[core] track texture state to avoid redundand binds

2 files changed, 10 insertions, 4 deletions

diff --git a/src/mbgl/gl/gl_config.cpp b/src/mbgl/gl/gl_config.cpp
index 97d2f26f6c..9031c3d34f 100644
--- a/src/mbgl/gl/gl_config.cpp
+++ b/src/mbgl/gl/gl_config.cpp
@@ -20,7 +20,8 @@ const ClearColor::Type ClearColor::Default = { 0, 0, 0, 0 };
 const ClearStencil::Type ClearStencil::Default = 0;
 const Program::Type Program::Default = 0;
 const LineWidth::Type LineWidth::Default = 1;
-const ActiveTexture::Type ActiveTexture::Default = GL_TEXTURE0;
+const ActiveTexture::Type ActiveTexture::Default = 0;
+const BindTexture::Type BindTexture::Default = 0;
 
 #ifndef GL_ES_VERSION_2_0
 const PixelZoom::Type PixelZoom::Default = { 1, 1 };
diff --git a/src/mbgl/gl/gl_config.hpp b/src/mbgl/gl/gl_config.hpp
index 9d7dfb3b6c..41bee8fab7 100644
--- a/src/mbgl/gl/gl_config.hpp
+++ b/src/mbgl/gl/gl_config.hpp
@@ -13,13 +13,17 @@ template <typename T>
 class Value {
 public:
     void operator=(const typename T::Type& value) {
-        if (dirty || current != value) {
+        if (*this != value) {
             dirty = false;
             current = value;
             T::Set(current);
         }
     }
 
+    bool operator!=(const typename T::Type& value) const {
+        return dirty || current != value;
+    }
+
     void reset() {
         *this = T::Default;
     }
@@ -28,11 +32,11 @@ public:
         dirty = true;
     }
 
-    typename T::Type getCurrent() {
+    typename T::Type getCurrent() const {
         return current;
     }
 
-    bool getDirty() {
+    bool getDirty() const {
         return dirty;
     }
 
@@ -115,6 +119,7 @@ public:
     Value<PixelZoom> pixelZoom;
     Value<RasterPos> rasterPos;
 #endif // GL_ES_VERSION_2_0
+    std::array<Value<BindTexture>, 2> texture;
 };
 
 } // namespace gl