[core] move draw mode and primitives to gfx namespace

3 files changed, 115 insertions, 0 deletions

diff --git a/src/mbgl/gfx/draw_mode.hpp b/src/mbgl/gfx/draw_mode.hpp
new file mode 100644
index 0000000000..a0a9b6c575
--- /dev/null
+++ b/src/mbgl/gfx/draw_mode.hpp
@@ -0,0 +1,72 @@
+#pragma once
+
+#include <mbgl/gfx/types.hpp>
+#include <mbgl/gfx/primitives.hpp>
+
+#include <cassert>
+
+namespace mbgl {
+namespace gfx {
+
+class Points {
+public:
+    using Primitive = Point;
+
+    static constexpr std::size_t bufferGroupSize = 1;
+    static constexpr PrimitiveType primitiveType = PrimitiveType::Points;
+
+    explicit Points(float pointSize_) : pointSize(pointSize_) {}
+
+    float pointSize;
+};
+
+class Lines {
+public:
+    using Primitive = Line;
+
+    static constexpr std::size_t bufferGroupSize = 2;
+    static constexpr PrimitiveType primitiveType = PrimitiveType::Lines;
+
+    explicit Lines(float lineWidth_) : lineWidth(lineWidth_) {
+        assert(lineWidth > 0);
+    }
+
+    float lineWidth;
+};
+
+class LineStrip {
+public:
+    // LineStrip is a form of "Line" rendering, but the element buffer
+    // cannot be grouped into logical elements beyond a single Point.
+    using Primitive = Line;
+
+    static constexpr std::size_t bufferGroupSize = 1;
+    static constexpr PrimitiveType primitiveType = PrimitiveType::LineStrip;
+
+    explicit LineStrip(float lineWidth_) : lineWidth(lineWidth_) {
+        assert(lineWidth > 0);
+    }
+
+    float lineWidth;
+};
+
+class Triangles {
+public:
+    using Primitive = Triangle;
+
+    static constexpr std::size_t bufferGroupSize = 3;
+    static constexpr PrimitiveType primitiveType = PrimitiveType::Triangles;
+};
+
+class TriangleStrip {
+public:
+    // TriangleStrip is a form of "Triangle" rendering, but the element buffer
+    // cannot be grouped into logical elements beyond a single Point.
+    using Primitive = Triangle;
+
+    static constexpr std::size_t bufferGroupSize = 1;
+    static constexpr PrimitiveType primitiveType = PrimitiveType::TriangleStrip;
+};
+
+} // namespace gfx
+} // namespace mbgl
diff --git a/src/mbgl/gfx/primitives.hpp b/src/mbgl/gfx/primitives.hpp
new file mode 100644
index 0000000000..f92b1ec525
--- /dev/null
+++ b/src/mbgl/gfx/primitives.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <cstddef>
+
+namespace mbgl {
+namespace gfx {
+
+class Point {
+public:
+    static constexpr std::size_t vertexCount = 1;
+};
+
+class Line {
+public:
+    static constexpr std::size_t vertexCount = 2;
+};
+
+class Triangle {
+public:
+    static constexpr std::size_t vertexCount = 3;
+};
+
+} // namespace gfx
+} // namespace mbgl
diff --git a/src/mbgl/gfx/types.hpp b/src/mbgl/gfx/types.hpp
new file mode 100644
index 0000000000..ea7b2da5dc
--- /dev/null
+++ b/src/mbgl/gfx/types.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstdint>
+
+namespace mbgl {
+namespace gfx {
+
+enum class PrimitiveType : uint8_t {
+    Points,
+    Lines,
+    LineLoop,
+    LineStrip,
+    Triangles,
+    TriangleStrip,
+    TriangleFan
+};
+
+} // namespace gfx
+} // namespace mbgl