Add scene time based rotation

Added time based scene rotation as a proof of concept.
Based on this implementation, I can not only move
scene using external data (like mouse, in the future)
but also I can use provided functionality to get high resolution
timer for future use

Signed-off-by: Piotr Krygier <piotrkrygier@everyonecancode@xyz>

graphics/src/rse_graphics.c

@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 #include <vulkan/vulkan_core.h>
 
 #include "descriptor_builder.h"
@@ -28,15 +29,19 @@ struct rse_graphics_context_t
     struct graphics_context_t* context;
 };
 
+#define NS_TO_S(time) (time/1000000000)
 static void model_view_projection_update(struct graphics_context_t* context)
 {
     vec3 eye = {0};
     vec3 center = {0};
     vec3 up = {0};
-    vec3 rotation_vec = {1.0f, 0.0f, 0.0f};
+    vec3 rotation_vec = {0.0f, 0.0f, 1.0f};
     float fovy;
     float z_near;
     float z_far;
+    double diff_time = 0.0;
+    struct timespec now = {0};
+    static struct timespec last_time = {0};
 
     eye[2] = -5.0f;
 
@@ -46,9 +51,17 @@ static void model_view_projection_update(struct graphics_context_t* context)
     z_near = 0.1f;
     z_far = 20.0f;
 
+    if (last_time.tv_nsec == 0) {
+        timespec_get(&last_time, TIME_UTC);
+    }
+
+    timespec_get(&now, TIME_UTC);
+
+    diff_time = NS_TO_S((double)(now.tv_nsec - last_time.tv_nsec)) + (now.tv_sec - last_time.tv_sec);
+
     glm_mat4_identity(context->mvp_data.model);
 
-    glm_rotate(context->mvp_data.model, glm_rad(0.0f), rotation_vec);
+    glm_rotate(context->mvp_data.model, diff_time * glm_rad(90.0f), rotation_vec);
     glm_lookat(eye, center, up, context->mvp_data.view);
     glm_perspective(
         fovy,