From e3561c5c4d0b2caf00a0e50ce85c11a9fb62aa72 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 16 Oct 2016 11:16:38 +0300
Subject: [PATCH] Add basic support for geometry shaders

---
 extensions/ext_geometry_shader4.glext |  1 +
 source/program.cpp                    |  6 ++++++
 source/program.h                      |  1 +
 source/shader.cpp                     | 12 ++++++++++++
 source/shader.h                       |  8 ++++++++
 5 files changed, 28 insertions(+)
 create mode 100644 extensions/ext_geometry_shader4.glext

diff --git a/extensions/ext_geometry_shader4.glext b/extensions/ext_geometry_shader4.glext
new file mode 100644
index 00000000..0bc0f85d
--- /dev/null
+++ b/extensions/ext_geometry_shader4.glext
@@ -0,0 +1 @@
+extension EXT_geometry_shader4
diff --git a/source/program.cpp b/source/program.cpp
index 30c73f33..021b2348 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -319,6 +319,7 @@ Program::Loader::Loader(Program &p):
 {
 	add("attribute",       &Loader::attribute);
 	add("fragment_shader", &Loader::fragment_shader);
+	add("geometry_shader", &Loader::geometry_shader);
 	add("standard",        &Loader::standard);
 	add("vertex_shader",   &Loader::vertex_shader);
 }
@@ -338,6 +339,11 @@ void Program::Loader::fragment_shader(const string &src)
 	obj.attach_shader_owned(new FragmentShader(src));
 }
 
+void Program::Loader::geometry_shader(const string &src)
+{
+	obj.attach_shader_owned(new GeometryShader(src));
+}
+
 void Program::Loader::standard()
 {
 	ProgramBuilder::StandardFeatures feat;
diff --git a/source/program.h b/source/program.h
index 53daaa76..53f060d2 100644
--- a/source/program.h
+++ b/source/program.h
@@ -31,6 +31,7 @@ public:
 
 		void attribute(unsigned, const std::string &);
 		void fragment_shader(const std::string &);
+		void geometry_shader(const std::string &);
 		void standard();
 		void vertex_shader(const std::string &);
 	};
diff --git a/source/shader.cpp b/source/shader.cpp
index 1b3455f1..17bf3fad 100644
--- a/source/shader.cpp
+++ b/source/shader.cpp
@@ -1,6 +1,7 @@
 #include <msp/gl/extensions/arb_fragment_shader.h>
 #include <msp/gl/extensions/arb_shader_objects.h>
 #include <msp/gl/extensions/arb_vertex_shader.h>
+#include <msp/gl/extensions/ext_geometry_shader4.h>
 #include "error.h"
 #include "misc.h"
 #include "shader.h"
@@ -31,6 +32,8 @@ void Shader::init(GLenum t)
 		static Require _req(ARB_fragment_shader);
 	else if(t==GL_VERTEX_SHADER)
 		static Require _req(ARB_vertex_shader);
+	else if(t==GL_GEOMETRY_SHADER)
+		static Require _req(EXT_geometry_shader4);
 
 	id = glCreateShader(t);
 }
@@ -91,5 +94,14 @@ FragmentShader::FragmentShader(const string &src):
 	Shader(GL_FRAGMENT_SHADER, src)
 { }
 
+
+GeometryShader::GeometryShader():
+	Shader(GL_GEOMETRY_SHADER)
+{ }
+
+GeometryShader::GeometryShader(const string &src):
+	Shader(GL_GEOMETRY_SHADER, src)
+{ }
+
 } // namespace GL
 } // namespace Msp
diff --git a/source/shader.h b/source/shader.h
index 961cb694..bab11a7e 100644
--- a/source/shader.h
+++ b/source/shader.h
@@ -52,6 +52,14 @@ public:
 	FragmentShader(const std::string &);
 };
 
+
+class GeometryShader: public Shader
+{
+public:
+	GeometryShader();
+	GeometryShader(const std::string &);
+};
+
 } // namespace GL
 } // namespace Msp
 
-- 
2.43.0