From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 21 Jun 2019 08:22:08 +0000 (+0300)
Subject: Consider extensions when checking GLSL features
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=7189f63c549e9061789c47726ff8d6d12afca1a0

Consider extensions when checking GLSL features
---

diff --git a/extensions/arb_explicit_attrib_location.glext b/extensions/arb_explicit_attrib_location.glext
new file mode 100644
index 00000000..77222b92
--- /dev/null
+++ b/extensions/arb_explicit_attrib_location.glext
@@ -0,0 +1 @@
+extension ARB_explicit_attrib_location
diff --git a/extensions/arb_gpu_shader5.glext b/extensions/arb_gpu_shader5.glext
new file mode 100644
index 00000000..2fbb4fc1
--- /dev/null
+++ b/extensions/arb_gpu_shader5.glext
@@ -0,0 +1 @@
+extension ARB_gpu_shader5
diff --git a/scripts/extgen.py b/scripts/extgen.py
index 92c78b50..15ef167b 100755
--- a/scripts/extgen.py
+++ b/scripts/extgen.py
@@ -399,7 +399,7 @@ def detect_backport_extension(host_api, things):
 			best_ext = e
 			best_count = count
 
-	if best_count*2>=total_count:
+	if total_count and best_count*2>=total_count:
 		print "Warning: Inconsistent backport extension %s"%best_ext.name
 
 def collect_extensions(thing, api, exts):
diff --git a/source/programcompiler.cpp b/source/programcompiler.cpp
index 3dc07d80..6b8d2eb8 100644
--- a/source/programcompiler.cpp
+++ b/source/programcompiler.cpp
@@ -1,4 +1,8 @@
+#include <msp/core/algorithm.h>
 #include <msp/core/raii.h>
+#include <msp/gl/extensions/arb_explicit_attrib_location.h>
+#include <msp/gl/extensions/arb_gpu_shader5.h>
+#include <msp/gl/extensions/arb_uniform_buffer_object.h>
 #include <msp/gl/extensions/ext_gpu_shader4.h>
 #include <msp/strings/format.h>
 #include <msp/strings/utils.h>
@@ -321,6 +325,11 @@ void ProgramCompiler::Formatter::apply(ProgramSyntax::Stage &s)
 		formatted += '\n';
 	}
 
+	for(vector<const Extension *>::const_iterator i=s.required_extensions.begin(); i!=s.required_extensions.end(); ++i)
+		formatted += format("#extension %s: require\n", (*i)->get_name());
+	if(!s.required_extensions.empty())
+		formatted += '\n';
+
 	Visitor::apply(s);
 }
 
@@ -1776,6 +1785,18 @@ bool ProgramCompiler::LegacyConverter::check_version(const Version &feature_vers
 	return true;
 }
 
+bool ProgramCompiler::LegacyConverter::check_extension(const Extension &extension) const
+{
+	if(!extension)
+		return false;
+
+	vector<const Extension *>::iterator i = find(stage->required_extensions, &extension);
+	if(i==stage->required_extensions.end())
+		stage->required_extensions.push_back(&extension);
+
+	return true;
+}
+
 bool ProgramCompiler::LegacyConverter::supports_unified_interface_syntax() const
 {
 	if(target_api==OPENGL_ES2)
@@ -1844,24 +1865,30 @@ bool ProgramCompiler::LegacyConverter::supports_interface_layouts() const
 {
 	if(target_api==OPENGL_ES2)
 		return check_version(Version(3, 0));
+	else if(check_version(Version(3, 30)))
+		return true;
 	else
-		return check_version(Version(3, 30));
+		return check_extension(ARB_explicit_attrib_location);
 }
 
 bool ProgramCompiler::LegacyConverter::supports_centroid_sampling() const
 {
 	if(target_api==OPENGL_ES2)
 		return check_version(Version(3, 0));
+	else if(check_version(Version(1, 20)))
+		return true;
 	else
-		return check_version(Version(1, 20));
+		return check_extension(EXT_gpu_shader4);
 }
 
 bool ProgramCompiler::LegacyConverter::supports_sample_sampling() const
 {
 	if(target_api==OPENGL_ES2)
 		return check_version(Version(3, 20));
+	else if(check_version(Version(4, 0)))
+		return true;
 	else
-		return check_version(Version(4, 0));
+		return check_extension(ARB_gpu_shader5);
 }
 
 void ProgramCompiler::LegacyConverter::visit(VariableDeclaration &var)
@@ -1923,8 +1950,12 @@ bool ProgramCompiler::LegacyConverter::supports_interface_blocks(const string &i
 		else
 			return check_version(Version(3, 20));
 	}
+	else if(check_version(Version(1, 50)))
+		return true;
+	else if(iface=="uniform")
+		return check_extension(ARB_uniform_buffer_object);
 	else
-		return check_version(Version(1, 50));
+		return false;
 }
 
 void ProgramCompiler::LegacyConverter::visit(InterfaceBlock &iface)
diff --git a/source/programcompiler.h b/source/programcompiler.h
index 1f0601b5..76e9eef3 100644
--- a/source/programcompiler.h
+++ b/source/programcompiler.h
@@ -360,6 +360,7 @@ private:
 		LegacyConverter(const Version &);
 
 		bool check_version(const Version &) const;
+		bool check_extension(const Extension &) const;
 		using Visitor::visit;
 		bool supports_unified_interface_syntax() const;
 		virtual void visit(ProgramSyntax::VariableReference &);
diff --git a/source/programsyntax.h b/source/programsyntax.h
index 6a03f40f..1f26bc56 100644
--- a/source/programsyntax.h
+++ b/source/programsyntax.h
@@ -389,6 +389,7 @@ struct Stage
 	std::map<std::string, VariableDeclaration *> out_variables;
 	std::map<std::string, unsigned> locations;
 	Version required_version;
+	std::vector<const Extension *> required_extensions;
 
 	Stage(StageType);
 };