9 files changed, 46 insertions, 2 deletions
diff --git a/include/mbgl/map/backend.hpp b/include/mbgl/map/backend.hpp
index 23a75b82ae..2e73ad994c 100644
--- a/include/mbgl/map/backend.hpp
+++ b/include/mbgl/map/backend.hpp
@@ -62,6 +62,7 @@ protected:
     // It sets the internal assumed state to the supplied values.
     void assumeFramebufferBinding(gl::FramebufferID fbo);
     void assumeViewport(int32_t x, int32_t y, const Size&);
+    void assumeScissorTest(bool);
 
     // Returns true when assumed framebuffer binding hasn't changed from the implicit binding.
     bool implicitFramebufferBound();
@@ -70,6 +71,7 @@ protected:
     // supplied values.
     void setFramebufferBinding(gl::FramebufferID fbo);
     void setViewport(int32_t x, int32_t y, const Size&);
+    void setScissorTest(bool);
 
 protected:
     std::unique_ptr<gl::Context> context;
diff --git a/platform/default/mbgl/gl/offscreen_view.cpp b/platform/default/mbgl/gl/offscreen_view.cpp
index 5424e03c96..e7cf7cffe5 100644
--- a/platform/default/mbgl/gl/offscreen_view.cpp
+++ b/platform/default/mbgl/gl/offscreen_view.cpp
@@ -24,6 +24,7 @@ public:
             context.bindFramebuffer = framebuffer->framebuffer;
         }
 
+        context.scissorTest = false;
         context.viewport = { 0, 0, size };
     }
 
diff --git a/src/mbgl/gl/context.cpp b/src/mbgl/gl/context.cpp
index 6a68c3ff69..2a36100dfd 100644
--- a/src/mbgl/gl/context.cpp
+++ b/src/mbgl/gl/context.cpp
@@ -468,8 +468,8 @@ void Context::reset() {
 }
 
 void Context::setDirtyState() {
-    // Note: does not set viewport/bindFramebuffer to dirty since they are handled separately in
-    // the view object.
+    // Note: does not set viewport/scissorTest/bindFramebuffer to dirty
+    // since they are handled separately in the view object.
     stencilFunc.setDirty();
     stencilMask.setDirty();
     stencilTest.setDirty();
diff --git a/src/mbgl/gl/context.hpp b/src/mbgl/gl/context.hpp
index 56c0618989..9086b8c955 100644
--- a/src/mbgl/gl/context.hpp
+++ b/src/mbgl/gl/context.hpp
@@ -199,6 +199,7 @@ public:
     State<value::ActiveTexture> activeTexture;
     State<value::BindFramebuffer> bindFramebuffer;
     State<value::Viewport> viewport;
+    State<value::ScissorTest> scissorTest;
     std::array<State<value::BindTexture>, 2> texture;
     State<value::BindVertexArray, const Context&> vertexArrayObject { *this };
     State<value::Program> program;
diff --git a/src/mbgl/gl/value.cpp b/src/mbgl/gl/value.cpp
index c081c941f5..32c632d101 100644
--- a/src/mbgl/gl/value.cpp
+++ b/src/mbgl/gl/value.cpp
@@ -267,6 +267,18 @@ Viewport::Type Viewport::Get() {
              { static_cast<uint32_t>(viewport[2]), static_cast<uint32_t>(viewport[3]) } };
 }
 
+const constexpr ScissorTest::Type ScissorTest::Default;
+
+void ScissorTest::Set(const Type& value) {
+    MBGL_CHECK_ERROR(value ? glEnable(GL_SCISSOR_TEST) : glDisable(GL_SCISSOR_TEST));
+}
+
+ScissorTest::Type ScissorTest::Get() {
+    Type scissorTest;
+    MBGL_CHECK_ERROR(scissorTest = glIsEnabled(GL_SCISSOR_TEST));
+    return scissorTest;
+}
+
 const constexpr BindFramebuffer::Type BindFramebuffer::Default;
 
 void BindFramebuffer::Set(const Type& value) {
diff --git a/src/mbgl/gl/value.hpp b/src/mbgl/gl/value.hpp
index aa5cca6fec..b8656db5b0 100644
--- a/src/mbgl/gl/value.hpp
+++ b/src/mbgl/gl/value.hpp
@@ -182,6 +182,13 @@ struct Viewport {
     static Type Get();
 };
 
+struct ScissorTest {
+    using Type = bool;
+    static const constexpr Type Default = false;
+    static void Set(const Type&);
+    static Type Get();
+};
+
 constexpr bool operator!=(const Viewport::Type& a, const Viewport::Type& b) {
     return a.x != b.x || a.y != b.y || a.size != b.size;
 }
diff --git a/src/mbgl/map/backend.cpp b/src/mbgl/map/backend.cpp
index 4c84453c1f..83c2fed00b 100644
--- a/src/mbgl/map/backend.cpp
+++ b/src/mbgl/map/backend.cpp
@@ -38,6 +38,11 @@ void Backend::assumeViewport(int32_t x, int32_t y, const Size& size) {
     assert(gl::value::Viewport::Get() == getContext().viewport.getCurrentValue());
 }
 
+void Backend::assumeScissorTest(bool enabled) {
+    getContext().scissorTest.setCurrentValue(enabled);
+    assert(gl::value::ScissorTest::Get() == getContext().scissorTest.getCurrentValue());
+}
+
 bool Backend::implicitFramebufferBound() {
     return getContext().bindFramebuffer.getCurrentValue() == ImplicitFramebufferBinding;
 }
@@ -54,6 +59,11 @@ void Backend::setViewport(int32_t x, int32_t y, const Size& size) {
     assert(gl::value::Viewport::Get() == getContext().viewport.getCurrentValue());
 }
 
+void Backend::setScissorTest(bool enabled) {
+    getContext().scissorTest = enabled;
+    assert(gl::value::ScissorTest::Get() == getContext().scissorTest.getCurrentValue());
+}
+
 Backend::~Backend() = default;
 
 } // namespace mbgl
diff --git a/src/mbgl/util/offscreen_texture.cpp b/src/mbgl/util/offscreen_texture.cpp
index fe24774b7c..77a1416e48 100644
--- a/src/mbgl/util/offscreen_texture.cpp
+++ b/src/mbgl/util/offscreen_texture.cpp
@@ -33,6 +33,7 @@ public:
         }
 
         context.activeTexture = 0;
+        context.scissorTest = false;
         context.viewport = { 0, 0, size };
     }
 
diff --git a/test/util/offscreen_texture.test.cpp b/test/util/offscreen_texture.test.cpp
index feaabf2630..0149b1a8dd 100644
--- a/test/util/offscreen_texture.test.cpp
+++ b/test/util/offscreen_texture.test.cpp
@@ -14,6 +14,11 @@ TEST(OffscreenTexture, EmptyRed) {
     HeadlessBackend backend { test::sharedDisplay() };
     BackendScope scope { backend };
     OffscreenView view(backend.getContext(), { 512, 256 });
+
+    // Scissor test shouldn't leak after OffscreenView::bind().
+    MBGL_CHECK_ERROR(glScissor(64, 64, 128, 128));
+    backend.getContext().scissorTest.setCurrentValue(true);
+
     view.bind();
 
     MBGL_CHECK_ERROR(glClearColor(1.0f, 0.0f, 0.0f, 1.0f));
@@ -128,6 +133,11 @@ void main() {
     // Then, create a texture, bind it, and render yellow to that texture. This should not
     // affect the originally bound FBO.
     OffscreenTexture texture(context, { 128, 128 });
+
+    // Scissor test shouldn't leak after OffscreenTexture::bind().
+    MBGL_CHECK_ERROR(glScissor(32, 32, 64, 64));
+    context.scissorTest.setCurrentValue(true);
+
     texture.bind();
 
     context.clear(Color(), {}, {});