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/test/loopwave.c

@@ -0,0 +1,182 @@
+/*
+  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.
+*/
+
+/* Program to load a wave file and loop playing it using SDL audio */
+
+/* loopwaves.c is much more robust in handling WAVE files --
+    This is only for simple WAVEs
+*/
+#include <stdlib.h>
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten/emscripten.h>
+#endif
+
+#include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h>
+#include <SDL3/SDL_test.h>
+#include "testutils.h"
+
+static struct
+{
+    SDL_AudioSpec spec;
+    Uint8 *sound;    /* Pointer to wave data */
+    Uint32 soundlen; /* Length of wave data */
+} wave;
+
+static SDL_AudioStream *stream;
+
+static void fillerup(void)
+{
+    const int minimum = (wave.soundlen / SDL_AUDIO_FRAMESIZE(wave.spec)) / 2;
+    if (SDL_GetAudioStreamQueued(stream) < minimum) {
+        SDL_PutAudioStreamData(stream, wave.sound, wave.soundlen);
+    }
+}
+
+/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
+static void
+quit(int rc)
+{
+    SDL_Quit();
+    /* Let 'main()' return normally */
+    if (rc != 0) {
+        exit(rc);
+    }
+}
+
+static void
+close_audio(void)
+{
+    if (stream) {
+        SDL_DestroyAudioStream(stream);
+        stream = NULL;
+    }
+}
+
+static void
+open_audio(void)
+{
+    stream = SDL_OpenAudioDeviceStream(SDL_AUDIO_DEVICE_DEFAULT_OUTPUT, &wave.spec, NULL, NULL);
+    if (!stream) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create audio stream: %s\n", SDL_GetError());
+        SDL_free(wave.sound);
+        quit(2);
+    }
+    SDL_ResumeAudioDevice(SDL_GetAudioStreamDevice(stream));
+}
+
+
+static int done = 0;
+
+
+
+#ifdef __EMSCRIPTEN__
+static void loop(void)
+{
+    if (done) {
+        emscripten_cancel_main_loop();
+    } else {
+        fillerup();
+    }
+}
+#endif
+
+int main(int argc, char *argv[])
+{
+    int i;
+    char *filename = NULL;
+    SDLTest_CommonState *state;
+
+    /* Initialize test framework */
+    state = SDLTest_CommonCreateState(argv, 0);
+    if (state == NULL) {
+        return 1;
+    }
+
+    /* Enable standard application logging */
+    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
+
+    /* Parse commandline */
+    for (i = 1; i < argc;) {
+        int consumed;
+
+        consumed = SDLTest_CommonArg(state, i);
+        if (!consumed) {
+            if (!filename) {
+                filename = argv[i];
+                consumed = 1;
+            }
+        }
+        if (consumed <= 0) {
+            static const char *options[] = { "[sample.wav]", NULL };
+            SDLTest_CommonLogUsage(state, argv[0], options);
+            exit(1);
+        }
+
+        i += consumed;
+    }
+
+    /* Load the SDL library */
+    if (SDL_Init(SDL_INIT_AUDIO | SDL_INIT_EVENTS) < 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
+        return 1;
+    }
+
+    filename = GetResourceFilename(filename, "sample.wav");
+
+    if (filename == NULL) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "%s\n", SDL_GetError());
+        quit(1);
+    }
+
+    /* Load the wave file into memory */
+    if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == -1) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
+        quit(1);
+    }
+
+    /* Show the list of available drivers */
+    SDL_Log("Available audio drivers:");
+    for (i = 0; i < SDL_GetNumAudioDrivers(); ++i) {
+        SDL_Log("%i: %s", i, SDL_GetAudioDriver(i));
+    }
+
+    SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());
+
+    open_audio();
+
+#ifdef __EMSCRIPTEN__
+    emscripten_set_main_loop(loop, 0, 1);
+#else
+    while (!done) {
+        SDL_Event event;
+
+        while (SDL_PollEvent(&event) > 0) {
+            if (event.type == SDL_EVENT_QUIT) {
+                done = 1;
+            }
+        }
+
+        fillerup();
+        SDL_Delay(100);
+    }
+#endif
+
+    /* Clean up on signal */
+    close_audio();
+    SDL_free(wave.sound);
+    SDL_free(filename);
+    SDL_Quit();
+    SDLTest_CommonDestroyState(state);
+    return 0;
+}