add new GLMeshMapping structure

src/shader.h

@@ -14,7 +14,8 @@ struct gl_buffer
 	GLenum target;
 	GLenum data_type;
 	GLuint data_size;
-	GLuint binding_idx;
+	GLuint location; // NOTE: if used as backing for vertex attribute
+	GLuint binding_idx; // NOTE: if used as backing from unifor buffer object
 	char* name;
 };
 
@@ -53,6 +54,7 @@ struct shader_program
 	u32 num_uniforms;
 	gl_uniform* uniforms;
 
+	// FIXME: better name would be vertex_attribs
 	u32 num_buffers;
 	gl_buffer* buffers;
 
@@ -99,6 +101,13 @@ struct GLmesh
 	GLuint idx_buf_id;
 };
 
+// NOTE: attempt to resolve GLmesh to shader_program mapping issue
+struct GLmeshMapping
+{
+	u32 mesh_idx;
+	u32 shader_idx;
+};
+
 struct PointLight
 {
 	glm::vec3 position;