[glfw] Remove GL state restoration

We're doing all of this in our own context anyway, so no need to restore the state

3 files changed, 10 insertions, 69 deletions

diff --git a/platform/glfw/glfw_view.cpp b/platform/glfw/glfw_view.cpp
index 82f075fd6f..b8cf285bdd 100644
--- a/platform/glfw/glfw_view.cpp
+++ b/platform/glfw/glfw_view.cpp
@@ -12,9 +12,6 @@
 #include <mbgl/map/backend_scope.hpp>
 #include <mbgl/map/camera.hpp>
 
-#include <mbgl/gl/state.hpp>
-#include <mbgl/gl/value.hpp>
-
 #include <cassert>
 #include <cstdlib>
 
@@ -567,14 +564,9 @@ void showDebugImage(std::string name, const char *data, size_t width, size_t hei
     glfwGetFramebufferSize(debugWindow, &fbWidth, &fbHeight);
     float scale = static_cast<float>(fbWidth) / static_cast<float>(width);
 
-    {
-        gl::PreserveState<gl::value::PixelZoom> pixelZoom;
-        gl::PreserveState<gl::value::RasterPos> rasterPos;
-
-        MBGL_CHECK_ERROR(glPixelZoom(scale, -scale));
-        MBGL_CHECK_ERROR(glRasterPos2f(-1.0f, 1.0f));
-        MBGL_CHECK_ERROR(glDrawPixels(width, height, GL_LUMINANCE, GL_UNSIGNED_BYTE, data));
-    }
+    MBGL_CHECK_ERROR(glPixelZoom(scale, -scale));
+    MBGL_CHECK_ERROR(glRasterPos2f(-1.0f, 1.0f));
+    MBGL_CHECK_ERROR(glDrawPixels(width, height, GL_LUMINANCE, GL_UNSIGNED_BYTE, data));
 
     glfwSwapBuffers(debugWindow);
 
@@ -604,21 +596,13 @@ void showColorDebugImage(std::string name, const char *data, size_t logicalWidth
     float xScale = static_cast<float>(fbWidth) / static_cast<float>(width);
     float yScale = static_cast<float>(fbHeight) / static_cast<float>(height);
 
-    {
-        gl::PreserveState<gl::value::ClearColor> clearColor;
-        gl::PreserveState<gl::value::Blend> blend;
-        gl::PreserveState<gl::value::BlendFunc> blendFunc;
-        gl::PreserveState<gl::value::PixelZoom> pixelZoom;
-        gl::PreserveState<gl::value::RasterPos> rasterPos;
-
-        MBGL_CHECK_ERROR(glClearColor(0.8, 0.8, 0.8, 1));
-        MBGL_CHECK_ERROR(glClear(GL_COLOR_BUFFER_BIT));
-        MBGL_CHECK_ERROR(glEnable(GL_BLEND));
-        MBGL_CHECK_ERROR(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
-        MBGL_CHECK_ERROR(glPixelZoom(xScale, -yScale));
-        MBGL_CHECK_ERROR(glRasterPos2f(-1.0f, 1.0f));
-        MBGL_CHECK_ERROR(glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8_REV, data));
-    }
+    MBGL_CHECK_ERROR(glClearColor(0.8, 0.8, 0.8, 1));
+    MBGL_CHECK_ERROR(glClear(GL_COLOR_BUFFER_BIT));
+    MBGL_CHECK_ERROR(glEnable(GL_BLEND));
+    MBGL_CHECK_ERROR(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
+    MBGL_CHECK_ERROR(glPixelZoom(xScale, -yScale));
+    MBGL_CHECK_ERROR(glRasterPos2f(-1.0f, 1.0f));
+    MBGL_CHECK_ERROR(glDrawPixels(width, height, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8_REV, data));
 
     glfwSwapBuffers(debugWindow);
 
diff --git a/src/mbgl/gl/state.hpp b/src/mbgl/gl/state.hpp
index f3268229d1..17503cc043 100644
--- a/src/mbgl/gl/state.hpp
+++ b/src/mbgl/gl/state.hpp
@@ -66,34 +66,5 @@ private:
     const std::tuple<Args...> params;
 };
 
-// Helper struct that stores the current state and restores it upon destruction. You should not use
-// this code normally, except for debugging purposes.
-template <typename T, typename... Args>
-class PreserveState {
-public:
-    PreserveState(Args&&... args)
-        : params(std::forward_as_tuple(std::forward<Args>(args)...)),
-          value(get(std::index_sequence_for<Args...>{})) {
-    }
-    ~PreserveState() {
-        set(std::index_sequence_for<Args...>{});
-    }
-
-private:
-    template <std::size_t... I>
-    typename T::Type get(std::index_sequence<I...>) {
-        return T::Get(std::get<I>(params)...);
-    }
-
-    template <std::size_t... I>
-    void set(std::index_sequence<I...>) {
-        T::Set(value, std::get<I>(params)...);
-    }
-
-private:
-    const std::tuple<Args...> params;
-    const typename T::Type value;
-};
-
 } // namespace gl
 } // namespace mbgl
diff --git a/test/gl/object.test.cpp b/test/gl/object.test.cpp
index 5d2bf6735e..b5a055f4ca 100644
--- a/test/gl/object.test.cpp
+++ b/test/gl/object.test.cpp
@@ -26,20 +26,6 @@ struct MockGLObject {
 
 const bool MockGLObject::Default = false;
 
-TEST(GLObject, PreserveState) {
-    getFlag = false;
-    setFlag = false;
-
-    auto object = std::make_unique<gl::PreserveState<MockGLObject>>();
-    EXPECT_TRUE(getFlag);
-    EXPECT_FALSE(setFlag);
-
-    getFlag = false;
-    object.reset();
-    EXPECT_FALSE(getFlag);
-    EXPECT_TRUE(setFlag);
-}
-
 TEST(GLObject, Value) {
     setFlag = false;