wtf

genfont.c: In function ‘main’:
genfont.c:9:5: error: unknown type name ‘FT_Library’
     FT_Library library;
     ^~~~~~~~~~
genfont.c:10:5: error: unknown type name ‘FT_Error’
     FT_Error error;
     ^~~~~~~~
genfont.c:11:5: error: unknown type name ‘FT_Face’; did you mean ‘FT_PFR_H’?
     FT_Face face;
     ^~~~~~~
     FT_PFR_H
genfont.c:12:18: warning: implicit declaration of function ‘FT_Init_FreeType’ [-Wimplicit-function-declaration]
     if ((error = FT_Init_FreeType(&library)) ||
                  ^~~~~~~~~~~~~~~~
genfont.c:13:19: warning: implicit declaration of function ‘FT_New_Face’ [-Wimplicit-function-declaration]
         ((error = FT_New_Face(library, "/usr/share/fonts/fonts-master/apache/robotomono/RobotoMono-Medium.ttf", 0, &face)) &&
                   ^~~~~~~~~~~
genfont.c:15:18: warning: implicit declaration of function ‘FT_Set_Char_Size’ [-Wimplicit-function-declaration]
         (error = FT_Set_Char_Size(face, 0, 550, 0, 141)) ||
                  ^~~~~~~~~~~~~~~~
genfont.c:16:18: warning: implicit declaration of function ‘FT_Load_Char’ [-Wimplicit-function-declaration]
         (error = FT_Load_Char(face, U'w', FT_LOAD_DEFAULT))) return error;
                  ^~~~~~~~~~~~
genfont.c:16:43: error: ‘FT_LOAD_DEFAULT’ undeclared (first use in this function)
         (error = FT_Load_Char(face, U'w', FT_LOAD_DEFAULT))) return error;
                                           ^~~~~~~~~~~~~~~
genfont.c:16:43: note: each undeclared identifier is reported only once for each function it appears in
genfont.c:17:21: error: invalid type argument of ‘->’ (have ‘int’)
     int width = face->glyph->advance.x >> 6, height = face->size->metrics.height >> 6, height_bytes = (height + 1) >> 1;
                     ^~
genfont.c:17:59: error: invalid type argument of ‘->’ (have ‘int’)
     int width = face->glyph->advance.x >> 6, height = face->size->metrics.height >> 6, height_bytes = (height + 1) >> 1;
                                                           ^~
genfont.c:18:15: error: ‘PATH_MAX’ undeclared (first use in this function); did you mean ‘INT8_MAX’?
     char path[PATH_MAX];
               ^~~~~~~~
               INT8_MAX
genfont.c:50:22: warning: implicit declaration of function ‘FT_Render_Glyph’ [-Wimplicit-function-declaration]
             (error = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL))) return error;
                      ^~~~~~~~~~~~~~~
genfont.c:50:42: error: invalid type argument of ‘->’ (have ‘int’)
             (error = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL))) return error;
                                          ^~
genfont.c:50:51: error: ‘FT_RENDER_MODE_NORMAL’ undeclared (first use in this function)
             (error = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL))) return error;
                                                   ^~~~~~~~~~~~~~~~~~~~~
genfont.c:57:36: error: invalid type argument of ‘->’ (have ‘int’)
         for (int sy = 0, dy = (face->size->metrics.ascender >> 6) - face->glyph->bitmap_top; sy != face->glyph->bitmap.rows; ++sy, ++dy) {
                                    ^~
genfont.c:57:73: error: invalid type argument of ‘->’ (have ‘int’)
         for (int sy = 0, dy = (face->size->metrics.ascender >> 6) - face->glyph->bitmap_top; sy != face->glyph->bitmap.rows; ++sy, ++dy) {
                                                                         ^~
genfont.c:57:104: error: invalid type argument of ‘->’ (have ‘int’)
         for (int sy = 0, dy = (face->size->metrics.ascender >> 6) - face->glyph->bitmap_top; sy != face->glyph->bitmap.rows; ++sy, ++dy) {
                                                                                                        ^~
genfont.c:58:39: error: invalid type argument of ‘->’ (have ‘int’)
             for (int sx = 0, dx = face->glyph->bitmap_left; sx != face->glyph->bitmap.width; ++sx, ++dx) {
                                       ^~
genfont.c:58:71: error: invalid type argument of ‘->’ (have ‘int’)
             for (int sx = 0, dx = face->glyph->bitmap_left; sx != face->glyph->bitmap.width; ++sx, ++dx) {
                                                                       ^~
genfont.c:60:33: error: invalid type argument of ‘->’ (have ‘int’)
                 uint8_t g = face->glyph->bitmap.buffer[sy * face->glyph->bitmap.pitch + sx];
                                 ^~
genfont.c:60:65: error: invalid type argument of ‘->’ (have ‘int’)
                 uint8_t g = face->glyph->bitmap.buffer[sy * face->glyph->bitmap.pitch + sx];