first commit

nodes/proc/vp_expr_check_node.cpp

@@ -0,0 +1,77 @@
+
+#include "vp_expr_check_node.h"
+#include "../../third_party/tinyexpr/tinyexpr.h"
+
+namespace vp_nodes {
+    
+    vp_expr_check_node::vp_expr_check_node(std::string node_name):vp_node(node_name) {
+        this->initialized();  
+    }
+    
+    vp_expr_check_node::~vp_expr_check_node() {
+        deinitialized();
+    }
+
+    std::shared_ptr<vp_objects::vp_meta> vp_expr_check_node::handle_frame_meta(std::shared_ptr<vp_objects::vp_frame_meta> meta) {
+        for (auto& i: meta->text_targets) {
+            auto& text = i->text;
+            auto left_right = vp_utils::string_split(text, '=');
+
+            // only deal with equation such as `1+1=2`, excluding `1+1` or `1+1=` or `=1+1`
+            /*
+            * 1. yes means equation is right
+            * 2. no means equation is wrong
+            * 3. invalid means expression is not valid
+            */
+            if (left_right.size() == 2) {
+                auto left = left_right[0];
+                auto right = left_right[1];
+                
+                // replace specific symbols
+                left = std::regex_replace(left, std::regex("x"), "*");
+                left = std::regex_replace(left, std::regex("÷"), "/");
+                //...
+
+                if (left.empty()) {
+                    i->flags = "invalid";
+                    continue;
+                }
+
+                if (right.empty()) {
+                    i->flags = "invalid";
+                    continue;
+                }
+
+                double right_value;
+                try {
+                    right_value = std::stod(right);
+                }
+                catch(const std::exception& e) {
+                    i->flags = "invalid";
+                    continue;
+                }
+
+                // parse and calculate the left part
+                int error;
+                auto cal_value = te_interp(left.c_str(), &error);
+
+                if (error != 0) {
+                    i->flags = "invalid";
+                    continue;
+                }
+                
+                if (cal_value == right_value) {
+                    i->flags = "yes_" + vp_utils::round_any(cal_value, 2);
+                }
+                else {
+                    i->flags = "no_" + vp_utils::round_any(cal_value, 2);
+                }
+            }
+            else {
+                i->flags = "invalid";
+            }
+        }
+        
+        return meta;
+    }
+}