raze-gles/source/core/textures/textureid.h

#pragma once

class FTextureID
{
	friend class FTextureManager;

public:
	FTextureID() = default;
	bool isNull() const { return texnum == 0; }
	bool isValid() const { return texnum > 0; }
	bool Exists() const { return texnum >= 0; }
	void SetInvalid() { texnum = -1; }
	void SetNull() { texnum = 0; }
	bool operator ==(const FTextureID &other) const { return texnum == other.texnum; }
	bool operator !=(const FTextureID &other) const { return texnum != other.texnum; }
	FTextureID operator +(int offset) throw();
	int GetIndex() const { return texnum; }	// Use this only if you absolutely need the index!

											// The switch list needs these to sort the switches by texture index
	int operator -(FTextureID other) const { return texnum - other.texnum; }
	bool operator < (FTextureID other) const { return texnum < other.texnum; }
	bool operator > (FTextureID other) const { return texnum > other.texnum; }

protected:
	FTextureID(int num) { texnum = num; }
private:
	int texnum;
};

// This is for the script interface which needs to do casts from int to texture.
class FSetTextureID : public FTextureID
{
public:
	FSetTextureID(int v) : FTextureID(v) {}
};