examples/shader.lisp

   1 (require '#:asdf)
   2 (asdf:oos 'asdf:load-op '#:cl-glfw-opengl-version_2_0)
   3
   4 (defparameter *shader-program* nil)
   5 (defparameter *uniform-time* nil)
   6
   7 (glfw:do-window ("An OpenGL 2.0 Shader Example")
   8     ((gl:with-setup-projection
   9        (glu:perspective 45 4/3 0.1 50))
  10      (setf *shader-program*
  11            (gl:make-program
  12             (gl:make-shader gl:+vertex-shader+ "
  13 varying vec3 colour;
  14 void main()
  15 {
  16   colour = gl_Color.rgb;
  17   gl_Position = ftransform();
  18 }
  19 ")
  20             (gl:make-shader gl:+fragment-shader+ "
  21 uniform float time;
  22 varying vec3 colour;
  23 const float pi2=2.0*3.14159265;
  24 void main()
  25 {
  26   gl_FragColor = vec4(pow(sin(colour.r*pi2*4.0+mod(time*8.0,pi2)),2.0),
  27                       pow(sin(colour.g*pi2*4.0+mod(time*8.0,pi2)),2.0),
  28                       pow(sin(colour.b*pi2*4.0+mod(time*8.0,pi2)),2.0),
  29                       1.0);
  30 }
  31 ")))
  32      (gl:use-program *shader-program*)
  33      (setf *uniform-time* (gl:get-uniform-location *shader-program* "time")))
  34   (gl:clear gl:+color-buffer-bit+)
  35   (gl:load-identity)
  36   (gl:translate-f 0 0 -5)
  37   (gl:rotate-d (* 10 (glfw:get-time)) 1 1 0)
  38   (gl:rotate-d (* 90 (glfw:get-time)) 0 0 1)
  39   (gl:uniform-1f *uniform-time* (coerce (glfw:get-time) 'single-float))
  40   (gl:with-begin gl:+triangles+
  41     (gl:color-3f 1 0 0) (gl:vertex-3f  1  0 0)
  42     (gl:color-3f 0 1 0) (gl:vertex-3f -1  1 0)
  43     (gl:color-3f 0 0 1) (gl:vertex-3f -1 -1 0)))