Added a texture cache

Note this probably doesn't work properly yet since I haven't properly implemented shared management
of textures in their wrapper class.

src/image.cpp

@@ -32,6 +32,7 @@
 #include "serialization/base64.hpp"
 #include "serialization/string_utils.hpp"
 #include "sdl/rect.hpp"
+#include "sdl/texture.hpp"
 #include "utils/general.hpp"
 
 #include <SDL_image.h>
@@ -161,6 +162,8 @@ image::locator::locator_finder_t locator_finder;
 image::image_cache images_, scaled_to_zoom_, hexed_images_, scaled_to_hex_images_, tod_colored_images_,
 		brightened_images_;
 
+image::texture_cache textures_;
+
 // cache storing if each image fit in a hex
 image::bool_cache in_hex_info_;
 
@@ -1090,6 +1093,51 @@ surface get_image(const image::locator& i_locator, TYPE type)
 #endif //_OPENMP
 	i_locator.add_to_cache(*imap, res);
 
+	// Add the raw image to the texture cache.
+	if(type == UNSCALED && res != nullptr) {
+#ifdef _OPENMP
+#pragma omp critical(texture_cache)
+#endif //_OPENMP
+		i_locator.add_to_cache(textures_, texture(res));
+	}
+
+	return res;
+}
+
+texture get_texture(const image::locator& i_locator)
+{
+	// Returned the cached texture if applicable. If the image is already cached, the corresponding
+	// unscaled/unmodified surface has already been loaded from disk.
+	texture res;
+
+	if(i_locator.is_void()) {
+		return res;
+	}
+
+	bool in_cache;
+
+#ifdef _OPENMP
+#pragma omp critical(texture_cache)
+#endif //_OPENMP
+	in_cache = i_locator.in_cache(textures_);
+
+	if(in_cache) {
+#ifdef _OPENMP
+#pragma omp critical(texture_cache)
+#endif //_OPENMP
+		res = i_locator.locate_in_cache(textures_);
+		return res;
+	}
+
+	// Else, no texture was cached. Fetch the surface from disk, which adds the corresponding texture
+	// to the texture cache. We ignore the returned surface and fetch the cached surface to avoid
+	// creating a new texture in memory for the same surface twice.
+	get_image(i_locator);
+#ifdef _OPENMP
+#pragma omp critical(texture_cache)
+#endif //_OPENMP
+	res = i_locator.locate_in_cache(textures_);
+
 	return res;
 }
 

src/image.hpp

@@ -22,6 +22,7 @@
 #include <unordered_map>
 
 class surface;
+class texture;
 
 ///this module manages the cache of images. With an image name, you can get
 ///the surface corresponding to that image.
@@ -125,8 +126,8 @@ namespace image {
 
 	surface load_from_disk(const locator &loc);
 
-
 	typedef cache_type<surface> image_cache;
+	typedef cache_type<texture> texture_cache;
 	typedef cache_type<bool> bool_cache;
 
 	typedef std::map<t_translation::terrain_code, surface> mini_terrain_cache_map;
@@ -193,6 +194,8 @@ namespace image {
 	///function to get the surface corresponding to an image.
 	surface get_image(const locator& i_locator, TYPE type=UNSCALED);
 
+	texture get_texture(const image::locator& i_locator);
+
 	///function to get the surface corresponding to an image.
 	///after applying the lightmap encoded in ls
 	///type should be HEXED or SCALED_TO_HEX