Prevent redundant glBindBuffer calls.

--HG--
branch : minor

src/modules/graphics/opengl/ParticleSystem.cpp

@@ -137,6 +137,7 @@ void ParticleSystem::draw(const Matrix4 &m)
 
 	gl.useVertexAttribArrays(ATTRIBFLAG_POS | ATTRIBFLAG_TEXCOORD | ATTRIBFLAG_COLOR);
 
+	gl.bindBuffer(BUFFER_VERTEX, 0);
 	glVertexAttribPointer(ATTRIB_COLOR, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex), &particleVerts[0].r);
 	glVertexAttribPointer(ATTRIB_POS, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &particleVerts[0].x);
 	glVertexAttribPointer(ATTRIB_TEXCOORD, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &particleVerts[0].s);
@@ -148,6 +149,7 @@ void ParticleSystem::draw(const Matrix4 &m)
 	// at least one graphics driver (the one for Kepler nvidia GPUs in OS X
 	// 10.11) fails to render geometry if an index buffer is used with
 	// client-side vertex arrays.
+	gl.bindBuffer(BUFFER_INDEX, 0);
 	gl.drawElements(GL_TRIANGLES, count, gltype, quadIndices.getIndices(0));
 }