Draw the graphicsView in a texture.

5 files changed, 231 insertions, 44 deletions

diff --git a/declarativeviewtexture.cpp b/declarativeviewtexture.cpp
new file mode 100644
index 0000000..2af4879
--- /dev/null
+++ b/declarativeviewtexture.cpp
@@ -0,0 +1,93 @@
+#include "declarativeviewtexture.h"
+
+#include <QtGui/QPainter>
+#include <QtGui/QImage>
+#include <QtGui/QPaintEvent>
+#include <QtCore/QDebug>
+
+static inline void qgl_byteSwapImage(QImage &img, GLenum pixel_type)
+{
+    const int width = img.width();
+    const int height = img.height();
+
+    if (pixel_type == GL_UNSIGNED_BYTE && QSysInfo::ByteOrder == QSysInfo::LittleEndian)
+    {
+        for (int i = 0; i < height; ++i) {
+            uint *p = (uint *) img.scanLine(i);
+            for (int x = 0; x < width; ++x)
+                p[x] = ((p[x] << 16) & 0xff0000) | ((p[x] >> 16) & 0xff) | (p[x] & 0xff00ff00);
+        }
+    } else {
+        for (int i = 0; i < height; ++i) {
+            uint *p = (uint *) img.scanLine(i);
+            for (int x = 0; x < width; ++x)
+                p[x] = (p[x] << 8) | ((p[x] >> 24) & 0xff);
+        }
+    }
+}
+
+DeclarativeViewTexture::DeclarativeViewTexture(QWidget *parent) :
+    QDeclarativeView(parent),
+    m_bufferPainter(0)
+{
+    setAttribute(Qt::WA_DontShowOnScreen);
+    setOptimizationFlag(QGraphicsView::IndirectPainting);
+
+    glGenTextures(1, &m_textureId);
+}
+
+DeclarativeViewTexture::~DeclarativeViewTexture()
+{
+
+}
+
+void DeclarativeViewTexture::paintEvent(QPaintEvent *event)
+{
+    // Render the view in an offscreen image
+    if (m_bufferPainter)
+        delete m_bufferPainter;
+    m_bufferPainter = new QPainter;
+
+    QRegion exposedRegion = event->region();
+    QImage im(exposedRegion.boundingRect().size(), QImage::Format_ARGB32_Premultiplied);
+    im.fill(Qt::transparent);
+    m_bufferPainter->begin(&im);
+    m_bufferPainter->translate(-exposedRegion.boundingRect().topLeft());
+    m_bufferPainter->setClipRegion(exposedRegion);
+
+    QDeclarativeView::paintEvent(event);
+
+    m_bufferPainter->end();
+
+    // Upload the image in graphics memory
+    glBindTexture(GL_TEXTURE_2D, m_textureId);
+    qgl_byteSwapImage(im, GL_UNSIGNED_BYTE);
+    foreach (const QRect &rect, exposedRegion.rects()) {
+        if (rect.size() == size()) {
+            glTexImage2D(GL_TEXTURE_2D, 0, 4, rect.width(), rect.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, im.bits());
+            glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
+            glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
+            break;
+        } else {
+            QRect adjustedRect = rect.translated(-exposedRegion.boundingRect().topLeft());
+            QImage subIm = im.copy(adjustedRect);
+            glTexSubImage2D(GL_TEXTURE_2D, 0, rect.left(), rect.top(), rect.width(), rect.height(), GL_RGBA, GL_UNSIGNED_BYTE, subIm.bits());
+        }
+    }
+    glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+void DeclarativeViewTexture::drawItems(QPainter *painter, int numItems, QGraphicsItem *items[], const QStyleOptionGraphicsItem options[])
+{
+    QDeclarativeView::drawItems(m_bufferPainter, numItems, items, options);
+}
+
+void DeclarativeViewTexture::drawBackground(QPainter *painter, const QRectF &rect)
+{
+    QDeclarativeView::drawBackground(m_bufferPainter, rect);
+}
+
+void DeclarativeViewTexture::drawForeground(QPainter *painter, const QRectF &rect)
+{
+    QDeclarativeView::drawForeground(m_bufferPainter, rect);
+}
diff --git a/declarativeviewtexture.h b/declarativeviewtexture.h
new file mode 100644
index 0000000..edf93e3
--- /dev/null
+++ b/declarativeviewtexture.h
@@ -0,0 +1,28 @@
+#ifndef DECLARATIVEVIEWTEXTURE_H
+#define DECLARATIVEVIEWTEXTURE_H
+
+#include <QtDeclarative/QDeclarativeView>
+#include <QtOpenGL/qgl.h>
+
+class DeclarativeViewTexture : public QDeclarativeView
+{
+    Q_OBJECT
+public:
+    explicit DeclarativeViewTexture(QWidget *parent = 0);
+    ~DeclarativeViewTexture();
+
+    GLuint textureId() const
+    { return m_textureId; }
+
+protected:
+    void paintEvent(QPaintEvent *event);
+    void drawItems(QPainter *painter, int numItems, QGraphicsItem *items[], const QStyleOptionGraphicsItem options[]);
+    void drawBackground(QPainter *painter, const QRectF &rect);
+    void drawForeground(QPainter *painter, const QRectF &rect);
+
+private:
+    QPainter *m_bufferPainter;
+    GLuint m_textureId;
+};
+
+#endif // DECLARATIVEVIEWTEXTURE_H
diff --git a/ogrewidget.cpp b/ogrewidget.cpp
index 7b5d0e5..991bf2a 100644
--- a/ogrewidget.cpp
+++ b/ogrewidget.cpp
@@ -1,5 +1,7 @@
 #include "ogrewidget.h"
 
+#include "declarativeviewtexture.h"
+
 #include <OgreRoot.h>
 #include <OgreRenderWindow.h>
 #include <OgreColourValue.h>
@@ -7,7 +9,7 @@
 #include <OgreSceneNode.h>
 #include <OgreEntity.h>
 #include <OgreResourceGroupManager.h>
-#include <QtGui/QResizeEvent>
+#include <OgreMaterialManager.h>
 #include <QtCore/QDebug>
 
 #if defined(Q_WS_X11)
@@ -15,19 +17,19 @@
 #endif
 
 OgreWidget::OgreWidget(QWidget *parent) :
-    QWidget(parent),
+    QGLWidget(parent),
     m_root(0),
     m_camera(0),
     m_sceneManager(0),
     m_renderWindow(0),
-    m_viewport(0)
+    m_viewport(0),
+    m_QmlUI(0)
 {
-    setAttribute(Qt::WA_PaintOnScreen);
-    setAttribute(Qt::WA_NoSystemBackground);
+    setAutoBufferSwap(false);
+    setFormat(QGLFormat(QGL::DoubleBuffer | QGL::SampleBuffers));
+    setAttribute(Qt::WA_OpaquePaintEvent);
     resize(1024, 768);
 
-    initOgre();
-
     startTimer(16);
 }
 
@@ -48,6 +50,90 @@ OgreWidget::~OgreWidget()
     delete m_root;
 }
 
+void OgreWidget::paintGL()
+{
+    // Render Ogre
+    Ogre::WindowEventUtilities::messagePump();
+    m_root->renderOneFrame();
+
+    // Set a clear pass to give the renderer a clear renderstate
+    static Ogre::Pass* clearPass = 0;
+    if (!clearPass)
+    {
+        Ogre::MaterialPtr clearMat = Ogre::MaterialManager::getSingleton().getByName("BaseWhite");
+        clearPass = clearMat->getTechnique(0)->getPass(0);
+    }
+    m_sceneManager->_setPass(clearPass, true, false);
+
+    // Render the QDeclarativeView texture on top
+    glBindTexture(GL_TEXTURE_2D, m_QmlUI->textureId());
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+    glEnable(GL_TEXTURE_2D);
+    glDisable(GL_LIGHTING);
+    glEnable(GL_BLEND);
+    glEnable(GL_DEPTH_TEST);
+
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+    /*float top = qMax(-1.f, qMin(1.f, (rect().center().y() - m_QmlUI->pos().y()) / float(rect().center().y())));
+    float left = qMax(-1.f, qMin(1.f, (rect().center().x() - m_QmlUI->pos().x()) / float(-rect().center().x())));
+    float bottom = qMax(-1.f, qMin(1.f, (rect().center().y() - m_QmlUI->pos().y() - m_QmlUI->height()) / float(rect().center().y())));
+    float right = qMax(-1.f, qMin(1.f, (rect().center().x() - m_QmlUI->pos().x() - m_QmlUI->width()) / float(-rect().center().x())));
+    float texTop = qMin(1.f, qMax(-m_QmlUI->pos().y() / float(m_QmlUI->height()), 0.f));
+    float texLeft = qMin(1.f, qMax(-m_QmlUI->pos().x() / float(m_QmlUI->width()), 0.f));
+    float texBottom = qMax(0.f, qMin(height() - m_QmlUI->pos().y() / float(m_QmlUI->height()), 1.f));
+    float texRight = qMax(0.f, qMin(width() - m_QmlUI->pos().x() / float(m_QmlUI->width()), 1.f));*/
+
+    float top = (rect().center().y() - m_QmlUI->pos().y()) / float(rect().center().y());
+    float left = (rect().center().x() - m_QmlUI->pos().x()) / float(-rect().center().x());
+    float bottom = (rect().center().y() - m_QmlUI->pos().y() - m_QmlUI->height()) / float(rect().center().y());
+    float right = (rect().center().x() - m_QmlUI->pos().x() - m_QmlUI->width()) / float(-rect().center().x());
+
+    glBegin(GL_QUADS);
+    /*glTexCoord2f(texLeft, texTop); glVertex3f(left, top, -1.0f); // Top Left
+    glTexCoord2f(texLeft, texBottom); glVertex3f(left, bottom, -1.0f); // Bottom Left
+    glTexCoord2f(texRight, texBottom); glVertex3f(right, bottom, -1.0f); // Bottom Right
+    glTexCoord2f(texRight, texTop); glVertex3f(right, top, -1.0f); // Top Right*/
+    glTexCoord2f(0, 0); glVertex3f(left, top, -1.0f); // Top Left
+    glTexCoord2f(0, 1); glVertex3f(left, bottom, -1.0f); // Bottom Left
+    glTexCoord2f(1, 1); glVertex3f(right, bottom, -1.0f); // Bottom Right
+    glTexCoord2f(1, 0); glVertex3f(right, top, -1.0f); // Top Right
+    glEnd();
+
+    glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+void OgreWidget::timerEvent(QTimerEvent *e)
+{
+    Q_UNUSED(e)
+    paintGL();
+    swapBuffers();
+}
+
+void OgreWidget::initializeGL()
+{
+    initOgre();
+
+    m_QmlUI = new DeclarativeViewTexture(this);
+}
+
+void OgreWidget::resizeGL(int w, int h)
+{
+    if (m_renderWindow) {
+        m_renderWindow->resize(w, h);
+        m_renderWindow->windowMovedOrResized();
+    }
+    if (m_camera) {
+        Ogre::Real aspectRatio = Ogre::Real(w) / Ogre::Real(h);
+        m_camera->setAspectRatio(aspectRatio);
+    }
+}
+
+
 void OgreWidget::initOgre()
 {
     m_root = new Ogre::Root;
@@ -60,9 +146,6 @@ void OgreWidget::initOgre()
     Ogre::NameValuePairList params;
     Ogre::String externalWindowHandleParams;
 
-    //Accept input focus
-    //setFocusPolicy(Qt::StrongFocus);
-
 #if defined(Q_WS_WIN)
     //positive integer for W32 (HWND handle) - According to Ogre Docs
     externalWindowHandleParams = Ogre::StringConverter::toString((unsigned int)(winId()));
@@ -86,6 +169,9 @@ void OgreWidget::initOgre()
     params["parentWindowHandle"] = externalWindowHandleParams;
 #endif
 
+    params["externalGLControl"] = "true";
+    params["currentGLContext"] = "true";
+
     //Finally create our window.
     m_renderWindow = m_root->createRenderWindow("OgreWindow", width(), height(), false, &params);
     m_renderWindow->setVisible(true);
@@ -119,30 +205,3 @@ void OgreWidget::initOgre()
     m_camera->move(Ogre::Vector3(0, 0, 300));
     m_camera->lookAt(0, 0, 0);
 }
-
-void OgreWidget::render()
-{
-    Ogre::WindowEventUtilities::messagePump();
-    m_root->renderOneFrame();
-}
-
-void OgreWidget::timerEvent(QTimerEvent *e)
-{
-    Q_UNUSED(e)
-    render();
-}
-
-void OgreWidget::resizeEvent(QResizeEvent *e)
-{
-    const QSize &newSize = e->size();
-    if (m_renderWindow) {
-        m_renderWindow->resize(newSize.width(), newSize.height());
-        m_renderWindow->windowMovedOrResized();
-    }
-    if (m_camera) {
-        Ogre::Real aspectRatio = Ogre::Real(newSize.width()) / Ogre::Real(newSize.height());
-        m_camera->setAspectRatio(aspectRatio);
-    }
-
-    QWidget::resizeEvent(e);
-}
diff --git a/ogrewidget.h b/ogrewidget.h
index 6b940a3..d1a2ec4 100644
--- a/ogrewidget.h
+++ b/ogrewidget.h
@@ -1,7 +1,7 @@
 #ifndef OGREWIDGET_H
 #define OGREWIDGET_H
 
-#include <QWidget>
+#include <QGLWidget>
 
 #define STRINGIFY_(x) #x
 #define STRINGIFY(x) STRINGIFY_(x)
@@ -15,8 +15,9 @@ class RenderWindow;
 class Viewport;
 class RenderTarget;
 }
+class DeclarativeViewTexture;
 
-class OgreWidget : public QWidget
+class OgreWidget : public QGLWidget
 {
     Q_OBJECT
 public:
@@ -36,9 +37,11 @@ public:
 
 protected:
     void initOgre();
-    void render();
     void timerEvent(QTimerEvent *);
-    void resizeEvent(QResizeEvent *);
+
+    void initializeGL();
+    void resizeGL(int w, int h);
+    void paintGL();
 
 private:
     Ogre::Root *m_root;
@@ -46,6 +49,8 @@ private:
     Ogre::SceneManager *m_sceneManager;
     Ogre::RenderWindow *m_renderWindow;
     Ogre::Viewport *m_viewport;
+
+    DeclarativeViewTexture *m_QmlUI;
 };
 
 #endif // OGREWIDGET_H
diff --git a/qmlogre.pro b/qmlogre.pro
index ac72c56..e0308a0 100644
--- a/qmlogre.pro
+++ b/qmlogre.pro
@@ -1,5 +1,5 @@
 CONFIG += qt
-QT += opengl
+QT += opengl declarative
 TEMPLATE = app
 TARGET = qmlogre
 
@@ -40,7 +40,9 @@ MOC_DIR = ./.moc
 
 
 SOURCES += main.cpp \
-    ogrewidget.cpp
+    ogrewidget.cpp \
+    declarativeviewtexture.cpp
 
 HEADERS += \
-    ogrewidget.h
+    ogrewidget.h \
+    declarativeviewtexture.h