render: context: Use GL parameters.

* sly/render/context.scm (%set-render-context-blend-mode!,
  %set-render-context-depth-test!?, %set-render-context-texture!,
  %set-render-context-shader!, %set-render-context-mesh!): Delete.
  (make-render-context): Create GL parameters.
  (render-context-reset!): Reset GL parameters.
  (define-context-setter): New syntax.
  (set-render-context-blend-mode!, set-render-context-depth-test!?,
  set-render-context-texture!, set-render-context-shader!,
  set-render-context-mesh!): Define in terms of 'define-context-setter'.

1 files changed, 34 insertions, 54 deletions

diff --git a/sly/render/context.scm b/sly/render/context.scm
index aec04b0..1e23f17 100644
--- a/sly/render/context.scm
+++ b/sly/render/context.scm
@@ -65,11 +65,11 @@
   (%make-render-context blend-mode depth-test? texture shader
                         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!)
-  (mesh render-context-mesh %set-render-context-mesh!)
+  (blend-mode render-context-blend-mode)
+  (depth-test? render-context-depth-test?)
+  (texture render-context-texture)
+  (shader render-context-shader)
+  (mesh render-context-mesh)
   (transform-stack render-context-transform-stack))
 
 (define (make-null-transform)
@@ -84,64 +84,44 @@
     stack))
 
 (define* (make-render-context #:optional (transform-stack-size 32))
-  (%make-render-context #f #f #f #f #f
+  (%make-render-context (make-gl-parameter #f apply-blend-mode)
+                        (make-gl-parameter #t apply-depth-test)
+                        (make-gl-parameter null-texture apply-texture)
+                        (make-gl-parameter null-shader-program
+                                           apply-shader-program)
+                        (make-gl-parameter null-mesh apply-mesh)
                         (make-transform-stack transform-stack-size)))
 
 (define (render-context-reset! context)
-  (gl-disable (enable-cap blend))
-  (%set-render-context-blend-mode! context #f)
-  (gl-disable (enable-cap depth-test))
-  (%set-render-context-depth-test?! context #f)
-  (glBindTexture (texture-target texture-2d) 0)
-  (%set-render-context-texture! context null-texture)
-  (glUseProgram 0)
-  (%set-render-context-shader! context #f)
-  (glBindVertexArray 0)
-  (%set-render-context-mesh! context null-mesh))
+  (gl-parameter-reset! (render-context-blend-mode context))
+  (gl-parameter-reset! (render-context-depth-test? context))
+  (gl-parameter-reset! (render-context-texture context))
+  (gl-parameter-reset! (render-context-shader context))
+  (gl-parameter-reset! (render-context-mesh context)))
 
 (define-syntax-rule (with-render-context context body ...)
   (begin (render-context-reset! context)
          body ...
          (render-context-reset! context)))
 
-(define (set-render-context-blend-mode! context blend-mode)
-  (unless (equal? (render-context-blend-mode context) blend-mode)
-    (if blend-mode
-        (begin
-          (gl-enable (enable-cap blend))
-          (apply-blend-mode blend-mode))
-        ;; Turn off blending if there is no blend-mode specified.
-        (gl-disable (enable-cap blend)))
-    (%set-render-context-blend-mode! context blend-mode)))
-
-(define (set-render-context-depth-test?! context depth-test?)
-  (unless (eq? (render-context-depth-test? context) depth-test?)
-    (if depth-test?
-        (gl-enable (enable-cap depth-test))
-        (gl-disable (enable-cap depth-test)))
-    (%set-render-context-depth-test?! context depth-test?)))
-
-(define (set-render-context-texture! context texture)
-  (let ((current-texture (render-context-texture context)))
-    (unless (equal? current-texture texture)
-      (if texture
-          (begin
-            ;; Enable texturing if it was disabled.
-            (unless current-texture
-              (gl-enable (enable-cap texture-2d)))
-            (apply-texture texture))
-          (gl-disable (enable-cap texture-2d)))
-      (%set-render-context-texture! context texture))))
-
-(define (set-render-context-shader! context shader)
-  (unless (equal? (render-context-shader context) shader)
-    (apply-shader-program shader)
-    (%set-render-context-shader! context shader)))
-
-(define (set-render-context-mesh! context mesh)
-  (unless (equal? (render-context-mesh context) mesh)
-    (apply-mesh mesh)
-    (%set-render-context-mesh! context mesh)))
+(define-syntax-rule (define-context-setter name accessor)
+  (define (name context value)
+    (gl-parameter-set! (accessor context) value)))
+
+(define-context-setter set-render-context-blend-mode!
+  render-context-blend-mode)
+
+(define-context-setter set-render-context-depth-test?!
+  render-context-depth-test?)
+
+(define-context-setter set-render-context-texture!
+  render-context-texture)
+
+(define-context-setter set-render-context-shader!
+  render-context-shader)
+
+(define-context-setter set-render-context-mesh!
+  render-context-mesh)
 
 ;; emacs: (put 'with-temp-transform 'scheme-indent-function 2)
 (define-syntax-rule (with-temp-transform context name body ...)