Commit 1e07dba09b0a3ee6a39fdbd1ebaa46fedd3b2d4e
2021-06-09T15:26:38
x11: Use glXChooseFBConfig when available in X11_GL_GetVisual When choosing an X11 Visual for a window based on its GLX capabilities, first try glXChooseFBConfig (if available) before falling back to glXChooseVisual. This normally does not make a difference because most GLX drivers create a Visual for every GLXFBConfig, exposing all of the same capabilities. For GLX render offload configurations (also know as "PRIME") where one GPU is providing GLX rendering support for windows on an X screen running on a different GPU, the GPU doing the offloading needs to use the Visuals that were created by the host GPU's driver rather than being able to add its own. This means that there may be fewer Visuals available for all of the GLXFBConfigs the guest driver wants to expose. In order to handle that situation, the NVIDIA GLX driver creates many GLXFBConfigs that map to the same Visual when running in a render offload configuration. This can result in a glXChooseVisual request failing to find a supported Visual when there is a GLXFBConfig for that configuration that would have worked. For example, when the game "Unnamed SDVX Clone" [1] tries to create a configuration with multisample, glXChooseVisual fails because the Visual assigned to the multisample GLXFBConfigs is shared with the GLXFBConfigs without multisample. Avoid this problem by using glXChooseFBConfig, when available, to find a GLXFBConfig with the requested capabilities and then using glXGetVisualFromFBConfig to find the corresponding X11 Visual. This allows the game to run, although it doesn't make me any better at actually playing it... Signed-off-by: Aaron Plattner <aplattner@nvidia.com> Fixes: https://forums.developer.nvidia.com/t/prime-run-cannot-create-window-x-glxcreatecontext/180214 [1] https://github.com/Drewol/unnamed-sdvx-clone
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diff --git a/src/video/x11/SDL_x11opengl.c b/src/video/x11/SDL_x11opengl.c
index 0e7fed9..bb9baf4 100644
--- a/src/video/x11/SDL_x11opengl.c
+++ b/src/video/x11/SDL_x11opengl.c
@@ -1,6 +1,7 @@
/*
Simple DirectMedia Layer
Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
+ Copyright (C) 2021 NVIDIA Corporation
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
@@ -420,6 +421,9 @@ X11_GL_InitExtensions(_THIS)
_this->gl_data->glXChooseFBConfig =
(GLXFBConfig *(*)(Display *, int, const int *, int *))
X11_GL_GetProcAddress(_this, "glXChooseFBConfig");
+ _this->gl_data->glXGetVisualFromFBConfig =
+ (XVisualInfo *(*)(Display *, GLXFBConfig))
+ X11_GL_GetProcAddress(_this, "glXGetVisualFromFBConfig");
}
/* Check for GLX_EXT_visual_rating */
@@ -598,7 +602,7 @@ X11_GL_GetVisual(_THIS, Display * display, int screen)
{
/* 64 seems nice. */
int attribs[64];
- XVisualInfo *vinfo;
+ XVisualInfo *vinfo = NULL;
int *pvistypeattr = NULL;
if (!_this->gl_data) {
@@ -606,12 +610,33 @@ X11_GL_GetVisual(_THIS, Display * display, int screen)
return NULL;
}
- X11_GL_GetAttributes(_this, display, screen, attribs, 64, SDL_FALSE, &pvistypeattr);
- vinfo = _this->gl_data->glXChooseVisual(display, screen, attribs);
+ if (_this->gl_data->glXChooseFBConfig &&
+ _this->gl_data->glXGetVisualFromFBConfig) {
+ GLXFBConfig *framebuffer_config = NULL;
+ int fbcount = 0;
+
+ X11_GL_GetAttributes(_this, display, screen, attribs, 64, SDL_TRUE, &pvistypeattr);
+ framebuffer_config = _this->gl_data->glXChooseFBConfig(display, screen, attribs, &fbcount);
+ if (!framebuffer_config && (pvistypeattr != NULL)) {
+ *pvistypeattr = None;
+ framebuffer_config = _this->gl_data->glXChooseFBConfig(display, screen, attribs, &fbcount);
+ }
+
+ if (framebuffer_config) {
+ vinfo = _this->gl_data->glXGetVisualFromFBConfig(display, framebuffer_config[0]);
+ }
+
+ X11_XFree(framebuffer_config);
+ }
- if (!vinfo && (pvistypeattr != NULL)) {
- *pvistypeattr = None;
+ if (!vinfo) {
+ X11_GL_GetAttributes(_this, display, screen, attribs, 64, SDL_FALSE, &pvistypeattr);
vinfo = _this->gl_data->glXChooseVisual(display, screen, attribs);
+
+ if (!vinfo && (pvistypeattr != NULL)) {
+ *pvistypeattr = None;
+ vinfo = _this->gl_data->glXChooseVisual(display, screen, attribs);
+ }
}
if (!vinfo) {
diff --git a/src/video/x11/SDL_x11opengl.h b/src/video/x11/SDL_x11opengl.h
index 37ea20b..105c697 100644
--- a/src/video/x11/SDL_x11opengl.h
+++ b/src/video/x11/SDL_x11opengl.h
@@ -53,6 +53,7 @@ struct SDL_GLDriverData
GLXContext (*glXCreateContext) (Display*,XVisualInfo*,GLXContext,Bool);
GLXContext (*glXCreateContextAttribsARB) (Display*,GLXFBConfig,GLXContext,Bool,const int *);
GLXFBConfig *(*glXChooseFBConfig) (Display*,int,const int *,int *);
+ XVisualInfo *(*glXGetVisualFromFBConfig) (Display*,GLXFBConfig);
void (*glXDestroyContext) (Display*, GLXContext);
Bool(*glXMakeCurrent) (Display*,GLXDrawable,GLXContext);
void (*glXSwapBuffers) (Display*, GLXDrawable);