diff options
| author | David Thompson <dthompson2@worcester.edu> | 2016-01-08 21:38:32 -0500 |
|---|---|---|
| committer | David Thompson <dthompson2@worcester.edu> | 2016-01-08 21:38:32 -0500 |
| commit | 33863df70267b72aaeb94e4b1c0165cb1ec94b74 (patch) | |
| tree | 07e01a9629fdfaa199a04b56a21d5198c7af0302 | |
| parent | 6b2ecade1079c5bef1c066b9f092a8179d78d932 (diff) | |
video: Add SDL_GL_SetSwapInterval binding.
* sdl2/bindings.scm (sdl-gl-set-swap-interval): New procedure.
* sdl2/video.scm (set-gl-swap-interval!): New procedure.
| -rw-r--r-- | sdl2/bindings.scm | 3 | ||||
| -rw-r--r-- | sdl2/video.scm | 22 |
2 files changed, 24 insertions, 1 deletions
diff --git a/sdl2/bindings.scm b/sdl2/bindings.scm index 6c638ab..b6f9431 100644 --- a/sdl2/bindings.scm +++ b/sdl2/bindings.scm @@ -202,6 +202,9 @@ RETURN-TYPE and accept arguments of ARG-TYPES." (define-foreign sdl-gl-set-attribute int "SDL_GL_SetAttribute" (list int int)) +(define-foreign sdl-gl-set-swap-interval + int "SDL_GL_SetSwapInterval" (list int)) + (define-public SDL_RENDERER_SOFTWARE #x00000001) (define-public SDL_RENDERER_ACCELERATED #x00000002) (define-public SDL_RENDERER_PRESENTVSYNC #x00000004) diff --git a/sdl2/video.scm b/sdl2/video.scm index 7cf14ff..8c65023 100644 --- a/sdl2/video.scm +++ b/sdl2/video.scm @@ -56,7 +56,8 @@ delete-gl-context! call-with-gl-context swap-gl-window - set-gl-attribute!)) + set-gl-attribute! + set-gl-swap-interval!)) ;;; @@ -318,3 +319,22 @@ Possible values for ATTR are: ('framebuffer-srgb-capable ffi:SDL_GL_FRAMEBUFFER_SRGB_CAPABLE)))) (unless (zero? (ffi:sdl-gl-set-attribute attr-enum value)) (sdl-error "set-gl-attribute!" "failed to set OpenGL attribute")))) + +(define (set-gl-swap-interval! interval) + "Set the framebuffer swap interval for the current OpenGL context to +the type indicated by the symbol INTERVAL. Possible values of INTERVAL are: + +- immediate, for immediate updates +- vsync, for updates synchronized with the screen's vertical retrace +- late-swap-tear, for late swap tearing + +Late swap tearing works the same as vsync, but if the vertical retrace +has been missed for a given frame, buffers are swapped immediately, +which might be less jarring for the user during occasional framerate +drops." + (unless (zero? (ffi:sdl-gl-set-swap-interval + (match interval + ('immediate 0) + ('vsync 1) + ('late-swap-tear -1)))) + (sdl-error "set-gl-swap-interval!" "failed to set OpenGL swap interval"))) |