fix crashes, add custom texture cache, load textures from load directory

src/core/custom_tex_cache.cpp

@@ -0,0 +1,27 @@
+#include <stdexcept>
+#include <vector>
+#include "common/common_types.h"
+#include "custom_tex_cache.h"
+
+namespace Core {
+const bool CustomTexCache::IsTextureDumped(const u64 hash) {
+    return dumped_textures.find(hash) != dumped_textures.end();
+}
+
+void CustomTexCache::SetTextureDumped(const u64 hash) {
+    dumped_textures[hash] = true;
+}
+
+const bool CustomTexCache::IsTextureCached(const u64 hash) {
+    return custom_textures.find(hash) != custom_textures.end();
+}
+
+const CustomTexInfo& CustomTexCache::LookupTexture(const u64 hash) {
+    return custom_textures.at(hash);
+}
+
+void CustomTexCache::CacheTexture(const u64 hash, const std::vector<u8>& tex, u32 width,
+                                  u32 height) {
+    custom_textures[hash] = {width, height, tex};
+}
+} // namespace Core