From e455ed5e2d41cb5f8c0f4d536f650a40a9cdc534 Mon Sep 17 00:00:00 2001
From: Pierre-Antoine Rouby <contact@parouby.fr>
Date: Wed, 29 May 2019 22:43:27 +0200
Subject: render: Add SDL_RenderDrawPoints binding.

* sdl2/bindings.scm (sdl-render-draw-points): New procedure.
* sdl2/render.scm (render-draw-points): New procedure.
* doc/api.texi (Rendering): Document it.
---
 doc/api.texi      |  5 +++++
 sdl2/bindings.scm |  3 +++
 sdl2/render.scm   | 16 ++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/doc/api.texi b/doc/api.texi
index 0a154ae..b692725 100644
--- a/doc/api.texi
+++ b/doc/api.texi
@@ -1066,6 +1066,11 @@ Draw a point at (@var{x}, @var{y}) on the current rendering target
 of @var{renderer}.
 @end deffn
 
+@deffn {Procedure} render-draw-points renderer points
+Draw a multiple points from @var{points} on the current rendering
+target of @var{renderer}.
+@end deffn
+
 @deffn {Procedure} surface->texture renderer surface
 Convert @var{surface} to a texture suitable for @var{renderer}.
 @end deffn
diff --git a/sdl2/bindings.scm b/sdl2/bindings.scm
index c382a45..bf8db7a 100644
--- a/sdl2/bindings.scm
+++ b/sdl2/bindings.scm
@@ -255,6 +255,9 @@ RETURN-TYPE and accept arguments of ARG-TYPES."
 (define-foreign sdl-render-draw-point
   int "SDL_RenderDrawPoint" (list '* int int))
 
+(define-foreign sdl-render-draw-points
+  int "SDL_RenderDrawPoints" (list '* '* int))
+
 
 ;;;
 ;;; Events
diff --git a/sdl2/render.scm b/sdl2/render.scm
index 91236c6..326745f 100644
--- a/sdl2/render.scm
+++ b/sdl2/render.scm
@@ -40,6 +40,7 @@
             set-render-draw-color
             render-draw-line
             render-draw-point
+            render-draw-points
 
             delete-texture!
             surface->texture))
@@ -118,6 +119,21 @@ color."
   "Draw point on RENDERER."
   (ffi:sdl-render-draw-point (unwrap-renderer renderer) x y))
 
+(define (render-draw-points renderer points)
+  "Draw POINTS on RENDERER."
+  (define (fill-bv bv l n)
+    (match l
+      (() bv)
+      (((x y) . r)
+       (s32vector-set! bv n x)
+       (s32vector-set! bv (+ n 1) y)
+       (fill-bv bv r (+ 2 n)))))
+  (let* ((count (length points))
+         (bv (fill-bv (make-s32vector (* count 2)) points 0)))
+    (ffi:sdl-render-draw-points (unwrap-renderer renderer)
+                                (bytevector->pointer bv)
+                                count)))
+
 
 ;;;
 ;;; Texture
-- 
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