Add renderer and package readiness validation gates

src/app_core/app_thread.h

@@ -14,6 +14,9 @@ struct AppTaskDispatchPlan {
     bool notify_worker = false;
     bool wait_for_completion = false;
     bool request_redraw = false;
+    // When true, dispatch attempts from non-target threads are rejected instead
+    // of being queued for later execution.
+    bool reject_unsafe_cross_thread_dispatch = false;
 };
 
 struct AppAsyncRedrawPlan {
@@ -73,16 +76,20 @@ struct AppThreadStopPlan {
     std::size_t queued_task_count,
     bool worker_running,
     bool wait_for_completion,
-    bool request_redraw_after_dispatch) noexcept
+    bool request_redraw_after_dispatch,
+    bool reject_unsafe_cross_thread_dispatch = false) noexcept
 {
-    const bool queue_task = !already_on_target_thread;
+    const bool queue_task = !already_on_target_thread && !reject_unsafe_cross_thread_dispatch;
     return AppTaskDispatchPlan {
         .execute_immediately = already_on_target_thread,
         .queue_task = queue_task,
         .remove_matching_unique_task = queue_task && unique && queued_task_count > 0U,
         .notify_worker = queue_task,
         .wait_for_completion = queue_task && worker_running && wait_for_completion,
-        .request_redraw = request_redraw_after_dispatch,
+        .request_redraw = !(!already_on_target_thread && reject_unsafe_cross_thread_dispatch)
+            && request_redraw_after_dispatch,
+        .reject_unsafe_cross_thread_dispatch = !already_on_target_thread
+            && reject_unsafe_cross_thread_dispatch,
     };
 }
 

src/paint_renderer/compositor.h

@@ -8,6 +8,7 @@
 #include <array>
 #include <cstddef>
 #include <cstdint>
+#include <functional>
 #include <memory>
 #include <span>
 #include <string>
@@ -147,6 +148,11 @@ struct StrokePreviewCompositePlan {
     bool uses_pattern = false;
 };
 
+struct StrokePreviewCopySize {
+    int width = 0;
+    int height = 0;
+};
+
 struct CanvasBlendGateRequest {
     pp::renderer::Extent2D extent {};
     std::span<const int> layer_blend_modes;
@@ -530,6 +536,17 @@ export_document_animation_frames_equirectangular_pngs(
 [[nodiscard]] StrokePreviewCompositePlan plan_stroke_preview_composite(
     StrokePreviewCompositeRequest request) noexcept;
 
+[[nodiscard]] pp::foundation::Status copy_stroke_preview_result_to_texture(
+    std::function<void()> bind_preview_texture,
+    std::function<void(
+        int src_x,
+        int src_y,
+        int dst_x,
+        int dst_y,
+        int width,
+        int height)> copy_framebuffer_to_texture,
+    StrokePreviewCopySize copy_size) noexcept;
+
 [[nodiscard]] pp::foundation::Result<CanvasBlendGatePlan> plan_canvas_blend_gate(
     pp::renderer::RenderDeviceFeatures features,
     CanvasBlendGateRequest request) noexcept;
@@ -556,4 +573,26 @@ export_document_animation_frames_equirectangular_pngs(
 
 [[nodiscard]] const char* stroke_composite_path_name(StrokeCompositePath path) noexcept;
 
+inline pp::foundation::Status copy_stroke_preview_result_to_texture(
+    std::function<void()> bind_preview_texture,
+    std::function<void(
+        int src_x,
+        int src_y,
+        int dst_x,
+        int dst_y,
+        int width,
+        int height)> copy_framebuffer_to_texture,
+    StrokePreviewCopySize copy_size) noexcept
+{
+    bind_preview_texture();
+    copy_framebuffer_to_texture(
+        0,
+        0,
+        0,
+        0,
+        copy_size.width,
+        copy_size.height);
+    return pp::foundation::Status::success();
+}
+
 }