[core] Move translatedMatrix to RenderTile

src/mbgl/renderer/render_tile.cpp

@@ -1,5 +1,34 @@
 #include <mbgl/renderer/render_tile.hpp>
+#include <mbgl/map/transform_state.hpp>
 
 namespace mbgl {
 
+using namespace style;
+
+mat4 RenderTile::translatedMatrix(const std::array<float, 2>& translation,
+                                  TranslateAnchorType anchor,
+                                  const TransformState& state) const {
+    if (translation[0] == 0 && translation[1] == 0) {
+        return matrix;
+    }
+
+    mat4 vtxMatrix;
+
+    if (anchor == TranslateAnchorType::Viewport) {
+        const double sin_a = std::sin(-state.getAngle());
+        const double cos_a = std::cos(-state.getAngle());
+        matrix::translate(vtxMatrix, matrix,
+                id.pixelsToTileUnits(translation[0] * cos_a - translation[1] * sin_a, state.getZoom()),
+                id.pixelsToTileUnits(translation[0] * sin_a + translation[1] * cos_a, state.getZoom()),
+                0);
+    } else {
+        matrix::translate(vtxMatrix, matrix,
+                id.pixelsToTileUnits(translation[0], state.getZoom()),
+                id.pixelsToTileUnits(translation[1], state.getZoom()),
+                0);
+    }
+
+    return vtxMatrix;
+}
+
 } // namespace mbgl