[Piglit] [PATCH] glx: Fix glx-swap-exchange

[Thomas Hellstrom]

Fix the following problems with this test:

1) The spec is not referring to glXChooseVisual attributes, only to
glXChooseFBConfig attributes. So use glXChooseFBConfig.

2) Make sure we have an alpha channel.

3) Call piglit_dispatch_default_init before issuing GL commands.

4) Restrict the test to the RGB channels. At least temporary. The spec says
the front buffer contents should become the new back buffer contents but
I'm not 100% sure all implementations actually support front buffer alpha.
We might need to revisit this.

Signed-off-by: Thomas Hellstrom <thellstrom at vmware.com>
---
 tests/glx/glx-swap-exchange.c | 74 +++++++++++++++++++++++++++----------------
 1 file changed, 46 insertions(+), 28 deletions(-)

diff --git a/tests/glx/glx-swap-exchange.c b/tests/glx/glx-swap-exchange.c
index 3f045f8..137140f 100644
--- a/tests/glx/glx-swap-exchange.c
+++ b/tests/glx/glx-swap-exchange.c
@@ -1,5 +1,6 @@
 /*
  * Copyright © 2010 Intel Corporation
+ * Copyright © 2010 VMWare Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -22,6 +23,7 @@
  *
  * Authors:
  *    Eric Anholt <eric at anholt.net>
+ *    Thomas Hellstrom <thellstrom at vmware.com>
  *
  */
 
@@ -36,60 +38,63 @@
 
 int piglit_width = 50, piglit_height = 50;
 static Display *dpy;
-static Window win;
-static XVisualInfo *visinfo;
+static GLXFBConfig *config;
+static GLXContext ctx;
+static GLXWindow gwin;
 
 enum piglit_result
 draw(Display *dpy)
 {
 	GLboolean pass = GL_TRUE;
-	float green[] = {0.0, 1.0, 0.0, 0.0};
-	GLXContext ctx;
+	float green[] = {0.0, 1.0, 0.0, 0.3};
 
-	ctx = piglit_get_glx_context(dpy, visinfo);
-	glXMakeCurrent(dpy, win, ctx);
-
-	/* Clear background to gray */
-	glClearColor(0.0, 1.0, 0.0, 0.0);
+	glXMakeContextCurrent(dpy, gwin, gwin, ctx);
+	glClearColor(0.0, 1.0, 0.0, 0.3);
+	glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
 	glClear(GL_COLOR_BUFFER_BIT);
-	glXSwapBuffers(dpy, win);
-	glClearColor(1.0, 0.0, 0.0, 0.0);
+	glXSwapBuffers(dpy, gwin);
+	glClearColor(1.0, 0.0, 0.0, 0.5);
 	glClear(GL_COLOR_BUFFER_BIT);
-	glXSwapBuffers(dpy, win);
-
-	pass = piglit_probe_pixel_rgba(0, 0, green);
+	glXSwapBuffers(dpy, gwin);
 
-	glXSwapBuffers(dpy, win);
+	/*
+	 * Spec says the front buffer contents should be the new back buffer,
+	 * but are front buffer contents required to have alpha?
+	 * Ignore the alpha channel for now.
+	 */
+	pass = piglit_probe_pixel_rgb(0, 0, green);
 
 	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 }
 
 
-XVisualInfo *
-piglit_get_swap_exchange_visual(Display *dpy)
+static GLXFBConfig *
+piglit_get_swap_exchange_config(Display *dpy)
 {
-	XVisualInfo *visinfo;
+	GLXFBConfig *fbc;
+	int nele;
 	int attrib[] = {
-		GLX_RGBA,
-		GLX_RED_SIZE, 1,
-		GLX_GREEN_SIZE, 1,
-		GLX_BLUE_SIZE, 1,
-		GLX_DOUBLEBUFFER,
+		GLX_RENDER_TYPE, GLX_RGBA_BIT,
+		GLX_RED_SIZE, 8,
+		GLX_GREEN_SIZE, 8,
+		GLX_BLUE_SIZE, 8,
+		GLX_ALPHA_SIZE, 8,
 		GLX_SWAP_METHOD_OML, GLX_SWAP_EXCHANGE_OML,
+		GLX_DOUBLEBUFFER, True,
 		None
 	};
 	int screen = DefaultScreen(dpy);
 
-	visinfo = glXChooseVisual(dpy, screen, attrib);
-	if (visinfo == NULL) {
+	fbc = glXChooseFBConfig(dpy, screen, attrib, &nele);
+	if (fbc == NULL) {
 		fprintf(stderr,
 			"Couldn't get a GLX_SWAP_EXCHANGE_OML, RGBA, "
-			"double-buffered visual\n");
+			"double-buffered fbconfig\n");
 		piglit_report_result(PIGLIT_SKIP);
 		exit(1);
 	}
 
-	return visinfo;
+	return fbc;
 }
 
 int
@@ -97,6 +102,8 @@ main(int argc, char **argv)
 {
 	int i;
 	const char *glx_extension_list;
+	Window win;
+	XVisualInfo *visinfo;
 
 	for(i = 1; i < argc; ++i) {
 		if (!strcmp(argv[i], "-auto"))
@@ -117,10 +124,21 @@ main(int argc, char **argv)
 		piglit_report_result(PIGLIT_SKIP);
 	}
 
-	visinfo = piglit_get_swap_exchange_visual(dpy);
+	config = piglit_get_swap_exchange_config(dpy);
+	visinfo = glXGetVisualFromFBConfig(dpy, config[0]);
+	if (!visinfo) {
+		printf("Error: couldn't create a visual from fbconfig.\n");
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
 	win = piglit_get_glx_window(dpy, visinfo);
+	XFree(visinfo);
 
 	XMapWindow(dpy, win);
+	gwin = glXCreateWindow(dpy, config[0], win, NULL);
+	ctx = glXCreateNewContext(dpy, config[0], GLX_RGBA_TYPE, 0, GL_TRUE);
+	glXMakeContextCurrent(dpy, gwin, gwin, ctx);
+	piglit_dispatch_default_init(PIGLIT_DISPATCH_GL);
 
 	piglit_glx_event_loop(dpy, draw);
 
-- 
2.7.4