From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 24 Aug 2012 16:05:43 +0000 (+0300)
Subject: Query information about uniform blocks when linking a Program
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=02dc3bda81eb0d421670b744c1c56aaf1104d5bf

Query information about uniform blocks when linking a Program
---

diff --git a/source/program.cpp b/source/program.cpp
index 8ca8e336..40a38819 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -1,8 +1,12 @@
 #include <algorithm>
+#include <cstring>
 #include <msp/core/hash.h>
+#include <msp/core/maputils.h>
 #include <msp/strings/format.h>
 #include "arb_shader_objects.h"
+#include "arb_uniform_buffer_object.h"
 #include "arb_vertex_shader.h"
+#include "buffer.h"
 #include "error.h"
 #include "extension.h"
 #include "program.h"
@@ -235,29 +239,112 @@ void Program::link()
 		throw compile_error(get_info_log());
 
 	glGetObjectParameterivARB(id, GL_OBJECT_ACTIVE_UNIFORMS_ARB, &value);
-	for(int i=0; i<value; ++i)
+	unsigned count = value;
+	vector<UniformInfo *> uniforms_by_index(count);
+	for(unsigned i=0; i<count; ++i)
 	{
-		UniformInfo info;
 		char name[128];
 		int len = 0;
-		glGetActiveUniformARB(id, i, 128, &len, &info.size, &info.type, name);
-		if(len)
+		int size;
+		GLenum type;
+		glGetActiveUniformARB(id, i, 128, &len, &size, &type, name);
+		if(len && strncmp(name, "gl_", 3))
 		{
+			UniformInfo &info = uniforms[name];
 			info.name = name;
-			info.location = glGetUniformLocationARB(id, name);
-			uniforms[name] = info;
+			info.size = size;
+			info.type = type;
+			uniforms_by_index[i] = &info;
 		}
 	}
 
-	string layout_descriptor;
-	for(map<string, UniformInfo>::const_iterator i = uniforms.begin(); i!=uniforms.end(); ++i)
-		if(i->second.location>=0)
+	vector<const UniformInfo *> blockless_uniforms;
+
+	if(is_supported("GL_ARB_uniform_buffer_object"))
+	{
+		glGetObjectParameterivARB(id, GL_ACTIVE_UNIFORM_BLOCKS, &value);
+		count = value;
+		vector<bool> uniforms_in_blocks(uniforms_by_index.size());
+		for(unsigned i=0; i<count; ++i)
 		{
-			if(!layout_descriptor.empty())
-				layout_descriptor += '\n';
-			layout_descriptor += format("%d:%s:%x", i->second.location, i->second.name, i->second.type);
+			char name[128];
+			int len;
+			glGetActiveUniformBlockName(id, i, 128, &len, name);
+			UniformBlockInfo &info = uniform_blocks[name];
+			info.name = name;
+
+			glGetActiveUniformBlockiv(id, i, GL_UNIFORM_BLOCK_DATA_SIZE, &value);
+			info.data_size = value;
+
+			glGetActiveUniformBlockiv(id, i, GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS, &value);
+			vector<int> indices(value);
+			glGetActiveUniformBlockiv(id, i, GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES, &indices[0]);
+			for(vector<int>::iterator j=indices.begin(); j!=indices.end(); ++j)
+			{
+				if(!uniforms_by_index[*j])
+					throw logic_error("Program::link");
+				info.uniforms.push_back(uniforms_by_index[*j]);
+				uniforms_in_blocks[*j] = true;
+			}
+
+			vector<unsigned> indices2(indices.begin(), indices.end());
+			vector<int> values(indices.size());
+			glGetActiveUniformsiv(id, indices.size(), &indices2[0], GL_UNIFORM_OFFSET, &values[0]);
+			for(unsigned j=0; j<indices.size(); ++j)
+				uniforms_by_index[indices[j]]->location = values[j];
+
+			indices2.clear();
+			for(vector<int>::iterator j=indices.begin(); j!=indices.end(); ++j)
+				if(uniforms_by_index[*j]->size>1)
+					indices2.push_back(*j);
+			glGetActiveUniformsiv(id, indices2.size(), &indices2[0], GL_UNIFORM_ARRAY_STRIDE, &values[0]);
+			for(unsigned j=0; j<indices2.size(); ++j)
+				uniforms_by_index[indices[j]]->array_stride = values[j];
+
+			indices2.clear();
+			for(vector<int>::iterator j=indices.begin(); j!=indices.end(); ++j)
+			{
+				GLenum t = uniforms_by_index[*j]->type;
+				if(t==GL_FLOAT_MAT4 || t==GL_FLOAT_MAT3 || t==GL_FLOAT_MAT2 ||
+					t==GL_FLOAT_MAT2x3 || t==GL_FLOAT_MAT2x4 || t==GL_FLOAT_MAT3x2 ||
+					t==GL_FLOAT_MAT3x4 || t==GL_FLOAT_MAT4x2 || t==GL_FLOAT_MAT4x3)
+					indices2.push_back(*j);
+			}
+			glGetActiveUniformsiv(id, indices2.size(), &indices2[0], GL_UNIFORM_MATRIX_STRIDE, &values[0]);
+			for(unsigned j=0; j<indices2.size(); ++j)
+				uniforms_by_index[indices[j]]->matrix_stride = values[j];
+
+			info.layout_hash = compute_layout_hash(info.uniforms);
+			info.bind_point = info.layout_hash%BufferRange::get_n_uniform_buffer_bindings();
+			glUniformBlockBinding(id, i, info.bind_point);
 		}
-	uniform_layout_hash = hash32(layout_descriptor);
+
+		for(unsigned i=0; i<uniforms_by_index.size(); ++i)
+			if(uniforms_by_index[i] && !uniforms_in_blocks[i])
+			{
+				UniformInfo *info = uniforms_by_index[i];
+				info->location = glGetUniformLocationARB(id, info->name.c_str());
+				blockless_uniforms.push_back(info);
+			}
+	}
+	else
+	{
+		for(UniformMap::iterator i=uniforms.begin(); i!=uniforms.end(); ++i)
+		{
+			i->second.location = glGetUniformLocationARB(id, i->second.name.c_str());
+			blockless_uniforms.push_back(&i->second);
+		}
+	}
+
+	uniform_layout_hash = compute_layout_hash(blockless_uniforms);
+}
+
+unsigned Program::compute_layout_hash(const vector<const UniformInfo *> &uniforms)
+{
+	string layout_descriptor;
+	for(vector<const UniformInfo *>::const_iterator i = uniforms.begin(); i!=uniforms.end(); ++i)
+		layout_descriptor += format("%d:%s:%x:%d\n", (*i)->location, (*i)->name, (*i)->type, (*i)->size);
+	return hash32(layout_descriptor);
 }
 
 string Program::get_info_log() const
@@ -271,6 +358,16 @@ string Program::get_info_log() const
 	return log;
 }
 
+const Program::UniformBlockInfo &Program::get_uniform_block_info(const string &name) const
+{
+	return get_item(uniform_blocks, name);
+}
+
+const Program::UniformInfo &Program::get_uniform_info(const string &name) const
+{
+	return get_item(uniforms, name);
+}
+
 int Program::get_uniform_location(const string &n) const
 {
 	UniformMap::const_iterator i = uniforms.find(n);
@@ -284,7 +381,7 @@ int Program::get_uniform_location(const string &n) const
 				/* The requested name looks like an array.  glGetActiveUniform only
 				gives us the first element of the array, so try to look that up and
 				add an offset. */
-				int offset = lexical_cast<unsigned>(n.substr(open_bracket+1, n.size()-2-open_bracket));
+				unsigned offset = lexical_cast<unsigned>(n.substr(open_bracket+1, n.size()-2-open_bracket));
 				i = uniforms.find(n.substr(0, open_bracket)+"[0]");
 				if(i!=uniforms.end() && offset<i->second.size)
 					return i->second.location+offset;
diff --git a/source/program.h b/source/program.h
index 7e9676d3..40a7a33b 100644
--- a/source/program.h
+++ b/source/program.h
@@ -54,19 +54,32 @@ public:
 	struct UniformInfo
 	{
 		std::string name;
-		int location;
-		int size;
+		unsigned location;
+		unsigned size;
+		unsigned array_stride;
+		unsigned matrix_stride;
 		GLenum type;
 	};
 
+	struct UniformBlockInfo
+	{
+		std::string name;
+		unsigned data_size;
+		unsigned bind_point;
+		std::vector<const UniformInfo *> uniforms;
+		unsigned layout_hash;
+	};
+
 	typedef std::list<Shader *> ShaderList;
 	typedef std::map<std::string, UniformInfo> UniformMap;
+	typedef std::map<std::string, UniformBlockInfo> UniformBlockMap;
 
 private:
 	unsigned id;
 	ShaderList shaders;
 	ShaderList owned_data;
 	bool linked;
+	UniformBlockMap uniform_blocks;
 	UniformMap uniforms;
 	unsigned uniform_layout_hash;
 
@@ -91,10 +104,17 @@ public:
 	void bind_attribute(unsigned, const std::string &);
 
 	void link();
+private:
+	static unsigned compute_layout_hash(const std::vector<const UniformInfo *> &);
+public:
 	bool is_linked() const { return linked; }
 	std::string get_info_log() const;
 
 	unsigned get_uniform_layout_hash() const { return uniform_layout_hash; }
+	const UniformBlockMap &get_uniform_blocks() const { return uniform_blocks; }
+	const UniformBlockInfo &get_uniform_block_info(const std::string &) const;
+	const UniformMap &get_uniforms() const { return uniforms; }
+	const UniformInfo &get_uniform_info(const std::string &) const;
 	int get_uniform_location(const std::string &) const;
 
 	void bind() const;