obtaining a egl context

3 files changed, 86 insertions, 3 deletions

diff --git a/src/graphics.cc b/src/graphics.cc
index d9db4c8..5618824 100644
--- a/src/graphics.cc
+++ b/src/graphics.cc
@@ -1,10 +1,45 @@
 #include "graphics.h"
 
 #include <EGL/egl.h>
+#include <EGL/eglplatform.h>
 
 #include "utils.h"
 #include "wlstate.h"
 
+/* clang-format off */
+#define WAYC_OPENGL_MAJOR 4
+#define WAYC_OPENGL_MINOR 6
+#define WAYC_COLOR_BITS 8
+
+static EGLint WAYC_EGL_ATTRS[] = {
+    EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+    EGL_RED_SIZE,   WAYC_COLOR_BITS,
+    EGL_GREEN_SIZE, WAYC_COLOR_BITS,
+    EGL_BLUE_SIZE,  WAYC_COLOR_BITS,
+    EGL_ALPHA_SIZE, WAYC_COLOR_BITS,
+    EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
+    EGL_NONE
+};
+
+static EGLint WAYC_OGL_ATTRS[] = {
+    EGL_CONTEXT_MAJOR_VERSION, WAYC_OPENGL_MAJOR,
+    EGL_CONTEXT_MINOR_VERSION, WAYC_OPENGL_MINOR,
+    EGL_NONE
+};
+
+/* clang-format on */
+
+static bool wayc_graphics_config(EGLDisplay display, EGLConfig* config) {
+  wayc_notnull(display);
+  wayc_notnull(config);
+
+  EGLint nconfs = 0;
+  if (!eglChooseConfig(display, WAYC_EGL_ATTRS, config, 1, &nconfs))
+    return false;
+
+  return nconfs > 0;
+}
+
 enum graphics_error_e wayc_graphics_init(struct graphics_s* graphics,
                                          struct wlstate_s* state) {
   wayc_notnull(graphics);
@@ -13,16 +48,45 @@ enum graphics_error_e wayc_graphics_init(struct graphics_s* graphics,
   EGLDisplay display = eglGetDisplay(state->display);
   if (display == EGL_NO_DISPLAY) return GRAPHICS_ERROR_DISPLAY;
 
+  if (!eglInitialize(display, nullptr, nullptr)) {
+    eglTerminate(display);
+    return GRAPHICS_ERROR_DISPLAY;
+  }
+
+  if (!eglBindAPI(EGL_OPENGL_API)) {
+    eglTerminate(display);
+    return GRAPHICS_ERROR_BIND;
+  }
+
+  EGLConfig config;
+  if (!wayc_graphics_config(display, &config)) {
+    eglTerminate(display);
+    return GRAPHICS_ERROR_CONFIG;
+  }
+
+  EGLContext context =
+      eglCreateContext(display, config, EGL_NO_CONTEXT, WAYC_OGL_ATTRS);
+
+  if (context == EGL_NO_CONTEXT) {
+    eglDestroyContext(display, context);
+    eglTerminate(display);
+    return GRAPHICS_ERROR_CONTEXT;
+  }
+
   graphics->display = display;
+  graphics->config = config;
+  graphics->context = context;
   return GRAPHICS_ERROR_NONE;
 }
 
 void wayc_graphics_deinit(struct graphics_s* graphics) {
   wayc_notnull(graphics);
 
-  if (graphics->display == nullptr) return;
+  if (graphics->display == nullptr || graphics->context == nullptr) return;
 
-  eglMakeCurrent(graphics->display, EGL_NO_SURFACE, EGL_NO_SURFACE,
-                 EGL_NO_CONTEXT);
+  eglDestroyContext(graphics->display, graphics->context);
   eglTerminate(graphics->display);
+
+  graphics->display = nullptr;
+  graphics->context = nullptr;
 }
diff --git a/src/graphics.h b/src/graphics.h
index 1ab4651..0419f46 100644
--- a/src/graphics.h
+++ b/src/graphics.h
@@ -3,9 +3,14 @@
 #include <EGL/egl.h>
 #include <wayland-egl.h>
 
+#include "utils.h"
+
 enum graphics_error_e {
   GRAPHICS_ERROR_NONE = 0,
   GRAPHICS_ERROR_DISPLAY,
+  GRAPHICS_ERROR_CONFIG,
+  GRAPHICS_ERROR_BIND,
+  GRAPHICS_ERROR_CONTEXT,
 };
 
 struct graphics_s {
@@ -17,3 +22,10 @@ struct graphics_s {
 enum graphics_error_e wayc_graphics_init(struct graphics_s* graphics,
                                          struct wlstate_s* state);
 void wayc_graphics_deinit(struct graphics_s* graphics);
+static inline bool wayc_graphics_use(struct graphics_s* graphics) {
+  wayc_notnull(graphics);
+
+  eglMakeCurrent(graphics->display, EGL_NO_SURFACE, EGL_NO_SURFACE,
+                 graphics->context);
+  return true;
+}
diff --git a/src/wayclock.cc b/src/wayclock.cc
index 348b122..2c6a98b 100644
--- a/src/wayclock.cc
+++ b/src/wayclock.cc
@@ -3,6 +3,7 @@
 
 #include "events.h"
 #include "graphics.h"
+#include "utils.h"
 #include "window.h"
 
 #define WAYC_APP_NAME "Wayclock"
@@ -48,6 +49,12 @@ int main() {
   if (wayc_graphics_init(&graphics, &loop.state) != GRAPHICS_ERROR_NONE)
     wayc_panic("Failed to initialize graphics");
 
+  if (!wayc_graphics_use(&graphics)) {
+    wayc_graphics_deinit(&graphics);
+    wayc_eventloop_deinit(&loop);
+    wayc_panic("Failed to use graphics");
+  }
+
   struct window_s window;
   if (wayc_window_init(&window, WAYC_APP_NAME, &loop) != WINDOW_ERROR_NONE) {
     wayc_graphics_deinit(&graphics);