Selectable renderer implementation (#1247)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

BUILD.bazel

@@ -1,15 +1,32 @@
 load("//bazel:flags.bzl", "CPP_FLAGS", "MAPLIBRE_FLAGS")
 load("@bazel_skylib//rules:common_settings.bzl", "string_flag")
-load(
-    "//bazel:core.bzl",
-    "MLN_CORE_HEADERS",
-    "MLN_CORE_SOURCE",
-    "MLN_GENERATED_SHADER_HEADERS",
-    "MLN_GENERATED_STYLE_SOURCE",
-    "MLN_OPENGL_HEADERS",
-    "MLN_OPENGL_SOURCE",
-    "MLN_PRIVATE_GENERATED_STYLE_HEADERS",
-    "MLN_PUBLIC_GENERATED_STYLE_HEADERS",
+load("//bazel:core.bzl", "MLN_CORE_SOURCE", "MLN_CORE_HEADERS", "MLN_OPENGL_SOURCE", "MLN_OPENGL_HEADERS", "MLN_DRAWABLES_SOURCE", "MLN_DRAWABLES_HEADERS")
+
+string_flag(
+    name = "renderer",
+    build_setting_default = "drawable",
+    values=["legacy", "drawable", "split"]
+)
+
+config_setting(
+    name = "legacy_renderer",
+    flag_values = {
+        ":renderer": "legacy"
+    }
+)
+
+config_setting(
+    name = "drawable_renderer",
+        flag_values = {
+        ":renderer": "drawable"
+    }
+)
+
+config_setting(
+    name = "split_renderer",
+    flag_values = {
+        ":renderer": "split"
+    }
 )
 
 # Generate code required by the core
@@ -76,15 +93,24 @@ cc_library(
 # the prefix from the path.
 cc_library(
     name = "mbgl-core",
-    srcs = MLN_CORE_SOURCE +
-           MLN_GENERATED_STYLE_SOURCE +
-           MLN_OPENGL_SOURCE,
-    hdrs = MLN_CORE_HEADERS +
-           MLN_OPENGL_HEADERS,
+    srcs = MLN_CORE_SOURCE + select({
+        ":drawable_renderer": MLN_DRAWABLES_SOURCE,
+        ":split_renderer": MLN_DRAWABLES_SOURCE,
+        "//conditions:default": []
+    }) + MLN_OPENGL_SOURCE,
+    hdrs = MLN_CORE_HEADERS + select({
+        ":drawable_renderer": MLN_DRAWABLES_HEADERS,
+        ":split_renderer": MLN_DRAWABLES_HEADERS,
+        "//conditions:default": []
+    }) + MLN_OPENGL_HEADERS,
     copts = CPP_FLAGS + MAPLIBRE_FLAGS,
     defines = select({
+        ":legacy_renderer": ["MLN_LEGACY_RENDERER=1", "MLN_DRAWABLE_RENDERER=0"],
+        ":drawable_renderer": ["MLN_LEGACY_RENDERER=0", "MLN_DRAWABLE_RENDERER=1"],
+        ":split_renderer": ["MLN_LEGACY_RENDERER=1", "MLN_DRAWABLE_RENDERER=1", "MLN_RENDERER_SPLIT_VIEW=1"],
+    }) + select({
         "//:ios": ["GLES_SILENCE_DEPRECATION=1"],
-        "//conditions:default": [],
+        "//conditions:default": []
     }),
     includes = [
         "include",