sdl: reworked event handler a bit, still thinking about C++

2 files changed, 53 insertions, 43 deletions

diff --git a/sdl/event.c b/sdl/event.c
index 16e5f00..905a35f 100644
--- a/sdl/event.c
+++ b/sdl/event.c
@@ -18,22 +18,21 @@
 #include "event.h"
 
 extern int program_running;
-static struct platform *p;
 
-/* our function table */
-static struct event_vtbl event_tbl;
+/* an event handler struct that contains a table with function pointers */
+static struct event_handler event_handler;
 
 int event_handler_init(struct platform *plat, struct event_vtbl *tbl)
 {
     if (!tbl || !plat)
         return -1;
 
-    p = plat;
-    event_tbl = *tbl;
+    event_handler.funcs = *tbl;
+    event_handler.p = plat;
 
     /* predefined handlers that are automatically provided */
-    if (!event_tbl.windowresize)
-        event_tbl.windowresize = window_resize;
+    if (!event_handler.funcs.windowresize)
+        event_handler.funcs.windowresize = window_resize;
 
     return 0;
 }
@@ -43,10 +42,9 @@ void sdl_process_events(void)
 {
     SDL_Event event;
     SDLKey sym;
-    static unsigned int keys_held[323];
+    unsigned int *keys_held = event_handler.keys_held;
 
-    /* helper flag for event_keydown() */
-    int flag = 0;
+    event_handler.flag = 0;
 
     while (SDL_PollEvent(&event))
     {
@@ -64,14 +62,14 @@ void sdl_process_events(void)
             case SDL_KEYDOWN:
             {
                 keys_held[sym] = 1;
-                if (event_tbl.keydown)
-                    event_tbl.keydown(&event.key.keysym, keys_held, flag);
+                if (event_handler.funcs.keydown)
+                    event_handler.funcs.keydown(&event.key.keysym);
                 break;
             }
             case SDL_VIDEORESIZE:
             {
-                if (event_tbl.windowresize)
-                    event_tbl.windowresize(event.resize.w, event.resize.h);
+                if (event_handler.funcs.windowresize)
+                    event_handler.funcs.windowresize(event.resize.w, event.resize.h);
                 break;
             }
             case SDL_QUIT:
@@ -85,39 +83,24 @@ void sdl_process_events(void)
     }
 
     /* below code has to be placed here, check for keys that are being constantly held */
-    if (keys_held[SDLK_w] || keys_held[SDLK_s] || keys_held[SDLK_a] || keys_held[SDLK_d] ||
-        keys_held[SDLK_UP] || keys_held[SDLK_DOWN] || keys_held[SDLK_LEFT] || keys_held[SDLK_RIGHT] ||
-        keys_held[SDLK_n] || keys_held[SDLK_m])
+    if (keys_held[SDLK_w] || keys_held[SDLK_s] || keys_held[SDLK_a] ||
+        keys_held[SDLK_d] || keys_held[SDLK_UP] || keys_held[SDLK_DOWN] ||
+        keys_held[SDLK_LEFT] || keys_held[SDLK_RIGHT] || keys_held[SDLK_n] ||
+        keys_held[SDLK_m])
     {
-        flag = !flag;
-        event_keydown(NULL, keys_held, flag);
+        event_handler.flag = !event_handler.flag;
+        event_keydown(NULL);
     }
-    else
-        flag = !flag;
 }
 
 /* here are the event handler functions */
-void event_keydown(SDL_keysym *keysym, const unsigned int *keys_held, const int flag)
+void event_keydown(SDL_keysym *keysym)
 {
-    if (!flag)
-    {
-        switch (keysym->sym)
-        {
-        case SDLK_ESCAPE: program_running = 0; break;
-        case SDLK_w: p->c->xrot -= 5.0f; break;
-        case SDLK_s: p->c->xrot += 5.0f; break;
-        case SDLK_a: p->c->yrot -= 5.0f; break;
-        case SDLK_d: p->c->yrot += 5.0f; break;
-        case SDLK_UP: glframe_move_forward(&p->camera, 0.5f); break;
-        case SDLK_DOWN: glframe_move_forward(&p->camera, -0.5f); break;
-        case SDLK_LEFT: glframe_rotate_local_y(&p->camera, 0.1f); break;
-        case SDLK_RIGHT: glframe_rotate_local_y(&p->camera, -0.1f); break;
-        case SDLK_n: glframe_rotate_local_x(&p->camera, 0.1f); break;
-        case SDLK_m: glframe_rotate_local_x(&p->camera, -0.1f); break;
-        default: break;
-        }
-    }
-    else
+    const unsigned int *keys_held = event_handler.keys_held;
+    struct platform *p = event_handler.p;
+
+    /* a flag is toggled on if the we are interested in keys that are being held */
+    if (event_handler.flag)
     {
         if (keys_held[SDLK_w])
             p->c->xrot -= 5.0f;
@@ -142,6 +125,24 @@ void event_keydown(SDL_keysym *keysym, const unsigned int *keys_held, const int
         if (keys_held[SDLK_m])
             glframe_rotate_local_x(&p->camera, -0.02f);
     }
+    else
+    {
+        switch (keysym->sym)
+        {
+        case SDLK_ESCAPE: program_running = 0; break;
+        case SDLK_w: p->c->xrot -= 5.0f; break;
+        case SDLK_s: p->c->xrot += 5.0f; break;
+        case SDLK_a: p->c->yrot -= 5.0f; break;
+        case SDLK_d: p->c->yrot += 5.0f; break;
+        case SDLK_UP: glframe_move_forward(&p->camera, 0.5f); break;
+        case SDLK_DOWN: glframe_move_forward(&p->camera, -0.5f); break;
+        case SDLK_LEFT: glframe_rotate_local_y(&p->camera, 0.1f); break;
+        case SDLK_RIGHT: glframe_rotate_local_y(&p->camera, -0.1f); break;
+        case SDLK_n: glframe_rotate_local_x(&p->camera, 0.1f); break;
+        case SDLK_m: glframe_rotate_local_x(&p->camera, -0.1f); break;
+        default: break;
+        }
+    }
 
     p->c->xrot = (GLfloat) ((const int) p->c->xrot % 360);
     p->c->yrot = (GLfloat) ((const int) p->c->yrot % 360);
diff --git a/sdl/event.h b/sdl/event.h
index 0608fa7..b6a1084 100644
--- a/sdl/event.h
+++ b/sdl/event.h
@@ -6,14 +6,23 @@ struct platform;
 /* a table holding function pointers to functions that handle events */
 struct event_vtbl
 {
-    void (*keydown)(SDL_keysym *, const unsigned int *, const int);
+    void (*keydown)(SDL_keysym *);
     void (*windowresize)(int, int);
 };
 
+struct event_handler
+{
+    struct event_vtbl funcs;     /* table of event function handlers */
+    unsigned int keys_held[323]; /* keep track of the keys that were held */
+
+    struct platform *p;          /* reference to the host platform */
+    int flag;                    /* helper flag */
+};
+
 /* function prototypes */
 int event_handler_init(struct platform *, struct event_vtbl *);
 void sdl_process_events(void);
-void event_keydown(SDL_keysym *, const unsigned int *, const int);
+void event_keydown(SDL_keysym *);
 
 #endif