feat(gx): add incomplete 'CGxDeviceGLSDL' (#2)

* chore(build): add vendored SDL 3.0.0 library

* chore(build): add vendored glew-cmake-2.2.0 library

* feat(console): in the presence of -opengl launch flag, change GxApi to OpenGl

* feat(gx): add uncompleted CGxDeviceGLSDL targeting Windows and Linux

* chore(build): change SDL3 linkage from shared (bad) to to static (good)

src/gx/glsdl/GLTexture.hpp

@@ -0,0 +1,101 @@
+#ifndef GX_GL_SDL_GL_TEXTURE_HPP
+#define GX_GL_SDL_GL_TEXTURE_HPP
+
+#include "gx/glsdl/GL.hpp"
+#include "gx/glsdl/GLObject.hpp"
+#include "gx/glsdl/GLTypes.hpp"
+#include <list>
+#include <vector>
+#include <atomic>
+#include <bc/Thread.hpp>
+
+#define GLTFLAG_RENDERTARGET 0x1
+#define GLTFLAG_DEPTH 0x2
+#define GLTFLAG_STENCIL 0x4
+#define GLTFLAG_AUTOGEN_MIPMAP 0x8
+#define GLTFLAG_READ_ACCESS 0x10
+#define GLTFLAG_SYSTEM_BUFFER 0x20
+
+class CGxTex;
+class GLMipmap;
+class GLSDLDevice;
+
+class GLTexture : public GLObject {
+    public:
+        // Types
+        struct Binding {
+            uint8_t boundStages[16];
+            GLSDLDevice* device;
+        };
+
+        // Static variables
+        static Blizzard::Thread::TLSSlot m_Bindings[4];
+
+        // Static functions
+        static void* CreateBindings(void*);
+        static void DestroyBindings(void*);
+
+        // Member variables
+        uint32_t m_TextureID = 0;
+        GLEnum m_TextureType = 0;
+        GLMipmap** m_Mipmaps = nullptr;
+        std::list<GLTexture*>::iterator var7;
+        uint32_t m_LastFrameUsed;
+        uint32_t m_Width = 0;
+        uint32_t m_Height = 0;
+        uint32_t m_Depth = 0;
+        uint32_t var12 = 0;
+        uint32_t m_Size = 0;
+        GLTextureFormat m_Format = GLTF_INVALID;
+        uint32_t m_Flags = 0;
+        uint32_t m_NumMipmap = 0;
+        uint32_t m_RequestedNumMipmaps;
+        char* m_Data = nullptr;
+        std::atomic<int32_t> m_MappedMipmaps = { 0 };
+        GLStates::Sampler m_Sampler;
+        bool m_GenerateMipmaps = 0;
+        int32_t m_MaxMipmapLevel = 1000;
+        int32_t m_BaseMipmapLevel = 0;
+        int32_t m_CompareMode = 0;
+
+        // Member functions
+        void Bind(GLSDLDevice*, bool);
+        void FreeTexture();
+        std::vector<Binding>& GetBindings(void); // invented name
+        GLTextureFormat GetFormat(void);
+        TextureFormatInfo& GetFormatInfo(void);
+        GLMipmap* GetMipmap(uint32_t, GLEnum);
+        bool IsRenderTarget(void);
+        bool IsSystemBuffer(void);
+        bool IsValid(void);
+        void* Map(uint32_t, const GLRect*, uint32_t&, GLEnum);
+        void RecreateGLTexture(void);
+        void ResizeMipmaps(void);
+        void SetAddressModeR(GLEnum);
+        void SetAddressModeS(GLEnum);
+        void SetAddressModeT(GLEnum);
+        void SetBorderColor(const GLColor4f&);
+        void SetCompareMode(GLEnum);
+        void SetMagFilterMode(GLEnum);
+        void SetMaxAnisotropy(int32_t);
+        void SetMinFilterMode(GLEnum);
+        void SetupTexture(void);
+        void Unbind(GLSDLDevice*, uint32_t); // invented name
+        void Unmap(uint32_t level, GLEnum face);
+};
+
+class GLTexture2D : public GLTexture {
+    public:
+        // Static functions
+        static GLTexture2D* Create(uint32_t, uint32_t, uint32_t, GLTextureFormat, uint32_t);
+
+        // Virtual member functions
+        virtual void ReleaseObject();
+
+        // Member functions
+        GLTexture2D();
+};
+
+void GLSDLTexSetFlags(CGxTex*, GLTexture*);
+
+#endif