add support for external modules

src/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_subdirectory(engine)
 add_subdirectory(logic)
+add_subdirectory(scripts)
 
 add_executable(sc-eng main.cpp)
 target_link_libraries(sc-eng engine logic)

src/logic/logic.cpp

@@ -4,30 +4,73 @@
 #include "wren/vm/wren_vm.h"
 
 #include <cassert>
+#include <cstdio>
 #include <functional>
 #include <iostream>
+#include <string>
 
 void writeOutput(WrenVM *vm, const char *text) {
-    std::cout << "wren output:" << text << "\n";
+    std::cout << text;
 }
 
 void errorOutput(WrenVM *vm, WrenErrorType type, const char *module, int line, const char *message) {
-    std::cerr << "wren error [module \"" << module << "\", line " << line << "]: " << message << "\n";
+    if (module != nullptr) {
+        std::cerr << "wren error [module \"" << module << "\", line " << line << "]: " << message << "\n";
+    } else {
+        std::cerr << "wren error: " << message << "\n";
+    }
+}
+
+char *fileContent(const char *path) {
+    FILE *f = fopen(path, "rb");
+    if (f == NULL) {
+        return nullptr;
+    }
+
+    // Get the file length.
+    fseek(f, 0, SEEK_END);
+    size_t fileLength = ftell(f);
+    rewind(f);
+
+    // Read the file.
+    char *fileContent = (char *)malloc(fileLength + 1);
+    size_t bytesRead = fread(fileContent, sizeof(char), fileLength, f);
+    fclose(f);
+    if (fileLength != bytesRead) {
+        free(fileContent);
+        return nullptr;
+    }
+    fileContent[fileLength] = '\0';
+
+    return fileContent;
+}
+
+std::string getPath(const char *name) {
+    std::string root("/Users/ffreling/Code/scripted-engine/src/scripts/");
+    return root + name + ".wren";
+}
+
+char *loadModule(WrenVM *vm, const char *name) {
+    std::string path = getPath(name);
+
+    return fileContent(path.c_str());
 }
 
 Logic::Logic(Engine *engine) {
     WrenConfiguration wrenConfig;
     wrenInitConfiguration(&wrenConfig);
 
-    // Setup user-defined data such as pointer to "global" objects.
-    _bundleData.engine = engine;
-    wrenConfig.userData = &_bundleData;
-
     wrenConfig.bindForeignMethodFn = &Logic::bindForeignMethod;
     wrenConfig.writeFn = &writeOutput;
     wrenConfig.errorFn = &errorOutput;
+    wrenConfig.loadModuleFn = &loadModule;
 
     _wrenVm = wrenNewVM(&wrenConfig);
+
+    // Setup user-defined data such as pointer to "global" objects.
+    _bundleData.engine = engine;
+    wrenSetUserData(_wrenVm, &_bundleData);
+
     WrenInterpretResult result = wrenInterpret(_wrenVm, "scripted-engine", "System.print(\"I am running in a VM!\")");
     assert(result == WREN_RESULT_SUCCESS);
 }
@@ -38,7 +81,7 @@ Logic::~Logic() {
 
 void get_info(WrenVM *vm) {
     // Retrieve "global" objects defined in userData
-    BundleData *bundleData = reinterpret_cast<BundleData *>(vm->config.userData);
+    BundleData *bundleData = reinterpret_cast<BundleData *>(wrenGetUserData(vm));
     Engine *engine = bundleData->engine;
     assert(engine);
 
@@ -48,25 +91,24 @@ void get_info(WrenVM *vm) {
 
 WrenForeignMethodFn
 Logic::bindForeignMethod(WrenVM *vm, const char *module, const char *className, bool isStatic, const char *signature) {
-    if (strcmp(module, "scripted-engine") == 0) {
+    if (strcmp(module, "engine") == 0) {
         if (strcmp(className, "Engine") == 0) {
-            if (isStatic && strcmp(signature, "get_info()") == 0) {
+            if (isStatic && strcmp(signature, "getInfo()") == 0) {
                 return get_info;
             }
-            // Other foreign methods on Math...
+            // Other foreign methods on Engine...
         }
-        // Other classes in main...
+        // Other classes in engine...
     }
     // Other modules...
     return nullptr;
 }
 
-void Logic::interpret() {
+void Logic::interpret(const char *name) {
     assert(_wrenVm);
-    WrenInterpretResult result = wrenInterpret(_wrenVm, "scripted-engine", "class Engine {\
-                                               foreign static get_info())\
-}\
-Engine.get_info()");
+    std::string path = getPath(name);
+    char *script = fileContent(path.c_str());
+    WrenInterpretResult result = wrenInterpret(_wrenVm, name, script);
     assert(result == WREN_RESULT_SUCCESS);
 }
 

src/logic/logic.hpp

@@ -15,7 +15,7 @@ public:
 
     static WrenForeignMethodFn
     bindForeignMethod(WrenVM *vm, const char *module, const char *className, bool isStatic, const char *signature);
-    void interpret();
+    void interpret(const char *name);
 
     void add_item();
 

src/main.cpp

@@ -5,7 +5,7 @@ int main() {
     Engine e;
     Logic l(&e);
 
-    l.interpret();
+    l.interpret("logic");
 
     return 0;
 }

src/scripts/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(MODULE scripts)
+
+file(GLOB_RECURSE script_list "*.wren")
+add_custom_target(${MODULE} SOURCES ${script_list})

src/scripts/engine.wren

@@ -0,0 +1,3 @@
+class Engine {
+    foreign static getInfo()
+}

src/scripts/logic.wren

@@ -0,0 +1,4 @@
+import "engine" for Engine
+
+System.print("This is logic.wren")
+System.print(Engine.getInfo())