Reduce texture sampler state changes in Metal (#3236)

src/mbgl/mtl/texture2d.cpp

@@ -21,6 +21,11 @@ Texture2D::~Texture2D() {
 }
 
 gfx::Texture2D& Texture2D::setSamplerConfiguration(const SamplerState& samplerState_) noexcept {
+    if (samplerState.filter == samplerState_.filter && samplerState.wrapU == samplerState_.wrapU &&
+        samplerState.wrapV == samplerState_.wrapV) {
+        return *this;
+    }
+
     samplerState = samplerState_;
     samplerStateDirty = true;
     return *this;
@@ -216,6 +221,8 @@ void Texture2D::updateSamplerConfiguration() noexcept {
                                            ? MTL::SamplerAddressModeClampToEdge
                                            : MTL::SamplerAddressModeRepeat);
     metalSamplerState = context.createMetalSamplerState(samplerDescriptor);
+
+    samplerStateDirty = false;
 }
 
 void Texture2D::bind(RenderPass& renderPass, int32_t location) noexcept {