Add vectors and strings to frame loop example

Author: fwsGonzo

engine/scripts/src/level2.cpp

@@ -1,23 +1,35 @@
 #include "interface.hpp"
 #include <api.h>
 using namespace api;
+static_assert(sizeof(std::string) == 32,
+	"std::string must be 32 bytes in size to be compatible with the guest std::string SSO");
 
 PUBLIC(void start())
 {
 	print("Hello from Level 2!\n");
 	int value = gameplay_allowed_function(123);
 	print("Back in Level2! Got result value = ", value, "\n");
 
-	// Create a simple event loop
+	// Create a simple event loop with frame data
+	struct {
+		std::vector<std::string> strings;
+		std::vector<int> integers;
+		int frame;
+	} frame_data;
 	while (true) {
 		// Wait for a frame to complete
-		struct {
-			int frame = 0;
-		} frame_data;
 		Game::wait(frame_data);
 
 		// Do some work here, like updating game state, rendering, etc.
-		print("Frame ", frame_data.frame, " in Level2!\n");
+		print("Frame ", frame_data.frame, " in Level2 with strings: ");
+		for (const std::string& str : frame_data.strings) {
+			print("", str, ", ");
+		}
+		print(" and integers: ");
+		for (int i : frame_data.integers) {
+			print("", i, ", ");
+		}
+		print("\n");
 	}
 }
 

engine/src/main.cpp

@@ -73,6 +73,8 @@ int main()
 	   to frame data that is updated each frame. */
 	struct FrameData
 	{
+		riscv::GuestStdVector<Script::MARCH, riscv::GuestStdString<Script::MARCH>> strings;
+		riscv::GuestStdVector<Script::MARCH, int> integers;
 		int frame = 0;
 	};
 	/* When the guest pauses, the pointer to the frame data is the first argument (A0). */
@@ -87,6 +89,16 @@ int main()
 		/* Set the data for the current frame.
 		   This is accessible to the guest program when it resumes. */
 		frame_data->frame = i;
+		/* Wrappers around guest-stored vectors (and other types) always
+		   take the machine as the first argument. */
+		frame_data->strings.clear(level2.machine());
+		frame_data->strings.push_back(level2.machine(), "Hello");
+		frame_data->strings.push_back(level2.machine(), "World");
+
+		frame_data->integers.clear(level2.machine());
+		frame_data->integers.push_back(level2.machine(), i);
+		frame_data->integers.push_back(level2.machine(), i * 2);
+
 		/* Resume the level2 program, which unpauses the guest and continues
 		   execution until it loops around to the Game::wait() call again. */
 		if (!level2.resume(5'000)) {