Make sure we update filtering options on atlas textures.

We had had an optimization which tried to reduce state changes,
but filtering is also changed in QSGTexture::updateBindOptions
which Atlas::bind() didn't know anything about. Solution: don't
try to be so clever.

Task-number: QTBUG-35457
Change-Id: I39ac0106396921e1b652db2b2aa5a9923b35e825
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

src/quick/scenegraph/util/qsgatlastexture.cpp

@@ -140,7 +140,6 @@ Atlas::Atlas(const QSize &size)
     : m_allocator(size)
     , m_texture_id(0)
     , m_size(size)
-    , m_filtering(QSGTexture::Linear)
     , m_allocated(false)
 {
 
@@ -315,9 +314,8 @@ void Atlas::uploadBgra(Texture *texture)
 
 }
 
-bool Atlas::bind(QSGTexture::Filtering filtering)
+void Atlas::bind(QSGTexture::Filtering filtering)
 {
-    bool forceUpdate = false;
     if (!m_allocated) {
         m_allocated = true;
 
@@ -362,13 +360,12 @@ bool Atlas::bind(QSGTexture::Filtering filtering)
             glDeleteTextures(1, &m_texture_id);
             m_texture_id = 0;
         }
-        forceUpdate = true;
     } else {
         glBindTexture(GL_TEXTURE_2D, m_texture_id);
     }
 
     if (m_texture_id == 0)
-        return false;
+        return;
 
     // Upload all pending images..
     for (int i=0; i<m_pending_uploads.size(); ++i) {
@@ -403,16 +400,11 @@ bool Atlas::bind(QSGTexture::Filtering filtering)
 #endif
     }
 
-    if (filtering != m_filtering) {
-        GLenum f = filtering == QSGTexture::Nearest ? GL_NEAREST : GL_LINEAR;
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, f);
-        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, f);
-        m_filtering = filtering;
-    }
+    GLenum f = filtering == QSGTexture::Nearest ? GL_NEAREST : GL_LINEAR;
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, f);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, f);
 
     m_pending_uploads.clear();
-
-    return forceUpdate;
 }
 
 void Atlas::remove(Texture *t)

src/quick/scenegraph/util/qsgatlastexture_p.h

@@ -85,7 +85,7 @@ public:
     void invalidate();
 
     int textureId() const;
-    bool bind(QSGTexture::Filtering filteing);
+    void bind(QSGTexture::Filtering filtering);
 
     void upload(Texture *texture);
     void uploadBgra(Texture *texture);
@@ -104,8 +104,6 @@ private:
     GLuint m_internalFormat;
     GLuint m_externalFormat;
 
-    QSGTexture::Filtering m_filtering;
-
     uint m_allocated : 1;
     uint m_use_bgra_fallback: 1;
 

tests/auto/quick/scenegraph/data/render_ImageFiltering.qml

@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd, author: <gunnar.sletta@jollamobile.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.2
+
+/*
+    The test verifies that batching does not interfere with overlapping
+    regions.
+
+    #samples: 8
+                 PixelPos     R    G    B    Error-tolerance
+    #final:       10  10     0.0  0.0  0.0        0.0
+    #final:       20  10     1.0  1.0  1.0        0.0
+    #final:       30  10     0.0  0.0  0.0        0.0
+    #final:       40  10     0.5  0.5  0.5        0.1
+    #final:       50  10     0.0  0.0  0.0        0.0
+    #final:       60  10     1.0  1.0  1.0        0.0
+    #final:       70  10     0.0  0.0  0.0        0.0
+    #final:       80  10     0.5  0.5  0.5        0.1
+*/
+
+RenderTestBase
+{
+    Item {
+        x: 10
+        y: 10
+        scale: 10
+        Image { x: 0; source: "blacknwhite.png"; smooth: false }
+        Image { x: 2; source: "blacknwhite.png"; smooth: true }
+        Image { x: 4; source: "blacknwhite.png"; smooth: false }
+        Image { x: 6; source: "blacknwhite.png"; smooth: true }
+    }
+
+    finalStageComplete: true
+}

tests/auto/quick/scenegraph/scenegraph.pro

@@ -12,4 +12,5 @@ DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0
 
 OTHER_FILES += \
     data/render_OutOfFloatRange.qml \
-    data/simple.qml
+    data/simple.qml \
+    data/render_ImageFiltering.qml

tests/auto/quick/scenegraph/tst_scenegraph.cpp

@@ -327,6 +327,7 @@ void tst_SceneGraph::render_data()
           << "data/render_OutOfFloatRange.qml"
           << "data/render_StackingOrder.qml"
           << "data/render_Mipmap.qml"
+          << "data/render_ImageFiltering.qml"
         ;
 
     QRegExp sampleCount("#samples: *(\\d+)");