eglglessink: Disable vertex attribute arrays after drawing

Enable vertex attribute arrays which will be used by a GL program
and disable them after drawing. If a vertex attribute array not
required by a program is enabled, GL will try to read from it,
which may crash the application.

https://bugzilla.gnome.org/show_bug.cgi?id=730912

2 files changed, 21 insertions, 13 deletions

diff --git a/ext/eglgles/gstegladaptation.c b/ext/eglgles/gstegladaptation.c
index 3d9cc03bf..45098af4f 100644
--- a/ext/eglgles/gstegladaptation.c
+++ b/ext/eglgles/gstegladaptation.c
@@ -589,14 +589,6 @@ gst_egl_adaptation_init_surface (GstEglAdaptationContext * ctx,
   ctx->tex_scale_loc[0][2] =
       glGetUniformLocation (ctx->glslprogram[0], "tex_scale2");
 
-  glEnableVertexAttribArray (ctx->position_loc[0]);
-  if (got_gl_error ("glEnableVertexAttribArray"))
-    goto HANDLE_ERROR;
-
-  glEnableVertexAttribArray (ctx->texpos_loc[0]);
-  if (got_gl_error ("glEnableVertexAttribArray"))
-    goto HANDLE_ERROR;
-
   for (i = 0; i < ctx->n_textures; i++) {
     ctx->tex_loc[0][i] =
         glGetUniformLocation (ctx->glslprogram[0], texnames[i]);
@@ -612,10 +604,6 @@ gst_egl_adaptation_init_surface (GstEglAdaptationContext * ctx,
 
     ctx->position_loc[1] =
         glGetAttribLocation (ctx->glslprogram[1], "position");
-
-    glEnableVertexAttribArray (ctx->position_loc[1]);
-    if (got_gl_error ("glEnableVertexAttribArray"))
-      goto HANDLE_ERROR;
   }
 
   /* Generate textures */
diff --git a/ext/eglgles/gsteglglessink.c b/ext/eglgles/gsteglglessink.c
index 6f35cff81..270733096 100644
--- a/ext/eglgles/gsteglglessink.c
+++ b/ext/eglgles/gsteglglessink.c
@@ -1759,6 +1759,10 @@ gst_eglglessink_render (GstEglGlesSink * eglglessink)
     GST_DEBUG_OBJECT (eglglessink, "Drawing black border 1");
     glUseProgram (eglglessink->egl_context->glslprogram[1]);
 
+    glEnableVertexAttribArray (eglglessink->egl_context->position_loc[1]);
+    if (got_gl_error ("glEnableVertexAttribArray"))
+      goto HANDLE_ERROR;
+
     glVertexAttribPointer (eglglessink->egl_context->position_loc[1], 3,
         GL_FLOAT, GL_FALSE, sizeof (coord5), (gpointer) (8 * sizeof (coord5)));
     if (got_gl_error ("glVertexAttribPointer"))
@@ -1778,6 +1782,8 @@ gst_eglglessink_render (GstEglGlesSink * eglglessink)
     glDrawElements (GL_TRIANGLE_STRIP, 4, GL_UNSIGNED_SHORT, 0);
     if (got_gl_error ("glDrawElements"))
       goto HANDLE_ERROR;
+
+    glDisableVertexAttribArray (eglglessink->egl_context->position_loc[1]);
   }
 
   /* Draw video frame */
@@ -1798,6 +1804,14 @@ gst_eglglessink_render (GstEglGlesSink * eglglessink)
       goto HANDLE_ERROR;
   }
 
+  glEnableVertexAttribArray (eglglessink->egl_context->position_loc[0]);
+  if (got_gl_error ("glEnableVertexAttribArray"))
+    goto HANDLE_ERROR;
+
+  glEnableVertexAttribArray (eglglessink->egl_context->texpos_loc[0]);
+  if (got_gl_error ("glEnableVertexAttribArray"))
+    goto HANDLE_ERROR;
+
   if (eglglessink->orientation ==
       GST_VIDEO_GL_TEXTURE_ORIENTATION_X_NORMAL_Y_NORMAL) {
     glVertexAttribPointer (eglglessink->egl_context->position_loc[0], 3,
@@ -1829,6 +1843,9 @@ gst_eglglessink_render (GstEglGlesSink * eglglessink)
   if (got_gl_error ("glDrawElements"))
     goto HANDLE_ERROR;
 
+  glDisableVertexAttribArray (eglglessink->egl_context->position_loc[0]);
+  glDisableVertexAttribArray (eglglessink->egl_context->texpos_loc[0]);
+
   if (!gst_egl_adaptation_context_swap_buffers (eglglessink->egl_context)) {
     goto HANDLE_ERROR;
   }
@@ -1838,8 +1855,11 @@ gst_eglglessink_render (GstEglGlesSink * eglglessink)
   return GST_FLOW_OK;
 
 HANDLE_ERROR:
-  GST_ERROR_OBJECT (eglglessink, "Rendering disabled for this frame");
+  glDisableVertexAttribArray (eglglessink->egl_context->position_loc[0]);
+  glDisableVertexAttribArray (eglglessink->egl_context->texpos_loc[0]);
+  glDisableVertexAttribArray (eglglessink->egl_context->position_loc[1]);
 
+  GST_ERROR_OBJECT (eglglessink, "Rendering disabled for this frame");
   return GST_FLOW_ERROR;
 }