load_cube_data   xtlang

(bind-func load_cube_data
  (lambda (tex:Texture* flipped:i32 front:String* back:String* top:String* bottom:String* left:String* right:String*)
    ;; seems to need to be set
    (stbi_set_flip_vertically_on_load flipped)
    (let ((width_ptr:i32* (tref-ptr tex 2))
          (height_ptr:i32* (tref-ptr tex 3))
          (comp_ptr:i32* (salloc))
          (i:i32 0)
          (wp:i32* (salloc 6))
          (hp:i32* (salloc 6))
          (cp:i32* (salloc 6))
          (wpt:i32 0)
          (hpt:i32 0)
          (cpt:i32 0)
          (front_data (stbi_load (cstring front) (pref-ptr wp 0) (pref-ptr hp 0) (pref-ptr cp 0) 4))
          (back_data (stbi_load (cstring back) (pref-ptr wp 1) (pref-ptr hp 1) (pref-ptr cp 1) 4))
          (top_data (stbi_load (cstring top) (pref-ptr wp 2) (pref-ptr hp 2) (pref-ptr cp 2) 4))
          (bottom_data (stbi_load (cstring bottom) (pref-ptr wp 3) (pref-ptr hp 3) (pref-ptr cp 3) 4))
          (left_data (stbi_load (cstring left) (pref-ptr wp 4) (pref-ptr hp 4) (pref-ptr cp 4) 4))
          (right_data (stbi_load (cstring right) (pref-ptr wp 5) (pref-ptr hp 5) (pref-ptr cp 5) 4))
          (w:i32 (pref wp 0))
          (h:i32 (pref hp 0))
          (c:i32 (pref cp 0))
          (whc:i64 (convert (* w h 4))) ;; always 4 channels
          (data:i8* (alloc (* whc 6)))) ;; always allocate 4 channels
      ;; (println "CUBE LOAD: width:" w "height:" h "channels:" c)
      (dotimes (i 6)
        (set! wpt (+ wpt (pref wp i)))
        (set! hpt (+ hpt (pref hp i)))
        (set! cpt (+ cpt (pref cp i))))
      (if (<> (/ wpt 6) w)
          (begin (println "Bad cube map!  All 6 images must have the same width!" w)
                 (set! front_data null)))
      (if (<> (/ hpt 6) h)
          (begin (println "Bad cube map!  All 6 images must have the same height!" h)
                 (set! front_data null)))
      (if (<> (/ cpt 6) c)
          (begin (println "Bad cube map!  All 6 images must have the same number of components" c)
                 (set! front_data null)))
      (pset! width_ptr 0 w)
      (pset! height_ptr 0 h)
      (pset! comp_ptr 0 4) ;; we actually forced (stbi_load ... 4) to 4 channels
      (tset! tex 1 GL_RGBA) ;; 4 componenets
      (if (or (null? front_data)
              (null? back_data)
              (null? top_data)
              (null? bottom_data)
              (null? left_data)
              (null? right_data))
          (begin
            (println "failed to load some images" (stbi_failure_reason))
            1)
          (begin
            ;; front
            (memcpy (pref-ptr data (* whc 0)) front_data whc)
            ;; back
            (memcpy (pref-ptr data (* whc 1)) back_data whc)
            ;; top
            (memcpy (pref-ptr data (* whc 2)) top_data whc)
            ;; bottom
            (memcpy (pref-ptr data (* whc 3)) bottom_data whc)
            ;; left
            (memcpy (pref-ptr data (* whc 4)) left_data whc)
            ;; right
            (memcpy (pref-ptr data (* whc 5)) right_data whc)
            ;; back
            (tset! tex 4 data)
            1))
      void)))