Fix combining 3D shockwaves with framebuffer shockwaves.

If framebuffer shockwaves were enabled and a 3D shockwave was created, FSO would use a hardcoded reference to the second slot of the Shockwave_info vector to generate the framebuffer shockwave for it. This only makes sense if and only if:
- the 3D shockwave command-line flag is also enabled
- the default 3D shockwave and default 2D shockwave are both present and loaded
- its the first mission of the session (because after that any shockwave not in the 0th index got unloaded)

I've changed the code so that which index the default 2D shockwave got loaded into gets tracked and used instead of a hardcoded index... and if both default shockwaves are loaded, the first two Shockwave_info indices are both kept between missions instead of just the first. This should allow framebuffer shockwaves to work with 3D shockwaves, regardless of whether or not it's the first mission of the session and whether or not a custom 2D shockwave was loaded (and happened to wind up at index 1). Slight downside in that missing the default 2D shockwave file, but having a custom 2D shockwave loaded, will now result in framebuffer shockwaves not being drawn at all, rather than using the custom 2D shockwave by accident; not sure that's really all that much of a problem, though.

Author: MageKing17

code/weapon/shockwave.cpp

@@ -28,6 +28,7 @@
 
 static const char *Default_shockwave_2D_filename = "shockwave01";
 static const char *Default_shockwave_3D_filename = "shockwave.pof";
+static int Default_2D_shockwave_index = -1;
 static int Default_shockwave_loaded = 0;
 
 SCP_vector<shockwave_info> Shockwave_info;
@@ -395,11 +396,11 @@ void shockwave_render(object *objp, model_draw_list *scene)
 
 		model_render_queue( &render_info, scene, sw->model_id, &Objects[sw->objnum].orient, &sw->pos);
 
-		if ( Cmdline_fb_explosions ) {
+		if ( Cmdline_fb_explosions && Default_2D_shockwave_index > -1) {
 			g3_transfer_vertex(&p, &sw->pos);
 
 			float intensity = ((sw->time_elapsed / sw->total_time) > 0.9f) ? (1.0f - (sw->time_elapsed / sw->total_time))*10.0f : 1.0f;
-			batching_add_distortion_bitmap_rotated(Shockwave_info[1].bitmap_id + shockwave_get_framenum(objp->instance, Shockwave_info[1].bitmap_id), &p, fl_radians(sw->rot_angles.p), sw->radius, intensity);
+			batching_add_distortion_bitmap_rotated(Shockwave_info[Default_2D_shockwave_index].bitmap_id + shockwave_get_framenum(objp->instance, Shockwave_info[Default_2D_shockwave_index].bitmap_id), &p, fl_radians(sw->rot_angles.p), sw->radius, intensity);
 		}
 	} else {
 		g3_transfer_vertex(&p, &sw->pos);
@@ -493,6 +494,7 @@ void shockwave_level_init()
 				mprintf(("SHOCKWAVE =>  Default model load: SUCCEEDED!!\n"));
 			else
 				mprintf(("SHOCKWAVE =>  Default model load: FAILED!!  Falling back to 2D effect...\n"));
+			Assertion(i <= 0, "Default 3D shockwave should be the first shockwave loaded, but instead got loaded into index %d; get a coder!\n", i);
 		}
 
 		// next, try the 2d shockwave effect, unless the 3d effect was loaded
@@ -506,6 +508,8 @@ void shockwave_level_init()
 				mprintf(("SHOCKWAVE =>  Default animation load: SUCCEEDED!!\n"));
 			else
 				mprintf(("SHOCKWAVE =>  Default animation load: FAILED!!  Checking if 3d effect was already tried...\n"));
+			Assertion(i <= 1, "Default 2D shockwave should be either the first or second shockwave loaded, but instead got loaded into index %d; get a coder!\n", i);
+			Default_2D_shockwave_index = i;
 		}
 
 		// chief1983 - The first patch broke mods that don't provide a 2d shockwave or define a specific shockwave for each model/weapon (shame on them)
@@ -520,6 +524,7 @@ void shockwave_level_init()
 				mprintf(("SHOCKWAVE =>  Default model load: SUCCEEDED!!\n"));
 			else
 				mprintf(("SHOCKWAVE =>  Default model load: FAILED!!  No effect loaded...\n"));
+			Assertion(i <= 0, "Default 3D shockwave should be the first shockwave loaded, but instead got loaded into index %d; get a coder!\n", i);
 		}
 
 		if (i < 0)
@@ -566,6 +571,12 @@ void shockwave_level_close()
 		bm_unload( it->bitmap_id );
 	else if (it->model_id >= 0)
 		model_page_out_textures( it->model_id );
+	if (Default_2D_shockwave_index == 1) {
+		// 3D shockwaves and framebuffer shockwaves are both enabled and the default 2D shockwave is in the next slot of the vector
+		++it;
+		Assertion(it->bitmap_id >= 0, "Default 2D shockwave was loaded but is somehow missing its bitmap; get a coder!\n");
+		bm_unload(it->bitmap_id);
+	}
 
 	for (++it; it != Shockwave_info.end(); ++it) {
 		if (it->bitmap_id >= 0)
@@ -576,7 +587,7 @@ void shockwave_level_close()
 	}
 
 	// if there's no extra shockwaves, this is still fine (erasing from end() to end() is both valid and a no-op)
-	Shockwave_info.erase( Shockwave_info.begin() + 1, Shockwave_info.end() );
+	Shockwave_info.erase( Shockwave_info.begin() + (Default_2D_shockwave_index == 1 ? 2 : 1), Shockwave_info.end() );
 
 	Shockwave_inited = 0;
 }