why am I spending so much effort on this lol

code/graphics/2d.cpp

@@ -1896,7 +1896,7 @@ void gr_set_shader(shader *shade)
 }
 
 // new bitmap functions
-void gr_bitmap(int _x, int _y, int resize_mode)
+void gr_bitmap(int _x, int _y, int resize_mode, float scale_factor)
 {
 	GR_DEBUG_SCOPE("2D Bitmap");
 
@@ -1910,6 +1910,11 @@ void gr_bitmap(int _x, int _y, int resize_mode)
 
 	bm_get_info(gr_screen.current_bitmap, &_w, &_h, NULL, NULL, NULL);
 
+	if (scale_factor != 1.0f) {
+		_w = static_cast<int>(_w * scale_factor);
+		_h = static_cast<int>(_h * scale_factor);
+	}
+
 	x = i2fl(_x);
 	y = i2fl(_y);
 	w = i2fl(_w);

code/graphics/2d.h

@@ -1317,7 +1317,7 @@ void gr_create_shader(shader *shade, ubyte r, ubyte g, ubyte b, ubyte c);
 void gr_set_shader(shader *shade);
 
 // new bitmap functions
-void gr_bitmap(int x, int y, int resize_mode = GR_RESIZE_FULL);
+void gr_bitmap(int x, int y, int resize_mode = GR_RESIZE_FULL, float scale_factor = 1.0f);
 void gr_bitmap_uv(int _x, int _y, int _w, int _h, float _u0, float _v0, float _u1, float _v1, int resize_mode = GR_RESIZE_FULL);
 
 // special function for drawing polylines. this function is specifically intended for

code/graphics/generic.cpp

@@ -697,7 +697,7 @@ void generic_anim_render_variable_frame_delay(generic_anim* ga, float frametime,
  * @param [in] y  2D screen y co-ordinate to render at
  * @param [in] menu select if this is rendered in menu screen, or fullscreen
  */
-void generic_anim_render(generic_anim *ga, float frametime, int x, int y, bool menu, const generic_extras *ge)
+void generic_anim_render(generic_anim *ga, float frametime, int x, int y, bool menu, const generic_extras *ge, float scale_factor)
 {
 	if ((ge != nullptr) && (ga->use_hud_color == true)) {
 		Warning(LOCATION, "Monochrome generic anims can't use extra info (yet)");
@@ -719,11 +719,11 @@ void generic_anim_render(generic_anim *ga, float frametime, int x, int y, bool m
 		ga->previous_frame = ga->current_frame;
 
 		if(ga->use_hud_color) {
-			gr_aabitmap(x, y, (menu ? GR_RESIZE_MENU : GR_RESIZE_FULL));
+			gr_aabitmap(x, y, (menu ? GR_RESIZE_MENU : GR_RESIZE_FULL), false, scale_factor);
 		}
 		else {
 			if (ge == nullptr) {
-				gr_bitmap(x, y, (menu ? GR_RESIZE_MENU : GR_RESIZE_FULL));
+				gr_bitmap(x, y, (menu ? GR_RESIZE_MENU : GR_RESIZE_FULL), scale_factor);
 			}
 			else if (ge->draw == true) {
 				// currently only for lua streaminganim objects

code/graphics/generic.h

@@ -90,7 +90,7 @@ int generic_anim_load(generic_anim *ga);
 int generic_anim_stream(generic_anim *ga, const bool cache = true);
 int generic_bitmap_load(generic_bitmap *gb);
 void generic_anim_unload(generic_anim *ga);
-void generic_anim_render(generic_anim *ga, float frametime, int x, int y, bool menu = false, const generic_extras *ge = nullptr);
+void generic_anim_render(generic_anim *ga, float frametime, int x, int y, bool menu = false, const generic_extras *ge = nullptr, float scale_factor = 1.0f);
 void generic_anim_bitmap_set(generic_anim* ga, float frametime, const generic_extras* ge = nullptr);
 void generic_anim_reset(generic_anim *ga);
 #endif

code/menuui/fishtank.cpp

@@ -18,13 +18,14 @@
 typedef struct fish {
 	float x, y;              // x and y coords
 	float x_speed, y_speed;  // x and y speed
+	float scale;             // big fish or small fish?
 	bool left;	             // left or right
 	generic_anim anim;       // the animation
 	bool onscreen;           // visible? 			
 	bool swimming;           // whee
 } fish;
 
-constexpr int MAX_FISH = 24; // was 12.. bigger screens need more fish!
+constexpr size_t MAX_FISH = 24; // was 12.. bigger screens need more fish!
 SCP_vector<fish> All_fish;
 
 // fish anim names
@@ -51,7 +52,7 @@ void fish_generate()
 	fish* f = &(*it);
 
 	// Pick a direction randomly
-	f->left = frand_range(0.0f, 1.0f) < 0.5f ? false : true;
+	f->left = frand_range(0.0f, 1.0f) >= 0.5f;
 
 	// Let it freeeeeeee!
 	f->swimming = true;
@@ -75,6 +76,9 @@ void fish_generate()
 		}
 	}
 
+	// Pick a scale
+	f->scale = frand_range(0.5f, 1.0f);
+
 	// Pick a starting location
 	if(f->left){
 		f->x = gr_screen.max_w_unscaled_zoomed + frand_range(0.0f, 50.0f);
@@ -189,16 +193,50 @@ void fishtank_stop()
 	Fish_inited = 0;
 }
 
+void fishtank_change_speed(float& speed, float increase, float decrease, float multiplier)
+{
+	float speed_modifier = (frand_range(0.0f, 1.0f) < 0.5f) ? increase : decrease;
+	float min = 5.0f * multiplier;
+	float max = 20.0f * multiplier;
+
+	// Positive speed
+	if (speed > 0.0f) {
+		if ((speed < min && speed_modifier == decrease) || (speed > max && speed_modifier == increase)) {
+			speed_modifier = 1.0f;
+		}
+	// Negative speed
+	} else {
+		if ((speed > -min && speed_modifier == decrease) || (speed < -max && speed_modifier == increase)) {
+			speed_modifier = 1.0f;
+		}
+	}
+
+	speed = speed * speed_modifier;
+}
+
 void fishtank_process()
 {
 	if(!Fish_inited){
 		return;
 	}
 
+	// Small chance to add a fish
+	if (All_fish.size() < MAX_FISH) {
+		if (frand_range(0.0f, 1.0f) < 0.0005f) {
+			fish new_fish;
+			new_fish.swimming = false;
+			All_fish.push_back(new_fish);
+			fish_generate();
+		}
+	}
+
 	// Process all fish
-	for (fish& f : All_fish) {
+	for (auto it = All_fish.begin(); it != All_fish.end();) {
+		fish& f = *it;
+
 		// Not swimming?
 		if (!f.swimming) {
+			++it;
 			continue;
 		}
 
@@ -207,7 +245,16 @@ void fishtank_process()
 			f.y_speed *= -1;
 		}
 
-		// Move it along according to it's speed settings
+		// Small chance to slightly change speed
+		if (frand_range(0.0f, 1.0f) < 0.001f) {
+			if (frand_range(0.0f, 1.0f) < 0.5f) {
+				fishtank_change_speed(f.x_speed, 1.7f, 0.5f, gr_screen.max_w / 1024.0f);
+			} else {
+				fishtank_change_speed(f.y_speed, 1.1f, 0.9f, gr_screen.max_h / 786.0f);
+			}
+		}
+
+		// Move it along according to its speed settings
 		f.x += f.x_speed * flFrametime;
 		f.y += f.y_speed * flFrametime;
 
@@ -218,20 +265,27 @@ void fishtank_process()
 			onscreen = true;
 		}
 
-		// If it was onscreen before, but is no longer, flush it (down the toilet?!) and make a new fish
+		// If it was onscreen before but is no longer, yeet it or flush it
 		if (f.onscreen && !onscreen) {
-			fish_flush(&f);
-
-			fish_generate();
+			// Small chance to yeet the fish instead of flushing it. I didn't come up with this language. Don't ask me.
+			if (frand_range(0.0f, 1.0f) < 0.3f) {
+				it = All_fish.erase(it);
+			} else {
+				fish_flush(&f); // Flush the fish and keep it in the pool. How does that make sense?
+				fish_generate();
+				++it;
+			}
 			continue;
 		}
 
-		// Otherwise just mark its current status
+		// Otherwise, just mark its current status
 		f.onscreen = onscreen;
 
-		// Render the fishy!
+		// Render the fish if it's onscreen
 		if (f.onscreen) {
-			generic_anim_render(&f.anim, flFrametime, (int)f.x, (int)f.y);
+			generic_anim_render(&f.anim, flFrametime, (int)f.x, (int)f.y, false, nullptr, f.scale);
 		}
+
+		++it;
 	}
 }