breakdown loadScene function into discrete steps

src/main.cpp

@@ -270,14 +270,47 @@ addShaders(RenderState* rs)
 bool
 loadScene(RenderState* rs)
 {
-	shader_program* s_default = getShaderByName("default", rs->gl_ctx);
-	shader_program* s_debug = getShaderByName("debug", rs->gl_ctx);
-	if (!s_default || !s_debug) return false;
+	// TODO: come up with an easy to use interface for loading a model, setting
+	// 	up the buffer to attrib mappings, and initializing a render group
 
+	// NOTE: load model and mesh
 	model* tex_cube = getModelByPath(&rs->assets, "../data/textured_cube.gltf");
-	assert(tex_cube != nullptr);
+	assert(tex_cube);
 	const mesh& texmesh = tex_cube->meshes[0];
 
+	// NOTE: load shader
+	shader_program* s_default = getShaderByName("default", rs->gl_ctx);
+	assert(s_default);
+
+	// NOTE: set up mapping between shader attributes, and vertex buffers
+	GLVertexAttrib* df_pos_attrib =
+		getVertexAttribByName(s_default, "position");
+	GLVertexAttrib* df_uv_attrib = getVertexAttribByName(s_default, "uv");
+	assert(df_pos_attrib && df_uv_attrib);
+
+	GLBufferToAttribMapping default_mappings[2] = {
+		{ "position", df_pos_attrib, texmesh.vertices },
+		{ "uvs", df_uv_attrib, texmesh.uvs }
+	};
+
+	// NOTE: init new render group
+	RenderGroup* debug_cube_group = getFreeRenderGroup(rs);
+	assert(debug_cube_group);
+	initRenderGroup(debug_cube_group, rs->rg_arena, s_default, 1,
+			"orange_cubes");
+
+	// NOTE: init entity
+	Entity* e = getFreeEntity(debug_cube_group);
+	assert(e);
+
+	initEntity(e, rs->gl_ctx, rs->rg_arena, tex_cube,
+		2, default_mappings, "textured_box");
+	scaleEntity(e, 5);
+
+#if 0
+	shader_program* s_debug = getShaderByName("debug", rs->gl_ctx);
+	if (!s_debug) return false;
+
 	GLVertexAttrib* db_pos_attrib = getVertexAttribByName(s_debug, "position");
 	GLVertexAttrib* db_normal_attrib = getVertexAttribByName(s_debug, "normal");
 	if (!db_pos_attrib || !db_normal_attrib) return false;
@@ -314,26 +347,7 @@ loadScene(RenderState* rs)
 
 		setEntityPosition(e, cube_locs[i]);
 	}
-
-	RenderGroup* debug_cube_group = getFreeRenderGroup(rs);
-	assert(debug_cube_group != nullptr);
-	initRenderGroup(debug_cube_group, rs->rg_arena, s_default, 1,
-			"orange_cubes");
-	Entity* e = getFreeEntity(debug_cube_group);
-	assert(e != nullptr);
-
-	GLVertexAttrib* df_pos_attrib =
-		getVertexAttribByName(s_default, "position");
-	GLVertexAttrib* df_uv_attrib = getVertexAttribByName(s_default, "uv");
-	if (!df_pos_attrib  || !df_uv_attrib) return false;
-
-	GLBufferToAttribMapping default_mappings[2] = {
-		{ "position", df_pos_attrib, texmesh.vertices },
-		{ "uvs", df_uv_attrib, texmesh.uvs }
-	};
-
-	initEntity(e, rs->gl_ctx, rs->rg_arena, tex_cube,
-		2, default_mappings, "textured_box");
+#endif
 
 	return true;
 }