tests: Add EGL test for Epoxy API

We have a few public entry points that we ought to test properly.

Using the EGL API is easier to set up a test case, so let's just do
that.

test/Makefile.am

@@ -77,6 +77,7 @@ EGL_TESTS = \
 if HAVE_X11
 EGL_TESTS += \
 	egl_has_extension_nocontext \
+	egl_epoxy_api \
 	egl_gles2_without_glx \
 	$()
 
@@ -140,6 +141,8 @@ endif
 
 egl_has_extension_nocontext_LDADD = $(EPOXY) libegl_common.la $(X11_LIBS)
 
+egl_epoxy_api_LDADD = $(EPOXY) libegl_common.la $(X11_LIBS)
+
 egl_gl_LDADD = $(EPOXY) $(DLOPEN_LIBS) libegl_common.la $(X11_LIBS)
 
 egl_gles1_without_glx_CPPFLAGS = $(AM_CPPFLAGS) -DGLES_VERSION=1

test/egl_epoxy_api.c

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2018  Emmanuele Bassi
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+/**
+ * @file epoxy_api.c
+ *
+ * Tests the Epoxy API using EGL.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <err.h>
+#include "epoxy/gl.h"
+#include "epoxy/egl.h"
+
+#include "egl_common.h"
+
+static bool
+make_egl_current_and_test(EGLDisplay *dpy, EGLContext ctx)
+{
+    const char *string;
+    GLuint shader;
+    bool pass = true;
+
+    eglMakeCurrent(dpy, NULL, NULL, ctx);
+
+    if (!epoxy_is_desktop_gl()) {
+        fputs("Claimed to be desktop\n", stderr);
+        pass = false;
+    }
+
+    if (epoxy_gl_version() < 20) {
+        fprintf(stderr, "Claimed to be GL version %d\n",
+                epoxy_gl_version());
+        pass = false;
+    }
+
+    if (epoxy_glsl_version() < 100) {
+        fprintf(stderr, "Claimed to have GLSL version %d\n",
+                epoxy_glsl_version());
+        pass = false;
+    }
+
+    string = (const char *)glGetString(GL_VERSION);
+    printf("GL version: %s - Epoxy: %d\n", string, epoxy_gl_version());
+
+    string = (const char *)glGetString(GL_SHADING_LANGUAGE_VERSION);
+    printf("GLSL version: %s - Epoxy: %d\n", string, epoxy_glsl_version());
+
+    shader = glCreateShader(GL_FRAGMENT_SHADER);
+    pass = glIsShader(shader);
+
+    return pass;
+}
+
+static void
+init_egl(EGLDisplay *dpy, EGLContext *out_ctx)
+{
+    static const EGLint config_attribs[] = {
+	EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+	EGL_RED_SIZE, 1,
+	EGL_GREEN_SIZE, 1,
+	EGL_BLUE_SIZE, 1,
+	EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
+	EGL_NONE
+    };
+    static const EGLint context_attribs[] = {
+        EGL_CONTEXT_CLIENT_VERSION, 2,
+        EGL_NONE
+    };
+    EGLContext ctx;
+    EGLConfig cfg;
+    EGLint count;
+
+    if (!epoxy_has_egl_extension(dpy, "EGL_KHR_surfaceless_context"))
+        errx(77, "Test requires EGL_KHR_surfaceless_context");
+
+    if (!eglBindAPI(EGL_OPENGL_API))
+        errx(77, "Couldn't initialize EGL with desktop GL\n");
+
+    if (!eglChooseConfig(dpy, config_attribs, &cfg, 1, &count))
+        errx(77, "Couldn't get an EGLConfig\n");
+
+    ctx = eglCreateContext(dpy, cfg, NULL, context_attribs);
+    if (!ctx)
+        errx(77, "Couldn't create a GL context\n");
+
+    *out_ctx = ctx;
+}
+
+int
+main(int argc, char **argv)
+{
+    bool pass = true;
+
+    EGLContext egl_ctx;
+    EGLDisplay *dpy = get_egl_display_or_skip();
+    const char *extensions = eglQueryString(dpy, EGL_EXTENSIONS);
+    char *first_space;
+    char *an_extension;
+
+    /* We don't have any extensions guaranteed by the ABI, so for the
+     * touch test we just check if the first one is reported to be there.
+     */
+    first_space = strstr(extensions, " ");
+    if (first_space) {
+        an_extension = strndup(extensions, first_space - extensions);
+    } else {
+        an_extension = strdup(extensions);
+    }
+
+    if (!epoxy_extension_in_string(extensions, an_extension))
+        errx(1, "Implementation reported absence of %s", an_extension);
+
+    free(an_extension);
+
+    init_egl(dpy, &egl_ctx);
+    pass = make_egl_current_and_test(dpy, egl_ctx);
+
+    return pass != true;
+}

test/meson.build

@@ -39,6 +39,7 @@ if build_egl and build_x11_tests
 
   egl_tests = [
     [ 'egl_has_extension_nocontext', [], [ 'egl_has_extension_nocontext.c' ], true, ],
+    [ 'egl_epoxy_api', [], [ 'egl_epoxy_api.c' ], true ],
     [ 'egl_gles1_without_glx', [ '-DGLES_VERSION=1', ], [ 'egl_without_glx.c' ], has_gles1, ],
     [ 'egl_gles2_without_glx', [ '-DGLES_VERSION=2', ], [ 'egl_without_glx.c' ], has_gles2, ],
   ]