make the imgui window not be focused by default and put math_graphics into a namespace

src/main.cpp

@@ -2,6 +2,7 @@
 #include <stdint.h>
 #include <SDL3/SDL.h>
 #include <imgui.h>
+#include <imgui_internal.h>
 #include <imgui_impl_sdl3.h>
 #include <imgui_impl_sdlgpu3.h>
 
@@ -14,6 +15,8 @@
 #include "../assets/shader/basic_vertex_shader.h"
 #include "../assets/shader/basic_pixel_shader.h"
 
+using namespace M;
+
 SDL_GPUDevice *device;
 SDL_Window    *window;
 
@@ -750,6 +753,7 @@ int main(int argc, char **argv) {
     ImGui_ImplSDLGPU3_Init(&imgui_init_info);
 
     bool show_demo_window = true;
+    bool first_frame      = true;
 
     // MSG Message;
     while (Running) {
@@ -760,6 +764,11 @@ int main(int argc, char **argv) {
         if (show_demo_window)
             ImGui::ShowDemoWindow(&show_demo_window);
 
+        if (first_frame) {
+            ImGui::SetWindowFocus(NULL);
+            first_frame = false;
+        }
+
         SDL_GPUCommandBuffer *command_buffer = SDL_AcquireGPUCommandBuffer(device);
         if (!command_buffer) {
             log_error("Failed to acquire gpu command buffer (%s). Exiting.", SDL_GetError());

src/math_graphics.h

@@ -11,6 +11,7 @@
 #undef min
 #undef max
 
+namespace M {
 	//clamp
 	constexpr inline float clamp(float min, float a, float max) {
 		float result = a;
@@ -770,3 +771,4 @@ inline __m128 square_root(__m128 a) {
 	inline __m128 operator /(m128 a, m128 b) {
 		return _mm_div_ps(a.val, b.val);
 	}
+}