add getRenderGroupByName helper

src/tangerine.cpp

@@ -110,6 +110,24 @@ getFreeRenderGroup(RenderState* rs)
 	return nullptr;
 }
 
+RenderGroup*
+getRenderGroupByName(RenderState* rs, const char* name)
+{
+	RenderGroup* rg_out = nullptr;
+
+	for (u32 i = 0; i < rs->num_render_groups; i++) {
+		RenderGroup* rg = &rs->render_groups[i];
+
+		if (utilCStrMatch(name, rg->name))
+			rg_out = rg;
+	}
+
+	if (rg_out == nullptr)
+		LOGF(Error, "render group with name, \"%s\", not found\n", name);
+
+	return rg_out;
+}
+
 Entity*
 getFreeEntity(RenderGroup* rg)
 {

src/tangerine.h

@@ -182,6 +182,8 @@ void freeRenderGroup(RenderGroup* rg, MemoryArena* arena);
 
 RenderGroup* getFreeRenderGroup(RenderState* rs);
 
+RenderGroup* getRenderGroupByName(RenderState* rs, const char* name);
+
 Entity* getFreeEntity(RenderGroup* rg);
 
 // NOTE: callback function signature to use with renDoRenderLoop()