Added a hint to determine whether framebuffer texture acceleration should be used, and added default behaviors for the various platforms.

This commit is contained in:
Sam Lantinga 2011-02-05 10:03:12 -08:00
parent 7f7bf51bdb
commit ce1ef46aeb
2 changed files with 92 additions and 2 deletions

View file

@ -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;