Add function to retrieve opaque EGL config

celestiamobile · Feb 16, 2023 · 2850fab · 2850fab
1 parent aac6cb6
commit 2850fab
Showing 1 changed file with 32 additions and 3 deletions.
diff --git a/Celestia/src/main/cpp/CelestiaRenderer.cpp b/Celestia/src/main/cpp/CelestiaRenderer.cpp
@@ -101,6 +101,36 @@ JavaVM *CelestiaRenderer::jvm = nullptr;
 jmethodID CelestiaRenderer::flushTasksMethod = nullptr;
 jmethodID CelestiaRenderer::engineStartedMethod = nullptr;
 
+static bool ChooseOpaqueConfig(EGLDisplay dpy, const EGLint* attrib_list, EGLConfig* config)
+{
+    EGLint configCount = 0;
+    // Get config count
+    if (!eglChooseConfig(dpy, attrib_list, nullptr, 0, &configCount) || configCount == 0)
+        return false;
+    auto configs = new EGLConfig[configCount];
+    // Get all the configs
+    EGLint newConfigCount = 0;
+    if (!eglChooseConfig(dpy, attrib_list, configs, configCount, &newConfigCount) || newConfigCount == 0) {
+        delete[] configs;
+        return false;
+    }
+
+    // Find the first config that has an alpha size of 0
+    for (int i = 0; i < newConfigCount; i++) {
+        EGLint alphaSize = -1;
+        if (eglGetConfigAttrib(dpy, configs[i], EGL_ALPHA_SIZE, &alphaSize) && alphaSize == 0) {
+            *config = configs[i];
+            delete[] configs;
+            return true;
+        }
+    }
+
+    // If no config with alpha size of 0 was found, just return the first config
+    *config = configs[0];
+    delete[] configs;
+    return true;
+}
+
 bool CelestiaRenderer::initialize()
 {
     if (context == EGL_NO_CONTEXT)
@@ -124,7 +154,6 @@ bool CelestiaRenderer::initialize()
                 EGL_NONE
         };
 
-        EGLint numConfigs;
         LOG_INFO("Initializing context");
 
         if ((display = eglGetDisplay(EGL_DEFAULT_DISPLAY)) == EGL_NO_DISPLAY) {
@@ -140,13 +169,13 @@ bool CelestiaRenderer::initialize()
 
         if (enableMultisample) {
             // Try to enable multisample but fallback if not available
-            if (!eglChooseConfig(display, multisampleAttribs, &config, 1, &numConfigs) && !eglChooseConfig(display, attribs, &config, 1, &numConfigs)) {
+            if (!ChooseOpaqueConfig(display, multisampleAttribs, &config) && !ChooseOpaqueConfig(display, attribs, &config)) {
                 LOG_ERROR("eglChooseConfig() returned error %d", eglGetError());
                 destroy();
                 return false;
             }
         } else {
-            if (!eglChooseConfig(display, attribs, &config, 1, &numConfigs)) {
+            if (!ChooseOpaqueConfig(display, attribs, &config)) {
                 LOG_ERROR("eglChooseConfig() returned error %d", eglGetError());
                 destroy();
                 return false;