[core] Split layer type specific code in mbgl::Programs

Progams code for a certain layer type is encapsulted within
a dedicated `<layer type>Programs` class, inherited from
the generic base `LayerTypePrograms` class.

`mbgl::Programs::get<layer type>Programs()` lazily initializes the
layer type-specific programs code using pointer to the base class,
which allows LTO to remove this code from binaries (if the corresponding
`get<layer type>Programs()` method can never be invoked).

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mbgl/renderer/layers/render_hillshade_layer.cpp b/src/mbgl/renderer/layers/render_hillshade_layer.cpp
index ba7e782f16..8c245fa7fd 100644
--- a/src/mbgl/renderer/layers/render_hillshade_layer.cpp
+++ b/src/mbgl/renderer/layers/render_hillshade_layer.cpp
@@ -73,7 +73,7 @@ void RenderHillshadeLayer::render(PaintParameters& parameters, RenderSource* src
                      const auto& indexBuffer,
                      const auto& segments,
                      const UnwrappedTileID& id) {
-        auto& programInstance = parameters.programs.hillshade;
+        auto& programInstance = parameters.programs.getHillshadeLayerPrograms().hillshade;
 
         const HillshadeProgram::PaintPropertyBinders paintAttributeData{ evaluated, 0 };
 
@@ -138,7 +138,7 @@ void RenderHillshadeLayer::render(PaintParameters& parameters, RenderSource* src
             const Properties<>::PossiblyEvaluated properties;
             const HillshadePrepareProgram::PaintPropertyBinders paintAttributeData{ properties, 0 };
             
-            auto& programInstance = parameters.programs.hillshadePrepare;
+            auto& programInstance = parameters.programs.getHillshadeLayerPrograms().hillshadePrepare;
 
             const auto allUniformValues = programInstance.computeAllUniformValues(
                 HillshadePrepareProgram::UniformValues {