From e1672476c5a258ff67fe1fcb47dd9a40b89169cb Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 19 Oct 2014 17:25:56 +0300
Subject: [PATCH] Don't enable/disable textures on non-legacy units

---
 source/texture.cpp | 16 ++++++++++------
 source/texunit.cpp | 19 +++++++++++++++++++
 source/texunit.h   |  3 +++
 3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/source/texture.cpp b/source/texture.cpp
index 187c2533..81373c97 100644
--- a/source/texture.cpp
+++ b/source/texture.cpp
@@ -199,17 +199,20 @@ void Texture::bind_to(unsigned i) const
 	}
 
 	TexUnit &unit = TexUnit::get_unit(i);
-	const Texture *cur = unit.get_texture();
+	const Texture *old = unit.get_texture();
 	if(unit.set_texture(this))
 	{
 		if(manager)
 			manager->resource_used(*this);
 
 		unit.bind();
-		if(cur && cur->target!=target)
-			glDisable(cur->target);
-		if(!cur || cur->target!=target)
-			glEnable(target);
+		if(unit.supports_legacy())
+		{
+			if(old && old->target!=target)
+				glDisable(old->target);
+			if(!old || old->target!=target)
+				glEnable(target);
+		}
 		glBindTexture(target, id);
 
 		if(dirty_params)
@@ -233,7 +236,8 @@ void Texture::unbind_from(unsigned i)
 	{
 		unit.bind();
 		glBindTexture(cur->target, 0);
-		glDisable(cur->target);
+		if(unit.supports_legacy())
+			glDisable(cur->target);
 	}
 }
 
diff --git a/source/texunit.cpp b/source/texunit.cpp
index 9b905120..74a23246 100644
--- a/source/texunit.cpp
+++ b/source/texunit.cpp
@@ -1,6 +1,7 @@
 #include <stdexcept>
 #include <msp/gl/extensions/arb_multitexture.h>
 #include <msp/gl/extensions/arb_vertex_shader.h>
+#include <msp/gl/extensions/msp_legacy_features.h>
 #include "gl.h"
 #include "misc.h"
 #include "texunit.h"
@@ -14,6 +15,7 @@ vector<TexUnit> TexUnit::units;
 TexUnit *TexUnit::cur_unit = 0;
 
 TexUnit::TexUnit():
+	legacy(false),
 	texture(0)
 { }
 
@@ -46,6 +48,19 @@ unsigned TexUnit::get_n_units()
 	return count;
 }
 
+unsigned TexUnit::get_n_legacy_units()
+{
+	static int count = -1;
+	if(count<0)
+	{
+		if(MSP_legacy_features)
+			count = get_i(GL_MAX_TEXTURE_UNITS);
+		else
+			count = 0;
+	}
+	return count;
+}
+
 TexUnit &TexUnit::get_unit(unsigned n)
 {
 	if(n>0)
@@ -56,9 +71,13 @@ TexUnit &TexUnit::get_unit(unsigned n)
 	if(units.size()<=n)
 	{
 		unsigned i = units.size();
+		unsigned n_legacy = get_n_legacy_units();
 		units.resize(n+1, TexUnit());
 		for(; i<units.size(); ++i)
+		{
 			units[i].index = i;
+			units[i].legacy = (i<n_legacy);
+		}
 	}
 
 	return units[n];
diff --git a/source/texunit.h b/source/texunit.h
index f3f95e7e..0bba15d6 100644
--- a/source/texunit.h
+++ b/source/texunit.h
@@ -17,6 +17,7 @@ class TexUnit
 {
 private:
 	unsigned index;
+	bool legacy;
 	const Texture *texture;
 
 	static std::vector<TexUnit> units;
@@ -26,11 +27,13 @@ private:
 
 public:
 	unsigned get_index() const { return index; }
+	bool supports_legacy() const { return legacy; }
 	bool set_texture(const Texture *);
 	const Texture *get_texture() const { return texture; }
 	void bind();
 
 	static unsigned get_n_units();
+	static unsigned get_n_legacy_units();
 	static TexUnit &get_unit(unsigned);
 	static TexUnit &current();
 	static TexUnit *find_unit(const Texture *);
-- 
2.43.0