SDL2で日本語を表示することができない

前提・実現したいこと

SDL2でゲームを作っていたのですが、メッセージを表示する機能を実装中に以下のエラーが発生しました。

発生している問題・エラーメッセージ

日本語を入力すると文字化けしてしまいます。
英語ではできました。
]

該当のソースコード

C
1#include "SDL2/SDL.h"
2#include "SDL2/SDL_image.h"
3#include "SDL2/SDL_ttf.h"
4
5typedef struct
6{
7    SDL_Surface *image_f, *image_b, *image_r, *image_l;
8    SDL_Rect rect, rect_pos, rect_tmp;
9    SDL_Texture *texture_f, *texture_b, *texture_r, *texture_l;
10    SDL_Texture *texture_use;
11    int direction;
12} layer_dir;
13
14typedef struct
15{
16    SDL_Surface *image_small, *image_middle, *image_large;
17    SDL_Rect rect, rect_pos, rect_tmp;
18    SDL_Texture *texture_small, *texture_middle, *texture_large;
19    SDL_Texture *texture_use;
20} layer_ani;
21
22int Object[27][15] = {
23    {0, 0},
24    {0, 0}};
25
26int GetPos(SDL_Rect *from, SDL_Rect *to)
27{
28    to->x = from->x * 23;
29    to->y = from->y * 31;
30    return 0;
31}
32
33void maketex_dir(layer_dir *, SDL_Renderer *);
34void maketex_ani(layer_ani *undefined, SDL_Renderer *renderer);
35
36void LoadIMG_dir(const char front[20], const char back[20], const char right[20], const char left[20], layer_dir *undefined);
37void LoadIMG_ani(const char small[20], const char middle[20], const char large[20], layer_ani *undefined);
38
39void OpenBox(SDL_Renderer *);
40void PrintText(SDL_Renderer *, const char *, TTF_Font *, SDL_Color color);
41
42void destex_dir(layer_dir *);
43void destex_ani(layer_ani *);
44
45int main(int argc, const char *argv[])
46{
47    SDL_Window *Window;
48    SDL_Renderer *renderer;
49
50    int isFinish = 0;
51    int img = 0;
52    int scene = 1;
53    int Box = 0;
54    int msg = 0;
55
56    layer_dir charcter;
57
58    layer_ani enemy;
59
60    TTF_Font *font;
61    SDL_Color white = {255, 255, 0, 255};
62
63    SDL_Init(SDL_INIT_EVERYTHING);
64    TTF_Init();
65
66    Window = SDL_CreateWindow("Key", 0, 0, 640, 480, SDL_WINDOW_SHOWN);
67
68    font = TTF_OpenFont("rounded-x-mplus-1c-black.ttf", 24);
69
70    renderer = SDL_CreateRenderer(Window, -1, SDL_RENDERER_ACCELERATED);
71    SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
72
73    LoadIMG_dir("char/front.png", "char/back.png", "char/right.png", "char/left.png", &charcter);
74    LoadIMG_ani("enemy/small.png", "enemy/middle.png", "enemy/large.png", &enemy);
75
76    charcter.rect.x = 2;
77    charcter.rect.y = 0;
78    charcter.rect.w = charcter.image_f->w;
79    charcter.rect.h = charcter.image_f->h;
80
81    enemy.rect.x = 0;
82    enemy.rect.y = 0;
83    enemy.rect.h = enemy.image_small->h;
84    enemy.rect.w = enemy.image_small->w;
85
86    maketex_ani(&enemy, renderer);
87    maketex_dir(&charcter, renderer);
88
89    Object[0][0] = 1;
90    Object[0][1] = 1;
91
92    charcter.texture_use = charcter.texture_f;
93    enemy.texture_use = enemy.texture_small;
94
95    charcter.rect_pos = charcter.rect;
96    charcter.rect_tmp = charcter.rect;
97
98    enemy.rect_pos = enemy.rect;
99    while (isFinish == 0)
100    {
101
102        SDL_Event event;
103
104        while (SDL_PollEvent(&event))
105        {
106            switch (event.type)
107            {
108            case SDL_KEYDOWN:
109            {
110                switch (event.key.keysym.sym)
111                {
112                case SDLK_UP:
113                    charcter.rect_tmp.y -= 1;
114                    charcter.texture_use = charcter.texture_b;
115                    break;
116
117                case SDLK_DOWN:
118                    charcter.rect_tmp.y += 1;
119                    charcter.texture_use = charcter.texture_f;
120                    break;
121
122                case SDLK_RIGHT:
123                    charcter.rect_tmp.x += 1;
124                    charcter.texture_use = charcter.texture_r;
125                    break;
126
127                case SDLK_LEFT:
128                    charcter.rect_tmp.x -= 1;
129                    charcter.texture_use = charcter.texture_l;
130                    break;
131
132                case SDLK_ESCAPE:
133                    isFinish = 1;
134                    break;
135
136                case SDLK_SPACE:
137                    if (Box == 0)
138                    {
139                        Box = 1;
140                    }
141                    else
142                    {
143                        Box = 0;
144                    }
145
146                    if (msg == 0)
147                    {
148                        msg = 1;
149                    }
150                    else
151                    {
152                        msg = 0;
153                    }
154                    break;
155                }
156            }
157            }
158
159            if (charcter.rect_tmp.y < 0 ||
160                charcter.rect_tmp.y > 14 ||
161                charcter.rect_tmp.x < 0 ||
162                charcter.rect_tmp.x > 26 ||
163                Object[charcter.rect_tmp.y][charcter.rect_tmp.x] == 1)
164            {
165                charcter.rect_tmp = charcter.rect;
166            }
167            else
168            {
169                charcter.rect = charcter.rect_tmp;
170            }
171
172            GetPos(&charcter.rect, &charcter.rect_pos);
173        }
174
175        if (img < 500)
176        {
177            enemy.texture_use = enemy.texture_small;
178        }
179        else if (img < 1000)
180        {
181            enemy.texture_use = enemy.texture_middle;
182        }
183        else if (img < 1500)
184        {
185            enemy.texture_use = enemy.texture_large;
186        }
187        else
188        {
189            img = 0;
190        }
191
192        SDL_RenderClear(renderer);
193        SDL_RenderCopy(renderer, charcter.texture_use, NULL, &charcter.rect_pos);
194        SDL_RenderCopy(renderer, enemy.texture_use, NULL, &enemy.rect_pos);
195
196        if (Box == 1)
197        {
198            OpenBox(renderer);
199        }
200
201        switch (msg)
202        {
203        case 1:
204            PrintText(renderer, u8"あいうえお", font, white);
205            break;
206
207        default:
208            break;
209        }
210
211        img++;
212        SDL_RenderPresent(renderer);
213    }
214
215    SDL_DestroyRenderer(renderer);
216    destex_ani(&enemy);
217    destex_dir(&charcter);
218    SDL_DestroyWindow(Window);
219
220    SDL_Quit();
221
222    return 0;
223}
224
225void maketex_dir(layer_dir *undefined, SDL_Renderer *renderer)
226{
227    undefined->texture_f = SDL_CreateTextureFromSurface(renderer, undefined->image_f);
228    undefined->texture_b = SDL_CreateTextureFromSurface(renderer, undefined->image_b);
229    undefined->texture_r = SDL_CreateTextureFromSurface(renderer, undefined->image_r);
230    undefined->texture_l = SDL_CreateTextureFromSurface(renderer, undefined->image_l);
231
232    SDL_FreeSurface(undefined->image_f);
233    SDL_FreeSurface(undefined->image_b);
234    SDL_FreeSurface(undefined->image_r);
235    SDL_FreeSurface(undefined->image_l);
236}
237
238void LoadIMG_dir(const char front[20], const char back[20], const char right[20], const char left[20], layer_dir *undefined)
239{
240    undefined->image_f = IMG_Load(front);
241    undefined->image_b = IMG_Load(back);
242    undefined->image_r = IMG_Load(right);
243    undefined->image_l = IMG_Load(left);
244}
245
246void maketex_ani(layer_ani *undefined, SDL_Renderer *renderer)
247{
248    undefined->texture_small = SDL_CreateTextureFromSurface(renderer, undefined->image_small);
249    undefined->texture_middle = SDL_CreateTextureFromSurface(renderer, undefined->image_middle);
250    undefined->texture_large = SDL_CreateTextureFromSurface(renderer, undefined->image_large);
251
252    SDL_FreeSurface(undefined->image_small);
253    SDL_FreeSurface(undefined->image_middle);
254    SDL_FreeSurface(undefined->image_large);
255}
256
257void LoadIMG_ani(const char small[20], const char middle[20], const char large[20], layer_ani *undefined)
258{
259
260    undefined->image_small = IMG_Load(small);
261    undefined->image_middle = IMG_Load(middle);
262    undefined->image_large = IMG_Load(large);
263}
264
265void OpenBox(SDL_Renderer *renderer)
266{
267    SDL_Surface *surface = SDL_CreateRGBSurface(0, 608, 128, 32, 0, 0, 0, 255);
268    SDL_Texture *texture;
269    SDL_Rect rect;
270
271    rect.h = surface->h;
272    rect.w = surface->w;
273    rect.x = 16;
274    rect.y = 320;
275
276    texture = SDL_CreateTextureFromSurface(renderer, surface);
277    SDL_FreeSurface(surface);
278
279    SDL_RenderCopy(renderer, texture, NULL, &rect);
280}
281
282void PrintText(SDL_Renderer *renderer, const char *text, TTF_Font *font, SDL_Color color)
283{
284    SDL_Surface *surface = TTF_RenderText_Blended(font, text, color);
285    SDL_Texture *texture = SDL_CreateTextureFromSurface(renderer, surface);
286    SDL_Rect rect;
287
288    rect.h = surface->h;
289    rect.w = surface->w;
290    rect.x = 16;
291    rect.y = 320;
292
293    SDL_FreeSurface(surface);
294    SDL_RenderCopy(renderer, texture, NULL, &rect);
295}
296
297void destex_dir(layer_dir *layer)
298{
299
300    SDL_DestroyTexture(layer->texture_f);
301    SDL_DestroyTexture(layer->texture_b);
302    SDL_DestroyTexture(layer->texture_r);
303    SDL_DestroyTexture(layer->texture_l);
304    SDL_DestroyTexture(layer->texture_use);
305}
306
307void destex_ani(layer_ani *layer)
308{
309
310    SDL_DestroyTexture(layer->texture_small);
311    SDL_DestroyTexture(layer->texture_middle);
312    SDL_DestroyTexture(layer->texture_large);
313    SDL_DestroyTexture(layer->texture_use);
314}