#|
  This file is a part of stoe project.
  Copyright (c) 2015 Renaud Casenave-Péré (renaud@casenave-pere.fr)
|#

(uiop:define-package :stoe/engine/shaders
  (:nicknames :shaders)
  (:use :stoe/shader/compiler))
(in-package :stoe/engine/shaders)

(defshader simple-vertex ((position :vec4 :in)
                          (color :vec4 :in)
                          (out-color :vec4 :out :interp :smooth)
                          (camera-to-clip :mat4 :uniform)
                          (model-to-camera :mat4 :uniform))
  (setf gl-position (* camera-to-clip model-to-camera position)
        out-color color))

(defshader simple-fragment ((out-color :vec4 :in :interp :smooth)
                            (frag-color :vec4 :out))
  (setf frag-color out-color))

(defprogram simple-shader ()
  :vertex-shader simple-vertex
  :fragment-shader simple-fragment)

(defshader nocolor-vertex ((position :vec4 :in)
                           (camera-to-clip :mat4 :uniform)
                           (model-to-camera :mat4 :uniform))
  (setf gl-position (* camera-to-clip model-to-camera position)))

(defshader blue-fragment ((frag-color :vec4 :out))
  (setf frag-color (vec4 0.0 0.0 1.0 0.0)))

(defprogram blue-shader ()
  :vertex-shader nocolor-vertex
  :fragment-shader blue-fragment)