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authorDavid Thompson <dthompson2@worcester.edu>2014-10-25 11:20:03 -0400
committerDavid Thompson <dthompson2@worcester.edu>2014-10-25 11:20:03 -0400
commitc486ff8e897fda698ee1d2efcb982eb30ffca24a (patch)
treee642c37168c7643236ba043bf954989ac9bc8228
parent9d57623ae8da659153e0aa69f0316b06aed3566e (diff)
render: Add simple renderer.
* sly/render/renderer.scm: New file. * Makefile.am (SOURCES): Add it.
-rw-r--r--Makefile.am1
-rw-r--r--sly/render/renderer.scm110
2 files changed, 111 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am
index fbf85ae..d84c5ac 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -54,6 +54,7 @@ SOURCES = \
sly/window.scm \
sly/joystick.scm \
sly/render/vertex-array.scm \
+ sly/render/renderer.scm \
$(WRAPPER_SOURCES)
WRAPPER_SOURCES = \
diff --git a/sly/render/renderer.scm b/sly/render/renderer.scm
new file mode 100644
index 0000000..857c8bc
--- /dev/null
+++ b/sly/render/renderer.scm
@@ -0,0 +1,110 @@
+;;; 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:
+;;
+;; OpenGL renderer.
+;;
+;;; Code:
+
+(define-module (sly render renderer)
+ #:use-module (system foreign)
+ #:use-module (ice-9 match)
+ #:use-module (srfi srfi-9)
+ #:use-module (srfi srfi-26)
+ #:use-module (gl)
+ #:use-module (gl low-level)
+ #:use-module (sly camera)
+ #:use-module (sly shader)
+ #:use-module (sly texture)
+ #:use-module (sly transform)
+ #:use-module (sly render vertex-array)
+ #:export (make-render-op render-op?
+ render-op-transform render-op-vertex-array
+ render-op-texture render-op-shader
+ render-op-uniforms
+ make-renderer renderer?
+ renderer-cameras renderer-ops
+ render))
+
+;; Representation of a single OpenGL render call.
+(define-record-type <render-op>
+ (%make-render-op transform vertex-array texture shader uniforms
+ depth-test?)
+ render-op?
+ (transform render-op-transform)
+ (vertex-array render-op-vertex-array)
+ (texture render-op-texture)
+ (shader render-op-shader)
+ (uniforms render-op-uniforms)
+ (depth-test? render-op-depth-test?))
+
+(define* (make-render-op #:optional #:key (transform identity-transform)
+ (vertex-array #f) (texture #f) (shader #f)
+ (uniforms '()) (depth-test? #t))
+ "Create a new render operation object. Optional arguments include:
+TRANSFORM, a model transformation matrix. VERTEX-ARRAY, the geometry
+container. TEXTURE, the texture object to bind. SHADER, the shader
+program to bind. UNIFORMS, the variables to be passed to the shader.
+And DEPTH-TEST?, a flag that determines whether the depth buffer is
+activated or not."
+ (%make-render-op transform vertex-array texture shader uniforms depth-test?))
+
+(define-syntax-rule (with-texture-maybe texture body ...)
+ (if texture
+ (with-texture texture body ...)
+ (begin body ...)))
+
+(define (apply-render-op view op)
+ "Render the contents of OP. The transform of OP is multiplied by
+the VIEW transform before rendering and passed to the shader as the
+uniform variable 'mvp'."
+ (match op
+ (($ <render-op> transform vertex-array texture shader uniforms depth-test?)
+ (when depth-test?
+ (gl-enable (enable-cap depth-test)))
+ (with-shader-program shader
+ (for-each (lambda (uniform)
+ (match uniform
+ ((name value)
+ (uniform-set! shader name value))))
+ `(("mvp" ,(transform* view transform))
+ ,@uniforms))
+ (with-vertex-array vertex-array
+ (with-texture-maybe texture
+ (glDrawElements (begin-mode triangles)
+ (vertex-array-length vertex-array)
+ (data-type unsigned-int)
+ %null-pointer))))
+ (when depth-test?
+ (gl-disable (enable-cap depth-test))))))
+
+(define-record-type <renderer>
+ (make-renderer cameras ops)
+ renderer?
+ (cameras renderer-cameras)
+ (ops renderer-ops))
+
+(define (render renderer)
+ "Apply all of the render operations in RENDERER. The render
+operations are applied once for each camera."
+ (define (render-with-camera camera)
+ (let ((view (transform* (camera-projection camera)
+ (camera-location camera))))
+ (for-each (cut apply-render-op view <>)
+ (renderer-ops renderer))))
+ (for-each render-with-camera (renderer-cameras renderer)))