refactor: transparent render (#14)

* fix(renderer): defer uniform location retrieval and add view matrix in outline rendering

* refactor(gameplay): encapsulate per-type vertex data into VertexData struct

* feat(rendering): separate transparent blocks into discard and blend modes

* feat(renderer): implement order-independent transparency

* fix(shaders): reduce alpha discard threshold to 0.8

CMakeLists.txt

@@ -123,6 +123,7 @@ add_executable(${PROJECT_NAME}
     src/gameplay/river_worm.cpp
     src/gameplay/river_path.cpp
     src/block.cpp
+    src/gameplay/vertex_data.cpp
 )
 
 if(CMAKE_BUILD_TYPE STREQUAL "Debug")