Extract preview main pass orchestration

src/legacy_node_stroke_preview_execution_services.h

@@ -234,6 +234,60 @@ struct LegacyNodeStrokePreviewPassOrchestrationPlan {
     bool background_colorize = false;
 };
 
+template <typename Frame>
+struct LegacyNodeStrokePreviewMainLivePassRequestT {
+    std::function<void()> setup_blend_uniforms;
+    std::function<void()> bind_main_pass_textures;
+    std::function<void()> clear_target;
+    std::function<std::vector<Frame>()> compute_frames;
+    std::function<void(Frame&)> before_frame;
+    std::function<void(Frame&)> setup_sample_shader;
+    std::function<void(Frame&)> draw_sample;
+    std::function<void()> copy_pass_result;
+    std::function<void()> finish_main_pass;
+};
+
+template <typename Frame>
+[[nodiscard]] inline bool execute_legacy_node_stroke_preview_main_live_pass(
+    const LegacyNodeStrokePreviewMainLivePassRequestT<Frame>& request)
+{
+    if (!request.setup_blend_uniforms ||
+        !request.bind_main_pass_textures ||
+        !request.clear_target ||
+        !request.compute_frames ||
+        !request.before_frame ||
+        !request.setup_sample_shader ||
+        !request.draw_sample ||
+        !request.copy_pass_result ||
+        !request.finish_main_pass) {
+        return false;
+    }
+
+    request.setup_blend_uniforms();
+    request.bind_main_pass_textures();
+    pp::panopainter::execute_legacy_stroke_preview_live_pass(
+        [&] {
+            request.clear_target();
+        },
+        [&] {
+            return request.compute_frames();
+        },
+        [&](Frame& frame) {
+            request.before_frame(frame);
+        },
+        [&](Frame& frame) {
+            request.setup_sample_shader(frame);
+        },
+        [&](Frame& frame) {
+            request.draw_sample(frame);
+        },
+        [&] {
+            request.copy_pass_result();
+        });
+    request.finish_main_pass();
+    return true;
+}
+
 struct LegacyNodeStrokePreviewPassOrchestrationRequest {
     pp::renderer::RenderDeviceFeatures features {};
     glm::vec2 preview_size {};