shader_update_matrices   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
  (lambda (shader:ShaderProgram* m v p)
    (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)
      (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)))