examples: remove dependency on wlr_egl from clients

The specified clients in this commit used to rely on wlr_egl and
some of its related functions in order to render surfaces.

This is no longer the case as of this commit.

1 files changed, 127 insertions, 0 deletions

diff --git a/examples/egl_common.c b/examples/egl_common.c
new file mode 100644
index 00000000..0a53f543
--- /dev/null
+++ b/examples/egl_common.c
@@ -0,0 +1,127 @@
+#define _POSIX_C_SOURCE 200809L
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <wayland-client.h>
+#include <wlr/util/log.h>
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include "egl_common.h"
+
+EGLDisplay egl_display;
+EGLConfig egl_config;
+EGLContext egl_context;
+
+PFNEGLGETPLATFORMDISPLAYEXTPROC eglGetPlatformDisplayEXT;
+PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC eglCreatePlatformWindowSurfaceEXT;
+
+EGLint config_attribs[] = {
+	EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+	EGL_RED_SIZE, 1,
+	EGL_GREEN_SIZE, 1,
+	EGL_BLUE_SIZE, 1,
+	EGL_ALPHA_SIZE, 1,
+	EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+	EGL_NONE,
+};
+
+EGLint context_attribs[] = {
+	EGL_CONTEXT_CLIENT_VERSION, 2,
+	EGL_NONE,
+};
+
+bool egl_init(struct wl_display *display) {
+	const char *client_exts_str = 
+		eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
+	if (client_exts_str == NULL) {
+		if (eglGetError() == EGL_BAD_DISPLAY) {
+			wlr_log(WLR_ERROR, 
+				"EGL_EXT_client_extensions not supported");
+		} else {
+			wlr_log(WLR_ERROR, 
+				"Failed to query EGL client extensions");
+		}
+		return false;
+	}
+
+	if (!strstr(client_exts_str, "EGL_EXT_platform_base")) {
+		wlr_log(WLR_ERROR, "EGL_EXT_platform_base not supported");
+		return false;
+	}
+
+	if (!strstr(client_exts_str, "EGL_EXT_platform_wayland")) {
+		wlr_log(WLR_ERROR, "EGL_EXT_platform_wayland not supported");
+		return false;
+	}
+
+	eglGetPlatformDisplayEXT = 
+		(void *)eglGetProcAddress("eglGetPlatformDisplayEXT");
+	if (eglGetPlatformDisplayEXT == NULL) {
+		wlr_log(WLR_ERROR, "Failed to get eglGetPlatformDisplayEXT");
+		return false;
+	}
+
+	eglCreatePlatformWindowSurfaceEXT = 
+		(void *)eglGetProcAddress("eglCreatePlatformWindowSurfaceEXT");
+	if (eglCreatePlatformWindowSurfaceEXT == NULL) {
+		wlr_log(WLR_ERROR, 
+			"Failed to get eglCreatePlatformWindowSurfaceEXT");
+		return false;
+	}
+
+	egl_display = 
+		eglGetPlatformDisplayEXT(EGL_PLATFORM_WAYLAND_EXT, 
+			display, NULL);
+	if (egl_display == EGL_NO_DISPLAY) {
+		wlr_log(WLR_ERROR, "Failed to create EGL display");
+		goto error;
+	}
+
+	EGLint major, minor;
+	if (eglInitialize(egl_display, &major, &minor) == EGL_FALSE) {
+		wlr_log(WLR_ERROR, "Failed to initialize EGL");
+		goto error;
+	}
+
+	EGLint matched = 0;
+	if (!eglChooseConfig(egl_display, config_attribs, 
+			&egl_config, 1, &matched)) {
+		wlr_log(WLR_ERROR, "eglChooseConfig failed");
+		goto error;
+	}
+	if (matched == 0) {
+		wlr_log(WLR_ERROR, "Failed to match an EGL config");
+		goto error;
+	}
+
+	egl_context = 
+		eglCreateContext(egl_display, egl_config, 
+			EGL_NO_CONTEXT, context_attribs);
+	if (egl_context == EGL_NO_CONTEXT) {
+		wlr_log(WLR_ERROR, "Failed to create EGL context");
+		goto error;
+	}
+
+	return true;
+
+error:
+	eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, 
+		EGL_NO_SURFACE, EGL_NO_CONTEXT);
+	if (egl_display) {
+		eglTerminate(egl_display);
+	}
+	eglReleaseThread();
+	return false;
+}
+
+void egl_finish(void) {
+	eglMakeCurrent(egl_display, EGL_NO_SURFACE, 
+		EGL_NO_SURFACE, EGL_NO_CONTEXT);
+	eglDestroyContext(egl_display, egl_context);
+	eglTerminate(egl_display);
+	eglReleaseThread();
+}