diff options
| -rw-r--r-- | include/SDL_hints.h | 16 | ||||
| -rw-r--r-- | src/video/SDL_video.c | 78 |
2 files changed, 92 insertions, 2 deletions
diff --git a/include/SDL_hints.h b/include/SDL_hints.h index ed6401a5..4f3a00f3 100644 --- a/include/SDL_hints.h +++ b/include/SDL_hints.h @@ -50,6 +50,22 @@ extern "C" { /* *INDENT-ON* */ #endif +/** + * \brief A variable controlling how 3D acceleration is used to accelerate the SDL 1.2 screen surface. + * + * SDL can try to accelerate the SDL 1.2 screen surface by using streaming + * textures with a 3D rendering engine. This variable controls whether and + * how this is done. + * + * This variable can be set to the following values: + * "0" - Disable 3D acceleration + * "1" - Enable 3D acceleration, using the default renderer. + * "X" - Enable 3D acceleration, using X where X is one of the valid rendering drivers. (e.g. "direct3d", "opengl", etc.) + * + * By default SDL tries to make a best guess for each platform whether + * to use acceleration or not. + */ +#define SDL_HINT_FRAMEBUFFER_ACCELERATION "SDL_FRAMEBUFFER_ACCELERATION" /** diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c index cbb19ad9..ed758027 100644 --- a/src/video/SDL_video.c +++ b/src/video/SDL_video.c @@ -107,6 +107,80 @@ typedef struct { int bytes_per_pixel; } SDL_WindowTextureData; +static SDL_bool +ShouldUseTextureFramebuffer() +{ + const char *hint; + + /* If there's no native framebuffer support then there's no option */ + if (!_this->CreateWindowFramebuffer) { + return SDL_TRUE; + } + + /* See if the user or application wants a specific behavior */ + hint = SDL_GetHint(SDL_HINT_FRAMEBUFFER_ACCELERATION); + if (hint) { + if (*hint == '0') { + return SDL_FALSE; + } else { + return SDL_TRUE; + } + } + + /* Each platform has different performance characteristics */ +#if defined(__WIN32__) + /* GDI BitBlt() is way faster than Direct3D dynamic textures right now. + */ + return SDL_FALSE; + +#elif defined(__MACOSX__) + /* Mac OS X uses OpenGL as the native fast path */ + return SDL_TRUE; + +#elif defined(__LINUX__) + /* Properly configured OpenGL drivers are faster than MIT-SHM */ +#if SDL_VIDEO_OPENGL + /* Ugh, find a way to cache this value! */ + { + SDL_Window *window; + SDL_GLContext context; + SDL_bool hasAcceleratedOpenGL = SDL_FALSE; + + window = SDL_CreateWindow("OpenGL test", -32, -32, 32, 32, SDL_WINDOW_OPENGL); + if (window) { + context = SDL_GL_CreateContext(window); + if (context) { + const GLubyte *(APIENTRY * glGetStringFunc) (GLenum); + const char *vendor = NULL; + + glGetStringFunc = SDL_GL_GetProcAddress("glGetString"); + if (glGetStringFunc) { + vendor = (const char *) glGetStringFunc(GL_VENDOR); + } + /* Add more vendors here at will... */ + if (vendor && + (SDL_strstr(vendor, "ATI Technologies") || + SDL_strstr(vendor, "NVIDIA"))) { + hasAcceleratedOpenGL = SDL_TRUE; + } + SDL_GL_DeleteContext(context); + } + SDL_DestroyWindow(window); + } + return hasAcceleratedOpenGL; + } +#else + return SDL_FALSE; +#endif + +#else + /* Play it safe, assume that if there is a framebuffer driver that it's + optimized for the current platform. + */ + return SDL_FALSE; +#endif +} + static int SDL_CreateWindowTexture(_THIS, SDL_Window * window, Uint32 * format, void ** pixels, int *pitch) { @@ -401,8 +475,8 @@ SDL_VideoInit(const char *driver_name) return (-1); } - /* Add the renderer framebuffer emulation if needed */ - if (!_this->CreateWindowFramebuffer) { + /* Add the renderer framebuffer emulation if desired */ + if (ShouldUseTextureFramebuffer()) { _this->CreateWindowFramebuffer = SDL_CreateWindowTexture; _this->UpdateWindowFramebuffer = SDL_UpdateWindowTexture; _this->DestroyWindowFramebuffer = SDL_DestroyWindowTexture; |