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)

vendor/sdl-3.0.0/src/SDL_guid.c

@@ -0,0 +1,92 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+/* convert the guid to a printable string */
+int SDL_GUIDToString(SDL_GUID guid, char *pszGUID, int cbGUID)
+{
+    static const char k_rgchHexToASCII[] = "0123456789abcdef";
+    int i;
+
+    if (pszGUID == NULL) {
+        return SDL_InvalidParamError("pszGUID");
+    }
+    if (cbGUID <= 0) {
+        return SDL_InvalidParamError("cbGUID");
+    }
+
+    for (i = 0; i < sizeof(guid.data) && i < (cbGUID - 1) / 2; i++) {
+        /* each input byte writes 2 ascii chars, and might write a null byte. */
+        /* If we don't have room for next input byte, stop */
+        unsigned char c = guid.data[i];
+
+        *pszGUID++ = k_rgchHexToASCII[c >> 4];
+        *pszGUID++ = k_rgchHexToASCII[c & 0x0F];
+    }
+    *pszGUID = '\0';
+    return 0;
+}
+
+/*-----------------------------------------------------------------------------
+ * Purpose: Returns the 4 bit nibble for a hex character
+ * Input  : c -
+ * Output : unsigned char
+ *-----------------------------------------------------------------------------*/
+static unsigned char nibble(unsigned char c)
+{
+    if ((c >= '0') && (c <= '9')) {
+        return c - '0';
+    }
+
+    if ((c >= 'A') && (c <= 'F')) {
+        return c - 'A' + 0x0a;
+    }
+
+    if ((c >= 'a') && (c <= 'f')) {
+        return c - 'a' + 0x0a;
+    }
+
+    /* received an invalid character, and no real way to return an error */
+    /* AssertMsg1(false, "Q_nibble invalid hex character '%c' ", c); */
+    return 0;
+}
+
+/* convert the string version of a guid to the struct */
+SDL_GUID SDL_GUIDFromString(const char *pchGUID)
+{
+    SDL_GUID guid;
+    int maxoutputbytes = sizeof(guid);
+    size_t len = SDL_strlen(pchGUID);
+    Uint8 *p;
+    size_t i;
+
+    /* Make sure it's even */
+    len = (len) & ~0x1;
+
+    SDL_memset(&guid, 0x00, sizeof(guid));
+
+    p = (Uint8 *)&guid;
+    for (i = 0; (i < len) && ((p - (Uint8 *)&guid) < maxoutputbytes); i += 2, p++) {
+        *p = (nibble((unsigned char)pchGUID[i]) << 4) | nibble((unsigned char)pchGUID[i + 1]);
+    }
+
+    return guid;
+}