cute asset loading system

1 files changed, 101 insertions, 0 deletions

diff --git a/asset.cpp b/asset.cpp
new file mode 100644
index 0000000..09260e0
--- /dev/null
+++ b/asset.cpp
@@ -0,0 +1,101 @@
+#include "asset.hpp"
+
+extern "C" {
+#include "memory.h"
+#include "pack.h"
+#include "plat.h"
+#include "str.h"
+}
+
+#define max_asset_types 32
+
+struct RLoader {
+	char magic[4];
+	Asset_Loader* loader;
+};
+
+struct Manager {
+	RLoader loaders[max_asset_types];
+
+	Manager() {
+		int i;
+		for (i = 0; i < max_asset_types; i++) {
+			loaders[i].loader = 0;
+		}
+	}
+
+	RLoader* find_loader(const char* magic) {
+		uint32_t hash = hash_string(magic);
+		int bucket = (int)(hash % max_asset_types);
+		int i;
+		for (i = 0; i < max_asset_types; i++) {
+			RLoader& e = loaders[bucket];
+			if (!e.loader || (
+				e.magic[0] == magic[0] &&
+				e.magic[1] == magic[1] &&
+				e.magic[2] == magic[2] &&
+				e.magic[3] == magic[3]
+			)) return &e;
+			bucket = (bucket + 1) % max_asset_types;
+		}
+		return 0;
+	}
+
+	Asset_Loader& get_loader(const char* magic) {
+		RLoader* r = find_loader(magic);
+		assert(r != 0 && r->loader != 0);
+		return *r->loader;
+	}
+
+	void set_loader(const char* magic, Asset_Loader* l) {
+		RLoader* r = find_loader(magic);
+		assert(r != 0 && r->loader == 0);
+		r->magic[0] = magic[0];
+		r->magic[1] = magic[1];
+		r->magic[2] = magic[2];
+		r->magic[3] = magic[3];
+		r->loader = l;
+	}
+} manager;
+
+void register_asset_loader(
+	const char* magic,
+	Asset_Loader* loader
+) {
+	manager.set_loader(magic, loader);
+}
+
+void Asset_Arena::init(Arena* arena, const char* pack_name) {
+	p = pack_open(pack_name, arena);
+	a = arena;
+	assets = 0;
+}
+
+void Asset_Arena::destroy() {
+	Asset* a;
+	for (a = assets; a; a = a->next) {
+		a->unload(a->loader);
+	}
+	pack_close(p);
+}
+
+void Asset_Arena::claim(Asset* a) {
+	if (assets) {
+		a->next = assets;
+		assets = a;
+	} else assets = a;
+}
+
+Asset* Asset_Arena::load(const char* name) {
+	char magic[4];
+	Pack_File* f = pack_open_file(p, name);
+	if (!f) return 0;
+	pack_read(f, magic, 4);
+	pack_seek(f, 0, seek_rel_start);
+	Asset_Loader& loader = manager.get_loader(magic);
+	Asset* asset = loader.load(a, f);
+	asset->loader = &loader;
+	pack_close_file(f);
+	claim(asset);
+	return asset;
+}