Question

我有这门课

boost::optional

我已经获得了对我有用的实用工具类。

#ifndef WRAPPED_TEXTURE_H
#define WRAPPED_TEXTURE_H

#include <SDL2/SDL.h>
#include "../ui/utils/texture.h"

// color keying - CHROMA KEY!!!!

class WrappedTexture {

public:
    WrappedTexture() {
        raw_texture = NULL;
        width = 0;
        height = 0;
        bound_renderer = NULL;
    }
    WrappedTexture(SDL_Renderer* bound_renderer) {
        raw_texture = NULL;
        width = 0;
        height = 0;
        this->bound_renderer = bound_renderer;
    }
    ~WrappedTexture() {
        printf("Freeing resources!");
        free();
    }
    void free() {
        if (raw_texture != NULL) {
            SDL_DestroyTexture(raw_texture);
            raw_texture = NULL;
            width = 0;
            height = 0;
        }
    }
    void load_from_file(std::string path) {
        free();
        TextureLoader::load_texture_chroma(path, bound_renderer, NULL, std::vector<Uint8> { 0, 0xFF, 0xFF}, *this);
    }
    void render(int x, int y) {
        SDL_Rect render_frame = { x, y, width, height };
        SDL_RenderCopy(bound_renderer, raw_texture, NULL, &render_frame);
    }

    int get_width() {
        return width;
    }
    int get_height() {
        return height;
    }
    void set_width_height(int width, int height) {
        this->width = width;
        this->height = height;
    }
    void set_raw_texture(SDL_Texture* raw_texture) {
        this->raw_texture = raw_texture;
    }

private:
    SDL_Texture* raw_texture;
    int width;
    int height;
    SDL_Renderer* bound_renderer;
};

#endif

但我在 #ifndef TEXTURE_H #define TEXTURE_H #include <SDL2/SDL.h> #include <SDL2/SDL_image.h> #include <vector> #include "image.h" #include "../../domain/WrappedTexture.h" class TextureLoader { public: static WrappedTexture *create_wrapped_texture(int width, int height, SDL_Texture* raw, SDL_Renderer* render) { WrappedTexture* wt = new WrappedTexture(render); wt->set_width_height(width, height); wt->set_raw_texture(raw); return wt; } static SDL_Texture* load_texture_chroma(std::string path, SDL_Renderer* renderer, SDL_Surface* screen_surface, std::vector<Uint8> pixelColor, WrappedTexture& output) { int width = -1; int height = -1; SDL_Texture* new_texture = NULL; SDL_Surface* loaded_surface = ImageLoader::load_image(path, screen_surface); if (loaded_surface == NULL) { printf("Unable to load image %s! SDL_image Error: %s\n", path.c_str(), IMG_GetError()); } else { SDL_SetColorKey(loaded_surface, SDL_TRUE, SDL_MapRGB(loaded_surface->format, pixelColor[0], pixelColor[1], pixelColor[2])); new_texture = SDL_CreateTextureFromSurface(renderer, loaded_surface); if (new_texture == NULL) { printf("Unable to create texture %s! SDL Error: %s\n", path.c_str(), SDL_GetError()); } else { width = loaded_surface->w; height = loaded_surface->h; } SDL_FreeSurface(loaded_surface); } if (width != -1 && height != -1 && &output != NULL) { output = *TextureLoader::create_wrapped_texture(width, height, new_texture, renderer); } return new_texture; } }; #endif

行中出错了

incomplete type 'TextureLoader' used in nested name specifier

我试图在void load_from_file(std::string path) { free(); TextureLoader::load_texture_chroma(path, bound_renderer, NULL, std::vector<Uint8> { 0, 0xFF, 0xFF}, *this); // error }课程中声明class TextureLoader并在WrappedTexture中尝试class WrappedTexture，但它没有帮助。

问题是什么？

Answer 1

在完全声明类之前，问题可能是你对类的引用：

output = *TextureLoader::create_wrapped_texture(width, height, new_texture, renderer);

此时，类TextureLoader仍未完全声明。尝试将函数定义移动到.cpp文件。是否有理由在标题中实现所有功能？

不完整类型＆＃39; TextureLoader＆＃39;用于嵌套名称说明符

1 个答案: