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要使用C语言的sin()
函数绘制波形图,您需要使用一个库来绘制图形
#include<stdio.h> #include <math.h> #include <SDL2/SDL.h> const int WIDTH = 800; const int HEIGHT = 600; const double PI = 3.14159265358979323846; int main(int argc, char* argv[]) { SDL_Window* window = NULL; SDL_Renderer* renderer = NULL; SDL_Surface* surface = NULL; SDL_Texture* texture = NULL; // Initialize SDL if (SDL_Init(SDL_INIT_VIDEO) < 0) { printf("Error: %s\n", SDL_GetError()); return -1; } // Create window and renderer window = SDL_CreateWindow("Sine Wave", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, WIDTH, HEIGHT, SDL_WINDOW_SHOWN); if (window == NULL) { printf("Error: %s\n", SDL_GetError()); return -1; } renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED); if (renderer == NULL) { printf("Error: %s\n", SDL_GetError()); return -1; } // Set render draw color SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255); // Clear screen SDL_RenderClear(renderer); // Set render draw color for sine wave SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255); // Draw sine wave for (int x = 0; x < WIDTH; x++) { double angle = (double)x / WIDTH * 2 * PI; int y = HEIGHT / 2 + sin(angle) * HEIGHT / 4; SDL_RenderDrawPoint(renderer, x, y); } // Update screen SDL_RenderPresent(renderer); // Wait for key press to exit SDL_Event event; while (SDL_WaitEvent(&event)) { if (event.type == SDL_QUIT || (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_ESCAPE)) { break; } } // Cleanup SDL_DestroyRenderer(renderer); SDL_DestroyWindow(window); SDL_Quit(); return 0; }
这个示例程序使用了SDL2库来创建一个窗口并在其中绘制一个正弦波形。首先,我们初始化SDL并创建一个窗口和渲染器。然后,我们设置渲染器的绘制颜色并清除屏幕。接下来,我们遍历屏幕上的每个像素点,计算对应的正弦值,并将其绘制到屏幕上。最后,我们更新屏幕并等待用户按下键盘上的ESC键或单击窗口关闭按钮以退出程序。
要编译此程序,请确保已安装SDL2库,并使用以下命令进行编译:
gcc sinewave.c -o sinewave -lSDL2
运行生成的可执行文件(例如./sinewave
),您将看到一个包含正弦波形的窗口。