[core] Add face culling mode parameter to Program::draw

Add a parameter to Program::draw to control whether face culling should
be enabled. This will be used in a follow up commit to enable face
culling for fill extrusion layers.

1 files changed, 40 insertions, 0 deletions

diff --git a/src/mbgl/gl/cull_face_mode.hpp b/src/mbgl/gl/cull_face_mode.hpp
new file mode 100644
index 0000000000..a408d7a88c
--- /dev/null
+++ b/src/mbgl/gl/cull_face_mode.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <cstdint>
+
+namespace mbgl {
+namespace gl {
+
+class CullFaceMode {
+public:
+    enum CullFace : bool {
+        Disable = false,
+        Enable = true,
+    };
+
+    enum CullFaceSide : uint32_t {
+        Front = 0x0404,
+        Back = 0x0405,
+        FrontAndBack = 0x0408,
+    };
+
+    enum FrontFace : uint32_t {
+        Clockwise = 0x0900,
+        CounterClockwise = 0x0901
+    };
+
+    CullFace cullFace;
+    CullFaceSide side;
+    FrontFace frontFace;
+
+    static CullFaceMode disabled() {
+        return CullFaceMode { Disable, CullFaceSide::Back, FrontFace::CounterClockwise };
+    }
+
+    static CullFaceMode backCCW() {
+        return CullFaceMode { Enable, CullFaceSide::Back, FrontFace::CounterClockwise };
+    }
+};
+
+} // namespace gl
+} // namespace mbgl