ui: add egl-helpers

Add helper functions to initialize OpenGL using egl.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

configure

@@ -3166,7 +3166,7 @@ else
 fi
 
 if test "$opengl" != "no" ; then
-  opengl_pkgs="gl glesv2 epoxy"
+  opengl_pkgs="gl glesv2 epoxy egl"
   if $pkg_config $opengl_pkgs x11 && test "$have_glx" = "yes"; then
     opengl_cflags="$($pkg_config --cflags $opengl_pkgs) $x11_cflags"
     opengl_libs="$($pkg_config --libs $opengl_pkgs) $x11_libs"

include/ui/egl-helpers.h

@@ -0,0 +1,16 @@
+#ifndef EGL_HELPERS_H
+#define EGL_HELPERS_H
+
+#include <epoxy/gl.h>
+#include <epoxy/egl.h>
+
+extern EGLDisplay *qemu_egl_display;
+extern EGLConfig qemu_egl_config;
+
+EGLSurface qemu_egl_init_surface_x11(EGLContext ectx, Window win);
+
+int qemu_egl_init_dpy(EGLNativeDisplayType dpy, bool gles, bool debug);
+EGLContext qemu_egl_init_ctx(void);
+bool qemu_egl_has_ext(const char *haystack, const char *needle);
+
+#endif /* EGL_HELPERS_H */

ui/Makefile.objs

@@ -30,11 +30,14 @@ sdl.mo-cflags := $(SDL_CFLAGS)
 ifeq ($(CONFIG_OPENGL),y)
 common-obj-y += shader.o
 common-obj-y += console-gl.o
+common-obj-y += egl-helpers.o
 endif
 
 gtk.o-cflags := $(GTK_CFLAGS) $(VTE_CFLAGS)
 shader.o-cflags += $(OPENGL_CFLAGS)
 console-gl.o-cflags += $(OPENGL_CFLAGS)
+egl-helpers.o-cflags += $(OPENGL_CFLAGS)
 
 shader.o-libs += $(OPENGL_LIBS)
 console-gl.o-libs += $(OPENGL_LIBS)
+egl-helpers.o-libs += $(OPENGL_LIBS)

ui/egl-helpers.c

@@ -0,0 +1,148 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <glob.h>
+
+#include "ui/egl-helpers.h"
+
+EGLDisplay *qemu_egl_display;
+EGLConfig qemu_egl_config;
+
+/* ---------------------------------------------------------------------- */
+
+static bool egl_gles;
+static int egl_debug;
+
+#define egl_dbg(_x ...)                          \
+    do {                                         \
+        if (egl_debug) {                         \
+            fprintf(stderr, "egl: " _x);         \
+        }                                        \
+    } while (0);
+
+/* ---------------------------------------------------------------------- */
+
+EGLSurface qemu_egl_init_surface_x11(EGLContext ectx, Window win)
+{
+    EGLSurface esurface;
+    EGLBoolean b;
+
+    egl_dbg("eglCreateWindowSurface (x11 win id 0x%lx) ...\n",
+            (unsigned long) win);
+    esurface = eglCreateWindowSurface(qemu_egl_display,
+                                      qemu_egl_config,
+                                      (EGLNativeWindowType)win, NULL);
+    if (esurface == EGL_NO_SURFACE) {
+        fprintf(stderr, "egl: eglCreateWindowSurface failed\n");
+        return NULL;
+    }
+
+    b = eglMakeCurrent(qemu_egl_display, esurface, esurface, ectx);
+    if (b == EGL_FALSE) {
+        fprintf(stderr, "egl: eglMakeCurrent failed\n");
+        return NULL;
+    }
+
+    return esurface;
+}
+
+/* ---------------------------------------------------------------------- */
+
+int qemu_egl_init_dpy(EGLNativeDisplayType dpy, bool gles, bool debug)
+{
+    static const EGLint conf_att_gl[] = {
+        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+        EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
+        EGL_RED_SIZE,   5,
+        EGL_GREEN_SIZE, 5,
+        EGL_BLUE_SIZE,  5,
+        EGL_ALPHA_SIZE, 0,
+        EGL_NONE,
+    };
+    static const EGLint conf_att_gles[] = {
+        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+        EGL_RED_SIZE,   5,
+        EGL_GREEN_SIZE, 5,
+        EGL_BLUE_SIZE,  5,
+        EGL_ALPHA_SIZE, 0,
+        EGL_NONE,
+    };
+    EGLint major, minor;
+    EGLBoolean b;
+    EGLint n;
+
+    if (debug) {
+        egl_debug = 1;
+        setenv("EGL_LOG_LEVEL", "debug", true);
+        setenv("LIBGL_DEBUG", "verbose", true);
+    }
+
+    egl_dbg("eglGetDisplay (dpy %p) ...\n", dpy);
+    qemu_egl_display = eglGetDisplay(dpy);
+    if (qemu_egl_display == EGL_NO_DISPLAY) {
+        fprintf(stderr, "egl: eglGetDisplay failed\n");
+        return -1;
+    }
+
+    egl_dbg("eglInitialize ...\n");
+    b = eglInitialize(qemu_egl_display, &major, &minor);
+    if (b == EGL_FALSE) {
+        fprintf(stderr, "egl: eglInitialize failed\n");
+        return -1;
+    }
+
+    egl_dbg("eglBindAPI ...\n");
+    b = eglBindAPI(gles ? EGL_OPENGL_ES_API : EGL_OPENGL_API);
+    if (b == EGL_FALSE) {
+        fprintf(stderr, "egl: eglBindAPI failed\n");
+        return -1;
+    }
+
+    egl_dbg("eglChooseConfig ...\n");
+    b = eglChooseConfig(qemu_egl_display,
+                        gles ? conf_att_gles : conf_att_gl,
+                        &qemu_egl_config, 1, &n);
+    if (b == EGL_FALSE || n != 1) {
+        fprintf(stderr, "egl: eglChooseConfig failed\n");
+        return -1;
+    }
+
+    egl_gles = gles;
+    return 0;
+}
+
+EGLContext qemu_egl_init_ctx(void)
+{
+    static const EGLint ctx_att_gl[] = {
+        EGL_NONE
+    };
+    static const EGLint ctx_att_gles[] = {
+        EGL_CONTEXT_CLIENT_VERSION, 2,
+        EGL_NONE
+    };
+
+    EGLContext ectx;
+    EGLBoolean b;
+
+    egl_dbg("eglCreateContext ...\n");
+    ectx = eglCreateContext(qemu_egl_display, qemu_egl_config, EGL_NO_CONTEXT,
+                            egl_gles ? ctx_att_gles : ctx_att_gl);
+    if (ectx == EGL_NO_CONTEXT) {
+        fprintf(stderr, "egl: eglCreateContext failed\n");
+        return NULL;
+    }
+
+    b = eglMakeCurrent(qemu_egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, ectx);
+    if (b == EGL_FALSE) {
+        fprintf(stderr, "egl: eglMakeCurrent failed\n");
+        return NULL;
+    }
+
+    return ectx;
+}