partially done work on total source tree rework, separation of engine context and game context, generalization of renderer for different backends as well as web platform target

src/twn_engine_context_c.h

@@ -0,0 +1,50 @@
+#ifndef TWN_ENGINE_CONTEXT_H
+#define TWN_ENGINE_CONTEXT_H
+
+#include "twn_context.h"
+#include "textures/internal_api.h"
+#include "twn_input.h"
+
+#include <SDL2/SDL.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+
+
+typedef struct engine_context {
+    t_ctx game_context;
+
+    /* the program's actual argc and argv */
+    int argc;
+    char **argv;
+
+    struct primitive_2d *render_queue_2d;
+    struct mesh_batch_item *uncolored_mesh_batches;
+    struct text_cache text_cache;
+    struct texture_cache texture_cache;
+
+    struct audio_channel_item *audio_channels;
+    SDL_AudioDeviceID audio_device;
+    int audio_stream_frequency;
+    SDL_AudioFormat audio_stream_format;
+    uint8_t audio_stream_channel_count;
+
+    /* main loop machinery */
+    int64_t clocks_per_second;
+    int64_t prev_frame_time;
+    int64_t desired_frametime;  /* how long one tick should be */
+    int64_t frame_accumulator;
+    int64_t delta_averager_residual;
+    int64_t time_averager[4];
+
+    SDL_GLContext *gl_context;
+    SDL_Window *window;
+    uint32_t window_id;
+
+    bool resync_flag;
+    bool was_successful;
+} t_engine_ctx;
+
+extern t_engine_ctx ctx = ;
+
+#endif