From a170be7d2b295c4a3bbcea6585634bece3e1638b Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 21 Jun 2019 00:50:41 +0300
Subject: [PATCH] Store information about attributes in Program

---
 source/program.cpp | 27 ++++++++++++++++++++++++++-
 source/program.h   | 13 +++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/source/program.cpp b/source/program.cpp
index c3625f41..d8827ab5 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -283,7 +283,18 @@ void Program::query_attributes()
 		int size;
 		GLenum type;
 		glGetActiveAttrib(id, i, sizeof(name), &len, &size, &type, name);
-		if(len && !strncmp(name, "gl_", 3))
+		if(len && strncmp(name, "gl_", 3))
+		{
+			if(len>3 && !strcmp(name+len-3, "[0]"))
+				name[len-3] = 0;
+
+			AttributeInfo &info = attributes[name];
+			info.name = name;
+			info.location = glGetAttribLocation(id, name);
+			info.size = size;
+			info.type = type;
+		}
+		else
 			legacy_vars = true;
 	}
 }
@@ -333,6 +344,20 @@ int Program::get_uniform_location(const string &n) const
 	return i->second.block->bind_point<0 ? i->second.location : -1;
 }
 
+const Program::AttributeInfo &Program::get_attribute_info(const string &name) const
+{
+	return get_item(attributes, name);
+}
+
+int Program::get_attribute_location(const string &n) const
+{
+	if(n[n.size()-1]==']')
+		throw invalid_argument("Program::get_attribute_location");
+
+	AttributeMap::const_iterator i = attributes.find(n);
+	return i!=attributes.end() ? i->second.location : -1;
+}
+
 void Program::bind() const
 {
 	if(!linked)
diff --git a/source/program.h b/source/program.h
index 826a4963..d2032a5c 100644
--- a/source/program.h
+++ b/source/program.h
@@ -59,9 +59,18 @@ public:
 		LayoutHash layout_hash;
 	};
 
+	struct AttributeInfo
+	{
+		std::string name;
+		unsigned location;
+		unsigned size;
+		GLenum type;
+	};
+
 	typedef std::vector<Shader *> ShaderList;
 	typedef std::map<std::string, UniformInfo> UniformMap;
 	typedef std::map<std::string, UniformBlockInfo> UniformBlockMap;
+	typedef std::map<std::string, AttributeInfo> AttributeMap;
 
 private:
 	unsigned id;
@@ -71,6 +80,7 @@ private:
 	UniformBlockMap uniform_blocks;
 	UniformMap uniforms;
 	LayoutHash uniform_layout_hash;
+	AttributeMap attributes;
 	bool legacy_vars;
 
 public:
@@ -117,6 +127,9 @@ public:
 	const UniformMap &get_uniforms() const { return uniforms; }
 	const UniformInfo &get_uniform_info(const std::string &) const;
 	int get_uniform_location(const std::string &) const;
+	const AttributeMap &get_attributes() const { return attributes; }
+	const AttributeInfo &get_attribute_info(const std::string &) const;
+	int get_attribute_location(const std::string &) const;
 
 	bool uses_legacy_variables() const { return legacy_vars; }
 
-- 
2.43.0