not quite yet working live reload

hiisi/hiisi.cpp

@@ -3,18 +3,17 @@
 #define SDL_MAIN_USE_CALLBACKS 1  /* use the callbacks instead of main() */
 #include <SDL3/SDL.h>
 
-/* We will use this renderer to draw into this window every frame. */
-static SDL_Window *window = NULL;
-static SDL_Renderer *renderer = NULL;
-
 #define WINDOW_WIDTH 1280
 #define WINDOW_HEIGHT 720
 
 /* This function runs once at startup. */
-int init(void *appstate, int argc, char *argv[])
+int init(EngineData *state, int argc, char *argv[])
 {
     SDL_SetAppMetadata("Hiisi Engine", "0.0.1", "me.kitemoonsche.hiisi-engine");
 
+    SDL_Window *window = 0;
+    SDL_Renderer *renderer = 0;
+
     if (!SDL_Init(SDL_INIT_VIDEO)) {
         SDL_Log("Couldn't initialize SDL: %s", SDL_GetError());
         return SDL_APP_FAILURE;
@@ -25,11 +24,14 @@ int init(void *appstate, int argc, char *argv[])
         return SDL_APP_FAILURE;
     }
 
+    state->window = window;
+    state->renderer = renderer;
+
     return SDL_APP_CONTINUE;  /* carry on with the program! */
 }
 
 /* This function runs when a new event (mouse input, keypresses, etc) occurs. */
-int event(void *appstate)
+int event(EngineData* state)
 {
     SDL_Event event;
     while (SDL_PollEvent(&event)) {
@@ -41,8 +43,9 @@ int event(void *appstate)
 }
 
 /* This function runs once per frame, and is the heart of the program. */
-int iterate(void *appstate)
+int iterate(EngineData *state)
 {
+    SDL_Renderer *renderer = (SDL_Renderer*)state->renderer;
     SDL_FRect rects[16];
     const Uint64 now = SDL_GetTicks();
     int i;
@@ -52,7 +55,7 @@ int iterate(void *appstate)
     const float scale = ((float) (((int) (now % 1000)) - 500) / 500.0f) * direction;
 
     /* as you can see from this, rendering draws over whatever was drawn before it. */
-    SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);  /* black, full alpha */
+    SDL_SetRenderDrawColor(renderer, 0, 50, 50, SDL_ALPHA_OPAQUE);  /* black, full alpha */
     SDL_RenderClear(renderer);  /* start with a blank canvas. */
 
     /* Rectangles are comprised of set of X and Y coordinates, plus width and
@@ -63,7 +66,7 @@ int iterate(void *appstate)
     /* Let's draw a single rectangle (square, really). */
     rects[0].x = rects[0].y = 100;
     rects[0].w = rects[0].h = 100 + (100 * scale);
-    SDL_SetRenderDrawColor(renderer, 255, 0, 0, SDL_ALPHA_OPAQUE);  /* red, full alpha */
+    SDL_SetRenderDrawColor(renderer, 250, 0, 0, SDL_ALPHA_OPAQUE);  /* red, full alpha */
     SDL_RenderRect(renderer, &rects[0]);
 
     /* Now let's draw several rectangles with one function call. */
@@ -84,6 +87,7 @@ int iterate(void *appstate)
     SDL_SetRenderDrawColor(renderer, 0, 0, 255, SDL_ALPHA_OPAQUE);  /* blue, full alpha */
     SDL_RenderFillRect(renderer, &rects[0]);
 
+
     /* ...and also fill a bunch of rectangles at once... */
     for (i = 0; i < SDL_arraysize(rects); i++) {
         const float w = (float) (WINDOW_WIDTH / SDL_arraysize(rects));
@@ -102,7 +106,7 @@ int iterate(void *appstate)
 }
 
 /* This function runs once at shutdown. */
-void quit(void *appstate)
+void quit(EngineData *state)
 {
     /* SDL will clean up the window/renderer for us. */
 }

hiisi/hiisi.h

@@ -3,18 +3,23 @@
 
 extern "C" {
 
-    struct Engine {
-        void *module = 0;
-        int (*init)(void *, int, char**);
-        int (*event)(void *);
-        int (*iterate)(void *);
-        void (*quit)(void *);
+    struct EngineData {
+        void *window = 0;
+        void *renderer = 0;
     };
 
-    int init(void *appstate, int argc, char *argv[]);
-    int event(void *appstate);
-    int iterate(void *appstate);
-    void quit(void *appstate);
+    struct Engine {
+        void *module = 0;
+        int (*init)(EngineData *, int, char**);
+        int (*event)(EngineData *);
+        int (*iterate)(EngineData *);
+        void (*quit)(EngineData *);
+    };
+
+    int init(EngineData *state, int argc, char *argv[]);
+    int event(EngineData *state);
+    int iterate(EngineData *state);
+    void quit(EngineData *state);
 
 }
 #endif // HIISI_H_

hiisi/main.cpp

@@ -1,15 +1,23 @@
 #include "hiisi.h"
 
 #include <assert.h>
-#include <elf.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <dlfcn.h>
 #include <link.h>
+#include <signal.h>
+#include <atomic>
 
 struct app_state {};
 
-Engine load_hiisi(const char *name) {
+std::atomic<bool> reload_requested(false);
+
+void reload_signal_handler(int) {
+    reload_requested = true;
+}
+
+Engine load_hiisi() {
+    const char *name = "build/hiisi/libhiisi-engine.so";
     void *mod = dlopen(name, RTLD_NOW);
 
     Lmid_t list;
@@ -82,10 +90,11 @@ Engine load_hiisi(const char *name) {
 
 int main(int argc, char **argv) {
 
-    app_state state;
-    void *state_ptr = &state;
+    signal(SIGUSR1, reload_signal_handler);
 
-    Engine hiisi = load_hiisi("build/hiisi/libhiisi-engine.so");
+    EngineData state;
+
+    Engine hiisi = load_hiisi();
     if (!hiisi.module) {
         printf("%s\n", dlerror());
         return 1;
@@ -94,6 +103,11 @@ int main(int argc, char **argv) {
     hiisi.init(&state, argc, argv);
     while (hiisi.event(&state)) {
         hiisi.iterate(&state);
+        if (reload_requested) {
+            dlclose(hiisi.module);
+            hiisi = load_hiisi();
+            reload_requested = false;
+        }
     }
 
     dlclose(hiisi.module);