,11 +344,11 @@ void NodePanelGrid::draw_heightmap(const glm::mat4& proj, const glm::mat4& camer
                 auto aspect_ratio = static_cast<float>(viewport.height) / static_cast<float>(viewport.width);
                 apply_grid_capability(pp::renderer::gl::blend_state(), true);
                 apply_grid_capability(pp::renderer::gl::depth_test_state(), false);
-                ShaderManager::use(kShader::Texture);
+                pp::panopainter::setup_legacy_canvas_draw_merge_texture_shader({
-                ShaderManager::u_int(kShaderUniform::Tex, 0);
+                    .mvp = glm::ortho(-1.f, 1.f, -1.f, 1.f) *
-                ShaderManager::u_mat4(kShaderUniform::MVP, glm::ortho(-1.f, 1.f, -1.f, 1.f) *
+                        //glm::scale(glm::vec3(100)) *
-                    //glm::scale(glm::vec3(100)) *
+                        glm::translate(glm::vec3(p2d, 0)) * glm::scale(glm::vec3(.1f * aspect_ratio, .1f, 1.f)),
-                    glm::translate(glm::vec3(p2d, 0)) * glm::scale(glm::vec3(.1f * aspect_ratio, .1f, 1.f)));
+                    .texture_slot = 0});
                 set_grid_active_texture_unit(0U);
                 m_sampler_linear.bind(0);
                 constexpr auto sun_tex = const_hash("data/sun.png");

src/node_viewport.cpp

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 
+#include "legacy_canvas_draw_merge_services.h"
 #include "log.h"
 #include "legacy_ui_gl_dispatch.h"
 #include "node_viewport.h"
@@ -28,9 +29,7 @@ void NodeViewport::draw()
     TextureManager::get(m_tex_id).bind();
     m_sampler->bind(0);
     pp::legacy::ui_gl::set_blend_enabled(true, "NodeViewport");
-    ShaderManager::use(kShader::Texture);
+    pp::panopainter::setup_legacy_canvas_draw_merge_texture_shader({.mvp = proj * cam, .texture_slot = 0});
-    ShaderManager::u_int(kShaderUniform::Tex, 0);
-    ShaderManager::u_mat4(kShaderUniform::MVP, proj * cam);
     m_faces->draw_fill();
     m_sampler->unbind();
     TextureManager::get(m_tex_id).unbind();