1 files changed, 39 insertions, 0 deletions
diff --git a/include/mbgl/geometry/line_buffer.hpp b/include/mbgl/geometry/line_buffer.hpp
new file mode 100644
index 0000000000..5012bb12ac
--- /dev/null
+++ b/include/mbgl/geometry/line_buffer.hpp
@@ -0,0 +1,39 @@
+#ifndef MBGL_GEOMETRY_LINE_BUFFER
+#define MBGL_GEOMETRY_LINE_BUFFER
+
+#include "buffer.hpp"
+
+namespace mbgl {
+
+class LineVertexBuffer : public Buffer<
+    8 // 2 coordinates per vertex + 1 linesofar + 1 extrude coord pair == 4 (== 8 bytes)
+> {
+public:
+    typedef int16_t vertex_type;
+
+    /*
+     * Scale the extrusion vector so that the normal length is this value.
+     * Contains the "texture" normals (-1..1). This is distinct from the extrude
+     * normals for line joins, because the x-value remains 0 for the texture
+     * normal array, while the extrude normal actually moves the vertex to create
+     * the acute/bevelled line join.
+     */
+    static const int8_t extrudeScale = 63;
+
+    /*
+     * Add a vertex to this buffer
+     *
+     * @param {number} x vertex position
+     * @param {number} y vertex position
+     * @param {number} ex extrude normal
+     * @param {number} ey extrude normal
+     * @param {number} tx texture normal
+     * @param {number} ty texture normal
+     */
+    size_t add(vertex_type x, vertex_type y, float ex, float ey, int8_t tx, int8_t ty, int32_t linesofar = 0);
+};
+
+
+}
+
+#endif