rendering.c: only update opengl viewport once it's actually changed

src/context.h

@@ -62,6 +62,8 @@ typedef struct context {
     bool debug;
     bool is_running;
     bool resync_flag;
+
+    bool window_size_has_changed;
 } t_ctx;
 
 extern t_ctx ctx;

src/input.h

@@ -54,7 +54,6 @@ struct action_hash_item {
 
 struct input_state {
     struct action_hash_item *action_hash;
-    SDL_Renderer *renderer; /* some input relates to the screen in some way */
     const uint8_t *keyboard_state; /* array of booleans indexed by scancode */
     uint32_t mouse_state;          /* SDL mouse button bitmask */
     t_vec2 mouse_window_position;

src/main.c

@@ -23,6 +23,8 @@
 static void poll_events(void) {
     SDL_Event e;
 
+    ctx.window_size_has_changed = false;
+
     while (SDL_PollEvent(&e)) {
         switch (e.type) {
         case SDL_QUIT:
@@ -37,6 +39,7 @@ static void poll_events(void) {
             case SDL_WINDOWEVENT_RESIZED:
                 ctx.window_w = e.window.data1;
                 ctx.window_h = e.window.data2;
+                ctx.window_size_has_changed = true;
                 break;
             }
 

src/rendering.c

@@ -141,8 +141,8 @@ static void render_space(void) {
 void render(void) {
     textures_update_atlas(&ctx.texture_cache);
 
-    /* TODO: only do this when needed */
     /* fit rendering context onto the resizable screen */
+    if (ctx.window_size_has_changed) {
         if ((float)ctx.window_w / (float)ctx.window_h > RENDER_BASE_RATIO) {
             float ratio = (float)ctx.window_h / (float)RENDER_BASE_HEIGHT;
             int w = (int)((float)RENDER_BASE_WIDTH * ratio);
@@ -162,6 +162,7 @@ void render(void) {
                 h
             );
         }
+    }
 
     glClearColor((1.0f / 255) * 230,
                  (1.0f / 255) * 230,