From 58f2990bc5423f527655e136948cbd4eb859e954 Mon Sep 17 00:00:00 2001
From: sshutina <sshutina@opencascade.com>
Date: Wed, 15 Sep 2021 13:48:51 +0300
Subject: [PATCH] 0032461: Visualization - expensive call of
 glGetTexEnviv/glTexEnvi in each render of OpenGl_Text

 - removed the call of glGetTexEnviv, glTexEnvi
 - replaced on the OpenGl_Sampler::applyGlobalTextureParams/resetGlobalTextureParams
 - added the method in OpenGl_Font returning first texture
---
 src/OpenGl/OpenGl_Font.hxx    |  6 ++++++
 src/OpenGl/OpenGl_Sampler.hxx |  1 +
 src/OpenGl/OpenGl_Text.cxx    | 18 +++++++-----------
 3 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/OpenGl/OpenGl_Font.hxx b/src/OpenGl/OpenGl_Font.hxx
index 3373ac8918..7797674824 100755
--- a/src/OpenGl/OpenGl_Font.hxx
+++ b/src/OpenGl/OpenGl_Font.hxx
@@ -114,6 +114,12 @@ public:
                                     const Standard_Utf32Char      theUChar,
                                     Tile&                         theGlyph);
 
+  //! @return first texture.
+  const Handle(OpenGl_Texture)& Texture() const
+  {
+    return myTextures.First();
+  }
+
 protected:
 
   //! Render new glyph to the texture.
diff --git a/src/OpenGl/OpenGl_Sampler.hxx b/src/OpenGl/OpenGl_Sampler.hxx
index bca6e4416e..9e3ac27b32 100644
--- a/src/OpenGl/OpenGl_Sampler.hxx
+++ b/src/OpenGl/OpenGl_Sampler.hxx
@@ -27,6 +27,7 @@ class OpenGl_Sampler : public OpenGl_Resource
 {
   friend class OpenGl_Context;
   friend class OpenGl_Texture;
+  friend class OpenGl_Text;
   DEFINE_STANDARD_RTTIEXT(OpenGl_Sampler, OpenGl_Resource)
 public:
 
diff --git a/src/OpenGl/OpenGl_Text.cxx b/src/OpenGl/OpenGl_Text.cxx
index 05c36af339..f27d9d6c7e 100644
--- a/src/OpenGl/OpenGl_Text.cxx
+++ b/src/OpenGl/OpenGl_Text.cxx
@@ -16,6 +16,7 @@
 #include <OpenGl_Aspects.hxx>
 #include <OpenGl_GlCore11.hxx>
 #include <OpenGl_GraphicDriver.hxx>
+#include <OpenGl_Sampler.hxx>
 #include <OpenGl_ShaderManager.hxx>
 #include <OpenGl_ShaderProgram.hxx>
 #include <OpenGl_ShaderStates.hxx>
@@ -780,16 +781,10 @@ void OpenGl_Text::render (const Handle(OpenGl_Context)& theCtx,
   }
 #if !defined(GL_ES_VERSION_2_0)
   // activate texture unit
-  GLint aTexEnvParam = GL_REPLACE;
-  if (theCtx->core11ffp != NULL)
+  if (theCtx->core11ffp != NULL && theCtx->ActiveProgram().IsNull())
   {
-    theCtx->core11fwd->glDisable (GL_TEXTURE_1D);
-    theCtx->core11fwd->glEnable  (GL_TEXTURE_2D);
-    theCtx->core11ffp->glGetTexEnviv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, &aTexEnvParam);
-    if (aTexEnvParam != GL_REPLACE)
-    {
-      theCtx->core11ffp->glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
-    }
+    const Handle(OpenGl_Texture)& aTexture = myFont->Texture();
+    OpenGl_Sampler::applyGlobalTextureParams (theCtx, *aTexture, aTexture->Sampler()->Parameters());
   }
 #endif
 
@@ -861,9 +856,10 @@ void OpenGl_Text::render (const Handle(OpenGl_Context)& theCtx,
   }
 
 #if !defined(GL_ES_VERSION_2_0)
-  if (theCtx->core11ffp != NULL)
+  if (theCtx->core11ffp != NULL && theCtx->ActiveProgram().IsNull())
   {
-    theCtx->core11ffp->glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, aTexEnvParam);
+    const Handle(OpenGl_Texture)& aTexture = myFont->Texture();
+    OpenGl_Sampler::resetGlobalTextureParams (theCtx, *aTexture, aTexture->Sampler()->Parameters());
   }
 #endif