mesh-compiler.lisp

   1
   2
   3
   4 (in-package :mixamesh)
   5
   6
   7
   8 ;; as this uses extensions it has to be compiled and loaded with an active gl context
   9 (defun compile-mesh (mesh &rest args)
  10   "Given a mesh return a compiled mesh, which is a non-modifiable mesh optimised for rendering in foreign memory."
  11   (declare (ignorable args))
  12   (let ((self (gethash mesh *meshes*)))
  13     (flet ((make-buffer ()
  14              "Create a buffer-name for an OpenGL vertex buffer object"
  15              (let ((buffer-name (make-array 1 :element-type '(unsigned-byte 32))))
  16                (gl:gen-buffers-arb 1 buffer-name)
  17                (aref buffer-name 0))))
  18       (let ((result (make-instance 'compiled-mesh))
  19             (triangle-data (cffi::foreign-alloc :uint32 :count (* 3 (triangle-array-dimensions (faces-of self)))))
  20             (vertex-data (cffi:foreign-alloc :float :count (* 3 (vertex3d-array-dimensions (vertices-of self)))))
  21             (vertex-buffer (make-buffer))
  22             (triangle-buffer (make-buffer)))
  23         (flet ((copy-triangle-buffer ()
  24                  "Copy mesh triangle data into vertex buffer"
  25                  (iterate
  26                    (with face-index = 0)
  27                    (for (values a b c) in-triangles (faces-of self))
  28                    (setf (cffi:mem-aref triangle-data :uint32 face-index) a)
  29                    (incf face-index)
  30                    (setf (cffi:mem-aref triangle-data :uint32 face-index) b)
  31                    (incf face-index)
  32                    (setf (cffi:mem-aref triangle-data :uint32 face-index) c)
  33                    (incf face-index))
  34                  (gl:bind-buffer-arb gl:+element-array-buffer-arb+ triangle-buffer)
  35                  (gl:buffer-data-arb gl:+element-array-buffer-arb+
  36                                      (* 3 (triangle-array-dimensions (faces-of self)) (cffi:foreign-type-size :uint32))
  37                                      triangle-data
  38                                      gl:+static-draw-arb+))
  39                (copy-vertex-buffer ()
  40                  "Copy mesh vertex data into vertex buffer"
  41                  (iterate
  42                    (with vertex-index = 0)
  43                    (for (values x y z w) in-vertices (vertices-of self))
  44                    (setf (cffi:mem-aref vertex-data :float vertex-index) x)
  45                    (incf vertex-index)
  46                    (setf (cffi:mem-aref vertex-data :float vertex-index) y)
  47                    (incf vertex-index)
  48                    (setf (cffi:mem-aref vertex-data :float vertex-index) z)
  49                    (incf vertex-index))
  50                  (gl:bind-buffer-arb gl:+array-buffer-arb+ vertex-buffer)
  51                  (gl:buffer-data-arb gl:+array-buffer-arb+
  52                                      (* 3 (vertex3d-array-dimensions (vertices-of self)) (cffi:foreign-type-size :float))
  53                                      vertex-data
  54                                      gl:+static-draw-arb+)))
  55           (copy-vertex-buffer)
  56           (setf (slot-value result 'vertex-buffer) vertex-buffer)
  57           (copy-triangle-buffer)
  58           (setf (slot-value result 'triangle-buffer) triangle-buffer)
  59           (setf (slot-value result 'element-count) (* 3 (triangle-array-dimensions (faces-of self))))
  60           (cffi:foreign-free vertex-data)
  61           (cffi:foreign-free triangle-data)
  62           (setf (gethash mesh *compiled-meshes*) self))))))
  63
  64 (in-package :lambdamundo)
  65
  66 (defmethod render ((self compiled-mesh))
  67   (gl:enable-client-state gl:+vertex-array+)
  68   (gl:enable-client-state gl:+index-array+)
  69   (gl:bind-buffer-arb  gl:+array-buffer-arb+ (vertex-buffer-of self))
  70   (gl:bind-buffer-arb  gl:+element-array-buffer-arb+ (triangle-buffer-of self))
  71   (gl:vertex-pointer 3 gl:+float+ 0 0)
  72   (gl:draw-elements gl:+lines+  (element-count-of self) gl:+unsigned-int+ 0)
  73   (gl:disable-client-state gl:+vertex-array+)
  74   (gl:disable-client-state gl:+index-array+))
  75