Add FPS counter

Added console FPS counter. Thise required me to create
some time functions and remove FPS cap from Vulkan

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

graphics/src/rse_graphics.c

@@ -6,7 +6,6 @@
 #include <cglm/util.h>
 #include <stdint.h>
 #include <stdlib.h>
-#include <time.h>
 #include <vulkan/vulkan_core.h>
 
 #include "descriptor_builder.h"
@@ -18,6 +17,7 @@
 #include "src/vulkan_buffers.h"
 #include "utilities/commons.h"
 #include "utilities/errors_common.h"
+#include "utilities/time_utils.h"
 #include "vulkan_base.h"
 #include "vulkan_commons.h"
 #include "vulkan_image.h"
@@ -38,9 +38,6 @@ static void model_view_projection_update(struct graphics_context_t* context)
     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;
 
@@ -50,17 +47,9 @@ 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, diff_time * glm_rad(90.0f), rotation_vec);
+    glm_rotate(context->mvp_data.model, time_get_sec_from_start() * glm_rad(90.0f), rotation_vec);
     glm_lookat(eye, center, up, context->mvp_data.view);
     glm_perspective(
         fovy,

graphics/src/vulkan_swapchain.c

@@ -52,7 +52,7 @@ static rse_err_t create_swapchain(struct graphics_context_t* context)
     create_info.pQueueFamilyIndices = context->queue_family_indices;
     create_info.preTransform = physical_device_surface_capabilities.currentTransform;
     create_info.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
-    create_info.presentMode = VK_PRESENT_MODE_FIFO_KHR;
+    create_info.presentMode = VK_PRESENT_MODE_IMMEDIATE_KHR;
     create_info.clipped = VK_TRUE;
     create_info.oldSwapchain = VK_NULL_HANDLE;
 

graphics/src/window.c

@@ -20,9 +20,25 @@
 
 #include "utilities/commons.h"
 #include "utilities/errors_common.h"
+#include "utilities/time_utils.h"
 #include "vulkan/vulkan_core.h"
 #include "vulkan_base.h"
 
+static void fps_print(double* start_time)
+{
+    static uint32_t frame_counts = 0U;
+
+    double now = time_get_sec_from_start();
+
+    frame_counts++;
+    if ((now - *start_time) > 1.0) {
+        printf("\rFPS: %u", frame_counts);
+        fflush(stdout);
+        frame_counts = 0;
+        *start_time += 1.0;
+    }
+}
+
 rse_err_t window_init(SDL_Window** window_handle, bool* is_framebuffer_resized)
 {
     SDL_Init(SDL_INIT_VIDEO);  // TODO: Move to initial phase of RSE initialization
@@ -43,6 +59,9 @@ rse_err_t window_loop(struct graphics_context_t* context)
 {
     uint8_t done = 0;
     SDL_Event event;
+    double start_time;
+
+    start_time = time_get_sec_from_start();
 
     while (0 == done) {
         while (SDL_PollEvent(&event)) {
@@ -52,6 +71,7 @@ rse_err_t window_loop(struct graphics_context_t* context)
         }
 
         draw_frame(context);
+        fps_print(&start_time);
     }
 
     vkDeviceWaitIdle(context->vulkan_handles.device);

utilities/meson.build

@@ -1,5 +1,6 @@
 rse_utilities_srcs = [
-  'src/file_utils.c'
+  'src/file_utils.c',
+  'src/time_utils.c'
   ]
 
 cc = meson.get_compiler('c')

utilities/src/time_utils.c

@@ -0,0 +1,9 @@
+#include "time_utils.h"
+#include <stdint.h>
+#include "SDL3/SDL_timer.h"
+
+#define NS_TO_S(time) (time/1000000000)
+double time_get_sec_from_start(void)
+{
+    return NS_TO_S((double)SDL_GetTicksNS());
+}

utilities/time_utils.h

@@ -0,0 +1,17 @@
+/**
+ * @file file_utils.h
+ * @author Piotr Krygier (everyonecancode@gmail.com)
+ * @brief Common functionality for all modules
+ * @version 0.1
+ * @date 2026-02-11
+ *
+ * @copyright Copyright (c) 2023
+ *
+ */
+
+#ifndef TIME_UTILS_H_
+#define TIME_UTILS_H_
+
+double time_get_sec_from_start(void);
+
+#endif // !TIME_UTILS_H_