How to display pictures and text in c language code

In C language, images can be displayed through the SDL_image library (usage method: IMG_Load(file), file is the image path), and text can be displayed through the SDL_ttf library (usage method: load font TTF_OpenFont(file, ptsize), Render text TTF_RenderText_Solid(font, text, color), where file is the font path, ptsize is the font size, text is the text content, and color is the text color).

Display pictures and text in C language

In C language, you can use library functions to display images and text. The following describes the usage in detail:

Display image

Library function: SDL_Surface IMG_Load(const char file);

Function: Loads the image from the specified file and returns a pointer to the SDL_Surface structure.

Parameters:

• file: The path to the image file to be loaded.

Example:

<code class="c">#include <stdio.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_image.h>

int main() {
    SDL_Window* window = NULL;
    SDL_Renderer* renderer = NULL;
    SDL_Surface* image = NULL;

    // 初始化 SDL
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("SDL could not be initialized! SDL Error: %s\n", SDL_GetError());
        return 1;
    }

    // 创建窗口
    window = SDL_CreateWindow("Image Display", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
    if (window == NULL) {
        printf("Window could not be created! SDL Error: %s\n", SDL_GetError());
        return 1;
    }

    // 创建渲染器
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    if (renderer == NULL) {
        printf("Renderer could not be created! SDL Error: %s\n", SDL_GetError());
        return 1;
    }

    // 加载图像
    image = IMG_Load("image.png");
    if (image == NULL) {
        printf("Unable to load image! SDL_image Error: %s\n", IMG_GetError());
        return 1;
    }

    // 渲染图像到窗口
    SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, image);
    SDL_Rect dstrect = {0, 0, image->w, image->h};
    SDL_RenderCopy(renderer, texture, NULL, &dstrect);

    // 更新窗口
    SDL_RenderPresent(renderer);

    // 等待用户关闭窗口
    SDL_Event e;
    while (SDL_WaitEvent(&e)) {
        if (e.type == SDL_QUIT) {
            break;
        }
    }

    // 释放资源
    SDL_DestroyTexture(texture);
    SDL_FreeSurface(image);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}</code>

Display text

Library function: TTF_Font TTF_OpenFont(const char file, int ptsize);

<code>              SDL_Surface* TTF_RenderText_Solid(TTF_Font* font, const char* text, SDL_Color color);
</code>

Function: Load font and render text.

Parameters:

• file: The path to the font file to be loaded.
• ptsize: Font size in points.
• text: The text to render.
• color: text color.

Example:

<code class="c">#include <stdio.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>

int main() {
    SDL_Window* window = NULL;
    SDL_Renderer* renderer = NULL;
    TTF_Font* font = NULL;
    SDL_Surface* text_surface = NULL;

    // 初始化 SDL 和 SDL_ttf
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("SDL could not be initialized! SDL Error: %s\n", SDL_GetError());
        return 1;
    }
    if (TTF_Init() == -1) {
        printf("SDL_ttf could not be initialized! SDL_ttf Error: %s\n", TTF_GetError());
        return 1;
    }

    // 创建窗口
    window = SDL_CreateWindow("Text Display", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_SHOWN);
    if (window == NULL) {
        printf("Window could not be created! SDL Error: %s\n", SDL_GetError());
        return 1;
    }

    // 创建渲染器
    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    if (renderer == NULL) {
        printf("Renderer could not be created! SDL Error: %s\n", SDL_GetError());
        return 1;
    }

    // 加载字体
    font = TTF_OpenFont("font.ttf", 24);
    if (font == NULL) {
        printf("Font could not be loaded! SDL_ttf Error: %s\n", TTF_GetError());
        return 1;
    }

    // 渲染文本
    SDL_Color color = {255, 255, 255};
    text_surface = TTF_RenderText_Solid(font, "Hello World!", color);
    if (text_surface == NULL) {
        printf("Text could not be rendered! SDL_ttf Error: %s\n", TTF_GetError());
        return 1;
    }

    // 渲染文本到窗口
    SDL_Texture* text_texture = SDL_CreateTextureFromSurface(renderer, text_surface);
    SDL_Rect dstrect = {0, 0, text_surface->w, text_surface->h};
    SDL_RenderCopy(renderer, text_texture, NULL, &dstrect);

    // 更新窗口
    SDL_RenderPresent(renderer);

    // 等待用户关闭窗口
    SDL_Event e;
    while (SDL_WaitEvent(&e)) {
        if (e.type == SDL_QUIT) {
            break;
        }
    }

    // 释放资源
    SDL_DestroyTexture(text_texture);
    SDL_FreeSurface(text_surface);
    TTF_CloseFont(font);
    TTF_Quit();
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}</code>

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