twn_util: final cleaning up, introducton of powerful file_read()

apps/demos/platformer/game.c

@@ -29,10 +29,6 @@ void game_tick(void) {
         ctx.debug = !ctx.debug;
     }
 
-    if (input_action_just_pressed("debug_dump_atlases")) {
-        textures_dump_atlases();
-    }
-
     state->scene->tick(state);
 
     /* there's a scene switch pending, we can do it now that the tick is done */

apps/demos/scenery/game.c

@@ -30,10 +30,6 @@ void game_tick(void) {
         ctx.debug = !ctx.debug;
     }
 
-    if (input_action_just_pressed("debug_dump_atlases")) {
-        textures_dump_atlases();
-    }
-
     state->scene->tick(state);
 
     /* there's a scene switch pending, we can do it now that the tick is done */

apps/demos/scenery/scenes/ingame.c

@@ -109,6 +109,12 @@ static float height_at(SceneIngame *scn, Vec2 position);
 static Vec3 normal_at(SceneIngame *scn, Vec2 position);
 
 
+static inline float clampf(float f, float min, float max) {
+    const float t = f < min ? min : f;
+    return t > max ? max : t;
+}
+
+
 static void draw_vehicle(SceneIngame *scn) {
     for (size_t i = 0; i < 12; ++i)
         draw_line_3d(vbp[vbs[i][0]], vbp[vbs[i][1]], 1, (Color){255, 255, 255, 255});

apps/twnlua/bindgen.py

@@ -112,6 +112,9 @@ for procedure, procedure_desc in api["procedures"].items():
             binding += "    lua_pushnumber(L, (float)(%s(%s)));\n" % (procedure, ", ".join(param["name"] for param in procedure_desc["params"]))
         elif procedure_desc["return"] == "char *":
             binding += "    lua_pushstring(L, %s(%s));\n" % (procedure, ", ".join(param["name"] for param in procedure_desc["params"]))
+        elif procedure_desc["return"] == "String":
+            binding += "    String result = %s(%s);\n" % (procedure, ", ".join(param["name"] for param in procedure_desc["params"]))
+            binding += "    lua_pushlstring(L, result.data, (int)result.length);\n"
         elif type(procedure_desc["return"]) is dict or procedure_desc["return"] in api["types"]:
             type_desc = procedure_desc["return"] if type(procedure_desc["return"]) is dict else api["types"][procedure_desc["return"]]
             binding += "    %s result = %s(%s);\n" % (type_desc["c_type"], procedure, ", ".join(param["name"] for param in procedure_desc["params"]))

apps/twnlua/game.c

@@ -26,7 +26,7 @@ static int physfs_loader(lua_State *L) {
 
     static const char *name_breaker = NULL;
     if (name_breaker && SDL_strcmp(name, name_breaker) == 0) {
-        log_critical("Recursive load on itself from lua module (%s)", name_breaker);
+        log_string(name_breaker, "Recursive load on itself from lua module");
         return 0;
     } name_breaker = name;
 
@@ -40,26 +40,26 @@ static int physfs_loader(lua_State *L) {
     SDL_asprintf(&final_path, "/scripts/%s.lua", path_copy);
     SDL_free(path_copy);
 
-    if (!file_exists(final_path)) {
+    if (SDL_strcmp(file_read(final_path, ":exists").data, "yes") == 0) {
         char *error_message = NULL;
         SDL_asprintf(&error_message, "could not find module %s in filesystem", name);
         lua_pushstring(L, error_message);
-        free(error_message);
+        SDL_free(error_message);
 
-        free(final_path);
+        SDL_free(final_path);
         return 1;
     }
 
-    unsigned char *buf = NULL;
+    char *final_path_binary = NULL;
-    int64_t buf_size = file_to_bytes(final_path, &buf);
+    SDL_asprintf(&final_path_binary, "%s%s", final_path, ":binary");
-    free(final_path);
+
+    String file = file_read(final_path, ":binary");
+    SDL_free(final_path);
 
     /* TODO: use reader interface for streaming instead */
-    int const result = luaL_loadbuffer(L, (char *)buf, buf_size, name);
+    int const result = luaL_loadbuffer(L, file.data, (size_t)file.length, name);
-    free(buf);
-
     if (result != LUA_OK)
-        log_critical("%s", lua_tostring(L, -1));
+        log_string(lua_tostring(L, -1), NULL);
 
     return result == LUA_OK;
 }
@@ -110,7 +110,7 @@ static void *custom_alloc(void *ud, void *ptr, size_t osize, size_t nsize) {
 
 static void exchange_lua_states(lua_State *from, lua_State *to, int level, int index) {
     if (level >= UDATA_NESTING_LIMIT) {
-        log_critical("ctx.udata nesting limit is reached (%u)", UDATA_NESTING_LIMIT);
+        log_string("ctx.udata nesting limit is reached", NULL);
         return;
     }
 
@@ -143,7 +143,7 @@ static void exchange_lua_states(lua_State *from, lua_State *to, int level, int i
         break;
     default:
         /* TODO: provide a path and type of it for better diagnostic */
-        log_warn("Unserializable udata found and is ignored");
+        log_string("Unserializable udata found and is ignored", NULL);
         break;
     }
 }
@@ -167,7 +167,6 @@ void game_tick(void) {
             SDL_assert(!lua_isnoneornil(state->L, -1));
             SDL_assert(!lua_isnoneornil(state->L, -2));
             if (!lua_isnoneornil(state->L, -1)) {
-                log_info("Exchanging lua states...");
                 lua_newtable(new_state);
                 exchange_lua_states(state->L, new_state, 0, -1);
                 lua_setfield(new_state, -2, "udata");
@@ -216,24 +215,21 @@ void game_tick(void) {
         bindgen_load_twn(state->L);
 
         /* now finally get to running the code */
-        unsigned char *game_buf = NULL;
+        String file = file_read("/scripts/game.lua", ":binary");
-        size_t game_buf_size = file_to_bytes("/scripts/game.lua", &game_buf);
         /* TODO: use reader interface for streaming instead */
-        if (luaL_loadbuffer(state->L, (char *)game_buf, game_buf_size, "game.lua") == LUA_OK) {
+        if (luaL_loadbuffer(state->L, file.data, (size_t)file.length, "game.lua") == LUA_OK) {
             if (lua_pcall(state->L, 0, 0, 0) != LUA_OK) {
-                log_critical("%s", lua_tostring(state->L, -1));
+                log_string(luaL_tolstring(state->L, -1, NULL), "Error executing /scripts/game.lua entry");
                 lua_pop(state->L, 1);
             } else
                 state->loaded_successfully = true;
         } else {
             /* got some sort of error, it should be pushed on top of the stack */
             SDL_assert(lua_isstring(state->L, -1));
-            log_critical("Error loading /scripts/game.lua entry: %s", luaL_tolstring(state->L, -1, NULL));
+            log_string(luaL_tolstring(state->L, -1, NULL), "Error loading /scripts/game.lua entry");
             lua_pop(state->L, 1);
         }
 
-        SDL_free(game_buf);
-
         /* from this point we have access to everything defined in lua */
     }
 
@@ -251,7 +247,7 @@ void game_tick(void) {
 
         lua_getglobal(state->L, "game_tick");
         if (lua_pcall(state->L, 0, 0, 0) != LUA_OK) {
-            log_critical("%s", lua_tostring(state->L, -1));
+            log_string(luaL_tolstring(state->L, -1, NULL), "Error executing game_tick()");
             lua_pop(state->L, 1);
         }
 

include/twn_types.h

@@ -40,4 +40,12 @@ typedef struct Rect {
 } Rect;
 
 
+/* data packet exchanged between parties, assumed immutable */
+/* length is whole number */
+typedef struct String {
+    char *data;
+    float length;
+} String;
+
+
 #endif

include/twn_util.h

@@ -8,48 +8,37 @@
 #include <stddef.h>
 #include <stdbool.h>
 
+/* here as it's not part of standard C */
+#ifndef M_PI
+#define M_PI 3.14159265358979323846264338327950288   /**< pi */
+#endif
 
-#ifndef TWN_NOT_C
+/* read data from virtual filesystem, with assumption that you know what that underlying data is */
-    #include <math.h>
+/* this routine supports commands, which define operations performed on filepaths */
+/* empty result is returned when something goes wrong or file doesn't exist, with an error logged */
+/* defined commands: */
+/*  <path:string>   -- reads utf8 encoded file to null terminated string */
+/*  <path:binary>   -- reads arbitrary binary file, resulted encoding depends on environment (could be base64, for example) */
+/*  <path:exists>   -- returns "yes" or "no" ascii string */
+/*  <path:images>   -- returns newline separated utf8 list of image files in given path */
+TWN_API String file_read(char const *file, const char *operation);
 
-    #ifndef M_PI
+/* commit write to a file, which meaning depends on interpretation */
-    #define M_PI 3.14159265358979323846264338327950288   /**< pi */
+/* file_read should not be affected for current frame by this, operation is pending */
-    #endif
+/* defined commands: */
-
+/*  <path:string>   -- save utf8 file */
-    /* multiply by these to convert degrees <---> radians */
+/*  <path:binary>   -- save binary file */
-    #define DEG2RAD (M_PI / 180)
+/*  <path:image>    -- write image data to a PNG file, potentially updating running textures used */
-    #define RAD2DEG (180 / M_PI)
+/*                  -- format is: [width:2b][height:2][alpha:1][data:(3+alpha)*width*height] */
-
+TWN_API void file_write(char const *file, const char *operation, String string);
-    TWN_API void log_info(const char *restrict format, ...);
-    TWN_API void log_critical(const char *restrict format, ...);
-    TWN_API void log_warn(const char *restrict format, ...);
-
-    /* saves all texture atlases as BMP files in the write directory */
-    TWN_API void textures_dump_atlases(void);
-
-    /* TODO: this is why generics were invented. sorry, i'm tired today */
-    TWN_API float clampf(float f, float min, float max);
-
-    /* sets buf_out to a pointer to a byte buffer which must be freed. */
-    /* returns the size of this buffer. */
-    TWN_API int64_t file_to_bytes(const char *path, unsigned char **buf_out);
-
-    /* returns a pointer to a string which must be freed */
-    TWN_API char *file_to_str(const char *path);
-
-    /* returns true if the file exists in the filesystem */
-    TWN_API bool file_exists(const char *path);
-
-#endif /* TWN_NOT_C */
-
-/* read file to null terminated string, it is freed when the frame ends */
-TWN_API char const *file_read(char const *file);
 
+/* TODO: move to external templated lib */
 /* calculates the overlap of two rectangles */
 TWN_API Rect rect_overlap(Rect a, Rect b);
 /* returns true if two rectangles are intersecting */
 TWN_API bool rect_intersects(Rect a, Rect b);
 
+/* TODO: move to external templated lib */
 /* decrements a floating point second-based timer, stopping at 0.0f */
 /* meant for poll based real time logic in game logic */
 /* note that it should be decremented only on the next tick after its creation */
@@ -60,6 +49,8 @@ typedef struct TimerElapseSecondsResult {
 } TimerElapseSecondsResult;
 TWN_API TimerElapseSecondsResult timer_elapse_seconds(float seconds_left, float interval);
 
+TWN_API void log_string(char const *value, char const *identity);
+TWN_API void log_float(float value, char const *identity);
 TWN_API void log_vec2(Vec2 value, char const *identity);
 TWN_API void log_vec3(Vec3 value, char const *identity);
 TWN_API void log_rect(Rect value, char const *identity);

share/twn_api.json

@@ -312,9 +312,10 @@
             "symbol": "read",
             "header": "twn_util.h",
             "params": [
-                { "name": "file", "type": "char *" }
+                { "name": "file", "type": "char *" },
+                { "name": "operation", "type": "char *" }
             ],
-            "return": "char *",
+            "return": "String",
             "restriction": "asset"
         },
 

src/twn_loop.c

@@ -265,7 +265,7 @@ static void resolve_pack_dependencies(const char *pack_name) {
         /* no package manifest provided, abort */
         goto OK_NO_MANIFEST;
 
-    char *manifest_file = file_to_str(path);
+    char *manifest_file = file_to_str(path, NULL);
     if (!manifest_file) {
         CRY_PHYSFS("Pack manifest file loading failed");
         goto ERR_PACK_MANIFEST_FILE_LOADING;
@@ -375,7 +375,7 @@ static bool initialize(void) {
 
     /* load the config file into an opaque table */
     {
-        char *config_file = file_to_str("/twn.toml");
+        char *config_file = file_to_str("/twn.toml", NULL);
         if (config_file == NULL) {
             CRY("Configuration file loading failed", "Cannot access /twn.toml");
             goto fail;

src/twn_util.c

@@ -109,12 +109,6 @@ void *ccalloc(size_t num, size_t size) {
 }
 
 
-float clampf(float f, float min, float max) {
-  const float t = f < min ? min : f;
-  return t > max ? max : t;
-}
-
-
 int64_t file_to_bytes(const char *path, unsigned char **buf_out) {
     SDL_RWops *handle = PHYSFSRWOPS_openRead(path);
 
@@ -133,7 +127,7 @@ int64_t file_to_bytes(const char *path, unsigned char **buf_out) {
 }
 
 
-char *file_to_str(const char *path) {
+char *file_to_str(const char *path, size_t *out_len) {
     SDL_RWops *handle = PHYSFSRWOPS_openRead(path);
 
     if (handle == NULL) {
@@ -151,23 +145,62 @@ char *file_to_str(const char *path) {
 
     str_out[len] = '\0';
 
+    if (out_len)
+        *out_len = len;
+
     return str_out;
 }
 
-static char **read_files;
+static String *read_files;
 
-char const *file_read(char const *file) {
+String file_read(char const *file, char const *operation) {
-    char *s = file_to_str(file);
+    if (!file) {
+        log_warn("No file specified");
+        return (String){NULL, 0};
+    }
 
-    if (s) arrpush(read_files, s);
+    if (!operation) {
+        log_warn("No operation specified");
+        return (String){NULL, 0};
+    }
 
-    return s;
+    if (SDL_strncmp(operation, ":string", sizeof (":string") - 1) == 0) {
+        size_t length;
+        char *data = file_to_str(file, &length);
+
+        if (!data)
+            return (String){NULL, 0};
+
+        String s = {data, (float)length};
+        arrpush(read_files, s);
+
+        return s;
+    }
+
+    if (SDL_strncmp(operation, ":binary", sizeof (":binary") - 1) == 0) {
+        uint8_t *data;
+        int64_t length = file_to_bytes(file, &data);
+
+        if (length == -1)
+            return (String){NULL, 0};
+
+        String s = {(char *)data, (float)length};
+        arrpush(read_files, s);
+
+        return s;
+
+    } else
+        log_warn("No valid operation specified by %s", operation);
+
+    return (String){NULL, 0};
 }
 
 
 void file_read_garbage_collect(void) {
-    for (size_t i = 0; i < arrlenu(read_files); ++i)
+    for (size_t i = 0; i < arrlenu(read_files); ++i) {
-        SDL_free(read_files[i]);
+        SDL_assert_always(read_files[i].data && read_files[i].length >= 0);
+        SDL_free(read_files[i].data);
+    }
     arrfree(read_files);
     read_files = NULL;
 }
@@ -342,6 +375,18 @@ void profile_list_stats(void) {
     }
 }
 
+void log_string(char const *value, char const *message) {
+    if (!value) return;
+    if (!message)
+        log_info("%s", value);
+    else
+        log_info("%s: %s", message, value);
+}
+
+void log_float(float value, char const *message) {
+    if (!message) message = "float";
+    log_info("%s = %f", message, (double)value);
+}
 
 void log_vec2(Vec2 vector, char const *message) {
     if (!message) message = "Vec2";

src/twn_util_c.h

@@ -21,6 +21,10 @@ void cry_impl(const char *file, const int line, const char *title, const char *t
 #define CRY_PHYSFS(title)                                               \
 cry_impl(__FILE__, __LINE__, title, PHYSFS_getErrorByCode(PHYSFS_getLastErrorCode()))
 
+void log_info(const char *restrict format, ...);
+void log_critical(const char *restrict format, ...);
+void log_warn(const char *restrict format, ...);
+
 /* for when there's absolutely no way to continue */
 _Noreturn void die_abruptly(void);
 
@@ -31,6 +35,23 @@ void profile_list_stats(void);
 
 void file_read_garbage_collect(void);
 
+/* sets buf_out to a pointer to a byte buffer which must be freed. */
+/* returns the size of this buffer. */
+int64_t file_to_bytes(const char *path, unsigned char **buf_out);
+
+/* returns a pointer to a string which must be freed */
+char *file_to_str(const char *path, size_t *out_len);
+
+/* saves all texture atlases as BMP files in the write directory */
+void textures_dump_atlases(void);
+
+bool file_exists(const char *path);
+
+static inline float clampf(float f, float min, float max) {
+    const float t = f < min ? min : f;
+    return t > max ? max : t;
+}
+
 /* http://www.azillionmonkeys.com/qed/sqroot.html */
 static inline float fast_sqrt(float x)
 {