From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 30 Mar 2021 13:40:52 +0000 (+0300)
Subject: Add some precondition checks to Program
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=fc5a3640bd7a007c2da025308e6d6a33402eb098;p=libs%2Fgl.git

Add some precondition checks to Program

Adding stages from multiple modules presents some difficulties in matching
the interfaces.
---

diff --git a/source/core/program.cpp b/source/core/program.cpp
index 789fa324..c41976ed 100644
--- a/source/core/program.cpp
+++ b/source/core/program.cpp
@@ -80,6 +80,9 @@ Program::~Program()
 
 void Program::add_stages(const Module &mod, const map<string, int> &spec_values)
 {
+	if(!stage_ids.empty())
+		throw invalid_operation("Program::add_stages");
+
 	switch(mod.get_format())
 	{
 	case Module::GLSL: return add_glsl_stages(static_cast<const GlslModule &>(mod), spec_values);
@@ -220,6 +223,9 @@ void Program::bind_fragment_data(unsigned index, const string &name)
 
 void Program::link()
 {
+	if(stage_ids.empty())
+		throw invalid_operation("Program::link");
+
 	uniforms.clear();
 
 	glLinkProgram(id);