shader_update_matrices_lv   xtlang

;; when working with OpenGL
;; extempore's mmul is pre mutipled (not post as in GLSL)
;; so the same matrix mul is post in GLSL and pre in XTM (i.e. here!)
(bind-func shader_update_matrices_lv
  (let ((bias:float* (alloc 16)))
    (pfill! bias
            0.5 0.0 0.0 0.0
            0.0 0.5 0.0 0.0
            0.0 0.0 0.5 0.0
            0.5 0.5 0.5 1.0)
    (lambda (shader:ShaderProgram* m:float* v p:float* lv:float*) ;; lv light view
      (let ((mlv:float* (salloc 16))
            (mlvp:float* (salloc 16))
            (mlvpb:float* (salloc 16)))
        (mmmul m lv mlv)
        (mmmul mlv p mlvp)
        (mmmul mlvp bias mlvpb)
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "LightModelViewProjectionMatrix") 1 GL_FALSE mlvpb))
      (let ((mv (salloc 48))
            (mvp (pref-ptr mv 16))
            (mn (pref-ptr mv 32)))
        ;;(mmul m 4 4 v 4 4 mv) ;; final mv set
        (mmmul m v mv) ;; final mv set
        (mtrans mv 4 4 mn) ;; using mn as a temporary here!!
        (minverse mn 4 mvp) ;; using mvp as a temporary
        (mat4_to_mat3 mvp mn)  ;; final mn set
        ;;(mmul mv 4 4 p 4 4 mvp) ;; final mvp set
        (mmmul mv p mvp) ;; final mvp set
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "ModelMatrix") 1 GL_FALSE m)
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "ViewMatrix") 1 GL_FALSE v)
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "ProjectionMatrix") 1 GL_FALSE p)
        (glUniformMatrix3fv (glGetUniformLocation (id shader) "NormalMatrix") 1 GL_FALSE mn)
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "ModelViewMatrix") 1 GL_FALSE mv)
        (glUniformMatrix4fv (glGetUniformLocation (id shader) "ModelViewProjectionMatrix") 1 GL_FALSE mvp)
        void))))