Refactor, de-duplicate, and clean up tilesheet processing

The tilesheets in question are font.png, tiles.png, tiles2.png,
tiles3.png, entcolours.png, teleporter.png, sprites.png, and
flipsprites.png.

This patch removes the hardcoded dimensions when scanning the
tilesheets, because it's simpler that way. It also de-duplicates it so
it isn't a bunch of copy-paste, by using macros. (I had to use macros
because it was the easiest way to optionally pass in some extra code in
the innermost for-loop.)

Also, if the dimensions of a scanned tilesheet aren't exactly multiples
of the dimensions of the tile unit for that given tilesheet (e.g. if the
dimensions of a scanned tiles.png are not exact multiples of 8), then an
SDL_SimpleMessageBox will show up with the error message, a puts() of
the error message will be called, and the program will exit.

desktop_version/src/Graphics.cpp

@@ -200,20 +200,58 @@ void Graphics::updatetitlecolours()
     col_trinket = ct.colour;
 }
 
+#define PROCESS_TILESHEET_CHECK_ERROR(tilesheet, tile_square) \
+    if (grphx.im_##tilesheet->w % tile_square != 0 \
+    || grphx.im_##tilesheet->h % tile_square != 0) \
+    { \
+        const char* error = "Error: %s.png dimensions not exact multiples of %i!"; \
+        char message[128]; \
+        SDL_snprintf(message, sizeof(message), error, #tilesheet, tile_square); \
+        \
+        const char* error_title = "Error with %s.png"; \
+        char message_title[128]; \
+        SDL_snprintf(message_title, sizeof(message_title), error_title, #tilesheet); \
+        \
+        puts(message); \
+        \
+        SDL_ShowSimpleMessageBox( \
+            SDL_MESSAGEBOX_ERROR, \
+            message_title, \
+            message, \
+            NULL \
+        ); \
+        \
+        exit(1); \
+    }
+
+#define PROCESS_TILESHEET_RENAME(tilesheet, vector, tile_square, extra_code) \
+    PROCESS_TILESHEET_CHECK_ERROR(tilesheet, tile_square) \
+    \
+    for (int j = 0; j < grphx.im_##tilesheet->h / tile_square; j++) \
+    { \
+        for (int i = 0; i < grphx.im_##tilesheet->w / tile_square; i++) \
+        { \
+            SDL_Surface* temp = GetSubSurface( \
+                grphx.im_##tilesheet, \
+                i * tile_square, j * tile_square, \
+                tile_square, tile_square \
+            ); \
+            vector.push_back(temp); \
+            \
+            extra_code \
+        } \
+    }
+
+#define PROCESS_TILESHEET(tilesheet, tile_square, extra_code) \
+    PROCESS_TILESHEET_RENAME(tilesheet, tilesheet, tile_square, extra_code)
+
 void Graphics::Makebfont()
 {
-    for (int j =  0; j < (grphx.im_bfont->h / 8); j++)
+    PROCESS_TILESHEET(bfont, 8,
     {
-        for (int i = 0; i < 16; i++)
+        SDL_Surface* TempFlipped = FlipSurfaceVerticle(temp);
-        {
+        flipbfont.push_back(TempFlipped);
-
+    })
-            SDL_Surface* temp = GetSubSurface(grphx.im_bfont,i*8,j*8,8,8);
-            bfont.push_back(temp);
-
-            SDL_Surface* TempFlipped = FlipSurfaceVerticle(temp);
-            flipbfont.push_back(TempFlipped);
-        }
-    }
 
     unsigned char* charmap = NULL;
     size_t length;
@@ -241,65 +279,27 @@ int Graphics::bfontlen(uint32_t ch) {
 
 void Graphics::MakeTileArray()
 {
-    for(int j = 0; j <30; j++)
+    PROCESS_TILESHEET(tiles, 8, )
-    {
+    PROCESS_TILESHEET(tiles2, 8, )
-        for(int i = 0; i <40; i++)
+    PROCESS_TILESHEET(tiles3, 8, )
-        {
+    PROCESS_TILESHEET(entcolours, 8, )
-            SDL_Surface* temp = GetSubSurface(grphx.im_tiles,i*8,j*8,8,8);
-            tiles.push_back(temp);
-        }
-    }
-    for(int j = 0; j <30; j++)
-    {
-        for(int i = 0; i <40; i++)
-        {
-            SDL_Surface* temp = GetSubSurface(grphx.im_tiles2,i*8,j*8,8,8);
-            tiles2.push_back(temp);
-        }
-    }
-
-    for(int j = 0; j <30; j++)
-    {
-        for(int i = 0; i <30; i++)
-        {
-            SDL_Surface* temp = GetSubSurface(grphx.im_tiles3,i*8,j*8,8,8);
-            tiles3.push_back(temp);
-        }
-    }
-
-    for(int j = 0; j <60; j++)
-    {
-        for(int i = 0; i <12; i++)
-        {
-            SDL_Surface* temp = GetSubSurface(grphx.im_entcolours,i*8,j*8,8,8);
-            entcolours.push_back(temp);
-        }
-    }
 }
 
 void Graphics::maketelearray()
 {
-    for (int i = 0; i < 10; i++)
+    PROCESS_TILESHEET_RENAME(teleporter, tele, 96, )
-    {
-        SDL_Surface* temp = GetSubSurface(grphx.im_teleporter,i*96,0,96,96);
-        tele.push_back(temp);
-    }
 }
 
 void Graphics::MakeSpriteArray()
 {
-    for(int j = 0; j <16; j++)
+    PROCESS_TILESHEET(sprites, 32, )
-    {
+    PROCESS_TILESHEET(flipsprites, 32, )
-        for(int i = 0; i <12; i++)
-        {
-            SDL_Surface* temp = GetSubSurface(grphx.im_sprites,i*32,j*32,32,32);
-            sprites.push_back(temp);
-            temp = GetSubSurface(grphx.im_flipsprites,i*32,j*32,32,32);
-            flipsprites.push_back(temp);
-        }
-    }
 }
 
+#undef PROCESS_TILESHEET
+#undef PROCESS_TILESHEET_RENAME
+#undef PROCESS_TILESHEET_CHECK_ERROR
+
 
 void Graphics::map_tab(int opt, const std::string& text, bool selected /*= false*/)
 {