Add a few surface bindings.

* sdl2/bindings.scm (sdl-rw-from-file, sdl-free-surface,
  sdl-load-bmp-rw): New procedures.
* sdl2/surface.scm: New file.
* Makefile.am (SOURCES): Add it.

3 files changed, 86 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index bb37cb4..543b734 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -44,6 +44,7 @@ SOURCES =					\
   sdl2.scm					\
   sdl2/config.scm				\
   sdl2/bindings.scm				\
+  sdl2/surface.scm				\
   sdl2/render.scm				\
   sdl2/video.scm
 
diff --git a/sdl2/bindings.scm b/sdl2/bindings.scm
index 8925e6f..64e4313 100644
--- a/sdl2/bindings.scm
+++ b/sdl2/bindings.scm
@@ -228,3 +228,22 @@ RETURN-TYPE and accept arguments of ARG-TYPES."
 
 (define-foreign sdl-get-ticks
   uint32 "SDL_GetTicks" '())
+
+
+;;;
+;;; File I/O
+;;;
+
+(define-foreign sdl-rw-from-file
+  '* "SDL_RWFromFile" (list '* '*))
+
+
+;;;
+;;; Surface
+;;;
+
+(define-foreign sdl-free-surface
+  void "SDL_FreeSurface" '(*))
+
+(define-foreign sdl-load-bmp-rw
+  '* "SDL_LoadBMP_RW" (list '* int))
diff --git a/sdl2/surface.scm b/sdl2/surface.scm
new file mode 100644
index 0000000..b0a018b
--- /dev/null
+++ b/sdl2/surface.scm
@@ -0,0 +1,66 @@
+;;; guile-sdl2 --- FFI bindings for SDL2
+;;; Copyright © 2015 David Thompson <davet@gnu.org>
+;;;
+;;; This file is part of guile-sdl2.
+;;;
+;;; Guile-sdl2 is free software; you can redistribute it and/or modify
+;;; it under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation; either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-sdl2 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 Lesser General Public
+;;; License along with guile-sdl2.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; SDL surface manipulation.
+;;
+;;; Code:
+
+(define-module (sdl2 surface)
+  #:use-module (ice-9 format)
+  #:use-module (ice-9 match)
+  #:use-module (system foreign)
+  #:use-module ((sdl2 bindings) #:prefix ffi:)
+  #:use-module (sdl2)
+  #:export (surface?
+            delete-surface!
+            call-with-surface
+            load-bmp))
+
+(define-wrapped-pointer-type <surface>
+  surface?
+  wrap-surface unwrap-surface
+  (lambda (context port)
+    (format port "#<surface ~x>"
+            (pointer-address (unwrap-surface context)))))
+
+(define (delete-surface! surface)
+  "Free the memory used by SURFACE."
+  (ffi:sdl-free-surface (unwrap-surface surface)))
+
+(define (call-with-surface surface proc)
+  "Call PROC, passing it SURFACE and deleting SURFACE upon exit of
+PROC."
+  (dynamic-wind
+    (const #t)
+    (lambda ()
+      (proc surface))
+    (lambda ()
+      (delete-surface! surface))))
+
+;; The equivalent of the SDL_LoadBMP C macro.
+(define (load-bmp file)
+  "Create a new surface from the bitmap data in FILE."
+  (let ((ptr (ffi:sdl-load-bmp-rw (ffi:sdl-rw-from-file (string->pointer file)
+                                                        (string->pointer "rb"))
+                                  1)))
+    (if (null-pointer? ptr)
+        (sdl-error "load-bmp" "failed to load bitmap")
+        (wrap-surface ptr))))