Evas GL: Try harder to find a matching config for GLESv1

If MSAA was requested, it is very likely that no config was
found (depending on the driver), so we'll try again without
MSAA. Yeah, this might not look very smooth but it should be
better that failing at eglMakeCurrent.

diff --git a/src/modules/evas/engines/gl_x11/evas_engine.c b/src/modules/evas/engines/gl_x11/evas_engine.c
index 7effa53..3721d31 100644 (file)
--- a/src/modules/evas/engines/gl_x11/evas_engine.c
+++ b/src/modules/evas/engines/gl_x11/evas_engine.c
@@ -914,12 +914,13 @@ evgl_eng_gles1_surface_create(EVGL_Engine *evgl EINA_UNUSED, void *data,
 #ifdef GL_GLES
    EGLSurface egl_sfc;
    EGLConfig egl_cfg;
-   int i, num = 0, best = 0;
+   int i, num = 0, best = -1;
    EGLConfig configs[200];
    int config_attrs[40];
    Eina_Bool found = EINA_FALSE;
    int msaa = 0, depth = 0, stencil = 0;
    Visual *visual = NULL;
+   Eina_Bool retried = EINA_FALSE;
 
    /* Now we need to iterate over all EGL configurations to check the compatible
     * ones and finally check their visual ID. */
@@ -936,6 +937,7 @@ evgl_eng_gles1_surface_create(EVGL_Engine *evgl EINA_UNUSED, void *data,
        (cfg->multisample_bits <= EVAS_GL_MULTISAMPLE_HIGH))
      msaa = evgl->caps.msaa_samples[(int) cfg->multisample_bits - 1];
 
+try_again:
    i = 0;
    config_attrs[i++] = EGL_SURFACE_TYPE;
    config_attrs[i++] = EGL_PIXMAP_BIT;
@@ -1013,7 +1015,7 @@ evgl_eng_gles1_surface_create(EVGL_Engine *evgl EINA_UNUSED, void *data,
                {
                   if (xvi[j].depth >= colordepth)
                     {
-                       if (!best) best = i;
+                       if (best < 0) best = i;
                        if (alpha)
                          {
                             fmt = XRenderFindVisualFormat(eng_get_ob(re)->disp, xvi[j].visual);
@@ -1036,12 +1038,26 @@ evgl_eng_gles1_surface_create(EVGL_Engine *evgl EINA_UNUSED, void *data,
 
    if (!found)
      {
-        // This config will probably not work, but we try anyways.
-        ERR("XGetVisualInfo failed. Trying with EGL config #%d", best);
-        if (num)
-          egl_cfg = configs[best];
+        if (num && (best >= 0))
+          {
+             ERR("No matching config found. Trying with EGL config #%d", best);
+             egl_cfg = configs[best];
+          }
+        else if (msaa && !retried)
+          {
+             ERR("Trying again without MSAA.");
+             msaa = 0;
+             retried = EINA_TRUE;
+             goto try_again;
+          }
         else
-          egl_cfg = eng_get_ob(re)->egl_config;
+          {
+             // This config will probably not work, but we try anyways.
+             // NOTE: Maybe it would be safer to just return NULL here, leaving
+             // the app responsible for changing its config.
+             ERR("XGetVisualInfo failed. Trying with the window's EGL config.");
+             egl_cfg = eng_get_ob(re)->egl_config;
+          }
      }
 
    egl_sfc = eglCreatePixmapSurface(eng_get_ob(re)->egl_disp, egl_cfg, px, NULL);