SDL metadata strings and save data

32blit-sdl/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_library(BlitHalSDL STATIC
+	DefaultMetadata.cpp
 	File.cpp
 	Input.cpp
 	JPEG.cpp
@@ -90,15 +91,6 @@ if(SDL2_IMAGE_DLL)
 	install(FILES ${SDL2_IMAGE_DLL} DESTINATION bin)
 endif()
 
-if(NOT 32BLIT_SDL_TITLE)
-	set(32BLIT_SDL_TITLE CMake!)
-endif()
-
-target_compile_definitions(BlitHalSDL
-	PRIVATE
-		-DWINDOW_TITLE=\"${32BLIT_SDL_TITLE}\"
-)
-
 if(DEFINED VIDEO_CAPTURE AND VIDEO_CAPTURE)
 	find_path(AVCODEC_INCLUDE_DIR libavcodec/avcodec.h)
 	find_library(AVCODEC_LIBRARY avcodec)
@@ -188,4 +180,14 @@ function(blit_metadata TARGET FILE)
 		target_sources(${TARGET} PRIVATE ${ICON})
 		set_source_files_properties(${ICON} PROPERTIES MACOSX_PACKAGE_LOCATION Resources)
 	endif()
+
+	file(GENERATE OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/metadata.cpp
+		CONTENT "
+const char *metadata_title = \"${METADATA_TITLE}\";
+const char *metadata_author = \"${METADATA_AUTHOR}\";
+const char *metadata_description = \"${METADATA_DESCRIPTION}\";
+const char *metadata_version = \"${METADATA_VERSION}\";
+		"
+	)
+	target_sources(${TARGET} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/metadata.cpp)
 endfunction()

32blit-sdl/DefaultMetadata.cpp

@@ -0,0 +1,12 @@
+// Default metadata if there is non compiled into the game
+// There should be nothing else in this file so that the VS linker drops it when not needed
+#ifdef _MSC_VER
+#define WEAK
+#else
+#define WEAK [[gnu::weak]]
+#endif
+
+WEAK const char *metadata_title = "32Blit Game";
+WEAK const char *metadata_author = "Unknown";
+WEAK const char *metadata_description = "";
+WEAK const char *metadata_version = "v0.0.0";

32blit-sdl/File.cpp

@@ -13,6 +13,7 @@
 #include "SDL.h"
 
 #include "File.hpp"
+#include "UserCode.hpp"
 
 static std::string basePath;
 
@@ -36,6 +37,14 @@ void *open_file(const std::string &name, int mode) {
     return nullptr;
 
   auto file = SDL_RWFromFile((basePath + name).c_str(), str_mode);
+
+  if(!file) {
+    // check if the path is under the save path
+    auto save_path = get_save_path();
+    if(name.compare(0, save_path.length(), save_path) == 0)
+      file = SDL_RWFromFile(name.c_str(), str_mode);
+  }
+
   return file;
 }
 
@@ -178,4 +187,13 @@ bool rename_file(const std::string &old_name, const std::string &new_name) {
 
 bool remove_file(const std::string &path) {
   return remove((basePath + path).c_str()) == 0;
+}
+
+std::string get_save_path() {
+  auto tmp = SDL_GetPrefPath(metadata_author, metadata_title);
+  std::string ret(tmp);
+
+  SDL_free(tmp);
+
+  return ret;
 }

32blit-sdl/File.hpp

@@ -17,4 +17,5 @@ bool file_exists(const std::string &path);
 bool directory_exists(const std::string &path);
 bool create_directory(const std::string &path);
 bool rename_file(const std::string &old_name, const std::string &new_name);
-bool remove_file(const std::string &path);
+bool remove_file(const std::string &path);
+std::string get_save_path();

32blit-sdl/Main.cpp

@@ -13,15 +13,12 @@
 #include "System.hpp"
 #include "Renderer.hpp"
 #include "Audio.hpp"
+#include "UserCode.hpp"
 
 #ifdef VIDEO_CAPTURE
 #include "VideoCapture.hpp"
 #endif
 
-#ifndef WINDOW_TITLE
-#define WINDOW_TITLE "32blit development (SDL)"
-#endif
-
 static bool running = true;
 
 SDL_Window* window = nullptr;
@@ -112,13 +109,13 @@ void handle_event(SDL_Event &event) {
 			} else if (event.type == System::timer_event) {
 				switch(event.user.code) {
 					case 0:
-						SDL_SetWindowTitle(window, WINDOW_TITLE);
+						SDL_SetWindowTitle(window, metadata_title);
 						break;
 					case 1:
-						SDL_SetWindowTitle(window, WINDOW_TITLE " [SLOW]");
+						SDL_SetWindowTitle(window, (std::string(metadata_title) + " [SLOW]").c_str());
 						break;
 					case 2:
-						SDL_SetWindowTitle(window, WINDOW_TITLE " [FROZEN]");
+						SDL_SetWindowTitle(window, (std::string(metadata_title) + " [FROZEN]").c_str());
 						break;
 				}
 			}
@@ -149,7 +146,7 @@ int main(int argc, char *argv[]) {
 	}
 
 	window = SDL_CreateWindow(
-		WINDOW_TITLE,
+		metadata_title,
 		SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
 		System::width*2, System::height*2,
 		SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE

32blit-sdl/System.cpp

@@ -157,6 +157,7 @@ void System::run() {
 	blit::api.create_directory = ::create_directory;
 	blit::api.rename_file = ::rename_file;
 	blit::api.remove_file = ::remove_file;
+	blit::api.get_save_path = ::get_save_path;
 
 	blit::api.enable_us_timer = ::enable_us_timer;
 	blit::api.get_us_timer = ::get_us_timer;

32blit-sdl/UserCode.hpp

@@ -1,6 +1,11 @@
 #pragma once
 #include <string>
 
-	void init();
-	void update(uint32_t time);
-	void render(uint32_t time);
+void init();
+void update(uint32_t time);
+void render(uint32_t time);
+
+extern const char *metadata_title;
+extern const char *metadata_author;
+extern const char *metadata_description;
+extern const char *metadata_version;

32blit-stm32/Inc/executable.hpp

@@ -17,4 +17,14 @@ struct BlitGameHeader {
 
   uint32_t end;
   uint32_t start;
+};
+
+// missing the "BLITMETA" header and size
+struct RawMetadata {
+  uint32_t crc32;
+  char datetime[16];
+  char title[25];
+  char description[129];
+  char version[17];
+  char author[17];
 };

32blit-stm32/Inc/file.hpp

@@ -16,4 +16,5 @@ bool file_exists(const std::string &path);
 bool directory_exists(const std::string &path);
 bool create_directory(const std::string &path);
 bool rename_file(const std::string &old_name, const std::string &new_name);
-bool remove_file(const std::string &path);
+bool remove_file(const std::string &path);
+std::string get_save_path();

32blit-stm32/Src/32blit.cpp

@@ -429,6 +429,7 @@ void blit_init() {
     blit::api.create_directory = ::create_directory;
     blit::api.rename_file = ::rename_file;
     blit::api.remove_file = ::remove_file;
+    blit::api.get_save_path = ::get_save_path;
 
     blit::api.enable_us_timer = ::enable_us_timer;
     blit::api.get_us_timer = ::get_us_timer;
@@ -963,7 +964,14 @@ void blit_switch_execution(uint32_t address)
     if(game_header->magic == blit_game_magic) {
       // load function pointers
       auto init = (BlitInitFunction)((uint8_t *)game_header->init + address);
+
+      // set these up early so that blit_user_code_running works in code called from init
+      user_render = (BlitRenderFunction) ((uint8_t *)game_header->render + address);
+      user_tick = (BlitTickFunction) ((uint8_t *)game_header->tick + address);
+
       if(!init(address)) {
+        user_render = nullptr;
+        user_tick = nullptr;
         // this would just be a return, but qspi is already mapped by this point
         persist.reset_target = prtFirmware;
         SCB_CleanDCache();
@@ -973,8 +981,8 @@ void blit_switch_execution(uint32_t address)
 
       persist.last_game_offset = address;
 
-      blit::render = user_render = (BlitRenderFunction) ((uint8_t *)game_header->render + address);
-      do_tick = user_tick = (BlitTickFunction) ((uint8_t *)game_header->tick + address);
+      blit::render = user_render;
+      do_tick = user_tick;
       return;
     }
     // anything flashed at a non-zero offset should have a valid header

32blit-stm32/Src/file.cpp

@@ -1,9 +1,12 @@
 #include <cstdint>
+#include <cstring>
 #include <map>
 
 #include "fatfs.h"
 
 #include "file.hpp"
+#include "32blit.h"
+#include "executable.hpp"
 
 void *open_file(const std::string &file, int mode) {
   FIL *f = new FIL();
@@ -134,4 +137,39 @@ bool rename_file(const std::string &old_name, const std::string &new_name) {
 
 bool remove_file(const std::string &path) {
   return f_unlink(path.c_str()) == FR_OK;
+}
+
+std::string get_save_path() {
+  std::string app_name;
+
+  if(!directory_exists(".blit"))
+    create_directory(".blit");
+
+  if(!blit_user_code_running())
+    app_name = "_firmware";
+  else {
+    // TODO: this probably can be used for other things
+    auto game_ptr = reinterpret_cast<uint8_t *>(0x90000000 + persist.last_game_offset);
+
+    auto header = reinterpret_cast<BlitGameHeader *>(game_ptr);
+
+    if(header->magic == blit_game_magic) {
+      auto end_ptr = game_ptr + (header->end - 0x90000000);
+      if(memcmp(end_ptr, "BLITMETA", 8) == 0) {
+        auto meta = reinterpret_cast<RawMetadata *>(end_ptr + 10);
+        app_name = meta->title;
+      }
+    }
+
+    if(app_name.empty()) {
+      // fallback to offset
+      app_name = std::to_string(persist.last_game_offset);
+    }
+  }
+
+  // make sure it exists
+  if(!directory_exists(".blit/" + app_name))
+    create_directory(".blit/" + app_name);
+
+  return ".blit/" + app_name + "/";
 }

32blit/32blit.hpp

@@ -6,6 +6,7 @@
 #include "engine/output.hpp"
 #include "engine/input.hpp"
 #include "audio/audio.hpp"
+#include "engine/save.hpp"
 #include "engine/timer.hpp"
 #include "engine/tweening.hpp"
 #include "graphics/blend.hpp"

32blit/CMakeLists.txt

@@ -7,7 +7,8 @@ set(SOURCES
 	engine/output.cpp
 	engine/particle.cpp
 	engine/profiler.cpp
-	engine/running_average.cpp
+  engine/running_average.cpp
+  engine/save.cpp
 	engine/timer.cpp
 	engine/tweening.cpp
 	engine/version.cpp

32blit/engine/api_private.hpp

@@ -54,6 +54,7 @@ namespace blit {
     bool (*create_directory) (const std::string &path);
     bool (*rename_file) (const std::string &old_name, const std::string &new_name);
     bool (*remove_file) (const std::string &path);
+    std::string (*get_save_path)();
 
     // profiler
     void (*enable_us_timer)();

32blit/engine/save.cpp

@@ -0,0 +1,31 @@
+#include "save.hpp"
+#include "api_private.hpp"
+#include "file.hpp"
+
+namespace blit {
+  /**
+   * Read a block of save data from a save slot.
+   *
+   * \param data Pointer to store data into, should be at least `length` bytes
+   * \param length Expected length of save data
+   * \param slot Save slot to load, can be any number
+   * 
+   * \return `true` if a save exists and contains enough data
+   */
+  bool read_save(char *data, uint32_t length, int slot) {
+    File file(api.get_save_path() + "save" + std::to_string(slot));
+
+    return file.is_open() && uint32_t(file.read(0, length, data)) == length;
+  }
+
+  /**
+   * Write a block of save data to a save slot.
+   *
+   * \param data Pointer to data to write, should be `length` bytes
+   * \param length Length of data to write
+   * \param slot Save slot to write to, can be any number
+   */
+  void write_save(const char *data, uint32_t length, int slot) {
+    File(api.get_save_path() + "save" + std::to_string(slot), OpenMode::write).write(0, length, data);
+  }
+}

32blit/engine/save.hpp

@@ -0,0 +1,22 @@
+#include <cstdint>
+
+namespace blit {
+  bool read_save(char *data, uint32_t length, int slot = 0);
+  void write_save(const char *data, uint32_t length, int slot = 0);
+
+  /**
+   * \overload
+   */
+  template<class T>
+  bool read_save(T &data, int slot = 0) {
+    return read_save(reinterpret_cast<char *>(&data), sizeof(T), slot);
+  }
+
+  /**
+   * \overload
+   */
+  template<class T>
+  void write_save(const T &data, int slot = 0) {
+    write_save(reinterpret_cast<const char *>(&data), sizeof(T), slot);
+  }
+}

examples/CMakeLists.txt

@@ -20,6 +20,7 @@ add_subdirectory(profiler-test)
 #add_subdirectory(racer)
 add_subdirectory(raycaster)
 add_subdirectory(rotozoom)
+add_subdirectory(saves)
 add_subdirectory(scrolly-tile)
 add_subdirectory(serial-debug)
 add_subdirectory(shmup)

examples/saves/CMakeLists.txt

@@ -0,0 +1,8 @@
+
+cmake_minimum_required(VERSION 3.8)
+project (saves)
+set(32BLIT_PATH "../../" CACHE PATH "Path to 32blit.cmake")
+include (${32BLIT_PATH}/32blit.cmake)
+
+blit_executable (saves saves.cpp)
+blit_metadata (saves metadata.yml)

examples/saves/metadata.yml

@@ -0,0 +1,8 @@
+title: Saves
+description: Save data example.
+author: daft_freak
+splash:
+  file: ../no-image.png
+icon:
+  file: ../no-icon.png
+version: v1.0.0