0026424: Visualization, TKOpenGl - fix text rendering in core profile

OpenGl_Context::init() - fix condition on initializing alien OpenGL context within core profile.
OpenGl_Font::renderGlyph() - use GL_RED data format in core profile.
OpenGl_Text::render() - do not use GL_ALPHA_TEST in core profile.

Test-case for issue #26424

src/OpenGl/OpenGl_Context.cxx

@@ -1040,7 +1040,7 @@ void OpenGl_Context::init (const Standard_Boolean theIsCoreProfile)
     isCoreProfile = (theIsCoreProfile == Standard_True);
 
     // detect Core profile
-    if (isCoreProfile)
+    if (!isCoreProfile)
     {
       GLint aProfile = 0;
       ::glGetIntegerv (GL_CONTEXT_PROFILE_MASK, &aProfile);

src/OpenGl/OpenGl_Font.cxx

@@ -60,13 +60,16 @@ void OpenGl_Font::Release (OpenGl_Context* theCtx)
     return;
   }
 
-  // application can not handle this case by exception - this is bug in code
-  Standard_ASSERT_RETURN (theCtx != NULL,
-    "OpenGl_Font destroyed without GL context! Possible GPU memory leakage...",);
-
   for (Standard_Integer anIter = 0; anIter < myTextures.Length(); ++anIter)
   {
     Handle(OpenGl_Texture)& aTexture = myTextures.ChangeValue (anIter);
+    if (aTexture->IsValid())
+    {
+      // application can not handle this case by exception - this is bug in code
+      Standard_ASSERT_RETURN (theCtx != NULL,
+        "OpenGl_Font destroyed without GL context! Possible GPU memory leakage...",);
+    }
+
     aTexture->Release (theCtx);
     aTexture.Nullify();
   }
@@ -92,7 +95,12 @@ bool OpenGl_Font::Init (const Handle(OpenGl_Context)& theCtx)
   myTileSizeY   = myFont->GlyphMaxSizeY();
 
   myLastTileId = -1;
-  return createTexture (theCtx);
+  if (!createTexture (theCtx))
+  {
+    Release (theCtx.operator->());
+    return false;
+  }
+  return true;
 }
 
 // =======================================================================
@@ -151,6 +159,11 @@ bool OpenGl_Font::renderGlyph (const Handle(OpenGl_Context)& theCtx,
   }
 
   Handle(OpenGl_Texture)& aTexture = myTextures.ChangeLast();
+  if (aTexture.IsNull()
+  || !aTexture->IsValid())
+  {
+    return false;
+  }
 
   const Image_PixMap& anImg = myFont->GlyphImage();
   const Standard_Integer aTileId = myLastTileId + 1;
@@ -182,7 +195,7 @@ bool OpenGl_Font::renderGlyph (const Handle(OpenGl_Context)& theCtx,
 
   glTexSubImage2D (GL_TEXTURE_2D, 0,
                    myLastTilePx.Left, myLastTilePx.Top, (GLsizei )anImg.SizeX(), (GLsizei )anImg.SizeY(),
-                   GL_ALPHA, GL_UNSIGNED_BYTE, anImg.Data());
+                   aTexture->GetFormat(), GL_UNSIGNED_BYTE, anImg.Data());
 
   OpenGl_Font::Tile aTile;
   aTile.uv.Left   = GLfloat(myLastTilePx.Left)                / GLfloat(aTexture->SizeX());

src/OpenGl/OpenGl_Text.cxx

@@ -407,6 +407,8 @@ void OpenGl_Text::Render (const Handle(OpenGl_Workspace)& theWorkspace) const
             aTextAspect->SubtitleColor());
   }
 
+  aCtx->BindProgram (NULL);
+
   // restore aspects
   if (!aPrevTexture.IsNull())
   {
@@ -591,6 +593,7 @@ Handle(OpenGl_Font) OpenGl_Text::FindFont (const Handle(OpenGl_Context)& theCtx,
           aMsg += "' - initialization of GL resources has failed!";
           theCtx->PushMessage (GL_DEBUG_SOURCE_APPLICATION_ARB, GL_DEBUG_TYPE_ERROR_ARB, 0, GL_DEBUG_SEVERITY_HIGH_ARB, aMsg);
           aFontFt.Nullify();
+          aFont->Release (theCtx.operator->());
           aFont = new OpenGl_Font (aFontFt, theKey);
         }
       }
@@ -743,14 +746,14 @@ void OpenGl_Text::render (const Handle(OpenGl_PrinterContext)& thePrintCtx,
     theCtx->core15fwd->glActiveTexture (GL_TEXTURE0);
   }
 #if !defined(GL_ES_VERSION_2_0)
-  // setup alpha test
-  glAlphaFunc (GL_GEQUAL, 0.285f);
-  glEnable (GL_ALPHA_TEST);
-
   // activate texture unit
   GLint aTexEnvParam = GL_REPLACE;
   if (theCtx->core11 != NULL)
   {
+    // setup alpha test
+    glAlphaFunc (GL_GEQUAL, 0.285f);
+    glEnable (GL_ALPHA_TEST);
+
     glDisable (GL_TEXTURE_1D);
     glEnable  (GL_TEXTURE_2D);
     glGetTexEnviv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, &aTexEnvParam);
@@ -871,7 +874,10 @@ void OpenGl_Text::render (const Handle(OpenGl_PrinterContext)& thePrintCtx,
   glDisable (GL_BLEND);
   glDisable (GL_STENCIL_TEST);
 #if !defined(GL_ES_VERSION_2_0)
-  glDisable (GL_ALPHA_TEST);
+  if (theCtx->core11 != NULL)
+  {
+    glDisable (GL_ALPHA_TEST);
+  }
   glDisable (GL_COLOR_LOGIC_OP);
 #endif
 

tests/bugs/vis/bug26424

@@ -0,0 +1,31 @@
+puts "========"
+puts "OCC26424"
+puts "========"
+puts ""
+################################################################
+# Text is not rendered within core profile on Windows platform
+################################################################
+
+vcaps -core
+vinit View1
+vclear
+vaxo
+vzbufftrihedron
+
+if { [array get env os_type] != "" } {
+   set os $env(os_type)
+}
+if { [string compare $os "windows"] != 0 } {
+  # Linux platform
+  set ok_color "GRAY85"
+} else {
+  # Windows platform
+  set ok_color "GRAY52"
+}
+
+set bug_info [vreadpixel 71 350 rgb name]
+if {$bug_info != $ok_color} {
+  puts "ERROR: OCC26424 is reproduced. Trihedron does non have text labels."
+}
+
+set only_screen 1