render: Rename vertex-array to mesh.

* sly/render/vertex-array.scm: Delete.
* Makefile.am (SOURCES): Delete it.
* sly/render/mesh.scm: Move vertex-array code and rename to mesh.
* sly/render/model.scm (draw-model): s/vertex-array/mesh/
* sly/render/context.scm: Likewise.
* sly/render/shape.scm (make-cube): Return a model object.
* sly/render/font.scm (make-label): Likewise.
* sly/render/sprite.scm (make-sprite): Likewise.  Remove 'color'
  parameter.
  (load-sprite): Likewise.

8 files changed, 258 insertions, 308 deletions

diff --git a/Makefile.am b/Makefile.am
index c43415e..68805f6 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -55,7 +55,6 @@ SOURCES = 					\
   sly/render/shape.scm				\
   sly/render/sprite.scm				\
   sly/render/tileset.scm			\
-  sly/render/vertex-array.scm			\
   sly/render/context.scm			\
   $(WRAPPER_SOURCES)
 
diff --git a/sly/render/context.scm b/sly/render/context.scm
index d3bd0c3..fb28eda 100644
--- a/sly/render/context.scm
+++ b/sly/render/context.scm
@@ -33,7 +33,7 @@
   #:use-module (sly render shader)
   #:use-module (sly render texture)
   #:use-module (sly render utils)
-  #:use-module (sly render vertex-array)
+  #:use-module (sly render mesh)
   #:export (make-render-context
             render-context?
             with-render-context with-temp-transform
@@ -41,17 +41,17 @@
             render-context-depth-test? set-render-context-depth-test?!
             render-context-texture set-render-context-texture!
             render-context-shader set-render-context-shader!
-            render-context-vertex-array set-render-context-vertex-array!))
+            render-context-mesh set-render-context-mesh!))
 
 (define-record-type <render-context>
   (%make-render-context blend-mode depth-test? texture shader
-                        vertex-array transform-stack)
+                        mesh transform-stack)
   render-context?
   (blend-mode render-context-blend-mode %set-render-context-blend-mode!)
   (depth-test? render-context-depth-test? %set-render-context-depth-test?!)
   (texture render-context-texture %set-render-context-texture!)
   (shader render-context-shader %set-render-context-shader!)
-  (vertex-array render-context-vertex-array %set-render-context-vertex-array!)
+  (mesh render-context-mesh %set-render-context-mesh!)
   (transform-stack render-context-transform-stack))
 
 (define (make-null-transform)
@@ -79,7 +79,7 @@
   (glUseProgram 0)
   (%set-render-context-shader! context #f)
   (glBindVertexArray 0)
-  (%set-render-context-vertex-array! context #f))
+  (%set-render-context-mesh! context #f))
 
 (define-syntax-rule (with-render-context context body ...)
   (begin (render-context-reset! context) body ...))
@@ -118,10 +118,10 @@
     (apply-shader-program shader)
     (%set-render-context-shader! context shader)))
 
-(define (set-render-context-vertex-array! context vertex-array)
-  (unless (equal? (render-context-vertex-array context) vertex-array)
-    (apply-vertex-array vertex-array)
-    (%set-render-context-vertex-array! context vertex-array)))
+(define (set-render-context-mesh! context mesh)
+  (unless (equal? (render-context-mesh context) mesh)
+    (apply-mesh mesh)
+    (%set-render-context-mesh! context mesh)))
 
 ;; emacs: (put 'with-temp-transform 'scheme-indent-function 2)
 (define-syntax-rule (with-temp-transform context name body ...)
diff --git a/sly/render/font.scm b/sly/render/font.scm
index 6be7353..e50c96a 100644
--- a/sly/render/font.scm
+++ b/sly/render/font.scm
@@ -116,7 +116,7 @@ HEIGHT, 32 bit color bytevector."
                   0 0 1 1)))
 
 (define* (make-label font text #:optional #:key
-                     (anchor 'top-left) (color white)
+                     (anchor 'top-left)
                      (shader (load-default-shader)))
   (let ((texture (render-text font text)))
-    (make-sprite texture #:shader shader #:anchor anchor #:color color)))
+    (make-sprite texture #:shader shader #:anchor anchor)))
diff --git a/sly/render/mesh.scm b/sly/render/mesh.scm
index 992ef85..98510d3 100644
--- a/sly/render/mesh.scm
+++ b/sly/render/mesh.scm
@@ -17,29 +17,157 @@
 
 ;;; Commentary:
 ;;
-;; A mesh is a 2D/3D model comprised of a shader and vertex buffers.
+;; Meshes encapsulate the geometry for a single OpenGL draw call.
 ;;
 ;;; Code:
 
 (define-module (sly render mesh)
-  #:use-module (oop goops)
+  #:use-module (system foreign)
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-9)
-  #:use-module (system foreign)
+  #:use-module (srfi srfi-43)
+  #:use-module (rnrs bytevectors)
   #:use-module (gl)
   #:use-module (gl low-level)
   #:use-module (sly wrappers gl)
+  #:use-module (sly math vector)
   #:use-module (sly render color)
   #:use-module (sly render shader)
-  #:use-module (sly render texture)
-  #:use-module (sly math vector)
-  #:use-module (sly signal)
-  #:use-module (sly math transform)
-  #:use-module (sly render utils)
-  #:use-module (sly render vertex-array)
-  #:use-module (sly render model)
-  #:export (make-mesh))
-
-(define* (make-mesh #:optional #:key shader texture indices positions textures)
-  (make-model #:shader shader #:texture texture
-              #:mesh (make-vertex-array indices positions textures)))
+  #:export (make-mesh
+            mesh?
+            mesh-id mesh-length
+            apply-mesh with-mesh))
+
+;;;
+;;; Vertex Buffer
+;;;
+
+(define-record-type <vertex-buffer>
+  (%make-vertex-buffer id type attr-size length)
+  vertex-buffer?
+  (id vertex-buffer-id)
+  (type vertex-buffer-type)
+  (attr-size vertex-buffer-attr-size)
+  (length vertex-buffer-length))
+
+(define (generate-vertex-buffer)
+  (let ((bv (u32vector 1)))
+    (glGenBuffers 1 (bytevector->pointer bv))
+    (u32vector-ref bv 0)))
+
+(define (bind-vertex-buffer vbo)
+  (glBindBuffer (vertex-buffer-type vbo)
+                (vertex-buffer-id vbo)))
+
+(define-syntax-rule (with-vertex-buffer vbo body ...)
+  (let ((type (vertex-buffer-type vbo)))
+    (glBindBuffer type (vertex-buffer-id vbo))
+    body ...
+    (glBindBuffer type 0)))
+
+(define (vertices-bytevector vertices index?)
+  (let* ((elem (vector-ref vertices 0))
+         (bv (if index?
+                 (make-u32vector (vector-length vertices))
+                 (make-f32vector (* (vector-length vertices)
+                                    (attribute-size elem)))))
+         (setter (if index? u32vector-set! f32vector-set!)))
+    (vector-for-each
+     (match-lambda*
+      ((i (? number? k))
+       (setter bv i k))
+      ((i ($ <vector2> x y))
+       (let ((offset (* i 2)))
+         (setter bv offset x)
+         (setter bv (1+ offset) y)))
+      ((i ($ <vector3> x y z))
+       (let ((offset (* i 3)))
+         (setter bv offset x)
+         (setter bv (1+ offset) y)
+         (setter bv (+ offset 2) z)))
+      ((i ($ <vector4> x y z w))
+       (let ((offset (* i 4)))
+         (setter bv offset x)
+         (setter bv (1+ offset) y)
+         (setter bv (+ offset 2) z)
+         (setter bv (+ offset 3) w)))
+      ((i (color? c))
+       (let ((offset (* i 4)))
+         (setter bv offset (color-r c))
+         (setter bv (1+ offset) (color-g c))
+         (setter bv (+ offset 2) (color-b c))
+         (setter bv (+ offset 3) (color-a c)))))
+     vertices)
+    bv))
+
+(define attribute-size
+  (match-lambda
+   ((? number? _) 1)
+   ((? vector2? _) 2)
+   ((? vector3? _) 3)
+   ((or (? vector4? _)
+        (? color? _))
+    4)
+   (attr
+    (error "Unsupported vertex buffer attribute: " attr))))
+
+(define (gl-buffer-type index?)
+  (if index?
+      (arb-vertex-buffer-object element-array-buffer-arb)
+      (arb-vertex-buffer-object array-buffer-arb)))
+
+(define* (make-vertex-buffer vertices #:optional (index? #f))
+  (let ((bv (vertices-bytevector vertices index?))
+        (vbo (%make-vertex-buffer (generate-vertex-buffer)
+                                  (gl-buffer-type index?)
+                                  (attribute-size (vector-ref vertices 0))
+                                  (vector-length vertices))))
+    (with-vertex-buffer vbo
+      (glBufferData (vertex-buffer-type vbo)
+                    (bytevector-length bv)
+                    (bytevector->pointer bv)
+                    (arb-vertex-buffer-object static-draw-arb)))
+    vbo))
+
+;;;
+;;; Mesh
+;;;
+
+(define-record-type <mesh>
+  (%make-mesh id length)
+  mesh?
+  (id mesh-id)
+  (length mesh-length))
+
+(define (generate-vertex-array)
+  (let ((bv (u32vector 1)))
+    (glGenVertexArrays 1 (bytevector->pointer bv))
+    (u32vector-ref bv 0)))
+
+(define (apply-mesh vao)
+  (glBindVertexArray (mesh-id vao)))
+
+;; emacs: (put 'with-mesh 'scheme-indent-function 1)
+(define-syntax-rule (with-mesh vao body ...)
+  (begin
+    (apply-mesh vao)
+    body ...
+    (glBindVertexArray 0)))
+
+(define (vertex-attrib-pointer location vbo)
+  (glEnableVertexAttribArray location)
+  (with-vertex-buffer vbo
+    (glVertexAttribPointer location (vertex-buffer-attr-size vbo)
+                           (data-type float) #f 0 %null-pointer)))
+
+(define (make-mesh indices positions textures)
+  (let ((mesh (%make-mesh (generate-vertex-array)
+                          (vector-length indices)))
+        (positions (make-vertex-buffer positions))
+        (textures (make-vertex-buffer textures)))
+    (with-mesh mesh
+      (vertex-attrib-pointer vertex-position-location positions)
+      (if textures
+          (vertex-attrib-pointer vertex-texture-location textures))
+      (bind-vertex-buffer (make-vertex-buffer indices #t)))
+    mesh))
diff --git a/sly/render/model.scm b/sly/render/model.scm
index c766b76..7f9ead9 100644
--- a/sly/render/model.scm
+++ b/sly/render/model.scm
@@ -37,7 +37,7 @@
   #:use-module (sly render camera)
   #:use-module (sly render color)
   #:use-module (sly render context)
-  #:use-module (sly render vertex-array)
+  #:use-module (sly render mesh)
   #:export (make-model model model-inherit
             model?
             model-mesh model-texture model-shader model-color
@@ -49,8 +49,6 @@
 (define-record-type <model>
   (%make-model mesh texture shader color blend-mode depth-test?)
   model?
-  ;; This is a vertex array.
-  ;; TODO: Rename <vertex-array> to mesh and remove old mesh type.
   (mesh model-mesh)
   (texture model-texture)
   (shader model-shader)
@@ -103,13 +101,13 @@ CONTEXT."
        (set-render-context-depth-test?! context depth-test?)
        (set-render-context-blend-mode! context blend-mode)
        (set-render-context-shader! context shader)
-       (set-render-context-vertex-array! context mesh)
+       (set-render-context-mesh! context mesh)
        (set-render-context-texture! context texture)
        ;; TODO: Support user-defined uniforms.
        (uniform-set! shader "mvp" mvp)
        (uniform-set! shader "color" color)
        (glDrawElements (begin-mode triangles)
-                       (vertex-array-length mesh)
+                       (mesh-length mesh)
                        (data-type unsigned-int)
                        %null-pointer)))))
 
diff --git a/sly/render/shape.scm b/sly/render/shape.scm
index d6d9bf3..2df6b93 100644
--- a/sly/render/shape.scm
+++ b/sly/render/shape.scm
@@ -24,6 +24,7 @@
 (define-module (sly render shape)
   #:use-module (sly math)
   #:use-module (sly render mesh)
+  #:use-module (sly render model)
   #:use-module (sly render shader)
   #:use-module (sly render texture)
   #:use-module (sly math vector)
@@ -31,86 +32,84 @@
 
 (define* (make-cube size #:optional #:key (texture #f)
                     (shader (load-default-shader)))
-  (let ((half-size (half size)))
-    (make-mesh
-     #:shader shader
-     #:texture texture
-     #:indices #(
-                 ;; Front
-                 0 3 2 0 2 1
-                   ;; Back
-                   4 6 7 4 5 6
-                   ;; Top
-                   8 11 10 8 10 9
-                   ;; Bottom
-                   12 14 15 12 13 14
-                   ;; Left
-                   16 19 18 16 18 17
-                   ;; Right
-                   20 22 23 20 21 22)
-     #:positions (vector
-                  ;; Front
-                  (vector3 (- half-size) (- half-size) (- half-size))
-                  (vector3 half-size (- half-size) (- half-size))
-                  (vector3 half-size half-size (- half-size))
-                  (vector3 (- half-size) half-size (- half-size))
-                  ;; Back
-                  (vector3 (- half-size) (- half-size) half-size)
-                  (vector3 half-size (- half-size) half-size)
-                  (vector3 half-size half-size half-size)
-                  (vector3 (- half-size) half-size half-size)
-                  ;; Top
-                  (vector3 (- half-size) half-size (- half-size))
-                  (vector3 half-size half-size (- half-size))
-                  (vector3 half-size half-size half-size)
-                  (vector3 (- half-size) half-size half-size)
-                  ;; Bottom
-                  (vector3 (- half-size) (- half-size) (- half-size))
-                  (vector3 half-size (- half-size) (- half-size))
-                  (vector3 half-size (- half-size) half-size)
-                  (vector3 (- half-size) (- half-size) half-size)
-                  ;; Left
-                  (vector3 (- half-size) (- half-size) (- half-size))
-                  (vector3 (- half-size) half-size (- half-size))
-                  (vector3 (- half-size) half-size half-size)
-                  (vector3 (- half-size) (- half-size) half-size)
-                  ;; Right
-                  (vector3 half-size (- half-size) (- half-size))
-                  (vector3 half-size half-size (- half-size))
-                  (vector3 half-size half-size half-size)
-                  (vector3 half-size (- half-size) half-size))
-     #:textures (let ((s1 (texture-s1 texture))
-                      (t1 (texture-t1 texture))
-                      (s2 (texture-s2 texture))
-                      (t2 (texture-t2 texture)))
-                  (vector
-                   ;; Front
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2)
-                   ;; Back
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2)
-                   ;; Top
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2)
-                   ;; Bottom
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2)
-                   ;; Left
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2)
-                   ;; Right
-                   (vector2 s1 t1)
-                   (vector2 s2 t1)
-                   (vector2 s2 t2)
-                   (vector2 s1 t2))))))
+  (let* ((half-size (half size))
+         (mesh (make-mesh #(
+                            ;; Front
+                            0 3 2 0 2 1
+                              ;; Back
+                              4 6 7 4 5 6
+                              ;; Top
+                              8 11 10 8 10 9
+                              ;; Bottom
+                              12 14 15 12 13 14
+                              ;; Left
+                              16 19 18 16 18 17
+                              ;; Right
+                              20 22 23 20 21 22)
+                          (vector
+                           ;; Front
+                           (vector3 (- half-size) (- half-size) (- half-size))
+                           (vector3 half-size (- half-size) (- half-size))
+                           (vector3 half-size half-size (- half-size))
+                           (vector3 (- half-size) half-size (- half-size))
+                           ;; Back
+                           (vector3 (- half-size) (- half-size) half-size)
+                           (vector3 half-size (- half-size) half-size)
+                           (vector3 half-size half-size half-size)
+                           (vector3 (- half-size) half-size half-size)
+                           ;; Top
+                           (vector3 (- half-size) half-size (- half-size))
+                           (vector3 half-size half-size (- half-size))
+                           (vector3 half-size half-size half-size)
+                           (vector3 (- half-size) half-size half-size)
+                           ;; Bottom
+                           (vector3 (- half-size) (- half-size) (- half-size))
+                           (vector3 half-size (- half-size) (- half-size))
+                           (vector3 half-size (- half-size) half-size)
+                           (vector3 (- half-size) (- half-size) half-size)
+                           ;; Left
+                           (vector3 (- half-size) (- half-size) (- half-size))
+                           (vector3 (- half-size) half-size (- half-size))
+                           (vector3 (- half-size) half-size half-size)
+                           (vector3 (- half-size) (- half-size) half-size)
+                           ;; Right
+                           (vector3 half-size (- half-size) (- half-size))
+                           (vector3 half-size half-size (- half-size))
+                           (vector3 half-size half-size half-size)
+                           (vector3 half-size (- half-size) half-size))
+                          (let ((s1 (texture-s1 texture))
+                                (t1 (texture-t1 texture))
+                                (s2 (texture-s2 texture))
+                                (t2 (texture-t2 texture)))
+                            (vector
+                             ;; Front
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2)
+                             ;; Back
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2)
+                             ;; Top
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2)
+                             ;; Bottom
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2)
+                             ;; Left
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2)
+                             ;; Right
+                             (vector2 s1 t1)
+                             (vector2 s2 t1)
+                             (vector2 s2 t2)
+                             (vector2 s1 t2))))))
+    (make-model #:mesh mesh #:texture texture #:shader shader)))
diff --git a/sly/render/sprite.scm b/sly/render/sprite.scm
index 950a81b..a4e4cd4 100644
--- a/sly/render/sprite.scm
+++ b/sly/render/sprite.scm
@@ -34,6 +34,7 @@
   #:use-module (sly utils)
   #:use-module (sly math)
   #:use-module (sly render mesh)
+  #:use-module (sly render model)
   #:use-module (sly render shader)
   #:use-module (sly signal)
   #:use-module (sly render texture)
@@ -48,8 +49,7 @@
 
 (define* (make-sprite texture #:optional #:key
                       (shader (load-default-shader))
-                      (anchor 'center)
-                      (color white))
+                      (anchor 'center))
   "Return a 2D rectangular mesh that displays the image TEXTURE.  The
 size of the mesh is the size of TEXTURE, in pixels.  Optionally, a
 custom SHADER can be specified."
@@ -61,28 +61,27 @@ custom SHADER can be specified."
          (s1 (texture-s1 texture))
          (t1 (texture-t1 texture))
          (s2 (texture-s2 texture))
-         (t2 (texture-t2 texture)))
-    (make-mesh
-     #:shader shader
-     #:texture texture
-     #:indices #(0 3 2 0 2 1)
-     #:positions (vector
-                  (vector3 x1 y1 0)
-                  (vector3 x2 y1 0)
-                  (vector3 x2 y2 0)
-                  (vector3 x1 y2 0))
-     #:textures (vector
-                 (vector2 s1 t1)
-                 (vector2 s2 t1)
-                 (vector2 s2 t2)
-                 (vector2 s1 t2)))))
+         (t2 (texture-t2 texture))
+         (mesh (make-mesh #(0 3 2 0 2 1)
+                          (vector
+                           (vector3 x1 y1 0)
+                           (vector3 x2 y1 0)
+                           (vector3 x2 y2 0)
+                           (vector3 x1 y2 0))
+                          (vector
+                           (vector2 s1 t1)
+                           (vector2 s2 t1)
+                           (vector2 s2 t2)
+                           (vector2 s1 t2)))))
+    (make-model #:shader shader
+                #:texture texture
+                #:mesh mesh)))
 
 (define* (load-sprite file-name #:optional #:key (shader (load-default-shader))
-                      (anchor 'center) (color white))
+                      (anchor 'center))
   "Return a sprite mesh for the texture loaded from FILE-NAME.
 Optionally, a custom SHADER can be specified."
-  (make-sprite (load-texture file-name) #:shader shader
-               #:anchor anchor #:color color))
+  (make-sprite (load-texture file-name) #:shader shader #:anchor anchor))
 
 (define* (make-animated-sprite textures frame-duration #:optional #:key
                                (loop? #t)
diff --git a/sly/render/vertex-array.scm b/sly/render/vertex-array.scm
deleted file mode 100644
index 45fcdd7..0000000
--- a/sly/render/vertex-array.scm
+++ /dev/null
@@ -1,173 +0,0 @@
-;;; Sly
-;;; Copyright (C) 2014 David Thompson <davet@gnu.org>
-;;;
-;;; Sly is free software: you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation, either version 3 of the License, or
-;;; (at your option) any later version.
-;;;
-;;; Sly is distributed in the hope that it will be useful, but WITHOUT
-;;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-;;; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
-;;; License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with this program.  If not, see
-;;; <http://www.gnu.org/licenses/>.
-
-;;; Commentary:
-;;
-;; Vertex arrays encapsulate the geometry for a single OpenGL draw
-;; call.
-;;
-;;; Code:
-
-(define-module (sly render vertex-array)
-  #:use-module (system foreign)
-  #:use-module (ice-9 match)
-  #:use-module (srfi srfi-9)
-  #:use-module (srfi srfi-43)
-  #:use-module (rnrs bytevectors)
-  #:use-module (gl)
-  #:use-module (gl low-level)
-  #:use-module (sly wrappers gl)
-  #:use-module (sly math vector)
-  #:use-module (sly render color)
-  #:use-module (sly render shader)
-  #:export (make-vertex-array
-            vertex-array?
-            vertex-array-id vertex-array-length
-            apply-vertex-array with-vertex-array))
-
-;;;
-;;; Vertex Buffers
-;;;
-
-(define-record-type <vertex-buffer>
-  (%make-vertex-buffer id type attr-size length)
-  vertex-buffer?
-  (id vertex-buffer-id)
-  (type vertex-buffer-type)
-  (attr-size vertex-buffer-attr-size)
-  (length vertex-buffer-length))
-
-(define (generate-vertex-buffer)
-  (let ((bv (u32vector 1)))
-    (glGenBuffers 1 (bytevector->pointer bv))
-    (u32vector-ref bv 0)))
-
-(define (bind-vertex-buffer vbo)
-  (glBindBuffer (vertex-buffer-type vbo)
-                (vertex-buffer-id vbo)))
-
-(define-syntax-rule (with-vertex-buffer vbo body ...)
-  (let ((type (vertex-buffer-type vbo)))
-    (glBindBuffer type (vertex-buffer-id vbo))
-    body ...
-    (glBindBuffer type 0)))
-
-(define (vertices-bytevector vertices index?)
-  (let* ((elem (vector-ref vertices 0))
-         (bv (if index?
-                 (make-u32vector (vector-length vertices))
-                 (make-f32vector (* (vector-length vertices)
-                                    (attribute-size elem)))))
-         (setter (if index? u32vector-set! f32vector-set!)))
-    (vector-for-each
-     (match-lambda*
-      ((i (? number? k))
-       (setter bv i k))
-      ((i ($ <vector2> x y))
-       (let ((offset (* i 2)))
-         (setter bv offset x)
-         (setter bv (1+ offset) y)))
-      ((i ($ <vector3> x y z))
-       (let ((offset (* i 3)))
-         (setter bv offset x)
-         (setter bv (1+ offset) y)
-         (setter bv (+ offset 2) z)))
-      ((i ($ <vector4> x y z w))
-       (let ((offset (* i 4)))
-         (setter bv offset x)
-         (setter bv (1+ offset) y)
-         (setter bv (+ offset 2) z)
-         (setter bv (+ offset 3) w)))
-      ((i (color? c))
-       (let ((offset (* i 4)))
-         (setter bv offset (color-r c))
-         (setter bv (1+ offset) (color-g c))
-         (setter bv (+ offset 2) (color-b c))
-         (setter bv (+ offset 3) (color-a c)))))
-     vertices)
-    bv))
-
-(define attribute-size
-  (match-lambda
-   ((? number? _) 1)
-   ((? vector2? _) 2)
-   ((? vector3? _) 3)
-   ((or (? vector4? _)
-        (? color? _))
-    4)
-   (attr
-    (error "Unsupported vertex buffer attribute: " attr))))
-
-(define (gl-buffer-type index?)
-  (if index?
-      (arb-vertex-buffer-object element-array-buffer-arb)
-      (arb-vertex-buffer-object array-buffer-arb)))
-
-(define* (make-vertex-buffer vertices #:optional (index? #f))
-  (let ((bv (vertices-bytevector vertices index?))
-        (vbo (%make-vertex-buffer (generate-vertex-buffer)
-                                  (gl-buffer-type index?)
-                                  (attribute-size (vector-ref vertices 0))
-                                  (vector-length vertices))))
-    (with-vertex-buffer vbo
-      (glBufferData (vertex-buffer-type vbo)
-                    (bytevector-length bv)
-                    (bytevector->pointer bv)
-                    (arb-vertex-buffer-object static-draw-arb)))
-    vbo))
-
-;;;
-;;; Vertex Arrays
-;;;
-
-(define-record-type <vertex-array>
-  (%make-vertex-array id length)
-  vertex-array?
-  (id vertex-array-id)
-  (length vertex-array-length))
-
-(define (generate-vertex-array)
-  (let ((bv (u32vector 1)))
-    (glGenVertexArrays 1 (bytevector->pointer bv))
-    (u32vector-ref bv 0)))
-
-(define (apply-vertex-array vao)
-  (glBindVertexArray (vertex-array-id vao)))
-
-(define-syntax-rule (with-vertex-array vao body ...)
-  (begin
-    (apply-vertex-array vao)
-    body ...
-    (glBindVertexArray 0)))
-
-(define (vertex-attrib-pointer location vbo)
-  (glEnableVertexAttribArray location)
-  (with-vertex-buffer vbo
-    (glVertexAttribPointer location (vertex-buffer-attr-size vbo)
-                           (data-type float) #f 0 %null-pointer)))
-
-(define (make-vertex-array indices positions textures)
-  (let ((vao (%make-vertex-array (generate-vertex-array)
-                                 (vector-length indices)))
-        (positions (make-vertex-buffer positions))
-        (textures (make-vertex-buffer textures)))
-    (with-vertex-array vao
-      (vertex-attrib-pointer vertex-position-location positions)
-      (if textures
-          (vertex-attrib-pointer vertex-texture-location textures))
-      (bind-vertex-buffer (make-vertex-buffer indices #t)))
-    vao))