c++ - SDL 2.0放大纹理

Question

为了制作按钮，我以这种方式创建和渲染纹理:

typedef struct{
    SDL_Rect pos;
    SDL_Texture* texture;
    int hovered;
} button;

button getButton(int x, int y, char * label, TTF_Font* font, SDL_Color color){
    button btn;
    btn.hovered = false;
    btn.pos.x = x;
    btn.pos.y = y;
    SDL_Surface* surface = TTF_RenderText_Solid(font, label, color);
    btn.pos.w = surface->w;
    btn.pos.h = surface->h;
    btn.texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_FreeSurface(surface);
    return btn;
}

void drawButton(button btn){
    SDL_RenderCopyEx( renderer, btn.texture, NULL, &btn.pos, 0, NULL, SDL_FLIP_NONE);
    if(btn.hovered){
        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 0x00);
        SDL_RenderDrawRect(renderer, &btn.pos);
}

问题是我得到的纹理大小等于标签之一。如何在不拉伸(stretch)纹理像素大小的情况下增加纹理像素大小，即在其侧面添加空白？

Answer 1

类似

void drawButton(button btn){
    SDL_RenderCopyEx( renderer, btn.texture, NULL, &btn.pos, 0, NULL, SDL_FLIP_NONE);
    if(btn.hovered){
        int padding = 10;
        SDL_Rect pos = {btn.pos.x - padding,   btn.pos.y - padding, 
                        btn.pos.w + 2*padding, btn.pos.h + 2*padding };
        SDL_SetRenderDrawColor(renderer, 255, 255, 255, 0x00);
        SDL_RenderDrawRect(renderer, &pos);
    }
}

这样只有矩形的大小发生变化，显然我只是凭空拉出了 10 作为填充的大小，你需要自己选择合适的东西。