[core] don't force GL state to be set when calling .reset()

We are using Value::reset() to change a piece of GL state to its default value. However, the current implementation always executes the GL call, even if our state tracking system knows that it's already at that value. The new implementation of Value::reset() now respects that, resulting in a lot fewer GL calls.

1 files changed, 4 insertions, 0 deletions

diff --git a/include/mbgl/gl/gl_values.hpp b/include/mbgl/gl/gl_values.hpp
index 1e05984fbc..b15ef18f48 100644
--- a/include/mbgl/gl/gl_values.hpp
+++ b/include/mbgl/gl/gl_values.hpp
@@ -140,6 +140,10 @@ struct StencilOp {
     }
 };
 
+constexpr bool operator!=(const StencilOp::Type& a, const StencilOp::Type& b) {
+    return a.sfail != b.sfail || a.dpfail != b.dpfail || a.dppass != b.dppass;
+}
+
 struct DepthRange {
     struct Type { GLfloat near, far; };
     static const Type Default;