Add SDL2_image bindings.
authorDavid Thompson <dthompson2@worcester.edu>
Thu, 17 Dec 2015 04:15:21 +0000 (23:15 -0500)
committerDavid Thompson <dthompson2@worcester.edu>
Thu, 17 Dec 2015 04:15:21 +0000 (23:15 -0500)
* sdl2/bindings/image.scm: New file.
* sdl2/image.scm: New file.
* Makefile.am (SOURCES): Add them.

Makefile.am
sdl2/bindings/image.scm [new file with mode: 0644]
sdl2/image.scm [new file with mode: 0644]

index 80512fc..489c99e 100644 (file)
@@ -49,6 +49,14 @@ SOURCES =                                    \
   sdl2/video.scm                               \
   sdl2/events.scm
 
+if WITH_LIBSDL2_IMAGE
+
+SOURCES +=                                     \
+  sdl2/bindings/image.scm                      \
+  sdl2/image.scm
+
+endif
+
 EXTRA_DIST +=                                  \
   pre-inst-env.in                              \
   README                                       \
diff --git a/sdl2/bindings/image.scm b/sdl2/bindings/image.scm
new file mode 100644 (file)
index 0000000..cfdb31d
--- /dev/null
@@ -0,0 +1,56 @@
+;;; 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:
+;;
+;; Low-level FFI bindings for SDL2_image.
+;;
+;;; Code:
+
+(define-module (sdl2 bindings image)
+  #:use-module (system foreign)
+  #:use-module (sdl2 config))
+
+(define sdl-image-func
+  (let ((lib (dynamic-link %libsdl2-image)))
+    (lambda (return-type function-name arg-types)
+      "Return a procedure for the foreign function FUNCTION-NAME in
+the SDL2_image shared library.  That function must return a value of
+RETURN-TYPE and accept arguments of ARG-TYPES."
+      (pointer->procedure return-type
+                          (dynamic-func function-name lib)
+                          arg-types))))
+
+(define-syntax-rule (define-foreign name return-type func-name arg-types)
+  (define-public name
+    (sdl-image-func return-type func-name arg-types)))
+
+(define-public IMG_INIT_JPG  #x00000001)
+(define-public IMG_INIT_PNG  #x00000002)
+(define-public IMG_INIT_TIF  #x00000004)
+(define-public IMG_INIT_WEBP #x00000008)
+
+(define-foreign img-init
+  int "IMG_Init" (list int))
+
+(define-foreign img-quit
+  void "IMG_Quit" '())
+
+(define-foreign img-load
+  '* "IMG_Load" '(*))
diff --git a/sdl2/image.scm b/sdl2/image.scm
new file mode 100644 (file)
index 0000000..e741a04
--- /dev/null
@@ -0,0 +1,51 @@
+;;; 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:
+;;
+;; Image loading.
+;;
+;;; Code:
+
+(define-module (sdl2 image)
+  #:use-module (system foreign)
+  #:use-module (sdl2)
+  #:use-module ((sdl2 bindings image) #:prefix ffi:)
+  #:export (image-init
+            image-quit
+            load-image))
+
+(define (image-init)
+  "Initialize dynamically loaded image libraries."
+  (ffi:img-init (logior ffi:IMG_INIT_JPG
+                        ffi:IMG_INIT_PNG
+                        ffi:IMG_INIT_TIF
+                        ffi:IMG_INIT_WEBP))
+  *unspecified*)
+
+(define (image-quit)
+  "Clean up dynamically loaded image libraries."
+  (ffi:img-quit))
+
+(define (load-image file)
+  "Load the image in FILE and return an SDL surface."
+  (let ((ptr (ffi:img-load (string->pointer file))))
+    (if (null-pointer? ptr)
+        (sdl-error "load-image" "failed to load image: ~a" file)
+        ((@@ (sdl2 surface) wrap-surface) ptr))))