How to display frame rate in C language

Displaying frame rates in C language involves the following steps: Initialize variables and clocks. Render one frame. Calculate frame time. Calculate the frame rate. Show frame rate.

How to display frame rate in C

Displaying frame rates is a useful feature in gaming or graphics applications that can help developers understand the performance of their applications. In C, the frame rate can be displayed by the following steps:

1. Initialize variables and clocks

• Declare the variable fps to store the frame rate.
• Declare the variable seconds to store the elapsed time since the previous frame.
• Initialize the clock library (such as SDL or GLFW).

2. Render one frame

• Render a frame of the application.

3. Calculate frame time

• Gets the current time (e.g. SDL_GetTicks() or glfwGetTime() ).
• Calculate the elapsed time since the previous frame ( seconds = current_time - previous_time ).
• Update previous_time to current_time .

4. Calculate the frame rate

• Calculate the frame rate ( fps = 1.0 / seconds ).

5. Display frame rate

• Show frame rates on the screen (for example, using SDL_RenderDrawString() or GLFW_DrawText()).

Sample Code (SDL):

 <code class="c">#include <sdl2> int main(int argc, char* argv[]) { // 初始化SDL SDL_Init(SDL_INIT_EVERYTHING); // 设置窗口SDL_Window* window = SDL_CreateWindow("帧率显示", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, SDL_WINDOW_SHOWN); SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_SOFTWARE); // 初始化变量float fps = 0.0f; float seconds = 0.0f; Uint32 previous_time = SDL_GetTicks(); // 运行游戏循环while (running) { // 渲染一帧SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); SDL_RenderClear(renderer); // ... 其他渲染代码... SDL_RenderPresent(renderer); // 计算帧时间Uint32 current_time = SDL_GetTicks(); seconds = (float)(current_time - previous_time) / 1000.0f; previous_time = current_time; // 计算帧率fps = 1.0f / seconds; // 显示帧率char fps_text[16]; sprintf(fps_text, "FPS: %.2f", fps); SDL_Color text_color = {255, 255, 255, 255}; SDL_Surface* text_surface = TTF_RenderText_Solid(font, fps_text, text_color); SDL_Texture* text_texture = SDL_CreateTextureFromSurface(renderer, text_surface); SDL_FreeSurface(text_surface); SDL_Rect text_rect = {0, 0, text_surface->w, text_surface->h}; SDL_RenderCopy(renderer, text_texture, NULL, &text_rect); // 处理事件SDL_Event event; while (SDL_PollEvent(&event)) { if (event.type == SDL_QUIT) { running = false; } } } // 销毁SDL SDL_DestroyRenderer(renderer); SDL_DestroyWindow(window); SDL_Quit(); return 0; }</sdl2></code>

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