Add renderer bindings.

* sdl2/bindings.scm (SDL_RENDERER_SOFTWARE, SDL_RENDERER_ACCELERATED,
  SDL_RENDERER_PRESENTVSYNC, SDL_RENDERER_TARGETTEXTURE): New variables.
  (sdl-create-renderer, sdl-destroy-renderer, sdl-render-clear,
  sdl-render-present, sdl-render-copy, sdl-create-texture-from-surface):
  New procedures.
* sdl2/render.scm: New file.
* Makefile.am (SOURCES): Add it.

1 files changed, 133 insertions, 0 deletions

diff --git a/sdl2/render.scm b/sdl2/render.scm
new file mode 100644
index 0000000..b0a5b57
--- /dev/null
+++ b/sdl2/render.scm
@@ -0,0 +1,133 @@
+;;; 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 2D accelerated rendering.
+;;
+;;; Code:
+
+(define-module (sdl2 render)
+  #:use-module (ice-9 format)
+  #:use-module (ice-9 match)
+  #:use-module (system foreign)
+  #:use-module (sdl2)
+  #:use-module ((sdl2 bindings) #:prefix ffi:)
+  #:export (make-renderer
+            renderer?
+            delete-renderer!
+            call-with-renderer
+            clear-renderer
+            present-renderer
+            render-copy
+
+            surface->texture))
+
+
+;;;
+;;; Renderer
+;;;
+
+(define-wrapped-pointer-type <renderer>
+  renderer?
+  wrap-renderer unwrap-renderer
+  (lambda (context port)
+    (format port "#<renderer ~x>"
+            (pointer-address (unwrap-renderer context)))))
+
+(define (renderer-flags->bitmask flags)
+  (apply logior
+         (map (match-lambda
+                ('software    ffi:SDL_RENDERER_SOFTWARE)
+                ('accelerated ffi:SDL_RENDERER_ACCELERATED)
+                ('vsync       ffi:SDL_RENDERER_PRESENTVSYNC)
+                ('texture     ffi:SDL_RENDERER_TARGETTEXTURE))
+              flags)))
+
+(define* (make-renderer window #:optional (flags '(accelerated vsync)))
+  "Return a new renderer for WINDOW created with the options specified
+in FLAGS, a list of symbols.  The valid symbols that may appear in
+FLAGS are:
+
+* software, to use a software renderer fallback
+* accelerated, to use hardware acceleration
+* vsync, to synchronize rendering with the monitor's refresh rate
+* texture, for render to texture support"
+  (let ((ptr (ffi:sdl-create-renderer ((@@ (sdl2 video) unwrap-sdl-window)
+                                       window)
+                                      -1 ; pick driver automatically
+                                      (renderer-flags->bitmask flags))))
+    (if (null-pointer? ptr)
+        (sdl-error "make-renderer" "failed to create renderer")
+        (wrap-renderer ptr))))
+
+(define (delete-renderer! renderer)
+  "Delete the rendering context RENDERER."
+  (ffi:sdl-destroy-renderer (unwrap-renderer renderer)))
+
+(define (call-with-renderer renderer proc)
+  "Call PROC, passing it RENDERER and closing RENDERER upon exit of
+PROC."
+  (dynamic-wind
+    (const #t)
+    (lambda ()
+      (proc renderer))
+    (lambda ()
+      (delete-renderer! renderer))))
+
+(define (clear-renderer renderer)
+  "Clear the rendering target RENDERER with the current drawing
+color."
+  (unless (zero? (ffi:sdl-render-clear (unwrap-renderer renderer)))
+    (sdl-error "clear-renderer!" "failed to clear renderer")))
+
+(define (present-renderer renderer)
+  "Display RENDERER."
+  (ffi:sdl-render-present (unwrap-renderer renderer)))
+
+
+;;;
+;;; Texture
+;;;
+
+(define-wrapped-pointer-type <texture>
+  texture?
+  wrap-texture unwrap-texture
+  (lambda (context port)
+    (format port "#<texture ~x>"
+            (pointer-address (unwrap-texture context)))))
+
+(define (surface->texture renderer surface)
+  "Convert SURFACE to a texture suitable for RENDERER."
+  (let ((ptr (ffi:sdl-create-texture-from-surface
+              (unwrap-renderer renderer)
+              ((@@ (sdl2 surface) unwrap-surface) surface))))
+    (if (null-pointer? ptr)
+        (sdl-error "surface->texture" "failed to convert surface to texture")
+        (wrap-texture ptr))))
+
+;; TODO: Add srcrect and dstrect.
+(define (render-copy renderer texture)
+  "Copy TEXTURE to the rendering target of RENDERER."
+  (let ((result (ffi:sdl-render-copy (unwrap-renderer renderer)
+                                     (unwrap-texture texture)
+                                     %null-pointer
+                                     %null-pointer)))
+    (unless (zero? result)
+      (sdl-error "render-copy" "failed to copy texture"))))