sdl: introduce a vtbl for event handler

3 files changed, 43 insertions, 3 deletions

diff --git a/sdl/event.c b/sdl/event.c
index e6c4c00..c3120af 100644
--- a/sdl/event.c
+++ b/sdl/event.c
@@ -2,7 +2,7 @@
  *
  * Event Handler
  *
- * notes: I would be useful to create a following function
+ * notes: It would be useful to create a following function
  *        register_signal(SDL_HOLDDOWN, EVENT_ACTION_INCR, float *p, float val)
  *
  *        struct platform is still passed globally
@@ -20,6 +20,23 @@
 extern struct platform p;
 extern int program_running;
 
+/* our function table */
+static struct event_vtbl event_tbl;
+
+int event_handler_init(struct event_vtbl *tbl)
+{
+    if (!tbl)
+        return -1;
+
+    event_tbl = *tbl;
+
+    /* predefined handlers that are automatically provided */
+    if (!event_tbl.windowresize)
+        event_tbl.windowresize = window_resize;
+
+    return 0;
+}
+
 /* process SDL events */
 void sdl_process_events(void)
 {
@@ -46,12 +63,14 @@ void sdl_process_events(void)
             case SDL_KEYDOWN:
             {
                 keys_held[sym] = 1;
-                event_keydown(&event.key.keysym, keys_held, flag);
+                if (event_tbl.keydown)
+                    event_tbl.keydown(&event.key.keysym, keys_held, flag);
                 break;
             }
             case SDL_VIDEORESIZE:
             {
-                window_resize(event.resize.w, event.resize.h);
+                if (event_tbl.windowresize)
+                    event_tbl.windowresize(event.resize.w, event.resize.h);
                 break;
             }
             case SDL_QUIT:
@@ -76,6 +95,7 @@ void sdl_process_events(void)
         flag = !flag;
 }
 
+/* here are the event handler functions */
 void event_keydown(SDL_keysym *keysym, const unsigned int *keys_held, const int flag)
 {
     if (!flag)
diff --git a/sdl/event.h b/sdl/event.h
index 8b4d81b..468087b 100644
--- a/sdl/event.h
+++ b/sdl/event.h
@@ -1,7 +1,15 @@
 #ifndef _EVENT_H_
 #define _EVENT_H_
 
+/* a table holding function pointers to function that handle events */
+struct event_vtbl
+{
+    void (*keydown)(SDL_keysym *, const unsigned int *, const int);
+    void (*windowresize)(int, int);
+};
+
 /* function prototypes */
+int event_handler_init(struct event_vtbl *);
 void sdl_process_events(void);
 void event_keydown(SDL_keysym *, const unsigned int *, const int);
 
diff --git a/sdl/platform.c b/sdl/platform.c
index ea9dce6..138596a 100644
--- a/sdl/platform.c
+++ b/sdl/platform.c
@@ -12,11 +12,13 @@
 #include <SDL/SDL_image.h>
 #include <GL/glew.h>
 #include <string.h>
+#include "event.h"
 #include "gldraw.h"
 #include "gltools.h"
 #include "luatools.h"
 #include "platform.h"
 #include "sdltools.h"
+#include "window.h"
 
 /* few light arrays */
 const GLfloat fNoLight[]     = { 0.0f, 0.0f, 0.0f, 1.0f    };
@@ -40,6 +42,8 @@ extern unsigned int maxfps_w;
 
 void platform_init(struct platform *p)
 {
+    int ret;
+
     /* Lua */
     /* create new lua state */
     p->L = luaL_newstate();
@@ -63,6 +67,14 @@ void platform_init(struct platform *p)
     /* set the camera to <0,0,0> */
     glframe_reset(&p->camera);
 
+    /* setup and init the event handler */
+    struct event_vtbl event_tbl;
+    memset(&event_tbl, 0, sizeof(event_tbl));
+    event_tbl.keydown = event_keydown;
+    ret = event_handler_init(&event_tbl);
+    if (ret == -1)
+        fprintf(stderr, "platform: warning, failed to init event handler\n");
+
     /* init client */
     p->client_init(p->c);
 }