Move initial GL state policy into renderer GL

src/renderer_gl/opengl_capabilities.cpp

@@ -212,6 +212,18 @@ pp::renderer::RenderDeviceFeatures render_device_features(OpenGlCapabilities cap
     };
 }
 
+OpenGlInitialState panopainter_initial_state() noexcept
+{
+    return OpenGlInitialState {
+        .depth_test_enabled = false,
+        .depth_test_state = depth_test_state(),
+        .source_color_factor = source_alpha_blend_factor(),
+        .destination_color_factor = one_minus_source_alpha_blend_factor(),
+        .color_equation = add_blend_equation(),
+        .alpha_equation = max_blend_equation(),
+    };
+}
+
 std::uint32_t extension_count_query() noexcept
 {
     return gl_num_extensions;