03: refactor the code (client+server)

03-network/client/src/defs.h

@@ -7,6 +7,11 @@
 #define SERVER_ADDR "127.0.0.1"
 #define SERVER_PORT 9080
 
+// ERRORS 
+#define STDOK 0
+#define STDERR -1 
+#define MEMERR -2
+
 // SDL2 
 #define SCREEN_WIDTH 1000
 #define SCREEN_HEIGHT 480

03-network/client/src/format.c

@@ -0,0 +1,64 @@
+#include <SDL2/SDL.h>
+#include "defs.h"
+#include "structs.h"
+#include "format.h"
+
+extern SDL_Texture *idle_animation;
+extern SDL_Texture *run_animation;
+extern SDL_Texture *jump_animation;
+extern struct object *create_object(SDL_Texture *texture, int scale, int resolution);
+
+int handle_player_connect(int *message, struct object ***map, int *slots) {
+    int object_id = message[1]; 
+    
+    if (object_id >= *slots) {
+        *slots = object_id+1;
+        *map = realloc(*map, sizeof(struct object *)*(*slots));
+    }
+
+    if (*map == NULL) 
+        return MEMERR; 
+
+    struct object *new_object = create_object(idle_animation, 4, 48);
+    if (new_object == NULL) 
+        return MEMERR; 
+
+    new_object->id = object_id;
+    new_object->x = message[2]; 
+    new_object->y = message[3]; 
+    new_object->colliding = message[4]; 
+    new_object->force = message[5]; 
+    new_object->state = message[6];
+    (*map)[object_id] = new_object;
+
+    return STDOK;
+}
+
+int handle_object_properties(int *message, struct object ***map, int *slots) {
+    int object_id = message[1]; 
+
+    if (object_id >= *slots) {
+        *slots = object_id+1;
+        *map = realloc(*map, sizeof(struct object *)*(*slots));
+    }
+
+    if (*map == NULL)
+        return MEMERR;
+    
+    if ((*map)[object_id] == NULL) {
+        struct object *new_object = create_object(idle_animation, 4, 48);
+        if (new_object == NULL) 
+            return MEMERR;
+
+        new_object->id = object_id;
+        (*map)[object_id] = new_object;
+    }
+
+    (*map)[object_id]->x = message[2];
+    (*map)[object_id]->y = message[3];
+    (*map)[object_id]->colliding = message[4];
+    (*map)[object_id]->force = message[5];
+    (*map)[object_id]->state = message[6];
+
+    return STDOK;
+}

03-network/client/src/format.h

@@ -0,0 +1,9 @@
+#ifndef FORMAT_H
+#define FORMAT_H
+
+#include <stdlib.h>
+
+int handle_player_connect(int *message, struct object ***map, int *slots);
+int handle_object_properties(int *message, struct object ***map, int *slots);
+
+#endif

03-network/client/src/main.c

@@ -4,6 +4,7 @@
 #include <SDL2/SDL_net.h>
 #include "structs.h"
 #include "defs.h"
+#include "format.h"
 
 #define DEBUG 1
 
@@ -16,15 +17,12 @@ double last_frame;
 // network
 TCPsocket server_socket;
 
-// scene 
-struct object *player;
-
 // textures
 SDL_Texture *idle_animation;
-SDL_Texture *jump_animation;
 SDL_Texture *run_animation;
+SDL_Texture *jump_animation;
 
-
+// scene
 int objects_count = 0;
 struct object ** objects_map;
 
@@ -75,59 +73,6 @@ SDL_Texture *load_texture(const char *path) {
     return texture;
 }
 
-void switch_animation(struct object *object, SDL_Texture *animation) {
-    if (object->texture == animation)
-        return;
-
-    object->animation_slide = 0; 
-    object->texture = animation;
-}
-
-struct object *create_object(SDL_Texture *texture, int scale, int resolution) {
-    struct object *object = (struct object *) calloc(1, sizeof(struct object));
-
-    if (object == NULL) {
-        fprintf(stderr, "Error: failed allocating memory for new object\n");
-        return NULL;
-    }
-
-    object->texture = texture;
-    object->resolution = resolution;
-    object->animation_speed = 13;
-    object->scale = scale;
-
-    return object;
-}
-
-void draw_object(struct object *object) {
-    int texture_width; 
-    SDL_Rect src;
-    SDL_Rect dest;
-
-    src.x = object->animation_slide * object->resolution;
-    src.y = 0;
-
-    src.w = object->resolution;
-    src.h = object->resolution;
-
-    dest.x = object->x; 
-    dest.y = object->y; 
-    dest.w = object->resolution * object->scale;
-    dest.h = object->resolution * object->scale;
-
-    SDL_RenderCopyEx(game.renderer, object->texture, &src, &dest, 0, NULL, object->flip);
-
-    // update animation slide
-    SDL_QueryTexture(object->texture, NULL, NULL, &texture_width, NULL);
-
-    object->animation_clock += object->animation_speed*(delta_time/1000);
-
-    if (object->animation_clock >= 1) {
-        object->animation_clock = 0;    
-        object->animation_slide = (object->animation_slide+1) % (texture_width / object->resolution); // clock arithmetic: jump back to first animation slide 
-    }
-}
-
 void present_scene(void) {
     SDL_RenderPresent(game.renderer);
 }
@@ -168,28 +113,11 @@ int handle_server(void *data) {
             if (DEBUG) 
                 fprintf(stdout, "DEBUG: PLAYER CONNECT MESSAGE\n");
 
-            if (message[1] >= objects_count) {
+            int ret = handle_player_connect(message, &objects_map, &objects_count);
-                objects_map = (struct object **) realloc(objects_map, sizeof(struct object *)*message[1]);
+            if (ret == MEMERR) {
-                objects_count = message[1]+1;
+                fprintf(stderr, "MEMERR: Failed handling memory for player connect\n");
+                return MEMERR;
             }
-            if (objects_map == NULL) {
-                fprintf(stderr, "Error: failed reallocating objects hash map\n");
-                return -1;
-            }
-
-            struct object *new_object = create_object(idle_animation, 4, 48);
-            if (new_object == NULL) {
-                fprintf(stderr, "Error: failed allocating memory for new object\n");
-                return -1;
-            }
-
-            new_object->id = message[1];
-            new_object->x = message[2]; 
-            new_object->y = message[3]; 
-            new_object->colliding = message[4]; 
-            new_object->force = message[5]; 
-            new_object->state = message[6];
-            objects_map[message[1]] = new_object;
 
             continue; 
         }
@@ -198,32 +126,12 @@ int handle_server(void *data) {
             if (DEBUG) 
                 fprintf(stdout, "DEBUG: OBJECT PROPERTIES MESSAGE FOR ID %d\n", message[1]);
             
-            if (message[1] >= objects_count) {
+            int ret = handle_object_properties(message, &objects_map, &objects_count);
-                objects_map = (struct object **) realloc(objects_map, sizeof(struct object *)*message[1]);
+            if (ret == MEMERR) {
-                objects_count = message[1]+1;
+                fprintf(stderr, "MEMERR: Failed handling memory for new object properties\n");
-            }
+                return MEMERR;
-            if (objects_map == NULL) {
-                fprintf(stderr, "Error: failed reallocating objects hash map\n");
-                return -1;
             }
 
-            if (objects_map[message[1]] == NULL) {
-                struct object *new_object = create_object(idle_animation, 4, 48);
-                if (new_object == NULL) {
-                    fprintf(stderr, "Error: failed allocating memory for new object\n");
-                    return -1;
-                }
-
-                new_object->id = message[1];
-                objects_map[message[1]] = new_object;
-            }
-
-            objects_map[message[1]]->x = message[2];
-            objects_map[message[1]]->y = message[3];
-            objects_map[message[1]]->colliding = message[4];
-            objects_map[message[1]]->force = message[5];
-
-            objects_map[message[1]]->state = message[6];
             continue; 
         }
 
@@ -334,7 +242,7 @@ int main(int argc, char *argv[]) {
             if (obj->state & JUMP_MOVEMENT) 
                 switch_animation(obj, jump_animation);
 
-            draw_object(obj);
+            draw_object(&game, obj);
         }
 
         present_scene();

03-network/client/src/object.c

@@ -0,0 +1,54 @@
+#include "structs.h"
+
+extern double delta_time;
+
+struct object *create_object(SDL_Texture *texture, int scale, int resolution) {
+    struct object *object = (struct object *) calloc(1, sizeof(struct object));
+
+    if (object == NULL) 
+        return NULL;
+
+    object->texture = texture;
+    object->resolution = resolution;
+    object->animation_speed = 13;
+    object->scale = scale;
+
+    return object;
+}
+
+void draw_object(struct game *game, struct object *object) {
+    int texture_width; 
+    SDL_Rect src;
+    SDL_Rect dest;
+
+    src.x = object->animation_slide * object->resolution;
+    src.y = 0;
+
+    src.w = object->resolution;
+    src.h = object->resolution;
+
+    dest.x = object->x; 
+    dest.y = object->y; 
+    dest.w = object->resolution * object->scale;
+    dest.h = object->resolution * object->scale;
+
+    SDL_RenderCopyEx(game->renderer, object->texture, &src, &dest, 0, NULL, object->flip);
+
+    // update animation slide
+    SDL_QueryTexture(object->texture, NULL, NULL, &texture_width, NULL);
+
+    object->animation_clock += object->animation_speed*(delta_time/1000);
+
+    if (object->animation_clock >= 1) {
+        object->animation_clock = 0;    
+        object->animation_slide = (object->animation_slide+1) % (texture_width / object->resolution); // clock arithmetic: jump back to first animation slide 
+    }
+}
+
+void switch_animation(struct object *object, SDL_Texture *animation) {
+    if (object->texture == animation)
+        return;
+
+    object->animation_slide = 0; 
+    object->texture = animation;
+}

03-network/client/src/structs.h

@@ -22,8 +22,8 @@ struct animation {
 struct object {
     SDL_Texture *texture;
     int resolution;                 // of the texture/every tile
-
     int id;
+
     int x; 
     int y;
     int scale;
@@ -40,4 +40,8 @@ struct object {
     int force;
 };
 
+struct object *create_object(SDL_Texture *texture, int scale, int resolution);
+void draw_object(struct game *game, struct object *object);
+void switch_animation(struct object *object, SDL_Texture *animation); 
+
 #endif 

03-network/server/src/defs.h

@@ -5,6 +5,10 @@
 #define GENERAL_DEBUG   0x0001
 #define PLAYER_DEBUG    0x0010
 
+// ERRORS 
+#define STDERR -1
+#define MEMERR -2
+
 // MCS: Message Communication Standard
 #define SERVER_MESSAGE_LEN 10
 #define CLIENT_MESSAGE_LEN 7

03-network/server/src/hashmap.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "hashmap.h"
+#include "defs.h"
+
+int find_empty_slot(void **map, int slots) {
+    int slot = 0; 
+
+    if (slots <= 0) 
+        return slot;
+
+    if (map == NULL) 
+        return slot;
+
+    while (slot < slots) {
+        if (map[slot] == NULL)
+            break;
+        
+        slot++;
+    }
+
+    return slot;
+}
+
+int allocate_value(void ***map, int *slots, int bytes) {
+    int empty_slot = find_empty_slot(*map, *slots); 
+
+    if (empty_slot == *slots) {
+        (*slots)++;
+        *map = realloc(*map, sizeof(void *)*(*slots));
+    }
+
+    if (*map == NULL)
+        return MEMERR; 
+
+    void *new_value = calloc(1, bytes);
+    if (new_value == NULL) 
+        return MEMERR;
+
+    (*map)[empty_slot] = new_value;
+
+    return empty_slot;
+}

03-network/server/src/hashmap.h

@@ -0,0 +1,9 @@
+#ifndef HASHMAP_H
+#define HASHMAP_H
+
+#include "structs.h"
+
+int find_empty_slot(void **map, int slots);
+int allocate_value(void ***map, int *slots, int bytes);
+
+#endif

03-network/server/src/main.c

@@ -4,8 +4,9 @@
 #include <SDL2/SDL.h>
 #include <SDL2/SDL_net.h>
 #include <SDL2/SDL_error.h>
-#include "structs.h"
 #include "defs.h"
+#include "structs.h"
+#include "hashmap.h"
 
 #define DEBUG 0x0010
 #define PORT 9080
@@ -44,36 +45,7 @@ void handle_player_physics(struct object *obj) {
     obj->y += obj->force;
 }
 
-void send_player_positions(TCPsocket socket, int player_id) {
+int broadcast_event(int format, int object_id) {
-    if (objects_map == NULL)
-        return;
-
-    for (int iter = 0; iter < objects_count; iter++) {
-        struct object *obj = objects_map[iter];
-        if (obj == NULL) 
-            continue;
-
-        // Update the client with every object's information
-        // Note: the order OBVIOUSLY matters
-        int reply[] = {
-            OBJECT_PROPERTIES_FORMAT,
-            obj->id,
-            obj->x,
-            obj->y,
-            obj->colliding,
-            obj->force,
-            obj->state
-        };
-
-        if (DEBUG & PLAYER_DEBUG) 
-            fprintf(stdout, "PLAYER_DEBUG: player '%d' properties (%d, %d, %d, %d)\n", 
-                    obj->id, obj->x, obj->y, obj->colliding, obj->force);
-
-        SDLNet_TCP_Send(socket, reply, sizeof(int)*CLIENT_MESSAGE_LEN);
-    }
-}
-
-int send_player_connect_event(int object_id) {
     struct object *obj = objects_map[object_id];
 
     for (int iter = 0; iter < connections_count; iter++) {
@@ -82,7 +54,7 @@ int send_player_connect_event(int object_id) {
             continue; 
 
         int message[] = {
-            PLAYER_CONNECT_FORMAT,
+            format, 
             obj->id, 
             obj->x, 
             obj->y, 
@@ -91,36 +63,6 @@ int send_player_connect_event(int object_id) {
             obj->state
         };
 
-        if (DEBUG & PLAYER_DEBUG)
-            fprintf(stdout, "PLAYER_DEBUG: new player '%d' has connected to the server\n", obj->id);
-
-        SDLNet_TCP_Send(con->socket, message, sizeof(int)*CLIENT_MESSAGE_LEN);
-    }
-
-    return 0;
-}
-
-int send_player_disconnect_event(int object_id) {
-    struct object *obj = objects_map[object_id];
-
-    for (int iter = 0; iter < connections_count; iter++) {
-        struct connection *con = connections_map[iter]; 
-        if (con == NULL) 
-            continue; 
-
-        int message[] = {
-            PLAYER_DISCONNECT_FORMAT, 
-            obj->id, 
-            obj->x, 
-            obj->y, 
-            obj->colliding, 
-            obj->force,
-            obj->state
-        };
-
-        if (DEBUG & PLAYER_DEBUG)
-            fprintf(stdout, "PLAYER_DEBUG: player '%d' has disconnected from the server\n", obj->id);
-
         SDLNet_TCP_Send(con->socket, message, sizeof(int)*CLIENT_MESSAGE_LEN);
     }
 
@@ -143,7 +85,7 @@ int handle_player(void *data) {
         return -1;
     }
 
-    send_player_connect_event(connection_data->obj_id); 
+    broadcast_event(PLAYER_CONNECT_FORMAT, connection_data->obj_id);
 
     for (;;) {
         char message[SERVER_MESSAGE_LEN]; 
@@ -170,11 +112,11 @@ int handle_player(void *data) {
 
     update_client:
         handle_player_physics(obj);
-        send_player_positions(connection_data->socket, connection_data->obj_id);
+        broadcast_event(OBJECT_PROPERTIES_FORMAT, connection_data->obj_id);
     }
 
     // Communicate client disconnect
-    send_player_disconnect_event(connection_data->obj_id);
+    broadcast_event(PLAYER_DISCONNECT_FORMAT, connection_data->obj_id);
 
     SDLNet_FreeSocketSet(set);
     SDLNet_TCP_Close(connection_data->socket);
@@ -244,47 +186,28 @@ int main(int argc, char *argv[]) {
 
         fprintf(stdout, "Notice: accepted a connection from client!\n"); 
 
-        int new_object_position = new_key_position((void **) objects_map, objects_count); 
+        int new_object_slot = allocate_value((void ***) &objects_map, &objects_count, sizeof(struct object));
-        if (new_object_position == objects_count) {
+        if (new_object_slot == MEMERR) {
-            objects_map = (struct object **) realloc(objects_map, sizeof(struct object *)*objects_count);
+            fprintf(stderr, "MEMERR: failed allocating memory for new object\n");
-            objects_count++;
+            return STDERR;
-        }
-        if (objects_map == NULL) {
-            fprintf(stderr, "Error: failed reallocating objects hash map\n");
-            return -1;
         }
 
-        struct object *new_object = (struct object *) calloc(1, sizeof(struct object));
+        int new_connection_slot = allocate_value((void ***) &connections_map, &connections_count, sizeof(struct connection));
-        if (new_object == NULL) {
+        if (new_connection_slot == MEMERR) {
-            fprintf(stderr, "Error: failed allocating memory for new object\n");
+            fprintf(stderr, "MEMERR: failed allocating memory for new connection\n");
-            return -1;
+            return STDERR;
         }
 
-        int new_connection_position = new_key_position((void **) connections_map, connections_count);
+        struct object *new_object = objects_map[new_object_slot];
-        if (new_connection_position == connections_count) {
+        struct connection *new_connection = connections_map[new_connection_slot];
-            connections_map = (struct connection **) realloc(connections_map, sizeof(struct connection *)*connections_count);
-            connections_count++;
-        }
-        if (connections_map == NULL) {
-            fprintf(stderr, "Error: failed reallocating connections hash map\n");
-            return -1;
-        }
 
-        struct connection *new_connection = (struct connection *) calloc(1, sizeof(struct connection));
+        new_object->id = new_object_slot;
-        if (new_connection == NULL) {
+        new_connection->id = new_connection_slot;
-            fprintf(stderr, "Error: failed allocating memory for new connection object\n");
-            return -1;
-        }
-
-        objects_map[new_object_position] = new_object;
-        connections_map[new_connection_position] = new_connection;
-        new_object->id = new_object_position;
-        new_connection->id = new_connection_position;
         new_connection->socket = client;
-        new_connection->obj_id = new_object_position;
+        new_connection->obj_id = new_object_slot;
 
         if (DEBUG & PLAYER_DEBUG) 
-            fprintf(stdout, "Notice: new player object id: %d\n", new_object_position);
+            fprintf(stdout, "Created connection with id '%d' and object '%d'\n", new_connection->id, new_object->id);
 
         SDL_CreateThread(handle_player, "client", new_connection);
     }