Added initial CachedSvgItem implementation

Texture is regenerated each time item is scaled
but it's reused during rotation, unlike the default
DeviceCoordinateCache mode.

ground/openpilotgcs/src/libs/utils/cachedsvgitem.cpp

@@ -0,0 +1,155 @@
+/**
+ ******************************************************************************
+ *
+ * @file       cachedsvgitem.h
+ * @author     Dmytro Poplavskiy Copyright (C) 2011.
+ * @{
+ * @brief OpenGL texture cached SVG item
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "cachedsvgitem.h"
+#include <QGLContext>
+#include <QDebug>
+
+CachedSvgItem::CachedSvgItem(QGraphicsItem * parent) :
+    QGraphicsSvgItem(parent),
+    m_context(0),
+    m_texture(0),
+    m_scale(1.0)
+{
+    setCacheMode(NoCache);
+}
+
+CachedSvgItem::CachedSvgItem(const QString & fileName, QGraphicsItem * parent):
+    QGraphicsSvgItem(fileName, parent),
+    m_context(0),
+    m_texture(0),
+    m_scale(1.0)
+{
+    setCacheMode(NoCache);
+}
+
+CachedSvgItem::~CachedSvgItem()
+{
+    if (m_context && m_texture) {
+        m_context->makeCurrent();
+        glDeleteTextures(1, &m_texture);
+    }
+}
+
+void CachedSvgItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
+{
+
+    if (painter->paintEngine()->type() != QPaintEngine::OpenGL &&
+            painter->paintEngine()->type() != QPaintEngine::OpenGL2) {
+        //Fallback to direct painting
+        QGraphicsSvgItem::paint(painter, option, widget);
+        return;
+    }
+
+    QRectF br = boundingRect();
+    QTransform transform = painter->worldTransform();
+    qreal sceneScale = transform.map(QLineF(0,0,1,0)).length();
+
+    bool stencilTestEnabled = glIsEnabled(GL_STENCIL_TEST);
+    bool scissorTestEnabled = glIsEnabled(GL_SCISSOR_TEST);
+
+    painter->beginNativePainting();
+
+    if (stencilTestEnabled)
+        glEnable(GL_STENCIL_TEST);
+    if (scissorTestEnabled)
+        glEnable(GL_SCISSOR_TEST);
+
+    bool dirty = false;
+    if (!m_texture) {
+        glGenTextures(1, &m_texture);
+        m_context = const_cast<QGLContext*>(QGLContext::currentContext());
+
+        dirty = true;
+    }
+
+    if (!qFuzzyCompare(sceneScale, m_scale)) {
+        m_scale = sceneScale;
+        dirty = true;
+    }
+
+    int textureWidth = (int(br.width()*m_scale) + 3) & ~3;
+    int textureHeight = (int(br.height()*m_scale) + 3) & ~3;
+
+    if (dirty) {
+        //qDebug() << "re-render image";
+
+        QImage img(textureWidth, textureHeight, QImage::Format_ARGB32);
+        {
+            img.fill(Qt::transparent);
+            QPainter p;
+            p.begin(&img);
+            p.setRenderHints(painter->renderHints());
+            p.translate(br.topLeft());
+            p.scale(m_scale, m_scale);
+            QGraphicsSvgItem::paint(&p, option, 0);
+            p.end();
+
+            img = img.rgbSwapped();
+        }
+
+        glEnable(GL_TEXTURE_2D);
+
+        glBindTexture(GL_TEXTURE_2D, m_texture);
+        glTexImage2D(
+                GL_TEXTURE_2D,
+                0,
+                GL_RGBA,
+                textureWidth,
+                textureHeight,
+                0,
+                GL_RGBA,
+                GL_UNSIGNED_BYTE,
+                img.bits());
+
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+        glDisable(GL_TEXTURE_2D);
+
+        dirty = false;
+    }
+
+    glEnable(GL_BLEND);
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glEnable(GL_TEXTURE_2D);
+
+    glBindTexture(GL_TEXTURE_2D, m_texture);
+
+    //texture may be slightly large than svn image, ensure only used area is rendered
+    qreal tw = br.width()*m_scale/textureWidth;
+    qreal th = br.height()*m_scale/textureHeight;
+
+    glBegin(GL_QUADS);
+    glTexCoord2d(0,  0 ); glVertex3d(br.left(), br.top(), -1);
+    glTexCoord2d(tw, 0 ); glVertex3d(br.right(), br.top(), -1);
+    glTexCoord2d(tw, th); glVertex3d(br.right(), br.bottom(), -1);
+    glTexCoord2d(0,  th); glVertex3d(br.left(), br.bottom(), -1);
+    glEnd();
+    glDisable(GL_TEXTURE_2D);
+
+    painter->endNativePainting();
+}

ground/openpilotgcs/src/libs/utils/cachedsvgitem.h

@@ -0,0 +1,52 @@
+/**
+ ******************************************************************************
+ *
+ * @file       cachedsvgitem.h
+ * @author     Dmytro Poplavskiy Copyright (C) 2011.
+ * @{
+ * @brief OpenGL texture cached SVG item
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef CACHEDSVGITEM_H
+#define CACHEDSVGITEM_H
+
+#include <QGraphicsSvgItem>
+#include <QGLContext>
+
+class QGLContext;
+
+//Cache Svg item as GL Texture.
+//Texture is regenerated each time item is scaled
+//but it's reused during rotation, unlike DeviceCoordinateCache mode
+class CachedSvgItem: public QGraphicsSvgItem
+{
+    Q_OBJECT
+public:
+    CachedSvgItem(QGraphicsItem * parent = 0);
+    CachedSvgItem(const QString & fileName, QGraphicsItem * parent = 0);
+    ~CachedSvgItem();
+
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
+
+private:
+    QGLContext *m_context;
+    GLuint m_texture;
+    qreal m_scale;
+};
+
+#endif

ground/openpilotgcs/src/libs/utils/utils.pro

@@ -3,7 +3,9 @@ TARGET = Utils
 
 QT += gui \
     network \
-    xml
+    xml \
+    svg \
+    opengl
 
 DEFINES += QTCREATOR_UTILS_LIB
 
@@ -48,7 +50,8 @@ SOURCES += reloadpromptutils.cpp \
 	homelocationutil.cpp \
     mytabbedstackwidget.cpp \
     mytabwidget.cpp \
-    mylistwidget.cpp
+    mylistwidget.cpp \
+    cachedsvgitem.cpp
 SOURCES += xmlconfig.cpp
 
 win32 {
@@ -102,7 +105,8 @@ HEADERS += utils_global.h \
 	homelocationutil.h \
     mytabbedstackwidget.h \
     mytabwidget.h \
-    mylistwidget.h
+    mylistwidget.h \
+    cachedsvgitem.h
 HEADERS += xmlconfig.h
 
 FORMS += filewizardpage.ui \