Move canvas action pixel mapping to renderer gl

docs/modernization/build-inventory.md

@@ -1,7 +1,7 @@
 # Build And Platform Inventory
 
 Status: live
-Last updated: 2026-06-01
+Last updated: 2026-06-02
 
 This inventory records the known build surfaces during the CMake migration.
 Keep it updated as platform paths move to shared CMake targets.
@@ -164,7 +164,9 @@ Known local toolchain state:
   used before runtime capability detection are cataloged here. Legacy font
   atlas texture formats, text mesh buffer targets, attribute component and
   normalization tokens, draw primitive/index type, upload usage, and active
-  texture unit selection also consume the backend mapping.
+  texture unit selection also consume the backend mapping. Canvas undo/redo
+  dirty-region texture updates and readbacks also consume the backend-owned 2D
+  texture target, RGBA pixel format, and unsigned-byte component mapping.
 - `windows-msvc-vcpkg-headless` validates manifest install/configure/build/test
   for the current headless component matrix; see DEBT-0007 for remaining app
   and platform triplet migration.

docs/modernization/roadmap.md

@@ -1,7 +1,7 @@
 # PanoPainter Modernization Roadmap
 
 Status: live
-Last updated: 2026-06-01
+Last updated: 2026-06-02
 
 This is the living roadmap for modernizing PanoPainter into independently
 testable C++23 components while retaining all existing functionality. Keep this
@@ -430,6 +430,9 @@ capability detection also live in `pp_renderer_gl`. Legacy font atlas texture
 formats, text mesh buffer targets, attribute component/normalization, draw
 primitive/index type, upload usage, and active texture unit selection also
 delegate to `pp_renderer_gl`; `Font` no longer spells GL enum names directly.
+Canvas undo/redo dirty-region texture updates and readbacks now also delegate
+their 2D texture target, RGBA pixel format, and unsigned-byte component type
+mapping to `pp_renderer_gl`.
 The existing renderer classes are not yet fully
 behind the renderer interfaces.
 
@@ -595,7 +598,7 @@ Acceptance for each phase:
 
 ## Verified Commands
 
-Last verified on 2026-06-01:
+Last verified on 2026-06-02:
 
 ```powershell
 cmake --preset windows-msvc-default

src/canvas_actions.cpp

@@ -4,6 +4,7 @@
 #include "canvas.h"
 #include "canvas_actions.h"
 #include "node_panel_layer.h"
+#include "renderer_gl/opengl_capabilities.h"
 
 void ActionStroke::undo()
 {
@@ -36,8 +37,21 @@ void ActionStroke::undo()
         {
             App::I->render_task([&]
             {
+                const auto texture_target = pp::renderer::gl::texture_2d_target();
+                const auto pixel_format = pp::renderer::gl::rgba_pixel_format();
+                const auto component_type = pp::renderer::gl::unsigned_byte_component_type();
+
                 m_canvas->m_layers[m_layer_idx]->rtt(i, m_frame_idx).bindTexture();
-                glTexSubImage2D(GL_TEXTURE_2D, 0, (int)m_box[i].x, (int)m_box[i].y, (int)box_sz.x, (int)box_sz.y, GL_RGBA, GL_UNSIGNED_BYTE, m_image[i].get());
+                glTexSubImage2D(
+                    texture_target,
+                    0,
+                    (int)m_box[i].x,
+                    (int)m_box[i].y,
+                    (int)box_sz.x,
+                    (int)box_sz.y,
+                    pixel_format,
+                    component_type,
+                    m_image[i].get());
                 m_canvas->m_layers[m_layer_idx]->rtt(i, m_frame_idx).unbindTexture();
             });
         }
@@ -76,11 +90,22 @@ Action* ActionStroke::get_redo()
         glm::vec2 box_sz = zw(box) - xy(box);
         if (box_sz.x > 0 && box_sz.y > 0 && box_sz.x <= layer->w && box_sz.y <= layer->h)
         {
-            action->m_image[i] = std::make_unique<uint8_t[]>(box_sz.x * box_sz.y * 4);
+            action->m_image[i] = std::make_unique<uint8_t[]>(
+                static_cast<size_t>((int)box_sz.x) * static_cast<size_t>((int)box_sz.y) * 4U);
             App::I->render_task([&]
             {
+                const auto pixel_format = pp::renderer::gl::rgba_pixel_format();
+                const auto component_type = pp::renderer::gl::unsigned_byte_component_type();
+
                 layer->rtt(i, m_frame_idx).bindFramebuffer();
-                glReadPixels(box_or.x, box_or.y, box_sz.x, box_sz.y, GL_RGBA, GL_UNSIGNED_BYTE, action->m_image[i].get());
+                glReadPixels(
+                    (int)box_or.x,
+                    (int)box_or.y,
+                    (int)box_sz.x,
+                    (int)box_sz.y,
+                    pixel_format,
+                    component_type,
+                    action->m_image[i].get());
                 layer->rtt(i, m_frame_idx).unbindFramebuffer();
             });
         }