Fix PGLListener init extension checks to pass on OpenGL ES 2.

Signed-off-by: Xerxes Rånby <xerxes@zafena.se>

Author: xranby

core/src/processing/opengl/PGL.java

@@ -3248,19 +3248,11 @@ public void init(GLAutoDrawable adrawable) {
       context = adrawable.getContext();
       capabilities = adrawable.getChosenGLCapabilities();
 
-      gl = context.getGL();
-      String extensions = gl.glGetString(GL.GL_EXTENSIONS);
-      if (-1 == extensions.indexOf("_framebuffer_object")) {
-        throw new RuntimeException("No framebuffer objects available");
-      }
-      if (-1 == extensions.indexOf("_vertex_buffer_object")) {
-        throw new RuntimeException("No vertex buffer objects available");
-      }
-      if (-1 == extensions.indexOf("_vertex_shader")) {
-        throw new RuntimeException("No vertex shaders available");
+      if (!context.hasBasicFBOSupport()) {
+        throw new RuntimeException("No basic FBO support is available");
       }
-      if (-1 == extensions.indexOf("_fragment_shader")) {
-        throw new RuntimeException("No fragment shaders available");
+      if (!context.hasGLSL()) {
+        throw new RuntimeException("No GLSL support is available");
       }
     }