《Assault Cube》中静态玩家指针需转换为CPlayer双重指针的技术疑问

Let's break this down step by step using your Assault Cube example—understanding the underlying memory layout is the key to solving this confusion.

First, clarify what ADDR_Player actually is #

• ADDR_Player is defined as 0x0050F4F4: this is a memory address, not a direct pointer to a CPlayer object.
• Inside the memory at 0x0050F4F4, the value stored is 0x00CA9000—this is the actual starting address of the dynamic CPlayer object you care about.

In plain terms: 0x0050F4F4 holds a pointer to the CPlayer object, not the object itself. That's why we need a double pointer here.

What does the CPlayer** cast do? #

In C++, a CPlayer** is a pointer to a CPlayer* (a pointer that points to another pointer). When we cast ADDR_Player to CPlayer**, we're telling the compiler:

"The memory at address 0x0050F4F4 contains a value that is a pointer to a CPlayer object."

When we dereference this cast with *(CPlayer**) ADDR_Player, we're reading the value stored at 0x0050F4F4—which is 0x00CA9000, the valid CPlayer* we need. Assigning that to pPlayer gives us a working pointer to the player object, so accessing pPlayer->m_nHealth works correctly.

Why your original approach was wrong #

Let's look at why CPlayer* pPlayer = *(CPlayer*) ADDR_Player; fails:

• Casting ADDR_Player to CPlayer* tells the compiler: "Treat 0x0050F4F4 as the starting address of a CPlayer object."
• Dereferencing this would try to read the memory starting at 0x0050F4F4 as a full CPlayer object, then attempt to assign that entire object to a CPlayer* variable. This is a type mismatch (you can't assign an object to a pointer), and critically, the memory at 0x0050F4F4 isn't a CPlayer object—it's just a pointer to one.

A simplified memory view #

To make this even clearer, here's how the relevant memory blocks look:

To get from 0x0050F4F4 to the CPlayer object, you have to:

1. Read the value stored at 0x0050F4F4 (which is 0x00CA9000)
2. Use that value as the pointer to the CPlayer object

That's exactly what *(CPlayer**) ADDR_Player handles correctly.

Summary #

In short, ADDR_Player is an address that stores a pointer (not an object), so we need to cast it to a pointer-to-pointer type to correctly read the underlying pointer value that points to the CPlayer object. Skipping the double pointer cast makes the compiler misinterpret what's stored at 0x0050F4F4, leading to invalid memory access or incorrect values.

内容的提问来源于stack exchange，提问作者localhost