SpriteHandler.h:

* Renaming functions fill*_r() and fill*_c() to fill*_vert() and fill*_horiz() respectively because the former naming scheme is a bit ambiguous (e.g. by fill*_r(), do we mean the range is by rows or are we filling along the rows?).

SpriteHandler.h

@@ -207,15 +207,15 @@ class BitmapSprite : public Sprite
     texture->characters.assign(area, ch);
   }
 
-  void fill_sprite_chars_r(int anim_frame, int r0, int r1, int c, char ch)
+  void fill_sprite_chars_vert(int anim_frame, int r0, int r1, int c, char ch)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
       for (int r = r0; r <= r1; ++r)
         texture->set_textel_char(r, c, ch);
   }
 
-  void fill_sprite_chars_c(int anim_frame, int r, int c0, int c1, char ch)
+  void fill_sprite_chars_horiz(int anim_frame, int r, int c0, int c1, char ch)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
@@ -281,15 +281,15 @@ class BitmapSprite : public Sprite
     texture->fg_colors.assign(area, fg_color);
   }
 
-  void fill_sprite_fg_colors_r(int anim_frame, int r0, int r1, int c, Color fg_color)
+  void fill_sprite_fg_colors_vert(int anim_frame, int r0, int r1, int c, Color fg_color)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
       for (int r = r0; r <= r1; ++r)
         texture->set_textel_fg_color(r, c, fg_color);
   }
 
-  void fill_sprite_fg_colors_c(int anim_frame, int r, int c0, int c1, Color fg_color)
+  void fill_sprite_fg_colors_horiz(int anim_frame, int r, int c0, int c1, Color fg_color)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
@@ -324,15 +324,15 @@ class BitmapSprite : public Sprite
     texture->bg_colors.assign(area, bg_color);
   }
 
-  void fill_sprite_bg_colors_r(int anim_frame, int r0, int r1, int c, Color bg_color)
+  void fill_sprite_bg_colors_vert(int anim_frame, int r0, int r1, int c, Color bg_color)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
       for (int r = r0; r <= r1; ++r)
         texture->set_textel_bg_color(r, c, bg_color);
   }
 
-  void fill_sprite_bg_colors_c(int anim_frame, int r, int c0, int c1, Color bg_color)
+  void fill_sprite_bg_colors_horiz(int anim_frame, int r, int c0, int c1, Color bg_color)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
@@ -367,15 +367,15 @@ class BitmapSprite : public Sprite
     texture->materials.assign(area, mat);
   }
 
-  void fill_sprite_materials_r(int anim_frame, int r0, int r1, int c, int mat)
+  void fill_sprite_materials_vert(int anim_frame, int r0, int r1, int c, int mat)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)
       for (int r = r0; r <= r1; ++r)
         texture->set_textel_material(r, c, mat);
   }
 
-  void fill_sprite_materials_c(int anim_frame, int r, int c0, int c1, int mat)
+  void fill_sprite_materials_horiz(int anim_frame, int r, int c0, int c1, int mat)
   {
     auto* texture = fetch_frame(anim_frame);
     if (texture != nullptr)