diff options
| -rw-r--r-- | Makefile.am | 1 | ||||
| -rw-r--r-- | sly/render/vertex-array.scm | 170 |
2 files changed, 171 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am index 84653e4..fbf85ae 100644 --- a/Makefile.am +++ b/Makefile.am @@ -53,6 +53,7 @@ SOURCES = \ sly/transition.scm \ sly/window.scm \ sly/joystick.scm \ + sly/render/vertex-array.scm \ $(WRAPPER_SOURCES) WRAPPER_SOURCES = \ diff --git a/sly/render/vertex-array.scm b/sly/render/vertex-array.scm new file mode 100644 index 0000000..fbe8f28 --- /dev/null +++ b/sly/render/vertex-array.scm @@ -0,0 +1,170 @@ +;;; 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 color) + #:use-module (sly shader) + #:export (make-vertex-array + vertex-array? + vertex-array-id vertex-array-length + 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-syntax-rule (with-vertex-array vao body ...) + (begin + (glBindVertexArray (vertex-array-id 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)) |