MaterialSystem: add more reversed types for texture streaming

Reverse engineered.

src/materialsystem/texturestreaming.h

@@ -1,8 +1,59 @@
+//=============================================================================//
+// 
+// Purpose: texture streaming and runtime management
+// 
+//-----------------------------------------------------------------------------
+// Some of these structs are based on the presentation held by the developer of
+// the texture streaming system in Titanfall 2 and Apex Legends, see the links:
+// - https://www.gdcvault.com/play/1024418/Efficient-Texture-Streaming-in-Titanfall
+// - https://www.youtube.com/watch?v=q0aKNGH8WbA
+//=============================================================================//
+
 #ifndef TEXTURESTREAMING_H
 #define TEXTURESTREAMING_H
 #include "public/rtech/istreamdb.h"
 
-inline void(*v_StreamDB_Init)(const char* const pszLevelName);
+struct TextureStreamMgr_Task_s
+{
+	TextureAsset_t* textureAsset;
+
+	// The mip level count to load or drop.
+	uint8 mipLevelCount;
+	char padding[3];
+
+	// The 'cost vs benefit' metric used to partially sort the task list to get
+	// the best and worst 16 textures.
+	float metric;
+};
+
+struct TextureStreamMgr_TaskList_s
+{
+	// STBSP async file handle and index to the current page.
+	int fileHandle;
+	int pageIndex;
+
+	// Whether we should update the current page state.
+	bool updatePageState;
+	int padding;
+
+	// Offset to the page in the STBSP to read up to size bytes.
+	uint64 pageOffset;
+	uint64 pageSize;
+
+	// - loadBegin points to the first texture load task.
+	// - loadEnd points to the last texture load task.
+	// - loadLimit points to the absolute end of the load task buffer.
+	TextureStreamMgr_Task_s* loadBegin;
+	TextureStreamMgr_Task_s* loadEnd;
+	TextureStreamMgr_Task_s* loadLimit;
+
+	// - dropBegin points to the first texture drop task.
+	// - dropEnd points to the last texture drop task.
+	// - dropLimit points to the absolute end of the drop task buffer.
+	TextureStreamMgr_Task_s* dropBegin;
+	TextureStreamMgr_Task_s* dropEnd;
+	TextureStreamMgr_Task_s* dropLimit;
+};
 
 struct TextureStreamMgr_s
 {
@@ -39,6 +90,8 @@ struct TextureStreamMgr_s
 	TextureAsset_t* streamableTextures[4];
 };
 
+inline void(*v_StreamDB_Init)(const char* const pszLevelName);
+
 inline TextureStreamMgr_s* s_textureStreamMgr;
 
 ///////////////////////////////////////////////////////////////////////////////