From 519bf8500be46ea3774b225ce8d322a1c769557c Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Sun, 3 Feb 2019 19:06:20 +0000
Subject: [PATCH] Prefer FBConfig with smaller depth + stencil buffer

Reduce GPU memory usage to what it was before fix-fbconfig.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 src/backend/gl/glx.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/backend/gl/glx.c b/src/backend/gl/glx.c
index b89d983..4de2d9b 100644
--- a/src/backend/gl/glx.c
+++ b/src/backend/gl/glx.c
@@ -10,6 +10,7 @@
  *
  */
 
+#include <limits.h>
 #include <GL/glx.h>
 #include <X11/Xlib-xcb.h>
 #include <assert.h>
@@ -96,8 +97,15 @@ glx_find_fbconfig(Display *dpy, int screen, xcb_render_pictforminfo_t *pictfmt,
 	} while (0)
 	int texture_tgts, y_inverted, texture_fmt;
 	bool found = false;
+	int min_cost = INT_MAX;
 	GLXFBConfig ret;
 	for (int i = 0; i < ncfg; i++) {
+		int depthbuf, stencil;
+		glXGetFBConfigAttribChecked(dpy, cfg[i], GLX_DEPTH_SIZE, &depthbuf);
+		glXGetFBConfigAttribChecked(dpy, cfg[i], GLX_STENCIL_SIZE, &stencil);
+		if (depthbuf + stencil >= min_cost) {
+			continue;
+		}
 		int red, green, blue;
 		glXGetFBConfigAttribChecked(dpy, cfg[i], GLX_RED_SIZE, &red);
 		glXGetFBConfigAttribChecked(dpy, cfg[i], GLX_BLUE_SIZE, &blue);
@@ -139,7 +147,7 @@ glx_find_fbconfig(Display *dpy, int screen, xcb_render_pictforminfo_t *pictfmt,
 		} else {
 			texture_fmt = rgb ? GLX_TEXTURE_FORMAT_RGB_EXT : GLX_TEXTURE_FORMAT_RGBA_EXT;
 		}
-		break;
+		min_cost = depthbuf + stencil;
 	}
 #undef glXGetFBConfigAttribChecked
 	free(cfg);