From d1a27666d996b3e441ef46ea1d74ec38d9dba5e4 Mon Sep 17 00:00:00 2001
From: Bastien Bouclet <bastien.bouclet@gmail.com>
Date: Sat, 16 Jan 2016 08:02:13 +0100
Subject: [PATCH] GRAPHICS: Add a method to unbind the active shader

---
 graphics/opengles2/shader.cpp | 11 ++++++++---
 graphics/opengles2/shader.h   |  4 ++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/graphics/opengles2/shader.cpp b/graphics/opengles2/shader.cpp
index d3b101da4d6..7cf7eccf5c0 100644
--- a/graphics/opengles2/shader.cpp
+++ b/graphics/opengles2/shader.cpp
@@ -124,6 +124,8 @@ struct SharedPtrProgramDeleter {
 	}
 };
 
+Shader* Shader::_previousShader = nullptr;
+
 Shader::Shader(const Common::String &name, GLuint vertexShader, GLuint fragmentShader, const char **attributes)
 	: _name(name) {
 	assert(attributes);
@@ -163,9 +165,8 @@ Shader *Shader::fromFiles(const char *vertex, const char *fragment, const char *
 }
 
 void Shader::use(bool forceReload) {
-	static Shader *previousShader = nullptr;
 	static uint32 previousNumAttributes = 0;
-	if (this == previousShader && !forceReload)
+	if (this == _previousShader && !forceReload)
 		return;
 
 	// The previous shader might have had more attributes. Disable any extra ones.
@@ -175,7 +176,7 @@ void Shader::use(bool forceReload) {
 		}
 	}
 
-	previousShader = this;
+	_previousShader = this;
 	previousNumAttributes = _attributes.size();
 
 	glUseProgram(*_shaderNo);
@@ -246,6 +247,10 @@ void Shader::disableVertexAttribute(const char *attrib, int size, const float *d
 		va._const[i] = data[i];
 }
 
+void Shader::unbind() {
+	glUseProgram(0);
+	_previousShader = nullptr;
+}
 }
 
 #endif
diff --git a/graphics/opengles2/shader.h b/graphics/opengles2/shader.h
index 64d74f489e4..fbeb9cfa7aa 100644
--- a/graphics/opengles2/shader.h
+++ b/graphics/opengles2/shader.h
@@ -143,6 +143,8 @@ public:
 
 	static Shader* fromStrings(const Common::String &name, const char *vertex, const char *fragment, const char **attributes);
 
+	void unbind();
+
 private:
 	Shader(const Common::String &name, GLuint vertexShader, GLuint fragmentShader, const char **attributes);
 
@@ -155,6 +157,8 @@ private:
 
 	Common::Array<VertexAttrib> _attributes;
 	Common::SharedPtr<UniformsMap> _uniforms;
+
+	static Shader *_previousShader;
 };
 
 }